Racial disparities in overall survival after the introduction of cyclin-dependent kinase 4/6 inhibitors for patients with hormone receptor-positive, HER2-negative metastatic breast cancer

PURPOSE

CDK4/6 inhibitors (CDK4/6i) combined with endocrine therapy have improved HR + /HER2- metastatic breast cancer (MBC) outcomes. However, it is still unclear whether the response to CDK4/6i is similar for all races. Therefore, we aimed to assess overall survival (OS) trends stratified by race in patients with HR + /HER2- MBC after the approval of CDK4/6i, as part of the standard of care, in 2015.

METHODS

We performed a population-based study using the SEER database. Patients with HR + /HER2- MBC were divided into two time-based cohorts: 1) pre-CDK4/6i era (diagnosed in 2011-2013) and 2) post-CDK4/6i era (diagnosed in 2015-2017). We used propensity score matching and identified 2,684 patients in each cohort that matched in several characteristics. Kaplan-Meier methods were used to estimate 2-year OS. Association between cohort and OS was evaluated using marginal Cox proportional hazards models with robust sandwich variance estimator. We conducted competing risk analysis to estimate the risk of breast cancer death in both cohorts.

RESULTS

The 2-year OS rate was 65% for the post-CDK4/6i era and 62% for the pre-CDK4/6i era (stratified log-rank p = 0.025). The 2-year OS for non-Hispanic White (NHW) patients improved in the post-CDK4/6i era compared to the pre-CDK4/6i era (67% vs. 63%, p = 0.033). However, OS did not improve for non-Hispanic Black (NHB) (54% vs. 54%, p = 0.876) or Hispanic (67% vs. 65%, p = 0.617) groups. The risk of breast cancer death decreased in the post-CDK4/6i era as compared to the pre-CDK4/6i era (2-year risk of breast cancer death: 33% vs. 30%, p = 0.015); however, this effect was observed only in NHW (sHR 0.84, p = 0.005) women, but not in NHB (sHR 0.94, p = 0.630) or Hispanic (sHR 0.91, p = 0.550) women.

CONCLUSIONS

Our study confirms that outcomes for HR + /HER2- MBC have improved after CDK4/6i were introduced in 2015. However, this effect is primarily driven by the improved OS in NHW patients, without significant improvement in OS in NHB or Hispanics.

HOLA COVID-19 Study: Evaluating the Impact of Caring for Patients With COVID-19 on Cancer Care Delivery in Latin America

PURPOSE

The HOLA COVID-19 study sought to evaluate the impact of COVID-19 on oncology practices across Latin America (LATAM), challenges faced by physicians, and how practices and physicians adapted while delivering care to patients with cancer.

METHODS

This international cross-sectional study of oncology physicians in LATAM included a 43-item anonymous online survey to evaluate changes and adaptations to clinical practice. Multivariable logistic regression analyses were used to evaluate the association of caring for patients with COVID-19 and changes to clinical practice.

RESULTS

A total of 704 oncology physicians from 19 countries completed the survey. Among respondents, the most common specialty was general oncology (34%) and 56% of physicians had cared for patients with COVID-19. The majority of physicians (70%) noted a decrease in the number of new patients evaluated during the COVID-19 pandemic when compared with prepandemic, and 73% reported adopting the use of telemedicine in their practice. More than half (58%) of physicians reported making changes to the treatments that they offered to patients with cancer. In adjusted models, physicians who had cared for patients with COVID-19 had higher odds of changing the type of chemotherapy or treatments that they offered (adjusted odds ratio 1.81; 95% CI, 1.30 to 2.53) and of delaying chemotherapy start (adjusted odds ratio 2.05; 95% CI, 1.49 to 2.81). Physicians identified significant delays in access to radiation and surgical services, diagnostic tests, and supportive care.

CONCLUSION

The COVID-19 pandemic has significantly disrupted global cancer care. Although changes to health care delivery are a necessary response to this global crisis, our study highlights the significant disruption and changes to the treatment plans of patients with cancer in LATAM resulting from the COVID-19 health care crisis.

