Taxanes for the treatment of breast cancer during pregnancy: an international cohort study

INTRODUCTION

The addition of taxanes to anthracycline-based chemotherapy is considered standard of care in the treatment of breast cancer. However, there are insufficient data regarding the safety of taxanes during pregnancy. The aim of this study was to describe the incidence of obstetric and neonatal adverse events associated with the use of taxane-containing chemotherapy regimens for the treatment of breast cancer during pregnancy.

METHODS

This is a multicenter, international cohort study of breast cancer patients treated with taxanes during pregnancy. A descriptive analysis was undertaken to synthetize available data.

RESULTS

A total of 103 patients were included, most of whom were treated with paclitaxel and anthracyclines given in sequence during gestation (90.1%). The median gestational age at taxane initiation was 28 weeks (range = 12-37 weeks). Grade 3-4 adverse events were reported in 7 of 103 (6.8%) patients. The most common reported obstetric complications were intrauterine growth restriction (n = 8 of 94, 8.5%) and preterm premature rupture of membranes (n = 5 of 94, 5.3%). The live birth rate was 92 of 94 (97.9%), and the median gestational age at delivery was 37 weeks (range = 32-40 weeks). Admission to an intensive care unit was reported in 14 of 88 (15.9%) neonates, and 17 of 70 (24.3%) live births resulted in small for gestational age neonates. Congenital malformations were reported in 2 of 93 (2.2%).

CONCLUSION

Obstetric and neonatal outcomes after taxane exposure during pregnancy were generally favorable and did not seem to differ from those reported in the literature with standard anthracycline-based regimens. This study supports the use of taxanes during gestation when clinically indicated.

Obstetric and neonatal outcomes following taxane use during pregnancy: a systematic review

BACKGROUND

The use of taxanes following the first trimester of pregnancy is endorsed by current clinical guidelines. However, evidence regarding their safety in terms of obstetric and neonatal outcomes is limited.

METHODS

A comprehensive literature search was performed using the MEDLINE, CENTRAL and Web of Sciences databases from their inception up to 12/16/2022. Eligibility criteria included gestational taxane use, presentation of original findings, and individual case data presented. A descriptive statistical analysis was undertaken.

RESULTS

A total of 159 patients treated with taxane-containing regimens during pregnancy were identified, resulting in 162 fetuses exposed in utero. The majority of patients had breast cancer (n = 88; 55.3%) or cervical cancer (n = 45; 28.3%). The most commonly employed taxane was paclitaxel (n = 131; 82.4%). A total of 111 (69.8%) patients were also treated with other cytotoxic drugs during pregnancy, including platinum salts (n = 70; 63.0%) and doxorubicin/cyclophosphamide (n = 20; 18.0%). While most patients received taxanes during the second trimester of pregnancy (n = 79; 70.0%), two were exposed to taxanes in the first trimester. Obstetric outcomes were reported in 105 (66.0%) cases, with the most frequent adverse events being preterm contractions or premature rupture of membranes (n = 12; 11.4%), pre-eclampsia/HELLP syndrome (n = 6; 5.7%), and oligohydramnios/anhydramnios (n = 6; 5.7%). All cases with pregnancy outcome available resulted in live births (n = 132). Overall, 72 (54.5%) neonates were delivered preterm, 40 (30.3%) were classified as small for gestational age (SGA), and 2 (1.5%) had an Apgar score of < 7 at 5 min. Perinatal complications included acute respiratory distress syndrome (n = 14; 10.6%), hyperbilirubinemia (n = 5; 3.8%), and hypoglycemia (n = 2; 1.5%). In addition, 7 (5.3%) cases of congenital malformations were reported. At a median follow-up of 16 months, offspring health status was available for 86 (65.2%), of which 13 (15.1%) had a documented complication, including delayed speech development, recurrent otitis media, and acute myeloid leukemia.

CONCLUSIONS

Taxanes appear to be safe following the first trimester of pregnancy, with obstetric and fetal outcomes being similar to those observed in the general obstetric population. Future studies should aim to determine the most effective taxane regimen and dosage for use during gestation, with a specific focus on treatment safety.

Pregnancy After Breast Cancer in Young BRCA Carriers: An International Hospital-Based Cohort Study

Importance

Young women with breast cancer who have germline pathogenic variants in BRCA1 or BRCA2 face unique challenges regarding fertility. Previous studies demonstrating the feasibility and safety of pregnancy in breast cancer survivors included limited data regarding BRCA carriers.

Objective

To investigate cumulative incidence of pregnancy and disease-free survival in young women who are BRCA carriers.

Design, Setting, and Participants

International, multicenter, hospital-based, retrospective cohort study conducted at 78 participating centers worldwide. The study included female participants diagnosed with invasive breast cancer at age 40 years or younger between January 2000 and December 2020 carrying germline pathogenic variants in BRCA1 and/or BRCA2. Last delivery was October 7, 2022; last follow-up was February 20, 2023.

Exposure

Pregnancy after breast cancer.

Main Outcomes and Measures

Primary end points were cumulative incidence of pregnancy after breast cancer and disease-free survival. Secondary end points were breast cancer-specific survival, overall survival, pregnancy, and fetal and obstetric outcomes.

Results

Of 4732 BRCA carriers included, 659 had at least 1 pregnancy after breast cancer and 4073 did not. Median age at diagnosis in the overall cohort was 35 years (IQR, 31-38 years). Cumulative incidence of pregnancy at 10 years was 22% (95% CI, 21%-24%), with a median time from breast cancer diagnosis to conception of 3.5 years (IQR, 2.2-5.3 years). Among the 659 patients who had a pregnancy, 45 (6.9%) and 63 (9.7%) had an induced abortion or a miscarriage, respectively. Of the 517 patients (79.7%) with a completed pregnancy, 406 (91.0%) delivered at term (≥37 weeks) and 54 (10.4%) had twins. Among the 470 infants born with known information on pregnancy complications, 4 (0.9%) had documented congenital anomalies. Median follow-up was 7.8 years (IQR, 4.5-12.6 years). No significant difference in disease-free survival was observed between patients with or without a pregnancy after breast cancer (adjusted hazard ratio, 0.99; 95% CI, 0.81-1.20). Patients who had a pregnancy had significantly better breast cancer-specific survival and overall survival.

Conclusions and Relevance

In this global study, 1 in 5 young BRCA carriers conceived within 10 years after breast cancer diagnosis. Pregnancy following breast cancer in BRCA carriers was not associated with decreased disease-free survival.

Trial Registration

ClinicalTrials.gov Identifier: NCT03673306.

The Landscape of BRCA Mutations among Egyptian Women with Breast Cancer

BACKGROUND

Deleterious germline mutations in BRCA1 and BRCA2 genes are associated with a high risk of breast and ovarian cancer. In many developing countries, including Egypt, the prevalence of BRCA1/2 mutations among women with breast cancer (BC) is unknown.

AIM

We aimed to determine the prevalence of deleterious germline BRCA mutations in Egyptian patients with breast cancer.

METHODS

We report the results of a cohort study of 81 Egyptian patients with breast cancer who were tested for germline BRCA1/2 mutations during routine clinical practice, mostly for their young age of presentation, BC subtype, or presence of family history. In addition, we searched five databases to retrieve studies that reported the prevalence of BRCA1/2 mutation status in Egyptian women with BC. A systematic review of the literature was performed, including prospective and retrospective studies.

RESULTS

In our patient cohort study, 12 patients (14.8%) were positive for either BRCA1/2 deleterious mutations. Moreover, 13 (16.1%) patients had a variant of unknown significance (VUS) of BRCA1/2 genes. Twelve studies were eligible for the systematic review, including 610 patients. A total of 19 deleterious germline mutations in BRCA1/2 were identified. The pooled prevalence of BRCA1/2 mutations was 40% (95% confidence interval 1-80%).

CONCLUSION

The reported prevalence was highly variable among the small-sized published studies that adopted adequate techniques. In our patient cohort, there was a high incidence of VUS in BRCA1/2 genes. Accordingly, there is an actual demand to conduct a prospective well-designed national study to accurately estimate the prevalence of BRCA1/2 mutations among patients with BC in Egypt.

Safety of pregnancy after breast cancer in young women with hormone receptor-positive disease: a systematic review and meta-analysis

BACKGROUND

Despite increasing evidence on the safety of pregnancy after anticancer treatments in breast cancer survivors, many physicians and patients remain concerned about a potential risk of pregnancy specifically in the case of hormone receptor-positive breast cancer.

MATERIALS AND METHODS

A systematic literature search of Medline, Embase and Cochrane library with no language or date restriction up to 31 March 2023 was carried out. To be included, articles had to be retrospective and prospective case-control and cohort studies as well as clinical trials comparing survival outcomes of premenopausal women with or without a pregnancy after prior diagnosis of hormone receptor-positive breast cancer. Disease-free survival (DFS) and overall survival (OS) were the outcomes of interest. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. Study protocol is registered in PROSPERO (n. CRD42023394232).

RESULTS

Out of 7796 screened studies, 8 were eligible to be included in the final analysis. A total of 3805 patients with hormone receptor-positive invasive early breast cancer were included in these studies, of whom 1285 had a pregnancy after breast cancer diagnosis. Median follow-up time ranged from 3.8 to 15.8 years and was similar in the pregnancy and non-pregnancy cohorts. In three studies (n = 987 patients) reporting on DFS, no difference was observed between patients with and those without a subsequent pregnancy (HR 0.96, 95% CI 0.75-1.24, P = 0.781). In the six studies (n = 3504 patients) reporting on OS, patients with a pregnancy after breast cancer had a statistically significant better OS than those without a pregnancy (HR 0.46, 95% CI 0.27-0.77, P < 0.05).

CONCLUSIONS

This systematic review and meta-analysis of retrospective cohort studies provides updated evidence that having a pregnancy in patients with prior history of hormone receptor-positive invasive early breast cancer appears safe without detrimental effect on prognosis.

ESMO Expert Consensus Statements on the management of breast cancer during pregnancy (PrBC)

The management of breast cancer during pregnancy (PrBC) is a relatively rare indication and an area where no or little evidence is available since randomized controlled trials cannot be conducted. In general, advances related to breast cancer (BC) treatment outside pregnancy cannot always be translated to PrBC, because both the interests of the mother and of the unborn should be considered. Evidence remains limited and/or conflicting in some specific areas where the optimal approach remains controversial. In 2022, the European Society for Medical Oncology (ESMO) held a virtual consensus-building process on this topic to gain insights from a multidisciplinary group of experts and develop statements on controversial topics that cannot be adequately addressed in the current evidence-based ESMO Clinical Practice Guideline. The aim of this consensus-building process was to discuss controversial issues relating to the management of patients with PrBC. The virtual meeting included a multidisciplinary panel of 24 leading experts from 13 countries and was chaired by S. Loibl and F. Amant. All experts were allocated to one of four different working groups. Each working group covered a specific subject area with two chairs appointed: Planning, preparation and execution of the consensus process was conducted according to the ESMO standard operating procedures.

Interrupting Endocrine Therapy to Attempt Pregnancy after Breast Cancer

BACKGROUND

Prospective data on the risk of recurrence among women with hormone receptor-positive early breast cancer who temporarily discontinue endocrine therapy to attempt pregnancy are lacking.

METHODS

We conducted a single-group trial in which we evaluated the temporary interruption of adjuvant endocrine therapy to attempt pregnancy in young women with previous breast cancer. Eligible women were 42 years of age or younger; had had stage I, II, or III disease; had received adjuvant endocrine therapy for 18 to 30 months; and desired pregnancy. The primary end point was the number of breast cancer events (defined as local, regional, or distant recurrence of invasive breast cancer or new contralateral invasive breast cancer) during follow-up. The primary analysis was planned to be performed after 1600 patient-years of follow-up. The prespecified safety threshold was the occurrence of 46 breast cancer events during this period. Breast cancer outcomes in this treatment-interruption group were compared with those in an external control cohort consisting of women who would have met the entry criteria for the current trial.

