Clinicopathological Features and Prognosis of Pregnancy Associated Breast Cancer – A Matched Case Control Study

Dual role of pregnancy in breast cancer risk

Reproductive history is one of the strongest risk factors for breast cancer in women. Pregnancy can promote short-term breast cancer risk, but also reduce a woman's lifetime risk of breast cancer. Changes in hormone levels before and after pregnancy are one of the key factors in breast cancer risk. This article summarizes the changes in hormone levels before and after pregnancy, and the roles of hormones in mammary gland development and breast cancer progression. Other factors, such as changes in breast morphology and mammary gland differentiation, changes in the proportion of mammary stem cells (MaSCs), changes in the immune and inflammatory environment, and changes in lactation before and after pregnancy, also play key roles in the occurrence and development of breast cancer. This review discusses the dual effects and the potential mechanisms of pregnancy on breast cancer risk from the above aspects, which is helpful to understand the complexity of female breast cancer occurrence.

Breast Cancer in Pregnant Young Women: Clinicopathological Profile, Survival, and Pregnancy Outcomes

Background Breast cancer is one of the most common cancer types diagnosed during pregnancy; the presence of any neoplasm in pregnant women faces clinical dilemmas and challenges in cancer and pregnancy management. Pregnancy-associated breast cancer (PABC) is defined as breast cancer diagnosed during pregnancy or within one year after delivery. The aim of this study was to describe tumor clinicopathological characteristics and pregnancy outcomes in PABC patients. Materials and methods This is a retrospective cohort assessing PABC patients. Qualitative variables were compared using Fisher's exact test. Kaplan-Meier method was used to calculate survival. Cox regression and logistic regression methods were used to estimate the hazard ratio (HR) and odds ratio (OR), respectively. Results We assessed 16 PABC patients. Women ≤ 35 years of age were mainly diagnosed at advanced stage (88.8%) with ER-negative disease (77.8%). Patients with >4 pathological lymph nodes (25%; p = 0.001) and ER-negative disease (50%; p = 0.646) showed poor five-year overall survival (OS). In the multivariate analysis, nodal involvement was the main predictor associated with poorer OS (HR = 1.4, 90% confidence interval [CI]: 1.14 to 1.8). The following risk factors might influence the risk of preterm delivery: maternal older age, gestational age at diagnosis, and intrauterine exposure to chemotherapy, but an adjusted OR of 0.61 (90% CI: 0.34 to 1), 0.80 (90% CI: 0.66 to 0.9), and 0.013 (90% CI: 0.00 to 0.9), respectively, did not statistically support such an effect. Conclusions Younger women with PABC had a more aggressive pathological profile that might partly explain the poor OS. Obstetrical adverse events related to preterm delivery should be avoided with better planning of specialized strategies.

Gestational Breast Cancer - a Review of Outcomes, Pathophysiology, and Model Systems

The onset of pregnancy marks the start of offspring development, and represents the key physiological event that induces re-organization and specialization of breast tissue. Such drastic tissue remodeling has also been linked to epithelial cell transformation and the establishment of breast cancer (BC). While patient outcomes for BC overall continue to improve across subtypes, prognosis remains dismal for patients with gestational breast cancer (GBC) and post-partum breast cancer (PPBC), as pregnancy and lactation pose additional complications and barriers to several gold standard clinical approaches. Moreover, delayed diagnosis and treatment, coupled with the aggressive time-scale in which GBC metastasizes, inevitably contributes to the higher incidence of disease recurrence and patient mortality. Therefore, there is an urgent and evident need to better understand the factors contributing to the establishment and spreading of BC during pregnancy. In this review, we provide a literature-based overview of the diagnostics and treatments available to patients with BC more broadly, and highlight the treatment deficit patients face due to gestational status. Further, we review the current understanding of the molecular and cellular mechanisms driving GBC, and discuss recent advances in model systems that may support the identification of targetable approaches to block BC development and dissemination during pregnancy. Our goal is to provide an updated perspective on GBC, and to inform critical areas needing further exploration to improve disease outcome.