Abstract P3-12-26: Baseline characteristics and survival of neuroendocrine carcinoma of the breast- A SEER database analysis

Background: Neuroendocrine carcinoma of the breast (NECB) is a malignancy. The estimated incidence of this type of tumor ranges from less than 1% to 5%. The scarcity of data about these tumors creates a challenge for treatment. Prior studies have reported that clinically most NECB behave as other type of cancer, being more common in post-menopausal women. Using population-based cancer data, our study aims to describe the baseline characteristics, tumor biology, and prognosis of patients with NECB. Methods: Using the SEER database of the National Cancer Institute, we identified 433 cases of NECB diagnosed between 2000 and 2018. We assessed the patient age, sex, race, stage, grade of the tumor and histologic type. The additional information of estrogen receptor (ER), progesterone receptor (PR) and HER2 status were also included when available. Kaplan-Meir methods were used to estimate overall survival (OS). Cox proportional-hazard model was used to create multivariable analysis for OS. Results: We found that 427 (98.6%) of the patient were female, while only 6 (1.3%) patients were male. The mean age of diagnosis was 64 years[JA1] , (SD : 14.2 years). Most patients were White (n= 353, 82%), while 52 (12%) were black, and 27 (6.2%) were other race. About the tumor histology, 375 (86.6%) cases were neuroendocrine tumor not otherwise specified, 30 (6.9%) cases were large cell neuroendocrine tumors and 28 (6.4%) were carcinoid tumor of the breast. ER was positive in 70%, PR was positive in 57% of the patients in which these receptors were tested. 194 patients were assessed for Her 2, and only 6(3%) were her2 positive. 183 (42%) had any chemotherapy use, while 250 (58%) had no known use of chemotherapy. 326 patients had a documented stage, of those 77 (17%) were AJCC stage I, 140 (32%) stage II, 39 (9%) stage III and 70 (16%) stage IV. The[JA2] median OS for stage I, II, III, and IV were not-reached, 129, 45 and 13 months, respectively[JA3] . In the univariate analysis for OS, only for tumor grade 3 (HR = 2.2; 95% CI: 1.98,2.52; p= 0.002) , ER negative (HR = 2.0; 95% CI: 1.86,3.62; p= <0.001), PR (HR = 2.4; 95% CI: 2.1,2.63; p= <0.001), surgery (HR = 0.26; 95% CI: 0.11,0.40; p= <0.001), metastasis (HR = 0.19; 95% CI: 0.04,0.34; p= <0.001), stage IV cancer (HR = 2.3; 95% CI: 2.0,2.5; p= <0.001) were statistically significantly associated with OS. In a multivariate model, including age, histology, grade, ER, PR, stage group, metastasis, surgery and chemotherapy. We found that large cell histology (HR = 2.0; 95% CI: 1.0,4.3; p= 0.04), negative ER (HR = 2.0; 95% CI: 1.2,3.5; p= 0.01), negative PR (HR = 2.5; 95% CI: 1.4,4.4; p= 0.002), treatment with surgery (HR = 0.39; 95% CI: 0.22,0.69; p= 0.001), receiving chemotherapy (HR = 0.5; 95% CI: 0.31,0.79; p= 0.003), negative metastasis at diagnosis (HR = 0.05; 95% CI: 0.024,0.12; p= <0.001), cancer stage (HR = 2.3 for stage II and 7.2 for stage III, p<0.01. Stage I used as reference); were significantly associated with OS. Conclusion: Our study shows that NECB is a rare malignancy, and that the AJCC cancer staging can be used to adequately assess prognosis. Large cell histology, ER/PR negative, and advanced AJCC stage were inversely associated with survival, whereas chemotherapy use, surgery, and no metastasis at diagnosis, were positively associated with survival. As in other histologies of breast cancer, surgery and chemotherapy need to be strongly considered when treating NECB.

Citation Format: Alvaro Alvarez Soto, Jesus Anampa. Baseline characteristics and survival of neuroendocrine carcinoma of the breast- A SEER database analysis [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 P3-12-26.

Abstract P3-08-24: Racial disparities in neutrophil counts among patients with metastatic breast cancer during treatment with CDK4/6 inhibitors

Background: Addition of cyclin-dependent kinase (CDK) 4/6 inhibitors to aromatase inhibitors or fulvestrant prolongs progression-free survival (PFS) in hormone-receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) metastatic breast cancer (MBC). Grade 3/4 neutropenia occurs in up to 65% of patients treated with CDK 4/6 inhibitors, often leading to dose delay and/or reduction. Black (B) race has been associated with neutropenia. We aimed to compare changes in neutrophil counts among patients with HR+/HER2- MBC treated with CDK4/6 inhibitors by racial groups.