RESULTS

Among 516 women, the median age was 37 years, the median time from breast cancer diagnosis to enrollment was 29 months, and 93.4% had stage I or II disease. Among 497 women who were followed for pregnancy status, 368 (74.0%) had at least one pregnancy and 317 (63.8%) had at least one live birth. In total, 365 babies were born. At 1638 patient-years of follow-up (median follow-up, 41 months), 44 patients had a breast cancer event, a result that did not exceed the safety threshold. The 3-year incidence of breast cancer events was 8.9% (95% confidence interval [CI], 6.3 to 11.6) in the treatment-interruption group and 9.2% (95% CI, 7.6 to 10.8) in the control cohort.

CONCLUSIONS

Among select women with previous hormone receptor-positive early breast cancer, temporary interruption of endocrine therapy to attempt pregnancy did not confer a greater short-term risk of breast cancer events, including distant recurrence, than that in the external control cohort. Further follow-up is critical to inform longer-term safety. (Funded by ETOP IBCSG Partners Foundation and others; POSITIVE ClinicalTrials.gov number, NCT02308085.).

Abstract GS4-09: Pregnancy Outcome and Safety of Interrupting Therapy for women with endocrine responsIVE breast cancer: Primary Results from the POSITIVE Trial (IBCSG 48-14/BIG 8-13)

Background: Pregnancy after breast cancer (BC) is of substantial importance for many young women at diagnosis and during follow-up. BC treatment including standard endocrine therapy (ET) (5-10 years) may reduce ovarian reserve and the chances of subsequent successful pregnancy, given conception is contraindicated during ET. A temporary interruption of ET to attempt and carry a pregnancy in this population has never been prospectively studied.

Methods: POSITIVE is a single-arm, prospective, investigator-initiated, international trial evaluating the safety and pregnancy outcomes of interrupting ET for young women with early-stage hormone-receptor-positive (HR+) BC who desire pregnancy. The primary objective is to assess the risk of BC relapse associated with ET interruption for ~2 years to achieve pregnancy. Women ≤42 years with stage I-III HR+ BC who received adjuvant ET (SERM alone, GnRH analogue plus SERM or AI) for 18 to 30 months and wished to interrupt ET to attempt pregnancy were eligible. The primary endpoint is breast cancer free interval (BCFI) defined as the time from enrollment to the first BC event (local, regional, distant recurrence or a new invasive contralateral BC). Planned sample size was 500 patients. Three interim analyses of BCFI were reviewed by the Data Safety Monitoring Committee (DSMC) to assure a 95% chance of stopping the trial early if the annual BCFI event rate exceeded 4%; with primary analysis triggered after 1600 patient years of follow-up (pyfu) and no more than 46 BCFI events defined as the safety threshold. The DSMC recommended continuing the study following each interim analysis. We now report the primary results.

Results: From 12/2014 to 12/2019, 518 women were enrolled. At enrollment, the median age of participants was 37 years (27-43 years); 75.0% were nulliparous, 93.4% had stage I/II disease, 66.3% node-negative. Median time from BC diagnosis to enrollment was 29 months (IQR: 25-32). Tamoxifen alone was the most prescribed ET (41.7%), followed by tamoxifen+ovarian function suppression (35.7%). 62.0% of participants had received neo/adjuvant chemotherapy. At a median follow-up of 41 months (1638 pyfu), 44 participants had experienced a BCFI event, not exceeding the pre-specified safety threshold of 46 events. The 3-year BCFI failure percent was 8.9% (95% CI: 6.3 to 11.6%), similar to the 9.2% (95% CI: 7.6 to 10.8%) calculated in the comparative external control cohort from the SOFT/TEXT trials (Sun et al, Breast 2020). Of 497 women followed for pregnancy status, 368 (74.0%) had at least one pregnancy, 317 (63.8%) had at least one live birth, with a total of 365 babies born. Based on competing risk analysis, 76.3% of patients resumed ET (half within 26 months), 8.3% had BCFI event/death before ET resumption, and 15.4% had not resumed ET yet.

Conclusions: The POSITIVE trial demonstrates that for young women with early HR+ BC desiring pregnancy, temporary interruption of ET to attempt pregnancy does not confer a greater short-term risk of recurrence than that observed in a modern historical control group that did not interrupt ET. Most participants have had a live birth. Further follow-up is planned to confirm long-term safety. These results should be considered in counselling BC patients desiring future pregnancy.

Citation Format: Ann Partridge, Olivia Pagani, Samuel M. Niman, Monica Ruggeri, Fedro Alessandro A. Peccatori, Hatem A. Azim, Marco Colleoni, Cristina Saura, Chikako Shimizu, Anna Saetersdal, Judith Kroep, Audrey Mailliez, Ellen Warner, Virginia F. Borges, Frédéric Amant, Andrea Gombos, Akemi Kataoka, Christine Rousset-Jablonski, Simona Borstnar, Junko Takei, Jeong Eon Lee, Janice Walshe, Manuel Ruiz Borrego, Halle Moore, Christobel Saunders, Vesna Bjelic-Radisic, Snezana Susnjar, Fatima Cardoso, Karen L. Smith, Teresa Ferreiro Vilarino, Karin Ribi, Kathryn Ruddy, Sarra El-Abed, Martine Piccart, Larissa A. Korde, Aron Goldhirsch, Richard D. Gelber. Pregnancy Outcome and Safety of Interrupting Therapy for women with endocrine responsIVE breast cancer: Primary Results from the POSITIVE Trial (IBCSG 48-14/BIG 8-13) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS4-09.

ESO-ESMO fifth international consensus guidelines for breast cancer in young women (BCY5)

We dedicate this manuscript in memory of a dear friend and colleague Bella Kaufman. The fifth International Consensus Symposium for Breast Cancer in Young Women (BCY5) took place virtually in October 2020, organized by the European School of Oncology (ESO) and the European Society of Medical Oncology (ESMO). Consensus recommendations for the management of breast cancer in young women were updated from BCY4 with incorporation of new evidence to inform the guidelines. Areas of research priorities as well as specificities in different geographic and minority populations were identified. This manuscript summarizes the ESO-ESMO international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA).

Abstract P3-23-03: Use of taxane-containing regimens during pregnancy for the treatment of breast cancer: A systematic review

Background: Concurrent diagnosis of breast cancer (BC) and pregnancy represents a therapeutic challenge as the indication of any treatment modality requires careful consideration of expected clinical benefit and fetal safety. Anthracycline-based chemotherapy regimens have been extensively studied and proven to be relatively safe to use during gestation. However, there is limited data about the safety of taxane-containing regimens during pregnancy or the predominant prescribing practices in real-world clinical settings despite NCCN and ESMO supporting their use when clinically indicated. This study aimed to systematically review and synthesize available evidence regarding gestational taxane use for BC treatment.. Methods: A literature search was conducted in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science from their inception up to April 14, 2021. Studies considered eligible for this analysis were those that reported gestational taxane use for BC, presented original findings, and disclosed patient-specific outcomes. The retrieved records were independently screened by two authors, with discrepancies resolved by a third. Descriptive statistics were undertaken. Results: A total of 438 unique records were retrieved, of which 32 reports describing 163 BC patients treated with taxane-containing regimens during pregnancy were identified. Of those, 25 publications disclosed sufficient detail to be included in the analysis (63 pregnancies, 64 newborns; median gestational age at taxane initiation = 24 weeks, range 14-32). The most commonly reported regimens were paclitaxel 80 mg/m2 weekly (20%) and docetaxel 75 mg/m2 every three weeks (15%). The median cumulative dose received during pregnancy was 550 mg/m2 (range: 240-1200) for patients treated with paclitaxel and 375 mg/m2 (range: 150-650) for those prescribed docetaxel. A total of 80% were exposed simultaneously or sequentially to other cytotoxic treatments during pregnancy, 13% were additionally treated with anti-HER2 agents, and 10% received G-CSF. Treatment-associated adverse effects or obstetric complications were reported in 41%, predominantly consisting of preterm contractions or rupture of membranes (11%), oligohydramnios (8%), preeclampsia/HELLP syndrome (8%), and cytopenias (8%). The outcome of all pregnancies was reported as live birth. Overall, 52% of deliveries were preterm (&lt;37 weeks) and 27% of the offspring were classified as small for their gestational age. Additionally, neonatal complications of the offspring exposed to taxanes in utero were documented in 18% of cases and consisted mainly of the need for resuscitation or respiratory support (11%) and hyperbilirubinemia (3%).

Conclusions: In this review, a high rate of maternal and fetal adverse outcomes was found in cases exposed to taxanes during pregnancy. Anecdotal evidence suggests that a wide variability of taxane-containing regimens are used in clinical practice, with most cases being exposed simultaneously or sequentially to other systemic treatments. Future studies are needed to fully elucidate the optimal taxane-containing regimen to be used during pregnancy, with a special emphasis on treatment safety.

Use of taxane-containing regimens during pregnancy. Data are shown as n (%). NR: Not reported Gestational age at taxane initiation 1rst trimester 1 (2%) 2nd trimester 26 (41%) 3rd trimester 13 (21%) NR 23 (37%) Taxane agent administered Paclitaxel 32 (51%) Docetaxel 19 (30%) Both/NR 12 (19%) Pregnancy complications Preterm delivery 33 (52%) Preterm contractions/PROM 7 (11%) Oligohydramnios 5 (8%) Pre-eclampsia/HELLP syndrome 5 (8%) IUGR 5 (8%) Method of delivery Vaginal 13 (20%) C-section 16 (25%) NR 35 (55%) Neonatal complications Preterm delivery 33 (52%) Small for gestational age (n=55) 15 (27%) Need for resuscitation or respiratory support 7 (11%) Hyperbilirubinemia 2 (3%)

Citation Format: Ana S. Ferrigno, Andrea Becerril-Gaitan, Bryan F. Vaca-Cartagena, Hatem A. Azim Jr., Cynthia Villarreal-Garza. Use of taxane-containing regimens during pregnancy for the treatment of breast cancer: A systematic review [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-23-03.