Breast Carcinogenesis during Pregnancy: Molecular Mechanisms, Maternal and Fetal Adverse Outcomes

Breast cancer is a common type of cancer diagnosed during pregnancy, with increasing incidence over the last years, as more women choose to delay childbearing. Compared to breast cancer in general population, pregnancy-associated breast cancer (PABC) is significantly different in its terms of epidemiology, diagnostic and therapeutic management, while it exhibits particularly aggressive behavior, deriving from its unique molecular and biological profile. Although not fully elucidated, the pathophysiological basis of PABC can be traced back to a combination of hormonal and immune changes during pregnancy, breast involution and altered gene expression. There is considerable controversy in the existing literature about the influence of PABC on pregnancy outcomes, regarding both short- and long-term effects on maternal and fetal/neonatal health. The majority of PABC patients have advanced-stage disease at initial diagnosis and face a significantly poorer prognosis, with decreased survival rates. The most commonly reported adverse obstetrical–fetal events are preterm delivery and prematurity-associated neonatal morbidity, while other neonatal treatment-associated complications might also occur, even when safe therapeutic options are applied during pregnancy. The objective of the present comprehensive review was to summarize current knowledge and up-to-date evidence about the pathophysiological, molecular and biological basis of PABC, as well as its association with adverse maternal, obstetrical, fetal and neonatal outcomes.

Pregnancy-Associated Breast Cancer: A Diagnostic and Therapeutic Challenge

Pregnancy-associated breast cancer (PABC) is commonly defined as a breast cancer occurring during pregnancy, throughout 1 year postpartum, or during lactation. Despite being a rare circumstance, PABC is one of the most common types of malignancies occurring during pregnancy and lactation, with growing incidence in developed countries, due both to decreasing age at onset of breast cancer and to increasing maternal age. Diagnosis and management of malignancy in the prenatal and postnatal settings are challenging for practitioners, as the structural and functional changes that the breast undergoes may be misleading for both the radiologist and the clinician. Furthermore, safety concerns for the mother and child, as well as psychological aspects in this unique and delicate condition, need to be constantly considered. In this comprehensive review, clinical, diagnostic, and therapeutic aspects of PABC (including surgery, chemotherapy and other systemic treatments, and radiotherapy) are presented and fully discussed, based on medical literature, current international clinical guidelines, and systematic practice.

Genomic copy number alterations as biomarkers for triple negative pregnancy-associated breast cancer

Background

PABC, commonly defined as breast cancer diagnosed during or ≤ 1 year after pregnancy, accounts for 7% of all breast cancers in women ≤ 45 years. Compared to age-matched non-PABC patients, PABC is characterized by a particularly aggressive histopathologic profile with poorly differentiated and estrogen- and progesterone receptor negative tumors and associated high mortality rates. This study assessed the genomic background of triple-negative PABC tumors by detection of copy number alterations (CNAs).

Methods

MLPA was used to compare CNAs in breast cancer-associated chromosomal loci between triple-negative PABC- and subtype-matched non-PABC patients. Both CNA patterns were evaluated by cluster analysis; associations between individual gene CNAs, pathological characteristics and survival were explored.

Results

Triple-negative PABC tumors exhibited unique CNAs compared to non-PABC tumors, including enrichment for TOP2A copy number loss, an independent predictor of worse overall survival (HR 8.96, p = 0.020). Cluster analysis based on CNA profiles identified a triple-negative PABC-subgroup with a particularly poor prognosis, characterized by chromosome 8p copy number loss. Individual gene CNAs analysis revealed that FGFR1 copy number loss on chromosome 8p11.23 was an independent predictor of poor outcome in multivariate analysis (HR 3.59, p = 0.053) and predicted the development of distant metastases (p = 0.048).

Conclusion

This study provides novel insights into the biology of triple-negative PABC tumors suggesting that CNAs, particularly 8p loss and TOP2A loss, are involved in the development of breast cancer during pregnancy. FGFR1 loss and TOP2A loss seem to be promising new biomarkers that independently identify subgroups of PABC patients with poor prognosis. These genomic biomarkers may provide clues for personalized therapy.

Breast cancer treatment patterns by age and time since last pregnancy in the Carolina Breast Cancer Study Phase III

PURPOSE

To describe breast cancer treatment patterns among premenopausal women by age and time since last pregnancy.

METHODS

Data were analyzed from 1179 women diagnosed with premenopausal breast cancer in the Carolina Breast Cancer Study. Of these, 160 had a recent pregnancy (within 5 years of cancer diagnosis). Relative frequency differences (RFDs) and 95% confidence intervals (CIs) were used to compare cancer stage, treatment modality received, treatment initiation delay (> 30 days), and prolonged treatment duration (> 2 to > 8 months depending on the treatment received) by age and recency of pregnancy.

RESULTS

Recently postpartum women were significantly more likely to have stage III disease [RFD (95% CI) 12.2% (3.6%, 20.8%)] and to receive more aggressive treatment compared to nulliparous women. After adjustment for age, race and standard clinical tumor characteristics, recently postpartum women were significantly less likely to have delayed treatment initiation [RFD (95% CI) - 11.2% (- 21.4%, - 1.0%)] and prolonged treatment duration [RFD (95% CI) - 17.5% (- 28.0%, - 7.1%)] and were more likely to have mastectomy [RFD (95% CI) 14.9% (4.8%, 25.0%)] compared to nulliparous. Similarly, younger women (< 40 years of age) were significantly less likely to experience prolonged treatment duration [RFD (95% CI) - 5.6% (- 11.1%, - 0.0%)] and more likely to undergo mastectomy [RFD (95% CI) 10.6% (5.2%, 16.0%)] compared to the study population as a whole.

CONCLUSION

These results suggest that recently postpartum and younger women often received prompt and aggressive breast cancer treatment. Higher mortality and recurrence among recently pregnant women are unlikely to be related to undertreatment.

MRI Evaluation of the Lactating Breast

Purpose of Review

To review the MRI appearance of physiologic lactational changes, common benign pathologies, and malignancies in the lactating breast.

Recent Findings

The prevalence of pregnancy-associated breast cancer has increased as more women delay childbirth and lactation. There is a transient increase in breast cancer risk after delivery when women may be lactating. MRI is more sensitive than mammography and ultrasound for the evaluation of the extent of disease in lactating women.

Summary

Understanding the key MRI findings of benign and malignant pathologies in the lactating breast is critical for accurate diagnosis and prompt evaluation of pregnancy-associated breast cancer.

Molecular and Clinical Characterization of Postpartum-Associated Breast Cancer in the Carolina Breast Cancer Study Phase I-III, 1993-2013

BACKGROUND

Breast cancers in recently postpartum women may have worse outcomes, but studies examining tumor molecular features by pregnancy recency have shown conflicting results.

METHODS

This analysis used Carolina Breast Cancer Study data to examine clinical and molecular tumor features among women less than 50 years of age who were recently (≤10 years prior) or remotely (>10 years prior) postpartum, or nulliparous. Prevalence odds ratios (POR) and 95% confidence intervals (CI) were estimated using multivariable models.

RESULTS

Recently postpartum women (N = 618) were more frequently lymph node-positive [POR (95% CI): 1.66 (1.26-2.19)], estrogen receptor (ER)-negative [1.37 (1.02-1.83)], and IHC-based triple negative [1.57 (1.00-2.47)] compared with nulliparous (N = 360) women. Some differences were identified between recent versus remotely postpartum; smaller tumor size [0.67 (0.52-0.86)], p53 wildtype [0.53 (0.36-0.77)], and non-basal-like phenotype [0.53 (0.33-0.84)] were more common among recently postpartum. Recently postpartum (vs. nulliparous) had significant enrichment for adaptive immunity, T cells, B cells, CD8 T cells, activated CD8 T cells/natural killer (NK) cells, and T follicular helper (Tfh) cells and higher overall immune cell scores. These differences were attenuated in remotely (compared with recently) postpartum women.

CONCLUSIONS

These results suggest a dominant effect of parity (vs. nulliparity) and a lesser effect of pregnancy recency on tumor molecular features, although tumor immune microenvironments were altered in association with pregnancy recency.

IMPACT

Our study is unique in examining tumor immune microenvironment and RNA-based markers according to time since last childbirth. Future studies should examine the interplay between tumor features, postdiagnostic treatment, and outcomes among recently postpartum women. See related commentary by McDonald et al., p. 518.

The Epidemiology of Pregnancy-Related Breast Cancers: Are We Ready to Deliver?