Abstract PD5-06: Safety of assisted reproductive technologies (ART) following treatment completion in young women with germline BRCA pathogenic variants having a pregnancy after breast cancer

BACKGROUND: Young breast cancer (BC) survivors are at risk of infertility. Ovarian stimulation for fertility preservation before (neo)adjuvant chemotherapy is standard of care. Research efforts have shown no negative prognostic effect of pregnancy following BC therapy, also among BRCA carriers. Currently, poor evidence is available on the safety to undergo ART following BC treatment, with no data in carriers of germline BRCA pathogenic variants. To provide evidence on the safety of fertility treatments in this specific population, we assessed the outcomes of a cohort of BRCA-mutated BC survivors who had a pregnancy after prior BC history by comparing the group of patients who underwent ART to achieve pregnancy to the group with spontaneous pregnancy. METHODS: We conducted a multicenter retrospective cohort study across 30 centers worldwide including women diagnosed at ≤ 40 years with stage I-III BC, between January 2000 and December 2012, bearing germline BRCA1/2 pathogenic variants. Survivors with a pregnancy (any outcome) after BC, with no disease-free survival (DFS) event before pregnancy, were assigned to the ART and non-ART group if their pregnancy was achieved through ART or spontaneously, respectively. ART procedures included ovulation induction, ovarian stimulation for in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), and embryo transfer under hormonal replacement therapy (HRT). RESULTS: Of 1,424 patients registered in the study, 168 with a pregnancy after BC were included in the present analysis. A total of 22 patients were included in the ART group and 146 in the non-ART group. Before BC diagnosis, 18.2% patients in the ART group had at least one child, compared to 38.4% in the non-ART group (P=0.030). Patients had a median age at BC diagnosis of 33.0 vs 30.2 years old in the ART group and in the non-ART group, respectively (P=0.004); 45.4% and 17.1% had grade 1-2 tumors, respectively (P=0.008), and 59.1% vs 31.5% had hormone receptor-positive tumors, respectively (P=0.016). Both cohorts had similar tumor size and nodal stage characteristics. Type and duration of endocrine therapy were comparable between groups. The type of ART was not specified in 5 survivors (22.7%). Ovulation induction was used in 1 patient (4.5%), ovarian stimulation in 7 patients (31.8%), embryo transfer under HRT following oocyte donation in 5 patients (22.7%), and embryo transfer under HRT following oocyte and/or embryo cryopreservation for fertility preservation in 4 patients (18.2%). Median age at conception among survivors was 39.7 years in the ART group versus 35.4 years in the non-ART group (P&lt;0.001). Overall, no differences in obstetrical outcomes were observed between groups, although there were more delivery complications in the ART group vs the non-ART group (22.1% vs 4.1%, respectively, P=0.011). Median follow-up from pregnancy was 3.4 years (range: 0.8-8.6) for patients in the ART group vs 5.0 years (range: 0.8-17.6) in the non-ART group (P=0.009). In the ART group, 2 patients (9.1%) experienced a DFS event (both were loco-regional recurrences) as compared to 40 patients (27.4%) in the non-ART group (P=0.182). No patients died in the ART group compared to 10 patients (6.9%) in the non-ART group. CONCLUSIONS: To our knowledge, this is the first study assessing the safety of ART in BC survivors bearing germline BRCA pathogenic variants. Even though the exposed cohort was small, results showed that the use of ART does not appear to increase the relapse risk at short-term follow-up. Further reproductive studies in BRCA-mutated BC patients are warranted.

Citation Format: Margherita Condorelli, Marco Bruzzone, Marcello Ceppi, Alberta Ferrari, Albert Grinshpun, Anne-Sophie Hamy, Evandro de Azambuja, Estela Carrasco, Fedro A. Peccatori, Antonio Di Meglio, Shani Paluch-Shimon, Philip D. Poorvu, Marta Venturelli, Christine Rousset-Jablonski, Claire Senechal, Luca Livraghi, Riccardo Ponzone, Laura De Marchis, Katarzyna Pogoda, Amir Sonnenblick, Cynthia Villarreal-Garza, Octavi Córdoba, Luis Teixeira, Florian Clatot, Kevin Punie, Rossella Graffeo Galbiati, Maria Vittoria Dieci, Alejandro Pérez-Fidalgo, Francois P. Duhoux, Fabio Puglisi, Arlindo R. Ferreira, Eva Blondeaux, Tamar Peretz-Yablonski, Olivier Caron, Claire Saule, Lieveke Ameye, Judith Balmaña, Ann H. Partridge, Hatem A. Azim, Jr, Isabelle Demeestere, Matteo Lambertini. Safety of assisted reproductive technologies (ART) following treatment completion in young women with germline BRCA pathogenic variants having a pregnancy after breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD5-06.

Knowledge, Practice, and Attitudes of Physicians in Low- and Middle-Income Countries on Fertility and Pregnancy-Related Issues in Young Women With Breast Cancer

Fertility and pregnancy-related issues are highly relevant for young (≤ 40 years) patients with breast cancer. Limited evidence exists on knowledge, practice, and attitudes of physicians from low- and middle-income countries (LMICs) regarding these issues.

Online in @ASCO_pubs #JCOGlobOncol large survey by @matteolambe et al. showing suboptimal practice and attitudes of physicians in #LMICs on #fertility and #pregnancy issues in young #BreastCancer patients: increased awareness and education in #oncofertility are needed@OncoAlert

Safety of assisted reproductive techniques in young women harboring germline pathogenic variants in BRCA1/2 with a pregnancy after prior history of breast cancer

BACKGROUND

Knowledge is growing on the safety of assisted reproductive techniques (ART) in cancer survivors. No data exist, however, for the specific population of breast cancer patients harboring germline BRCA1/2 pathogenic variants.

PATIENTS AND METHODS

This is a multicenter retrospective cohort study across 30 centers worldwide including women diagnosed at ≤40 years with stage I-III breast cancer, between January 2000 and December 2012, harboring known germline BRCA1/2 pathogenic variants. Patients included in this analysis had a post-treatment pregnancy either achieved through use of ART (ART group) or naturally (non-ART group). ART procedures included ovulation induction, ovarian stimulation for in vitro fertilization or intracytoplasmic sperm injection, and embryo transfer under hormonal replacement therapy.

RESULTS

Among the 1424 patients registered in the study, 168 were eligible for inclusion in the present analysis, of whom 22 were in the ART group and 146 in the non-ART group. Survivors in the ART group conceived at an older age compared with those in the non-ART group (median age: 39.7 versus 35.4 years, respectively). Women in the ART group experienced more delivery complications compared with those in the non-ART group (22.1% versus 4.1%, respectively). No other apparent differences in obstetrical outcomes were observed between cohorts. The median follow-up from pregnancy was 3.4 years (range: 0.8-8.6 years) in the ART group and 5.0 years (range: 0.8-17.6 years) in the non-ART group. Two patients (9.1%) in the ART group experienced a disease-free survival event (specifically, a locoregional recurrence) compared with 40 patients (27.4%) in the non-ART group. In the ART group, no patients deceased compared with 10 patients (6.9%) in the non-ART group.

CONCLUSION

This study provides encouraging safety data on the use of ART in breast cancer survivors harboring germline pathogenic variants in BRCA1/2, when natural conception fails or when they opt for ART in order to carry out preimplantation genetic testing.

Who are the women who enrolled in the POSITIVE trial: A global study to support young hormone receptor positive breast cancer survivors desiring pregnancy

Background

Premenopausal women with early hormone-receptor positive (HR+) breast cancer receive 5–10 years of adjuvant endocrine therapy (ET) during which pregnancy is contraindicated and fertility may wane. The POSITIVE study investigates the impact of temporary ET interruption to allow pregnancy.

Methods

POSITIVE enrolled women with stage I-III HR + early breast cancer, ≤42 years, who had received 18–30 months of adjuvant ET and wished to interrupt ET for pregnancy. Treatment interruption for up to 2 years was permitted to allow pregnancy, delivery and breastfeeding, followed by ET resumption to complete the planned duration.

Findings

From 12/2014 to 12/2019, 518 women were enrolled at 116 institutions/20 countries/4 continents. At enrolment, the median age was 37 years and 74.9 % were nulliparous. Fertility preservation was used by 51.5 % of women. 93.2 % of patients had stage I/II disease, 66.0 % were node-negative, 54.7 % had breast conserving surgery, 61.9 % had received neo/adjuvant chemotherapy. Tamoxifen alone was the most prescribed ET (41.8 %), followed by tamoxifen + ovarian function suppression (OFS) (35.4 %). A greater proportion of North American women were <35 years at enrolment (42.7 %), had mastectomy (59.0 %) and received tamoxifen alone (59.8 %). More Asian women were nulliparous (81.0 %), had node-negative disease (76.2%) and received tamoxifen + OFS (56.0 %). More European women had received chemotherapy (69.3 %).

Interpretation

The characteristics of participants in the POSITIVE study provide insights to which patients and doctors considered it acceptable to interrupt ET to pursue pregnancy. Similarities and variations from a regional, sociodemographic, disease and treatment standpoint suggest specific sociocultural attitudes across the world.

•

Fertility and pregnancy are priority concerns for young breast cancer survivors.

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POSITIVE explores a transient interruption of endocrine therapy to allow conception.

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Patients' characteristics highlight features considered suitable to study enrolment.

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Overall, patients enrolled had a relatively high median age and low-risk disease.

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Variations emerged across continents suggesting specific sociocultural attitudes.

Pregnancy After Breast Cancer: A Systematic Review and Meta-Analysis

PURPOSE

Many patients and physicians remain concerned about the potential detrimental effects of pregnancy after breast cancer (BC) in terms of reproductive outcomes and maternal safety. This systematic review and meta-analysis aimed at providing updated evidence on these topics.

METHODS

A systematic literature review was conducted to identify studies including patients with a pregnancy after BC (PROSPERO number CRD42020158324). Likelihood of pregnancy after BC, their reproductive outcomes, and maternal safety were assessed. Pooled relative risks, odds ratios (ORs), and hazard ratios (HRs) with 95% CIs were calculated using random effects models.

RESULTS

Of 6,462 identified records, 39 were included involving 8,093,401 women from the general population and 112,840 patients with BC of whom 7,505 had a pregnancy after diagnosis. BC survivors were significantly less likely to have a subsequent pregnancy compared with the general population (relative risk, 0.40; 95% CI, 0.32 to 0.49). Risks of caesarean section (OR, 1.14; 95% CI, 1.04 to 1.25), low birth weight (OR, 1.50; 95% CI, 1.31 to 1.73), preterm birth (OR, 1.45; 95% CI, 1.11 to 1.88), and small for gestational age (OR, 1.16; 95% CI, 1.01 to 1.33) were significantly higher in BC survivors, particularly in those with previous chemotherapy exposure, compared with the general population. No significantly increased risk of congenital abnormalities or other reproductive complications were observed. Compared to patients with BC without subsequent pregnancy, those with a pregnancy had better disease-free survival (HR, 0.66; 95% CI, 0.49 to 0.89) and overall survival (HR, 0.56; 95% CI, 0.45 to 0.68). Similar results were observed after correcting for potential confounders and irrespective of patient, tumor, and treatment characteristics, pregnancy outcome, and timing of pregnancy.

CONCLUSION

These results provide reassuring evidence on the safety of conceiving in BC survivors. Patients' pregnancy desire should be considered a crucial component of their survivorship care plan.

Prognosis of breast cancer diagnosed during pregnancy and early postpartum according to immunohistochemical subtype: A matched case-control study

PURPOSE

Pregnancy-associated breast cancer (PABC) poses a clinical challenge and its prognosis remains controversial. During the pregnancy and postpartum periods, the breast undergoes biological events that may uniquely influence disease behavior and treatment response. This study aimed to assess if a PABC diagnosis influences survival compared to non-PABC.

METHODS

A single-center record review was performed to identify PABC patients diagnosed from January 2007 through June 2018. Two controls were matched to each PABC case by stage, immunohistochemical (IHC) subtype, age (± 3) and year of diagnosis (± 2). Disease-free survival (DFS) and overall survival (OS) were estimated with the Kaplan-Meier method and compared with the log-rank test. Multivariate analysis was used to assess the impact of PABC on outcomes.

RESULTS

125 PABC patients (pregnant: 62; postpartum: 63) and 250 controls were included. Median follow-up was 67.7 and 73.4 months, respectively. 4-year DFS was 62% in pregnant vs 78% in controls (p = 0.010), and 63% in postpartum vs 83% in controls (p = 0.034). Subanalysis by IHC subtype revealed a significantly inferior DFS in PABC with hormone receptor-positive/HER2-negative (p = 0.032) and HER2-positive disease (p = 0.005) compared to corresponding non-PABC patients. 4-year OS was similar between case groups and controls. Multivariate analysis supported the independent impact of pregnant and postpartum status on DFS (p < 0.05).

CONCLUSION

Patients diagnosed during pregnancy and early postpartum are at high risk of recurrence. Further research is warranted to better characterize PABC tumor biology and enable the identification of novel therapeutic interventions to improve treatment outcomes.