The dual effect of pregnancy on breast cancer risk has long been recognized. The short-term increase in breast cancer after pregnancy, particularly cancers that are more aggressive, contrasts starkly with the longer-term decrease. It remains unclear how these opposing effects of pregnancy relate to molecular subtypes of breast cancer, which impacts translation. Several methodologic challenges remain related to the study and operationalization of key constructs, which remain complicated by the correlation between age at pregnancies, overall parity, and intervals between pregnancies and cancer diagnoses. In this issue of CEBP, Vohra and colleagues address some of these major gaps as well as present novel data on the breast tissue microenvironment. The increasing incidence of invasive breast cancer in women under age 50 years requires improved clinical translation and identification of higher risk women after pregnancy. Thus, it is crucial to address the gaps in our biological understanding of pregnancy-related breast cancers. See related article by Vohra et al., p. 561.

Prognosis of pregnancy-associated breast cancer: inferior outcome in patients diagnosed during second and third gestational trimesters and lactation

PURPOSE

Pregnancy-associated breast cancer, although most commonly defined as breast cancer diagnosed during pregnancy or ≤1 year following delivery, knows a variety of definitions, likely related to the diversity of reported clinicopathological features and prognosis. More insight into the different breast cancer subgroups during pregnancy, time after delivery and the postpartum period is therefore warranted.

METHODS

Patients with breast cancer diagnosed during pregnancy or ≤6 months postdelivery were included, and subdivided according to gestational trimester, and postpartum patients according to lactational status. Subgroups were compared to matched non-PABC patients, to investigate the influence of pregnancy and lactation on clinical course and outcome.

RESULTS

Overall, 662 PABC patients were included (median age 34 years, median follow-up 6.5 years). PABC patients showed an advanced stage at diagnosis and an inferior 5-years-OS (75.4% vs. 83.2%, p = 0.000) compared to 1392 matched non-PABC patients. In subgroup analysis, first trimester PABC patients showed a significantly lower tumor size and stage as compared to other trimesters. Patients diagnosed during the first trimester and postpartum non-lactating patients had a relatively good OS (81.3% and 77.9%, respectively) versus patients diagnosed during the second and third trimesters and during lactation (OS 60.0%, 64.9% and 65.6%, respectively, p = 0.003).

CONCLUSION

In this large (uniquely specified) PABC cohort, an inferior outcome was found for patients diagnosed within the second and third gestational trimesters and during lactation. These findings indicate that PABC is clinically a heterogeneous group of breast cancer patients that should be redefined based on trimester of diagnosis and lactational status.

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.

Mammary cell gene expression atlas links epithelial cell remodeling events to breast carcinogenesis

The female mammary epithelium undergoes reorganization during development, pregnancy, and menopause, linking higher risk with breast cancer development. To characterize these periods of complex remodeling, here we report integrated 50 K mouse and 24 K human mammary epithelial cell atlases obtained by single-cell RNA sequencing, which covers most lifetime stages. Our results indicate a putative trajectory that originates from embryonic mammary stem cells which differentiates into three epithelial lineages (basal, luminal hormone-sensing, and luminal alveolar), presumably arising from unipotent progenitors in postnatal glands. The lineage-specific genes infer cells of origin of breast cancer using The Cancer Genome Atlas data and single-cell RNA sequencing of human breast cancer, as well as the association of gland reorganization to different breast cancer subtypes. This comprehensive mammary cell gene expression atlas ( https://mouse-mammary-epithelium-integrated.cells.ucsc.edu ) presents insights into the impact of the internal and external stimuli on the mammary epithelium at an advanced resolution.

Clinicopathological features and prognosis of patients with pregnancy-associated breast cancer: A matched case control study

Aim

We aimed to clarify tumor features and prognosis of pregnancy‐associated breast cancer (PABC) among Chinese women.

Methods

PABC was defined as breast cancer diagnosed during pregnancy or within a year after delivery. Patients with PABC were selected from breast cancer cases of women ≤45 years treated at our institution between December 2012 and December 2017, and one non‐PABC control was matched for stage, age, and year of diagnosis for each case.