Abstract PD10-06: Clinical behavior and outcomes of BRCA-mutated breast cancer in young patients according to type of BRCA mutation and hormone receptor status: Results from an international cohort study

Background: Young breast cancer patients (pts) carrying a germline BRCA mutation (mBRCA) have similar outcomes as non-carriers. However, there is currently lack of evidence regarding the impact of mBRCA type and hormone receptor status on clinical behavior and outcomes of mBRCA breast cancer. We aim to address these questions in the largest dataset to date of young mBRCA breast cancer pts.

Methods: This was an international, multicenter, hospital-based, retrospective cohort study. Women harboring deleterious germline mBRCA1 or mBRCA2 that received a diagnosis of stage I-III invasive early breast cancer at age ≤40 years between January 2000 and December 2012 were included. Baseline pts, tumor, and treatment characteristics, pattern and risk over time of disease-free survival (DFS) events, and survival outcomes (DFS, distant recurrence-free interval [DRFI] and overall survival [OS]) were compared between mBRCA1 and mBRCA2 pts overall and by hormone receptor status. Multivariate Cox proportional hazard models were used to compare hazard rates (HRs).

Results: 1,236 young mBRCA breast cancer pts were included. Among 808 and 428 pts with mBRCA1 or mBRCA2, respectively, 191 (23.6%) and 356 (83.2%) had hormone receptor-positive tumors while 617 (76.4%) and 72 (16.8%) hormone receptor-negative disease (p&lt;0.001). Compared to mBRCA2 breast cancer pts, those with mBRCA1 were younger, more likely to have reported Jewish ancestry, had more grade 3 tumors, less nodal involvement, lobular histology and HER2 positivity, and received more frequently chemotherapy (all p&lt;0.001). More mBRCA1 pts with hormone receptor-positive tumors did not receive adjuvant endocrine therapy (14.7% vs. 4.2%, p&lt;0.001). No difference between mBRCA1 and mBRCA2 pts was observed in risk-reducing mastectomy (43.9% vs. 46.0%; p=0.371) or salpingo-oophorectomy (48.3% vs. 48.8%; p=1.0). Median follow-up was 7.9 years (range 5.6-10.6 years). Second primary breast cancers (17.0% vs. 12.2%, p=0.025) and non-breast primary malignancies (4.3% vs. 1.9%, p=0.033) were more frequent among mBRCA1 pts compared to mBRCA2 pts, while distant recurrences were less frequent (10.4% vs. 15.4%, p=0.013). 8-year DFS was 62.8% and 65.9% for mBRCA1 and mBRCA2 pts, respectively (adjusted HR 0.76; 95% CI 0.60-0.96). The worse DFS in mBRCA1 was observed regardless of hormone receptor status (pinteraction=0.848): hormone receptor-positive (adjusted HR 0.77; 95% CI 0.58-1.03) and hormone receptor-negative (adjusted HR 0.73; 95% CI 0.48-1.13). No differences in DRFI and OS were observed between mBRCA1 and mBRCA2 pts. Compared to pts with hormone receptor-negative disease, those with hormone receptor-positive breast cancer had higher chances of developing distant (± loco-regional) recurrences (16.1% vs. 9.0%; p&lt;0.001) and less frequent second primary malignancies (BC: 12.1% vs. 17.9%, p=0.005; non-BC: 2.8% vs. 4.0%, p=0.216). No differences in DFS and OS were observed between pts with hormone receptor-positive or negative breast cancer. However, there was a trend towards worse DRFI in women with hormone receptor-positive breast cancer as compared to those with hormone receptor-negative disease (8-year DRFI: 83.4% vs. 90.1%; adjusted HR 1.39; 95% CI 0.94-2.05).

Conclusions: In this large unique dataset, young mBRCA1 breast cancer pts had worse DFS than those with mBRCA2 mostly due to higher rates of second primary malignancies. Hormone receptor positivity had no positive prognostic value in young mBRCA breast cancer pts with a trend towards worse DRFI in those with hormone receptor-negative disease. These results provide important information for counseling young mBRCA breast cancer pts regarding treatment, prevention and follow-up care strategies.

Citation Format: Matteo Lambertini, Marcello Ceppi, Anne-Sophie Hamy, Olivier Caron, Philip D. Poorvu, Estela Carrasco, Albert Grinshpun, Kevin Punie, Christine Rousset-Jablonski, Alberta Ferrari, Shani Paluch-Shimon, Angela Toss, Claire Senechal, Fabio Puglisi, Katarzyna Pogoda, Jose Alejandro Pérez-Fidalgo, Laura De Marchis, Riccardo Ponzone, Luca Livraghi, Maria Del Pilar Estevez-Diz, Cynthia Villarreal-Garza, Maria Vittoria Dieci, Florian Clatot, Francois P. Duhoux, Rossella Graffeo, Luis Teixeira, Octavi Córdoba, Amir Sonnenblick, Arlindo R. Ferreira, Ann H. Partridge, Antonio Di Meglio, Claire Saule, Fedro A. Peccatori, Marco Bruzzone, Lucia Del Mastro, Lieveke Ameye, Judith Balmaña, Hatem A. Azim, Jr. Clinical behavior and outcomes of BRCA-mutated breast cancer in young patients according to type of BRCA mutation and hormone receptor status: Results from an international cohort study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD10-06.

Abstract PS12-17: Baseline characteristics of women enrolled in the POSITIVE trial (pregnancy outcome and safety of interrupting therapy for women with endocrine responsIVE breast cancer)

Background: Pregnancy is a major concern for young breast cancer (BC) survivors. Conception after BC in women with hormone receptor positive (HR+) disease is affected by the standard 5-10 years of adjuvant endocrine therapy (ET) during which pregnancy is contraindicated and fertility may be waning. The POSITIVE Trial (IBCSG 48-14/BIG 8-13/Alliance A221405/NCT02308085) investigates the impact of temporary ET interruption to allow pregnancy.

Methods: POSITIVE enrolled premenopausal women with stage I-III HR+ early BC, ≤42 years of age, who had received adjuvant ET (SERM alone, ovarian function suppression (OFS) plus SERM or AI) for 18 to 30 months, and wished to interrupt ET to attempt pregnancy. An interruption of ET for up to 2 years was foreseen to allow pregnancy (after a 3-month ET washout period), delivery, and breastfeeding if desired/feasible. Resumption of ET to complete 5-10 years of treatment was planned as soon as pregnancy/breastfeeding was completed or after it was ensured conception was not possible. We report baseline characteristics of participants enrolled in POSITIVE by region of enrollment.

Results: From 12/2014 to 12/2019, 518 participants were enrolled at 116 centers in 20 countries across 4 continents. The table shows the baseline characteristics of the enrolled women.

Several differences were seen across regions: A higher proportion of participants &lt;35 yrs (43%) enrolled in North America than in Europe (33%) or Asia (26%). Eighty-one percent of Asian women had no children at enrollment compared to 75% and 68% of European and North American women, respectively. Consistently, a greater percent of women in Asia (56%) had used fertility preservation measures, compared to Europe (53%) and North America (43%). Stage distribution was also different across continents: a greater percent of Asian participants had stage I, grade 1 and node-negative disease (51%, 29% and 76 %, respectively) compared to European (46%, 14% and 67%) and North American (43%, 16% and 55%) women. Only 19% of Asian women had either 1-3 positive nodes and grade 3 tumors, the proportion increased to 28% and 35% in Europe and to 41% and 38% in North America, respectively. North American women were more likely to have had mastectomy (60% vs. Asian (44%) and European (41%)); European women were more likely to have had chemotherapy (69% vs. North American (56%) and Asian (42%)). ET administration prior to enrollment differed substantially by region: Most North American women had SERM (T) alone (58%), and when OFS was added to oral ET, it was combined with AI in 19% and with T in 8% of participants, respectively. In Asia most women received T + OFS (55%), followed by T alone (36%), and AI + OFS (6%). In Europe, T + OFS was the most frequent treatment (40%), followed by T alone (37%) and AI + OFS (17%). Median duration of ET before enrollment was similar across regions (22-24 months).

Conclusion: Regional variation of baseline characteristics of women enrolled in the POSITIVE trial may provide important insights into different medical and sociocultural attributes and attitudes of the study participants and investigators from those regions.

Affiliation: POSITIVE Investigators, International Breast Cancer Study Group, Alliance for Clinical Trials in Oncology, Breast International Group, North American Breast Cancer Group

CharacteristicRegion: Europe / North America / Asia-Pacific61% / 23% / 16%Median age at enrollment, yrs (IQR)37 (33-39)Caucasian race77%No children prior to enrollment74%Prior fertility preservation measures taken51%Stage I / II46% / 45%0 / 1 positive nodes65% / 21%Grade 2 / 348% / 33%HER2-negative74%Mastectomy46%Chemotherapy61%ET: SERM alone / SERM+OFS / AI+OFS41% / 35% / 16%Median duration of prior ET, mos (IQR)23 (20-27)

Citation Format: Ann H Partridge, Samuel M Niman, Monica Ruggeri, Fedro A Peccatori, Hatem A Azim, Jr, Marco Colleoni, Cristina Saura, Chikako Shimizu, Anna Barbro Sætersdal, Judith Kroep, Ellen Warner, Virginia F Borges, Andrea Gombos, Akemi Kataoka, Christine Rousset-Jablonski, Simona Borstnar, Hideko Yamauchi, Jeong Eon Lee, Janice M Walshe, Manuel Ruíz Borrego, Halle CF Moore, Christobel Saunders, Fatima Cardoso, Snezana Susnjar, Vesna Bjelic-Radisic, Karen L Smith, Martine Piccart, Larissa A Korde, Aron Goldhirsch, Richard D Gelber, Olivia Pagani. Baseline characteristics of women enrolled in the POSITIVE trial (pregnancy outcome and safety of interrupting therapy for women with endocrine responsIVE breast cancer) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS12-17.

Clinical behavior and outcomes of breast cancer in young women with germline BRCA pathogenic variants

Young breast cancer (BC) patients carrying a germline BRCA pathogenic variant (mBRCA) have similar outcomes as non-carriers. However, the impact of the type of gene (BRCA1 vs. BRCA2) and hormone receptor status (positive [HR+] vs. negative [HR-]) on clinical behavior and outcomes of mBRCA BC remains largely unknown. This is an international, multicenter, hospital-based, retrospective cohort study that included mBRCA patients diagnosed, between January 2000 and December 2012, with stage I-III invasive early BC at age ≤40 years. From 30 centers worldwide, 1236 young mBRCA BC patients were included. Among 808 and 428 patients with mBRCA1 or mBRCA2, 191 (23.6%) and 356 (83.2%) had HR+tumors, respectively (P < 0.001). Median follow-up was 7.9 years. Second primary BC (P = 0.009) and non-BC malignancies (P = 0.02) were more frequent among mBRCA1 patients while distant recurrences were less frequent (P = 0.02). Irrespective of hormone receptor status, mBRCA1 patients had worse disease-free survival (DFS; adjusted HR = 0.76, 95% CI = 0.60-0.96), with no difference in distant recurrence-free interval (DRFI) and overall survival (OS). Patients with HR+ disease had more frequent distant recurrences (P < 0.001) and less frequent second primary malignancies (BC: P = 0.005; non-BC: P = 0.18). No differences in DFS and OS were observed according to hormone receptor status, with a tendency for worse DRFI (adjusted HR = 1.39, 95% CI = 0.94-2.05) in patients with HR+ BC. Type of mBRCA gene and hormone receptor status strongly impact BC clinical behavior and outcomes in mBRCA young patients. These results provide important information for patients' counseling on treatment, prevention, and surveillance strategies.

Inhibition of RANK signaling in breast cancer induces an anti-tumor immune response orchestrated by CD8+ T cells

Most breast cancers exhibit low immune infiltration and are unresponsive to immunotherapy. We hypothesized that inhibition of the receptor activator of nuclear factor-κB (RANK) signaling pathway may enhance immune activation. Here we report that loss of RANK signaling in mouse tumor cells increases leukocytes, lymphocytes, and CD8⁺ T cells, and reduces macrophage and neutrophil infiltration. CD8⁺ T cells mediate the attenuated tumor phenotype observed upon RANK loss, whereas neutrophils, supported by RANK-expressing tumor cells, induce immunosuppression. RANKL inhibition increases the anti-tumor effect of immunotherapies in breast cancer through a tumor cell mediated effect. Comparably, pre-operative single-agent denosumab in premenopausal early-stage breast cancer patients from the Phase-II D-BEYOND clinical trial (NCT01864798) is well tolerated, inhibits RANK pathway and increases tumor infiltrating lymphocytes and CD8⁺ T cells. Higher RANK signaling activation in tumors and serum RANKL levels at baseline predict these immune-modulatory effects. No changes in tumor cell proliferation (primary endpoint) or other secondary endpoints are observed. Overall, our preclinical and clinical findings reveal that tumor cells exploit RANK pathway as a mechanism to evade immune surveillance and support the use of RANK pathway inhibitors to prime luminal breast cancer for immunotherapy.

Receptor activator of nuclear factor-κB (RANK)/RANK-ligand (RANKL) signaling regulates the tumor-immune crosstalk. Here the authors show that systemic RANKL inhibition promotes CD8 + T cell infiltration in patients with early breast cancer and that loss of RANK signaling in tumor cells drives a T cell-dependent anti-tumor response in preclinical models.

Clinical utility of genomic signatures in young breast cancer patients: a systematic review

Risk stratification by genomic signatures has been shown to improve prognostication and guide treatment decisions among patients with hormone-sensitive breast cancer. However, their role in young women has not been fully elucidated. In this review, a systematic search was conducted for published articles and abstracts from major congresses that evaluated the use of genomic signatures in young breast cancer patients. A total of 71 studies were analyzed, including 561,188 patients of whom 27,748 (4.9%) were young. Women aged ≤40 years were subjected to genomic testing at a similar rate to older women but had a higher proportion of intermediate- to high-risk tumors when classified by EndoPredict (p = 0.04), MammaPrint (p < 0.01), and Oncotype DX (p < 0.01). In young women with low genomic risk, 6-year distant recurrence-free survival was 94%, while 5-year overall survival was nearly 100%. Nonetheless, young patients classified as low-risk had a higher tendency to receive chemotherapy compared to their older counterparts. In conclusion, genomic tests are useful tools for identifying young patients in whom chemotherapy omission is appropriate.

Pregnancy After Breast Cancer in Patients With Germline BRCA Mutations

PURPOSE

Young women with germline BRCA mutations have unique reproductive challenges. Pregnancy after breast cancer does not increase the risk of recurrence; however, very limited data are available in patients with BRCA mutations. This study investigated the impact of pregnancy on breast cancer outcomes in patients with germline BRCA mutations.

PATIENTS AND METHODS

This is an international, multicenter, hospital-based, retrospective cohort study. Eligible patients were diagnosed between January 2000 and December 2012 with invasive early breast cancer at age ≤ 40 years and harbored deleterious germline BRCA mutations. Primary end points were pregnancy rate, and disease-free survival (DFS) between patients with and without a pregnancy after breast cancer. Pregnancy outcomes and overall survival (OS) were secondary end points. Survival analyses were adjusted for guarantee-time bias controlling for known prognostic factors.

RESULTS

Of 1,252 patients with germline BRCA mutations (BRCA1, 811 patients; BRCA2, 430 patients; BRCA1/2, 11 patients) included, 195 had at least 1 pregnancy after breast cancer (pregnancy rate at 10 years, 19%; 95% CI, 17% to 22%). Induced abortions and miscarriages occurred in 16 (8.2%) and 20 (10.3%) patients, respectively. Among the 150 patients who gave birth (76.9%; 170 babies), pregnancy complications and congenital anomalies occurred in 13 (11.6%) and 2 (1.8%) cases, respectively. Median follow-up from breast cancer diagnosis was 8.3 years. No differences in DFS (adjusted hazard ratio [HR], 0.87; 95% CI, 0.61 to 1.23; P = .41) or OS (adjusted HR, 0.88; 95% CI, 0.50 to 1.56; P = .66) were observed between the pregnancy and nonpregnancy cohorts.

CONCLUSION

Pregnancy after breast cancer in patients with germline BRCA mutations is safe without apparent worsening of maternal prognosis and is associated with favorable fetal outcomes. These results provide reassurance to patients with BRCA-mutated breast cancer interested in future fertility.

Adjuvant ovarian function suppression and tamoxifen in premenopausal breast cancer patients: A meta-analysis

BACKGROUND

The benefit of adding ovarian function suppression (OFS) to tamoxifen in the adjuvant treatment of premenopausal women with breast cancer is uncertain. We conducted a meta-analysis of randomized controlled trials that addressed this question.

METHODS

Systematic search of PubMed, the web of science, and the meeting library of ASCO, ESMO, and SABCS was conducted using the following keywords: tamoxifen, ovarian suppression, and breast cancer. Eligible studies were those recruiting patients with breast cancer randomized to receive adjuvant tamoxifen and OFS versus tamoxifen alone. Pooled hazard ratio [HR]) for disease-free (DFS) and overall survival (OS) with 95% confidence interval (CI) were calculated using the fixed effect model.

RESULTS

We searched a total of 845 records, of which 5 clinical trials, including 7557 patients, were eligible for our analysis. Adding OFS to tamoxifen improved DFS with pooled HR: 0.88 (95% CI: 0.80-0.96, P= 0.004) and OS (pooled HR: 0.87 {95% CI: 0.77-0.98, P= 0.02}) compared to tamoxifen alone. The benefit of the addition of OFS to tamoxifen was mostly observed in patients younger than 40 years where the pooled HRs of DFS was 0.76 (95% CI: 0.63-0.91; P= 0.004), and in those who received adjuvant chemotherapy with pooled HRs of DFS 0.80 (95% CI: 0.65-0.99, P= 0.042). There was an increase in the incidence of all grade musculoskeletal symptoms and high-grade hot flushes with the addition of OFS with risk ratios of 1.12 (95% CI: 1.07-1.17, P< 0.001) and 2.14 (95% CI: 1.01-4.51, P= 0.047) respectively.

CONCLUSION

Our analysis indicates that the addition of OFS to tamoxifen improves DFS and OS. This strategy could be considered in patients in which tamoxifen alone is not deemed sufficient or in case of poor tolerance to OFS with aromatase inhibitors.

Estimation of historical control rate for a single arm de-escalation study - Application to the POSITIVE trial

BACKGROUND

Although randomized controlled clinical trials are optimal to evaluate the effect of an experimental therapy, single-arm trials are required whenever randomization is unethical or not feasible, such as de-escalation studies. We propose using prospectively identified historical controls to place results of single-arm, de-escalation trials into context.

METHODS

POSITIVE is a prospective, single-arm study in young women with hormone-receptor-positive early breast cancer to determine if temporarily interrupting adjuvant endocrine therapy in order to become pregnant increases the risk of a breast cancer event. After 272 women enrolled in POSITIVE, we identified a cohort of 1499 SOFT/TEXT patients potentially eligible to enroll in POSITIVE who did not interrupt endocrine therapy. Method I used the SOFT/TEXT cohort to calculate annualized hazard rates by a piecewise exponential model. Method II used the SOFT/TEXT cohort to group-match SOFT/TEXT patients to POSITIVE patients; sample sets of SOFT/TEXT patients were randomly drawn 5000 times to obtain sets having patient, disease, and treatment characteristics more balanced with POSITIVE participants.

RESULTS

Compared with SOFT/TEXT, POSITIVE participants were younger, less likely to be overweight/obese, had fewer positive nodes, and fewer received aromatase inhibitor or chemotherapy. The estimated 3-year breast cancer free interval event rates were 9.5% (95% CI: 7.9%,11.1%) for Method I and 9.4% (95% CI: 7.8%,10.9%) for Method II, compared with 5.8% initially assumed when POSITIVE was designed.

CONCLUSION

External control datasets should be identified before launching single-arm, de-escalation trials and methods applied during their conduct to provide context for interim monitoring and interpretation of the final analysis.

ESO-ESMO 4th International Consensus Guidelines for Breast Cancer in Young Women (BCY4)

The 4th International Consensus Conference for Breast Cancer in Young Women (BCY4) took place in October 2018, in Lugano, Switzerland, organized by the European School of Oncology (ESO) and the European Society of Medical Oncology (ESMO). Consensus recommendations for the management of breast cancer in young women were updated from BCY3 with incorporation of new evidence to inform the guidelines. Areas of research priorities were also identified. This article summarizes the ESO-ESMO international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA).

Fertility preservation in patients with BRCA mutation

Evidence suggests a likely negative impact of deleterious BRCA mutations on female fertility. Hence, different studies have aimed to address the reproductive potential and performance of fertility preservation strategies in BRCA-mutated breast cancer patients with a prime focus on their safety and efficacy. However, several uncertainties exist in many domains of this field. The aim of the current paper is to overview the reproductive potential and fertility preservation options in breast and ovarian cancer patients harbouring a BRCA mutation. We also discuss pre-implantation genetic testing in an attempt to help physicians during oncofertility counselling of these patients.

Abstract OT1-04-02: POSITIVE: A study evaluating pregnancy, disease outcome and safety of interrupting endocrine therapy for premenopausal women with endocrine responsive breast cancer who desire pregnancy (IBCSG 48-14/big 8-13)

Background: Young patients with breast cancer (BC) are often diagnosed before completing their families. The best available retrospective evidence suggests that pregnancy after BC does not negatively impact disease outcomes overall and in patients with endocrine responsive disease, and is safe for the offspring. However, given also the possibility of extended adjuvant endocrine therapy (ET) (5-10 years), it is not feasible for many of these women to delay pregnancy until completion of therapy. Prospectively evaluating the safety of temporary interruption of ET to allow conception is an unmet, patient-oriented, medical need.

Trial Design: Young patients with endocrine responsive early BC who desire pregnancy will interrupt ET for up to 2 yrs to attempt child-bearing. As resumption of menses and conception depends on many factors (e.g. patient’s age and adjuvant treatment received), the 2-yr interruption period is approximate, intended to include treatment wash-out (3 mos), conception (~3-6 mos), delivery (~9 mos), and breast feeding (~6 mos). Patients will be strongly advised to resume ET as soon as pregnancy attempts/deliveries are concluded, and to complete the planned 5-10 yrs of ET.

Major Eligibility Criteria

- Histologically-proven stage I-III endocrine-responsive BC.

- Patient’s wish to become pregnant.

- Age ≥ 18 and ≤ 42 years at enrollment.

- Adjuvant ET (selective estrogen receptor modulator [SERM] alone, GnRH analogue plus SERM or aromatase inhibitor) for ≥18 months but ≤30 months, stopped within 1 month prior to enrollment.

- Premenopausal status at BC diagnosis.

Specific Aims

1. To assess the risk of BC relapse associated with temporary interruption of ET to permit pregnancy.

2. To evaluate pregnancy success rate and offspring outcome.

Statistical Methods: With 500 pts enrolled and followed for a median of 3 years, the statistical design is based on the 95% CI for the 3-year BC recurrence rate. Interim monitoring assumes a 2% BC recurrence risk/yr with continuous ET and a recommendation to stop the study early if the BC risk exceeds 4%/yr with ET interruption.

Translational Research will evaluate fertility, pregnancy and BC biology determinants (e.g. ovarian function, uterine evaluation and circulating tumor DNA). Fresh frozen paraffin embedded tissue of the primary tumour will be collected to evaluate parameters related to the biology of BC in young women. All material will be banked centrally.

Psycho-oncological Companion Study (POCS) will evaluate fertility concerns, psychological well-being and decisional conflict. It is mandatory in North America and open to interested centers elsewhere.