Results

Forty‐one women with PABC were identified (22 diagnosed during pregnancy and 19 within 1 year of delivery). There were significantly more progesterone receptor (PR)‐ and triple‐negative tumors in the PABC (56.1% and 24.4%, respectively) than in the non‐PABC group (31.7% and 4.9%, respectively) (P = .045 and .026, respectively). Human epidermal growth factor receptor 2 positivity was the same in both groups (31.7%). Median disease‐free survival (DFS) was 29.0 months (95% confidence interval [CI], 6.5‐51.5 months) in the PABC and 40.9 months (95% CI, 22.8‐58.8 months) in the non‐PABC group (P = .167). Median overall survival (OS) was 82.8 months in the PABC (95% CI, 39.3‐126.5 months) versus 80.1 months (95% CI, 56.7‐103.6 months) in the non‐PABC group (P = .131).

Conclusion

Histological features were similar in both groups, except that PR‐ and triple‐negative tumors were more frequent in the PABC group. Survival analyses show similar OS for patients with PABC and non‐PABC. DFS tended to be shorter in the PABC group; however, this difference was not statistically significant.

Breast Cancer During Pregnancy: A Marked Propensity to Triple-Negative Phenotype

Breast and cervical cancers comprise 50% of all cancers during pregnancy. In particular, gestational breast cancer is considered one of the most aggressive types of cancers, which is a rare but fatal disease. However, the incidence of this type of cancer is increasing over the years and its prevalence is expected to rise further as more women delay childbearing. Breast cancer occurring after pregnancy is generally triple negative with specific characterizations of a poorer prognosis and outcome. On the other hand, it has been pointed out that this cancer is associated with a specific group of genes which can be used as precise targets to manage this deadly disease. Indeed, combination therapies consisting of gene-based agents with other cancer therapeutics is presently under consideration. We herein review recent progress in understanding the development of breast cancer during pregnancy and their unique subtype of triple negative which is the hallmark of this type of breast cancer.

Clinical Presentation, Diagnosis and Prognosis of Pregnancy-Associated Breast Cancer

Breast cancer in pregnancy is a rare entity generally presenting as a persistent breast mass, but is often a delayed finding due to the expected physiologic changes in the breast related to pregnancy and lactation. The preferred diagnostic workup of a persistent breast mass involves a combination of mammographic and ultrasonographic evaluation in addition to tissue diagnosis via core biopsy ; breast MRI is not recommended. Surgical excision should be reserved for definitive treatment in order to minimize fetal exposure to anesthesia. Evaluation for distant metastatic spread can be performed using radiographs and ultrasound to limit fetal radiation exposure . Similar to the non-pregnant patient, prognosis is primarily driven by tumor biology, however, there is limited and conflicting data regarding the impact of pregnancy on breast cancer outcomes with a distinct difference in survival among patients with breast cancer during pregnancy compared to those diagnosed postpartum.

Prognosis of pregnancy-associated breast cancer: a meta-analysis

BACKGROUND

Pregnancy-associated breast cancer (PABC) is defined as breast cancer that is diagnosed during pregnancy and/or the postpartum period. Definitions of the duration of the postpartum period have been controversial, and this variability may lead to diverse results regarding prognosis. Moreover, evidence on the dose-response association between the time from the last pregnancy to breast cancer diagnosis and overall mortality has not been synthesized.

METHODS

We systematically searched PubMed, Embase, and the Cochrane Library for observational studies on the prognosis of PABC published up to June 1, 2019. We estimated summary-adjusted hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs). Subgroup analyses based on diagnosis time, PABC definition, geographic region, year of publication and estimation procedure for HR were performed. Additionally, dose-response analysis was conducted by using the variance weighted least-squares regression (VWLS) trend estimation.

RESULTS

A total of 54 articles (76 studies) were included in our study. PABC was associated with poor prognosis for overall survival (OS), disease-free survival (DFS) and cause-specific survival (CSS), and the pooled HRs with 95% CIs were 1.45 (1.30-1.63), 1.39 (1.25-1.54) and 1.40 (1.17-1.68), respectively. The corresponding reference category was non-PABC patients. According to subgroup analyses, the varied definition of PABC led to diverse results. The dose-response analysis indicated a nonlinear association between the time from the last delivery to breast cancer diagnosis and the HR of overall mortality (P < 0.001). Compared to nulliparous women, the mortality was almost 60% higher in women with PABC diagnosed at 12 months after the last delivery (HR = 1.59, 95% CI 1.30-1.82), and the mortality was not significantly different at 70 months after the last delivery (HR = 1.14, 95% CI 0.99-1.25). This finding suggests that the definition of PABC should be extended to include patients diagnosed up to approximately 6 years postpartum (70 months after the last delivery) to capture the increased risk.