Accrual: Target: 500; Actual: 421 (30 June 2019)

Psycho-oncological Companion Study Accrual: Target: ~200; Actual: 196 (30 June 2019)

Contact Information: POSITIVE is conducted and sponsored by the International Breast Cancer Study Group. The Alliance for Clinical Trials in Oncology is the US sponsor for NCTN. Contact Monica Ruggeri, IBCSG Coordinating Center, monica.ruggeri@ibcsg.org, or Trial Coordinators at ibcsg48_positive@fstrf.org.

Citation Format: Olivia Pagani, Ann H Partridge, Fedro A Peccatori, Hatem A Azim, Chikako Shimizu, Cristina Saura, Ellen Warner, Anna B Sætersdal, Judith R Kroep, Monica Ruggeri, Richard D Gelber. POSITIVE: A study evaluating pregnancy, disease outcome and safety of interrupting endocrine therapy for premenopausal women with endocrine responsive breast cancer who desire pregnancy (IBCSG 48-14/big 8-13) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT1-04-02.

Understanding the benefits and challenges of first-line cyclin-dependent kinases 4 and 6 inhibitors in advanced breast cancer among postmenopausal women

Endocrine therapy (ET) has been regarded for many years as the standard treatment for patients with hormone receptor-positive (ER+), HER2-negative (HER2-) advanced breast cancer (ABC) without visceral crisis. However, the efficacy of single-agent ET is constrained by the development of resistance, attributed to alterations in several intracellular signaling pathways, including those related to cell cycle dysregulation. The cyclin-dependent kinases 4 and 6 (CDK4/6) are principal regulators of cell cycle progression from the G1-phase into the DNA synthesis (S)-phase. In vitro inhibition of CDK4/6 activity has potent antiproliferative properties against luminal breast cancer cell lines, which are enhanced when combined with traditional ET. This has led to a substantial interest in targeting this pathway to overcome endocrine resistance in the clinic. Three selective CDK4/6 inhibitors (palbociclib, ribociclib, and abemaciclib) have been approved as first-line therapy in combination with an aromatase inhibitor, or fulvestrant in the case of ribociclib in patients with ER+/HER2- ABC. To date, there is no clue as to which subgroup of patients might benefit most from these combinations. Here, we outline some of the established approaches to overcome endocrine resistance, with special emphasis on the unique mechanism of action of CDK4/6 inhibitors.

Dose-Ranging and Cohort-Expansion Study of Monalizumab (IPH2201) in Patients with Advanced Gynecologic Malignancies: A Trial of the Canadian Cancer Trials Group (CCTG): IND221

PURPOSE

Monalizumab binds CD94/NKG2A, preventing HLA-E inhibition of tumor lymphocytes. A dose-ranging/cohort expansion trial of monalizumab for recurrent gynecologic malignancies was conducted to determine the recommended phase II dose (RP2D) and to explore clinical activity, pharmacokinetics, pharmacodynamics, safety, and immunogenicity.

PATIENTS AND METHODS

Participants (and part 2 expansion cohorts) included (i) platinum-sensitive ovarian, (ii) platinum-resistant ovarian, (iii) squamous cervical (CX), and (iv) epithelial endometrial (END) carcinomas. Part 1 assessed monalizumab at 1, 4, or 10 mg/kg every 2 weeks. In part 2, ≥4 patients/cohort underwent pre- and on-treatment tumor biopsies. Preset criteria determined cohort expansion.

RESULTS

A total of 58 participants were evaluable. The RP2D was 10 mg/kg i.v. every 2 weeks. Dose proportionality and 100% NKG2A saturation were observed. Related adverse events were mild: headache, abdominal pain, fatigue, nausea, and vomiting. Grade 3 related adverse events were nausea (1), vomiting (1), dehydration (1), fatigue (2), anorexia (1), dyspnea (1), and proctitis (1). Dose-limiting toxicities were not observed. Hematologic and biochemical changes were mild and not dose related. Best response was SD: part 1, 7 of 18 (39%) [3.4 months (1.4-5.5)], and part 2, 7 of 39 (18%) [1.7 months (CX) to 14.8 months (END)]. Neither a predictive biomarker for SD nor evidence of pharmacodynamic effects was identified. There was a trend to significance between a reduction in lymphocyte HLA-E total score and pharmacodynamics.

CONCLUSIONS

Monalizumab 10 mg/kg i.v. every 2 week is well tolerated in patients with pretreated gynecologic cancers. Short-term disease stabilization was observed. Future studies should assess combinations with other agents, including immunotherapeutics.

IPH4102, a first-in-class anti-KIR3DL2 monoclonal antibody, in patients with relapsed or refractory cutaneous T-cell lymphoma: an international, first-in-human, open-label, phase 1 trial

BACKGROUND

IPH4102 is a first-in-class monoclonal antibody targeting KIR3DL2, a cell surface protein that is expressed in cutaneous T-cell lymphoma, and predominantly in its leukaemic form, Sézary syndrome. We aimed to assess the safety and activity of IPH4102 in cutaneous T-cell lymphoma.

METHODS

We did an international, first-in-human, open-label, phase 1 clinical trial with dose-escalation and cohort-expansion parts in five academic hospitals in the USA, France, the UK, and the Netherlands. Eligible patients had histologically confirmed relapsed or refractory primary cutaneous T-cell lymphoma, an Eastern Cooperative Oncology group performance score of 2 or less, were aged 18 years or older, and had received at least two previous systemic therapies. Ten dose levels of IPH4102, administered as an intravenous infusion, ranging from 0·0001 mg/kg to 10 mg/kg, were assessed using an accelerated 3 + 3 design. The primary endpoint was the occurrence of dose-limiting toxicities during the first 2 weeks of treatment, defined as toxicity grade 3 or worse lasting for 8 or more days, except for lymphopenia. Global overall response by cutaneous T-cell lymphoma subtype was a secondary endpoint. Safety and activity analyses were done in the per-protocol population. The study is ongoing and recruitment is complete. This trial is registered with ClinicalTrials.gov, number NCT02593045.

FINDINGS

Between Nov 4, 2015, and Nov 20, 2017, 44 patients were enrolled. 35 (80%) patients had Sézary syndrome, eight (18%) had mycosis fungoides, and one (2%) had primary cutaneous T-cell lymphoma, not otherwise specified. In the dose-escalation part, no dose limiting toxicity was reported and the trial's safety committee recommended a flat dose of 750 mg for the cohort-expansion, corresponding to the maximum administered dose. The most common adverse events were peripheral oedema (12 [27%] of 44 patients) and fatigue (nine [20%]), all of which were grade 1-2. Lymphopenia was the most common grade 3 or worse adverse event (three [7%]). One patient developed possibly treatment-related fulminant hepatitis 6 weeks after IPH4102 discontinuation and subsequently died. However, the patient had evidence of human herpes virus-6B infection. Median follow-up was 14·1 months (IQR 11·3-20·5). A confirmed global overall response was achieved in 16 (36·4% [95% CI 23·8-51·1]) of 44 patients, and of those, 15 responses were observed in 35 patients with Sézary syndrome (43% [28·0-59·1]).

INTERPRETATION

IPH4102 is safe and shows encouraging clinical activity in patients with relapsed or refractory cutaneous T-cell lymphoma, particularly those with Sézary syndrome. If confirmed in future trials, IPH4102 could become a novel treatment option for these patients. A multi-cohort, phase 2 trial (TELLOMAK) is underway to confirm the activity in patients with Sézary syndrome and explore the role of IPH4102 in other subtypes of T-cell lymphomas that express KIR3DL2.

FUNDING

Innate Pharma.

Safety of pregnancy following breast cancer (BC) in patients (pts) carrying a BRCA mutation (mBRCA): Results of an international cohort study

11506

Background: Very limited data are available on the safety of pregnancy and reproductive outcomes in mBRCA pts with prior BC history. We report the results of the largest study to date addressing these questions. Methods: This international, multicenter, hospital-based, retrospective cohort study included consecutive pts with invasive early BC (stage I-III) diagnosed between Jan-2000 and Dec-2012 at the age of ≤40 years and carrying a deleterious germline mBRCA. Primary endpoints were pregnancy rate and disease-free survival (DFS); overall survival (OS) and pregnancy outcomes were secondary endpoints. To account for guarantee-time bias, we performed two survival analyses: 1) Case-control approach matching pregnant and non-pregnant (1:3) pts for classic prognostic factors (each non-pregnant control had a disease-free interval ≥ than the time elapsing between BC diagnosis and date of pregnancy of the matched pregnant case); 2) Extended Cox model with time-varying covariates including all pts. Results: 1,252 mBRCA BC pts (811 mBRCA1, 430 mBRCA2, 11 mBRCA1&2) were included from 30 centers worldwide, of whom 195 pts had a pregnancy (pregnancy rate = 16% [95% CI 14-18]) after a median 4.5 years (range 3.1-6.7 years) following BC diagnosis. Pregnant pts were younger and had more ER-negative tumors (all p < 0.01). 16 (8.2%) and 20 (10.3%) pts had an induced and spontaneous abortion, respectively. Among the 150 (76.9%) pts who conceived (n = 170 babies), pregnancy complications and congenital anomalies were described in 13 (11.6%) and 2 (1.8%) cases, respectively. Median follow-up was 8.3 years (range 8.1-8.7 years). In the case-control analysis, pregnant pts had better DFS (HR 0.71; 95% CI 0.51-0.99; p = 0.045), with no difference in OS (HR 0.86; 95% CI 0.44-1.67; p = 0.65). Subgroup analysis suggested that the superior outcome was restricted to mBRCA1 pregnant pts (p-interaction < 0.01). Similar results were obtained in the second supportive analysis. Conclusions: Pregnancy following BC is safe in mBRCA pts, particularly mBRCA1, with no detrimental impact on maternal prognosis or fetal outcomes . These findings are of paramount importance for fertility counseling in young mBRCA BC pts.

Reproductive potential and performance of fertility preservation strategies in BRCA-mutated breast cancer patients

Background

Preclinical evidence suggests a possible negative impact of deleterious BRCA mutations on female fertility. However, limited and rather conflicting clinical data are available. This study assessed the reproductive potential and performance of fertility preservation strategies in BRCA-mutated breast cancer patients.

Patients and methods

This was a retrospective analysis of two prospective studies investigating oocyte cryopreservation and ovarian tissue cryopreservation in newly diagnosed early breast cancer patients. In the current analysis, baseline anti-Mullerian hormone (AMH) and performance of cryopreservation strategies were compared between patients with or without germline deleterious BRCA mutations.

Results

Out of 156 patients included, 101 had known BRCA status of whom 29 (18.6%) were BRCA-mutated and 72 (46.1%) had no mutation. Median age in the entire cohort was 31 years [interquartile range (IQR) 28-33). Median AMH levels were 1.8 μg/l (IQR 1.0-2.7) and 2.6 µg/l (IQR 1.5-4.1) in the BRCA-positive and BRCA-negative cohorts, respectively (P = 0.109). Among patients who underwent oocyte cryopreservation (N = 29), women in the BRCA-positive cohort tended to retrieve (6.5 versus 9; P = 0.145) and to cryopreserve (3.5 versus 6; P = 0.121) less oocytes than those in the BRCA-negative cohort. Poor response rate (i.e. retrieval of ≤4 oocytes) was 40.0% and 11.1% in the BRCA-positive and BRCA-negative cohorts, respectively (P = 0.147). Among patients who underwent ovarian tissue cryopreservation (N = 72), women in the BRCA-positive cohort tended to have a numerically lower number of oocytes per fragment (0.08 versus 0.14; P = 0.193) and per square millimeter (0.33 versus 0.78; P = 0.153) than those in the BRCA-negative cohort. Two BRCA-mutated patients were transplanted after chemotherapy and one delivered at term a healthy baby. No difference between BRCA1- and BRCA2-mutated patients was observed in any of the above-mentioned outcomes.