CONCLUSION

This meta-analysis suggests that PABC is associated with poor prognosis, and the definition of PABC should be extended to include patients diagnosed up to approximately 6 years postpartum.

Pregnancy-Associated Breast Cancer: A Multidisciplinary Approach

The diagnosis of breast cancer (BC) during pregnancy is uncommon. It has varied among different studies from 1:10,000 to 1:3000 of all pregnancies, with a median age of 33 years. Pregnancy-associated BC represents a challenge in terms of clinical management to guarantee both maternal and fetal security in choosing the right treatment. This situation is complex and requires a multidisciplinary approach, including the surgeon, anesthesiologist, oncologist, radiotherapist, psychologist, and maternal-fetal medicine specialist. In the present review, we examined the management of pregnancy-associated BC, focusing on pathophysiologic background, risk factors, diagnosis, staging procedures, anesthesia, surgical management, and systemic treatment.

Clinical features and survival of pregnancy-associated breast cancer: a retrospective study of 203 cases in China

Background

Pregnancy-associated breast cancer (PABC) is an aggressive disease, and since Chinese authority began to encourage childbearing in 2015, the incidence of PABC has increased. This study investigated the characteristics and survival of PABC patients.

Methods

Patients with PABC who underwent surgery at Fudan University, Shanghai Cancer Center between 2005 and 2018 were enrolled. Data concerning the tumor characteristics, maternal state (whether first or non-first pregnancy) and survival outcome were recorded. Pearson Chi-square tests were used to compare the characteristics of the tumors, and Kaplan-Meier methods were used to perform the survival analysis.

Results

Overall, 203 PABC patients were recruited. Since 2015, 65.5% of non-first pregnant women were diagnosed with breast cancer, it’s 5.7 fold of the incidence of PABC in non-first pregnant women. No significant differences in tumor characteristics were observed between the patients who were in their first pregnancy and those in non-first pregnancy. Among the entire PABC population, luminal B breast cancer accounted for the largest proportion (38.4%), followed by triple-negative breast cancer (TNBC, 30.0%). The distribution of the molecular subtypes of PABC and non-PABC differed (P < 0.001) as follows: in the PABC patients, Luminal B 38.4%, Triple negative breast cancer (TNBC) 30.1%, Human Epidermal Growth Factor Receptor 2 (HER-2) overexpression 15.8%, and Luminal A 10.8%; in the non-PABC patients, Luminal A 50.9%, Luminal B 20.1%, TNBC 17.4%, and HER-2 overexpression 8.0%. The 3-year disease free survival (DFS) of all PABC patients was 80.3%. The 3-year DFS of the patients in the first-pregnancy group was 78.4%, and that of the patients in the non-first-pregnancy group was 83.7% (P = 0.325).

Conclusions

Our study proved that the proportion of women who developed PABC during the second or third pregnancy was extremely high relative to the newborn populations. The patients in the PABC population tended to present more luminal B and TNBC breast cancer than the non-PABC patients.

Trastuzumab in the Treatment of Pregnant Breast Cancer Patients - an Overview of the Literature

Breast cancer is one of the most common malignancies which appear during pregnancy. Since women are increasingly not giving birth until they are at a more advanced age, it can be assumed that the incidence of pregnancy-related breast cancers will continue to increase in the future. Because of pregnancy-induced changes and conservative diagnosis, these carcinomas are frequently not detected until they are at an advanced stage and thus generally require systemic adjuvant therapy. The available data on optimal chemotherapeutic management are limited. Particularly for the use of the target agent trastuzumab which could crucially contribute to improving the prognosis in the therapy of HER2-overexpressing breast cancer in non-pregnant women, there is a lack of definitive information regarding the profile of action and safety in pregnancy as well as with regard to any long-term effects on the child. Thirty-eight pregnancies on trastuzumab for the treatment of breast cancer were able to be analysed in the literature currently available. Information can be gained from this and conclusions can be drawn which can individualise and decisively improve therapeutic options in the future for the pregnant breast cancer patient.

ACR Appropriateness Criteria® Breast Imaging of Pregnant and Lactating Women

Breast imaging during pregnancy and lactation is challenging due to unique physiologic and structural breast changes that increase the difficulty of clinical and radiological evaluation. Pregnancy-associated breast cancer (PABC) is increasing as more women delay child bearing into the fourth decade of life, and imaging of clinical symptoms should not be delayed. PABC may present as a palpable lump, nipple discharge, diffuse breast enlargement, focal pain, or milk rejection. Breast imaging during lactation is very similar to breast imaging in women who are not breast feeding. However, breast imaging during pregnancy is modified to balance both maternal and fetal well-being; and there is a limited role for advanced breast imaging techniques in pregnant women. Mammography is safe during pregnancy and breast cancer screening should be tailored to patient age and breast cancer risk. Diagnostic breast imaging during pregnancy should be obtained to evaluate clinical symptoms and for loco-regional staging of newly diagnosed PABC. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Placenta-conditioned extracellular matrix (ECM) activates breast cancer cell survival mechanisms: A key for future distant metastases

The extracellular matrix (ECM) affects cancer cell characteristics. Inability of normal epithelial cells to attach to the ECM induces apoptosis (anoikis). Cancer cells are often anoikis resistant, a prerequisite for their metastatic spread. Previously we demonstrated that the placenta manipulates its surrounding ECM in a way that prevents breast cancer cells (BCCL) attachment and induces their motility and aggregation. This fits with the fact that although breast cancer during pregnancy is often advanced, metastasis to the placenta is rarely observed. Placental intervillous space provides suitable conditions for cancer cell arrival. Yet, the outcome of the short communication between the placental ECM to the BCCL and its effect on BCCL malignant potential are unknown, and are the focus of our study. In the current study we analyzed the effect of placental ECM on BCCL survival pathways and drug resistance. Microarray analysis suggested activation of the NF-κB and stress response pathways. Indeed, the placenta-conditioned ECM induced autophagy in ERα + BCCL, inactivated the NF-κB inhibitor (IκB) and increased integrin α5 in the BCCL. The autophagy mediated MCF-7 and T47D migration and the placental ECM-BCCL interactions reduced the BCCL sensitivity to Taxol. We also demonstrated by using siRNA that integrin α5 was responsible for the MCF-7 autophagy and suggest this molecule as a suitable target for therapy.

Diagnostic pathways and management in women with pregnancy-associated breast cancer (PABC): no evidence of treatment delays following a first healthcare contact

Background

Women with pregnancy-associated breast cancer (PABC), i.e. diagnosed during or within 2 years of pregnancy, have a poor prognosis. We compared symptoms, diagnostics, treatments, and waiting times from first symptoms to treatment initiation in women diagnosed with PABC and non-PABC.

Materials and methods

Women diagnosed with PABC and non-PABC at ages 15–44 were identified in Swedish healthcare registers. Chart information was retrieved for 546 women (273 PABC cases and 273 age- and hospital-matched non-PABC controls) treated at 11 hospitals across Sweden between 1992 and 2009. Distributions of symptoms, diagnostics and treatments were compared. Median waiting times from initial symptoms to start of treatment, and time periods within, were estimated from Kaplan–Meier curves.

Results

Initial symptoms in women with PABC and non-PABC were similar. Women with PABC more often underwent biopsy and ultrasound than mammography at initial examination. Compared to non-PABC, rates of mastectomy and axillary clearance were higher in women with PABC, while endocrine treatment was less common. The time from symptoms to first healthcare contact was non-significantly longer in women diagnosed during or within 6 months of pregnancy. Waiting times from contact with healthcare to diagnosis and treatment were shorter or similar in women with PABC compared to women with non-PABC.

Conclusions

These findings do not support the notion that diagnostic and treatment delays following a first healthcare contact are more common in women diagnosed with breast cancer during or shortly after pregnancy. However, there was some evidence of delays in seeking healthcare among pregnant and lactating women.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-05083-x) contains supplementary material, which is available to authorized users.

Cancer during pregnancy - clinical characteristics, treatment outcomes and prognosis for mothers and infants

OBJECTIVE

To assess which obstetrical characteristics and treatment improved outcomes and prognosis of pregnant women with malignancy.