Conclusion

A consistent trend for reduced reproductive potential and performance of cryopreservation strategies was observed in BRCA-mutated breast cancer patients. Independent validation of these results is needed.

Abstract P6-18-16: Ribociclib (RIBO) + letrozole (LET) in older patients with hormone receptor-positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC): Preliminary subgroup results from the phase 3b CompLEEment-1 trial

Background: The cyclin-dependent kinase (CDK)4/6 inhibitor RIBO is approved in combination with an aromatase inhibitor (AI) for HR+, HER2– ABC in postmenopausal women with no prior therapy for ABC, based on the MONALEESA-2 trial (Hortobagyi et al. NEJM 2016). Although a high proportion of patients with HR+, HER2– ABC are &gt;65 years of age, older patients are often under-represented in clinical trials. Furthermore, treatment decisions may be complicated by comorbidities, functional status, and concurrent medications. Here, we report early safety results for patients ≥65 years of age enrolled in CompLEEment-1, an open-label, phase 3b trial evaluating RIBO+LET as first-line endocrine-based therapy in an expanded patient population.

Methods: Patients with HR+, HER2– ABC, ≤1 line of prior chemotherapy (CT), and no prior endocrine therapy for ABC received RIBO (600 mg/day, 3 weeks on/1 week off) + LET (2.5 mg/day); men and premenopausal women received concomitant goserelin (3.6-mg subcutaneous implant every 28 days). The primary outcome was safety and tolerability. A pre-planned interim analysis was conducted ˜15 months after first patient first visit.

Results: Of the first 1,008 patients enrolled who completed 56 days of follow-up or discontinued before the data cut-off date, 377 were ≥65 years of age. Of these, 157 (41.6%) were 65-&lt;70 years, 107 (28.4%) were 70-&lt;75 years, and 113 (30%) were ≥75 years. The majority of patients (94.4%) had an Eastern Cooperative Oncology Group performance status ≤1; 33.2% presented with stage IV disease at diagnosis; 9 patients were male. The most common sites of metastasis were bone (70.0%), lung (44.8%), and lymph nodes (29.7%). The most common all-grade adverse events (AEs) were neutropenia (58.4%), nausea (31.8%), and fatigue (24.1%). The most common grade 3/4 AEs were neutropenia (37.7%) and alanine aminotransferase increase (4.2%). QT prolongation events were mild (majority grade 1/2) and occurred in 6.1% of patients (0.5% grade 3/4). Dose reduction or interruption due to AEs occurred in 54.5% of patients; 6.9% of patients had AEs leading to treatment discontinuation. In the overall patient population, the most frequent grade 3/4 AEs were neutropenia (42.8%), leukopenia (3.4%), and increased alanine aminotransferase (2.9%); QT prolongation occurred in 5.4% of patients (0.5% grade 3/4).

Conclusions: Initial safety results from CompLEEment-1, from the first 56 days of follow-up, demonstrate the tolerability of RIBO+LET in older patients, consistent with the overall patient population. NCT02941926.

Citation Format: Ring A, Borstnar S, Ferreira A, Azim HA, Cottu P, Lu J, Martin M, Zamagni C, Beck JT, Zhou K, Wu J, Menon L, De Laurentiis M. Ribociclib (RIBO) + letrozole (LET) in older patients with hormone receptor-positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC): Preliminary subgroup results from the phase 3b CompLEEment-1 trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-16.

Abstract OT1-01-06: POSITIVE: A study evaluating Pregnancy, disease outcome and safety of interrupting endocrine therapy for premenopausal women with endocrine responsIVE breast cancer who desire pregnancy (IBCSG 48-14/BIG 8-13)

Background

Young patients with breast cancer (BC) are often diagnosed with the disease before completing their families. The best available retrospective evidence suggests that pregnancy after BC does not negatively impact disease outcomes in patients with endocrine responsive BC and is safe for the offspring. However, given the possibility of extended adjuvant endocrine therapy (ET) (5-10 years), it is not feasible for many of these women to delay pregnancy until completion of therapy and thus there is a need to study the safety of interrupting ET to allow pregnancy. To date, no prospective study has been conducted in BC survivors attempting future pregnancy.

Trial Design

Young patients with endocrine responsive early BC who desire pregnancy will interrupt ET for up to 2 yrs to attempt pregnancy. As resumption of menses and conception depends on many factors (e.g. patient's age and adjuvant treatment received), the 2-yr interruption period is approximate, intended to include treatment wash-out (3 mos), conception (˜3-6 mos), delivery (˜9 mos), and breast feeding (˜6 mos). Patients will be strongly advised to resume ET as soon as pregnancy attempts/deliveries are concluded, and to complete the planned 5-10 yrs of ET.

Major Eligibility Criteria

- Histologically-proven stage I-III endocrine-responsive BC.

- Patient's wish to become pregnant.

- Age ≥ 18 and ≤ 42 years at enrollment.

- Adjuvant ET (selective estrogen receptor modulator [SERM] alone, GnRH analogue plus SERM or aromatase inhibitor) for ≥18 months but ≤30 months, stopped within 1 month prior to enrollment.

- Premenopausal status at BC diagnosis.

Specific Aim

To assess the risk of BC relapse associated with the interruption of ET to permit pregnancy, and to evaluate pregnancy success rate and offspring outcome.

Statistical Methods

With 500 pts enrolled and followed for a median of 3 years, the statistical design is based on the 95% CI for the 3-year BC recurrence rate. Interim monitoring assumes a 2% BC recurrence risk/yr with continuous ET and a recommendation to stop the study early if the BC risk exceeds 4%/yr with ET interruption.

Translational Research will investigate various ovarian function and uterine parameters and circulating tumour DNA. Fresh frozen paraffin embedded tissue of the primary tumour will be collected to evaluate parameters related to the biology of BC in young women. All material will be banked centrally.

Psycho-oncological Companion Study (POCS) will evaluate fertility concerns, psychological well-being and decisional conflict. It is mandatory in North America and open to interested centers elsewhere.

Accrual: Target: 500; Actual: 262 (30 June 2018)

Psycho-oncological Companion Study Accrual: Target: 200; Actual: 138 (30 June 2018)

Citation Format: Pagani O, Partridge AH, Peccatori F, Azim HA, Colleoni M, Saura C, Kroep JR, Warner E, Gombos A, Sætersdal AB, Ruggeri M, Gelber RD, Sun Z. POSITIVE: A study evaluating Pregnancy, disease outcome and safety of interrupting endocrine therapy for premenopausal women with endocrine responsIVE breast cancer who desire pregnancy (IBCSG 48-14/BIG 8-13) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-01-06.

Knowledge, attitudes and practice of physicians towards fertility and pregnancy-related issues in youngBRCA-mutated breast cancer patients

RESEARCH QUESTION

This study explored the knowledge, attitudes and practice of physicians towards fertility and pregnancy-related issues in young BRCA-mutated breast cancer patients.

DESIGN

Physicians attending two international breast cancer conferences completed a 26-item questionnaire exploring fertility preservation, pregnancy during (BCP) or after breast cancer. A statistical comparison was carried out of the responses exploring the same issues in young breast cancer patients overall or specifically in those with BRCA mutations.

RESULTS

The survey was completed by 273 physicians. Ovarian tissue cryopreservation (33% versus 40%; P = 0.009) and gonadotrophin-releasing hormone analogues during chemotherapy (74% versus 81%; P = 0.001) were less commonly suggested in BRCA-mutated patients than in the overall breast cancer population. 42% of respondents agreed or were neutral on the statement that ovarian stimulation should not be considered safe in BRCA-mutated breast cancer patients. 45% and 30% agreed or were neutral on the statement that pregnancy in breast cancer survivors may increase the risk of recurrence in BRCA-mutated patients or in the overall breast cancer population, respectively (P < 0.001). 15% and 3% disagreed that transplanting the cryopreserved ovarian tissue can be considered safe in BRCA-mutated patients or in the overall breast cancer population, respectively (P < 0.001). 33.3% were against the addition of platinum agents as neoadjuvant chemotherapy in BRCA-mutated patients with BCP.

CONCLUSIONS

Several misconceptions on fertility preservation and pregnancy-related issues in breast cancer patients persist even among physicians directly involved in breast cancer care. Focused research efforts to address these issues in BRCA-mutated breast cancer patients and education to improve physicians' knowledge and adherence to available guidelines are urgently needed.

Pregnancies during and after trastuzumab and/or lapatinib in patients with human epidermal growth factor receptor 2-positive early breast cancer: Analysis from the NeoALTTO (BIG 1-06) and ALTTO (BIG 2-06) trials

BACKGROUND

Limited data exist on the safety of using anti-human epidermal growth factor receptor 2 (HER2) targeted agents during pregnancy. To date, only retrospective studies have assessed the prognosis of patients with a pregnancy after prior early breast cancer, with no data in HER2-positive patients.

METHODS

The Neoadjuvant Lapatinib and/or Trastuzumab Treatment Optimization (NeoALTTO) trial and the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization (ALTTO) trial were randomized phase 3 trials for patients with HER2-positive early breast cancer. In both trials, pregnancy information was prospectively collected. Pregnancy outcomes were compared between patients unintentionally exposed to trastuzumab and/or lapatinib during gestation (the exposed group) and those who became pregnant after trastuzumab and/or lapatinib completion (the unexposed group). In the ALTTO trial, disease-free survival (DFS) was compared between pregnant patients and those aged 40 years or younger without a subsequent pregnancy via an extended Cox model with time-varying covariates to account for a guarantee-time bias.

RESULTS

Ninety-two patients (12 in the exposed group and 80 in the unexposed group) had a pregnancy: 7 in the NeoALTTO trial and 85 in the ALTTO trial. Seven patients (58.3%) in the exposed group and 10 patients (12.5%) in the unexposed group opted for an induced abortion; in the unexposed group, 10 patients (12.5%) had a spontaneous abortion. No pregnancy/delivery complications were reported for the remaining cases, who successfully completed their pregnancy, with the exception of 1 fetus with trisomy 21 (Down syndrome). No significant difference in DFS (adjusted hazard ratio, 1.12; 95% confidence interval, 0.52-2.42) was observed between young patients with a pregnancy (n = 85) and young patients without a pregnancy (n = 1307).

CONCLUSIONS

For patients with HER2-positive early breast cancer, having a pregnancy after treatment completion appears to be safe without compromising fetal outcome or maternal prognosis.

Breast cancer diagnosed during pregnancy is associated with enrichment of non-silent mutations, mismatch repair deficiency signature and mucin mutations

Breast cancer diagnosed during pregnancy (BCP) is a rare and highly challenging disease. To investigate the impact of pregnancy on the biology of breast cancer, we conducted a comparative analysis of a cohort of BCP patients and non-pregnant control patients by integrating gene expression, copy number alterations and whole genome sequencing data. We showed that BCP exhibit unique molecular characteristics including an enrichment of non-silent mutations, a higher frequency of mutations in mucin gene family and an enrichment of mismatch repair deficiency mutational signature. This provides important insights into the biology of BCP and suggests that these features may be implicated in promoting tumor progression during pregnancy. In addition, it provides an unprecedented resource for further understanding the biology of breast cancer in young women and how pregnancy could modulate tumor biology.

Abstract CT101: D-BEYOND: A window of opportunity trial evaluating denosumab, a RANK-ligand (RANKL) inhibitor and its biological effects in young pre-menopausal women diagnosed with early breast cancer

Background

Breast cancer (BC) in young women has unique biology and poor prognosis. Previous reports suggest that they often express RANKL, which was also shown to play a role in mammary tumorigenesis and the etiology of BRCA1/2 related BC. Here, we present the primary results of D-BEYOND, a window of opportunity study investigating the biological activity of the RANKL inhibitor; denosumab in pre-menopausal BC patients.