METHODS

A prospective study, undertaken between 2005 and 2014, involving 35 pregnant women who were diagnosed with malignant tumors during pregnancy. Patients were followed-up for 1 year after delivery. The pregnancy course and outcome and parameters that could influence the condition of mother and fetus were evaluated.

RESULTS

Most malignancies were hematological, diagnosed in the second trimester and treated with combined therapy (surgery/adjuvant) after pregnancy. Most fetuses were in good state throughout pregnancy, but were delivered by caesarean section (CS) before term. Adjuvant therapy during pregnancy mostly caused transitory deterioration of fetal conditions. The majority of both mothers and infants were in a good state 12 months postpartum, although numerous mothers were still ill and on therapy. Surviving pregnancy and preventing tumors progression during pregnancy were the best predictors of mothers' future condition (P=0.022). High birthweight and term delivery were the most important factors for good outcome of the infants (P=0.001).

CONCLUSIONS

If the tumor is not progressing, pregnancy should be continued as long as possible to obtain adequate birthweight of the infant. Second trimester surgery is safe, while other therapies should preferably be applied after delivery.

Biology, staging, and treatment of breast cancer during pregnancy: reassessing the evidences

Breast cancer is one of the most frequently diagnosed malignancies during pregnancy. Here, we review the management of women with breast cancer during pregnancy (BCP), focusing on biology, diagnosis and staging, local and systemic treatments, obstetric care and long-term follow-up of children with prenatal exposure to anticancer treatments.

High incidence of triple negative breast cancers following pregnancy and an associated gene expression signature

Breast cancer risk increases transiently in the period following pregnancy; pregnancy-associated breast cancers (PABC) are more aggressive than cases diagnosed in nulliparous women. We have previously reported that in the normal human breast pregnancy results in the upregulation of a number of inflammation related genes, suggesting a pro-tumorigenic environment as well as downregulation of ESR1 (ERα) and ERBB2 (HER2) and upregulation of ESR2 (ERβ), suggesting a protective effect. In this study, we aimed to investigate the possibility of differential regulation of the same gene set modulated in the normal breast, in human breast tumors following pregnancy. Gene expression was measured by real-time PCR on tumor regions isolated by laser capture microdissection from paraffin sections. Immunohistochemistry was performed on tissue microarrays (TMA) for protein expression. Hierarchical clustering was performed using the average linkage method to determine coordinate expression of sets of genes. We find that breast cancers detected within 10 years following pregnancy display a different gene expression pattern than those detected in nulliparous breast cancer patients. The gene expression difference is mainly attributable to a triple negative (TNBC) subgroup found to be more frequent in PABCs up to 10 years following a pregnancy. We also show that protein and mRNA expression levels correlate in half of the proteins tested by TMA. Despite the fact that this is a small study of 53 patients, we identified a gene expression signature that is differentially expressed in pregnancy-associated TNBC.

Placenta-breast cancer cell interactions promote cancer cell epithelial mesenchymal transition via TGFβ/JNK pathway

Women diagnosed with pregnancy associated breast cancer often have advanced cancer with metastases and reduced expression of ERα compared to non-pregnant women. Nevertheless, metastases to the placenta are uncommon. Previously, we demonstrated that breast cancer cells (MCF-7/T47D) migrated from ex vivo human placental explant implantation sites. We aimed to analyze the effect of factors produced during placental implantation or as a result of the interaction between the implanted placentae to cancer cells on cancer cells migration and aggressiveness. We collected supernatants from implanted placentae and placental-breast cancer cells cocultures and analyzed their effects on cancer cells phenotype and pathways. Supernatants collected from breast cancer cells served as controls. We found that supernatants collected from implanted placentae induced modest cancer cells migration that was not accompanied by epithelial to mesenchymal transition (EMT), supported breast cancer cells survival and elevated MCF-7 cell number. The coculture supernatant induced excessive motility and EMT of the MCF-7 cells. This EMT was mediated by Smad3 and JNK/ERK activation. Both placenta and coculture supernatants reduced ERα expression in the cancer cells. Finally, we showed that MCF-7 cocultured with the human placental explants underwent continuous activation of JNK and Smad3 pathways and the EMT process, which led to their migration away from the placental implantation sites. These findings may explain the reduced ERα and elevated metastases found in breast cancer during pregnancy and highlights pathways involved in it.