Methods

D-BEYOND is a prospective, phase IIa, single-arm, multicenter study assessing the effect of denosumab on BC biology in premenopausal women with early BC (NCT01864798). Patients received two subcutaneous injections of denosumab (120mg), one week apart, followed by breast surgery. Blood, tumor and normal adjacent breast tissue were collected at baseline and at surgery. The primary endpoint was geometric mean change in tumor Ki67 assessed by immunohistochemistry (IHC) from baseline to surgery. Absolute Ki67 responders were defined as having &lt;2.7% IHC staining in the post-treatment tumor. Serum levels of soluble RANKL (sRANKL), OPG and C-terminal telopeptide (CTX) were assessed by ELISA. Ki67, RANK and RANKL expression were assessed by IHC. The percentage of tumor infiltrating lymphocytes (TILs) were also evaluated. Pre- and post-treatment values were compared using a paired t-test.

Results

A total of 27 patients were enrolled in the study between October 2013 and July 2016. The median age was 45 years (range 35-51 years). Tumors of 21 patients were hormone receptor positive (77.8%), 4 were HER2 positive (14.8%) and 2 were triple negative (7.4%). No serious adverse events were reported, the most frequent non-serious adverse event being arthralgia (14.8%). After treatment, serum levels of CTX and sRANKL decreased in all patients (P &lt; 0.001) whereas serum levels of OPG increased in 76.9% of patients (P = 0.009, 95% CI 0.56-0.91). There was no significant reduction of Ki67 values from baseline (geometric mean change after treatment; 0.98, 95% CI 0.76-1.26; P = 0.90) and there were no absolute Ki67 responders. Twenty-four pre- and post-treatment tumor pairs were available for RANK/L staining and TILs assessment. There was no significant difference in RANKL and RANK H-score in tumors after treatment (P = 0.842, P = 0.142, respectively) but we observed a decrease of RANKL H-score in 3 tumors (12.5%) and an increase of RANK H-score in 5 tumors (20%). Interestingly, there was a significant increase in the percentage of stromal TILs after treatment (geometric mean change of 2.51, 95% CI 1.58-3.97; P = 0.004). There were 10/24 patients (41.7%) with a change in TILs of at least 10%, all of them having an increase in TILs presence (P = 0.002).

Conclusion

Short course of denosumab did not reduce tumor proliferation rate. However, it induced a significant increase in TILs. These findings suggest that denosumab may potentiate immunotherapy efficacy, at least in young BC patients. Additional results including immune cell profiling by multiplex IHC and RNA-sequencing of tumor and normal tissues will be presented at the meeting.

Citation Format: Bastien Nguyen, Marion Maetens, Roberto Salgado, David Venet, Peter Vuylsteke, Laura Polastro, Hans Wieldiers, Philippe Simon, Geoff Lindeman, Denis Larsimont, Gert Van den Eynden, Chloe Velghe, Francoise Rothe, Soizic Garaud, Stefan Michiels, Karen Willard-gallo, Hatem A. Azim, Sherene Loi, Martine Piccart, Christos Sotiriou. D-BEYOND: A window of opportunity trial evaluating denosumab, a RANK-ligand (RANKL) inhibitor and its biological effects in young pre-menopausal women diagnosed with early breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT101.

Tumor PIK3CA Genotype and Prognosis in Early-Stage Breast Cancer: A Pooled Analysis of Individual Patient Data

Purpose Phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha ( PIK3CA) mutations are frequently observed in primary breast cancer. We evaluated their prognostic relevance by performing a pooled analysis of individual patient data. Patients and Methods Associations between PIK3CA status and clinicopathologic characteristics were tested by applying Cox regression models adjusted for age, tumor size, nodes, grade, estrogen receptor (ER) status, human epidermal growth factor receptor 2 (HER2) status, treatment, and study. Invasive disease-free survival (IDFS) was the primary end point; distant disease-free survival (DDFS) and overall survival (OS) were also assessed, overall and by breast cancer subtypes. Results Data from 10,319 patients from 19 studies were included (median OS follow-up, 6.9 years); 1,787 patients (17%) received chemotherapy, 4,036 (39%) received endocrine monotherapy, 3,583 (35%) received both, and 913 (9%) received none or their treatment was unknown. PIK3CA mutations occurred in 32% of patients, with significant associations with ER positivity, increasing age, lower grade, and smaller size (all P < .001). Prevalence of PIK3CA mutations was 18%, 22%, and 37% in the ER-negative/HER2-negative, HER2-positive, and ER-positive/HER2-negative subtypes, respectively. In univariable analysis, PIK3CA mutations were associated with better IDFS (HR, 0.77; 95% CI, 0.71 to 0.84; P < .001), with evidence for a stronger effect in the first years of follow-up (0 to 5 years: HR, 0.73; 95% CI, 0.66 to 0.81; P < .001; 5 to 10 years: HR, 0.82; 95% CI, 0.68 to 0.99; P = .037); > 10 years: (HR, 1.15; 95% CI, 0.84 to 1.58; P = .38; P heterogeneity = .02). In multivariable analysis, PIK3CA genotype remained significant for improved IDFS ( P = .043), but not for the DDFS and OS end points. Conclusion In this large pooled analysis, PIK3CA mutations were significantly associated with a better IDFS, DDFS, and OS, but had a lesser prognostic effect after adjustment for other prognostic factors.

Long-term Safety of Pregnancy Following Breast Cancer According to Estrogen Receptor Status

Safety of pregnancy in women with history of estrogen receptor (ER)-positive breast cancer remains controversial. In this multicenter case-control study, 333 patients with pregnancy after breast cancer were matched (1:3) to 874 nonpregnant patients of similar characteristics, adjusting for guaranteed time bias. Survival estimates were calculated using the Kaplan-Meier analysis; groups were compared with the log-rank test. All reported P values were two-sided. At a median follow-up of 7.2 years after pregnancy, no difference in disease-free survival was observed between pregnant and nonpregnant patients with ER-positive (hazard ratio [HR] = 0.94, 95% confidence interval [CI] = 0.70 to 1.26, P = .68) or ER-negative (HR = 0.75, 95% CI = 0.53 to 1.06, P = .10) disease. No overall survival (OS) difference was observed in ER-positive patients (HR = 0.84, 95% CI = 0.60 to 1.18, P = .32); ER-negative patients in the pregnant cohort had better OS (HR = 0.57, 95% CI = 0.36 to 0.90, P = .01). Abortion, time to pregnancy, breastfeeding, and type of adjuvant therapy had no impact on patients' outcomes. This study provides reassuring evidence on the long-term safety of pregnancy in breast cancer survivors, including those with ER-positive disease.

Abstract P2-05-01: Whole genome sequencing reveals enrichment of mutations in mucin gene family in breast cancer diagnosed during pregnancy

Background

Pregnancy is known to modulate breast cancer (BC) risk. Different reproductive behaviors have been shown to impact not only the risk of developing BC but also the phenotypes of these tumors. Breast cancer diagnosed during pregnancy (BCP) is a rare disease but could serve as a good model to understand how pregnancy modulates BC biology. In this project, we aim to interrogate the effect of pregnancy on the biology of BC by performing whole genome sequencing (WGS) using a unique series of BC patients diagnosed during pregnancy (BCP).

Method

Whole genome sequencing was performed for 35 BCP and 20 non-pregnant controls matched for age and stage with available clinic-pathological data. DNA extracted from primary tumor and matched adjacent normal FFPE tissues was assessed using WGS on Illumina HiSeqXTen platform targeting 60x and 30x coverage for tumor and normal DNA respectively. Briefly, 2x150bp paired end sequence data were generated, cleaned, trimmed and aligned to the reference genome (hg19) using bwa-mem. Somatic mutations were detected using Strelka and annotated using SnpEff. Mutational signatures were extracted using deconstructSigs. Differences on mutational profiles between BCP and case controls were assessed using Wilcoxon test for continuous variables and Fisher exact test for categorical variables.

Result

No difference in clinic-pathological features was observed between BCP and control patients. A median of 10084 and 13829 SNVs and of 26 and 21 indels were identified in the BCP and controls respectively, no significant difference between the two groups being observed (p = 0.703 and p = 0.851). Of interest, a significantly higher number of mutations was found in the BCP as compared to the control group when considering only mutations associated with a deleterious effect (median: 20 vs. 12, p = 0.027). As expected, TP53 and PIK3CA were the most frequently mutated genes both in BCP and control cases without any significant difference between the groups (34.3% vs. 22.2%, p = 0.53 and 20.0% vs. 16.7%, p = 1, respectively). Interestingly, there was a significant enrichment of non-silent mutations in the mucin genes family (MUC2, MUC4, MUC12, MUC16, MUC17, MUC20) in the BCP group: 45.7% of BCP vs. 11.1% of control cases had at least one such mutation (p = 0.015). A similar significant result (45.7% vs. 23.1%, p = 0.034) was found when comparing BCP with BC control cases from the TCGA dataset (selected to have similar age, ER and PR distribution, N = 56). When comparing the distribution of the twelve BC mutational signatures, a borderline significant enrichment with a signature depicting mismatch-repair deficiency (signature 20) was observed in the BCP patients (p = 0.059).

Conclusion

This is the first study reporting the mutational landscape of breast cancer diagnosed during pregnancy using WGS. We found that BCP are associated with a higher number of putative driver mutations including mutations in mucin genes, shown to be implicated in tumorigenesis. Furthermore, BCP were enriched with a mismatch-repair deficiency signature. These results could open new avenues for the development of targeted therapeutic approaches for patients diagnosed with breast cancer during pregnancy.

Citation Format: Nguyen B, Venet D, Desmedt C, Pruneri G, Peccatori F, Mardis ER, Azim HA, Rothé F, Sotiriou C. Whole genome sequencing reveals enrichment of mutations in mucin gene family in breast cancer diagnosed during pregnancy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-05-01.

Regional Nodal Irradiation After Breast Conserving Surgery for Early HER2-Positive Breast Cancer: Results of a Subanalysis From the ALTTO Trial

Background

Two randomized trials recently demonstrated that regional nodal irradiation (RNI) could reduce the risk of recurrence in early breast cancer; however, these trials were conducted in the pretrastuzumab era. Whether these results are applicable to human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients treated with anti-HER2-targeted therapy is unknown.

Methods

This retrospective analysis was performed on patients with node-positive breast cancer who were enrolled in the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization phase III adjuvant trial and subjected to BCS. The primary objective of the present study was to examine the effect of RNI on disease-free survival (DFS). A multivariable cox regression analysis adjusted for number of positive lymph nodes, tumor size, grade, age, hormone receptors status, presence of macrometastatis, treatment arm, and chemotherapy timing was carried out to investigate the relationship between RNI and DFS.

Results

One thousand six hundred sixty-four HER2-positive breast cancer patients were included, of whom 878 (52.8%) had received RNI to the axillary, supraclavicular, and/or internal mammary lymph nodes. Patients in the RNI group had higher nodal burden and more frequently had tumors larger than 2 cm. At a median follow-up of 4.5 years, DFS was 84.3% in the RNI group and 88.3% in the non-RNI group. No differences in regional recurrence (0.9 % vs 0.6 %) or in overall survival (93.6% vs 95.3%) were observed between the two groups. After adjustment in multivariable analysis, there was no statistically significant association between RNI and DFS (hazard ratio = 0.96, 95% confidence interval = 0.71 to 1.29).

Conclusions

Our analysis did not demonstrate a DFS benefit of RNI in HER2-positive, node-positive patients treated with adjuvant HER2-targeted therapy. The benefit of RNI in HER2-positive breast cancer needs further testing within randomized clinical trials.