Methods: Patients with HR+/HER2- MBC prescribed CDK4/6 inhibitors at Montefiore Medical Center/Albert Einstein Cancer Center were identified. Cases with unknown race were excluded. Data regarding clinical, pathological, and treatment characteristics were collected through manual chart review. Race was defined as Black (B) or Non-Black (NB). PFS was defined as the time from treatment initiation to progression of disease or death. Laboratory parameters evaluated included absolute neutrophil count (ANC) at baseline (ANC-0), at 14 days (C1D14) and during each month of treatment (ANC-2, ANC-3, etc.). Changes in ANC (Delta-ANC) from baseline were estimated at specific time-points.

Results: A total of 130 patients with a mean age of 65 years were included, of whom 60 (46.2%) were B and 70 (53.8%) were NB. There were 38 (29.2%) Hispanics. CDK4/6 inhibitors were given in combination with first-line endocrine therapy in 59 patients (45.4%), and palbociclib was the most commonly used agent (117; 90%). There were no differences in the baseline characteristics among B vs. NB. The median ANC-0 was lower in B vs. NB (3.0 vs. 3.9, p=0.02); however, there were no differences in the median ANC at C1D14 (1.3 vs. 1.3, p=0.85), C2 (1.4 vs. 1.8, p=0.07), C3 (1.5 vs. 1.6, p=0.13), C4 (1.8 vs. 1.6, p=0.36) and all other time-points when comparing B vs. NB, respectively. Rate of CDK 4/6 inhibitor dose reductions for B vs. NB was similar (19% vs. 18%, p=0.47), as well as all other side-effects including grade 3/4 neutropenia (62.7% vs 45.6%, p=0.052), grade 3/4 infection (7% vs. 3.1%, p=0.32), any-grade anemia (55.9% vs. 58%, p=0.82), and grade 3/4 thrombocytopenia (5.2% vs. 5.9%, p=0.86). Delta-ANC was significantly lower for B compared to NB at C1D14 (-1.7 vs. -2.6, p=0.02), C2 (-1.5 vs. -2.3, p=0.05) and C3 (-1.8 vs. -2.6, p=0.006). There was no difference in PFS among B vs. NB receiving CDK4/6 inhibitors plus endocrine therapy in the overall cohort (10.4 vs. 11 months, p=0.68) or as first-line treatment (15 months vs. 12.4 months, p=0.28).

Conclusions: Although blacks who received CDK4/6 inhibitors had lower baseline neutrophil counts than non-black patients, they experienced less declines in their neutrophil counts from baseline, had similar rates of grade 3/4 neutropenia and dose reductions, and had similar clinical outcomes.

Black n=60Non-Black n=70pAge, mean (SD)66 (13)63 (14)0.15BMI, mean (SD)27 (7)27 (7)0.80ANC0, median (IQ)3 (2.4-4.7)3.9 (3.1-5)0.02Median ANC C1D141.3 (0.9-1.9)1.3 (0.9-1.9)0.85Median ANC C31.5 (1-2)1.6 (1.2-1.3)0.13Δ ANC C1D14-1.7 (-2.8 to -1.1)-2.6 (-3.4 to -1.8)0.02Δ ANC C3-1.8 (-2.3 to -1.1)-2.6 (-3.4 to -1.9)0.006Median PFS (95%IC)10.4 (6.6-22.6)11 (7.8-13.3)0.68

Citation Format: Ashley Weiner, Ana Acuna-Villaorduna, Joseph Sparano, Jesus Anampa. Racial disparities in neutrophil counts among patients with metastatic breast cancer during treatment with CDK4/6 inhibitors [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 P3-08-24.

Abstract P2-08-18: Tumor microenvironment of metastasis (TMEM) score in residual breast carcinoma post-neoadjuvant chemotherapy as an independent prognosticator of distant recurrence

Background: Tumor microenvironment of metastasis (TMEM) is a microanatomical structure composed by 3 cells in direct contact, including a tumor cell expressing the actin-regulatory protein Mammalian-enabled (Mena), a perivascular Tie2hi/Vegfhi-expressing macrophage, and an endothelial cell. TMEM are intravasation sites that function as doorways for hematogenous tumor cell dissemination and metastases (Harney et al. Cancer Discovery 2015). TMEM may be identified and enumerated by triple immunohistochemistry in mouse and human mammary carcinomas. High TMEM score is associated with increased risk of distant metastasis in early stage breast cancer, and provides complementary prognostic information to IHC4 (Rohan et al. JNCI 2014) and Oncotype DX Recurrence Score in ER+, HER2-negative breast cancer (Sparano et al. NPJ Breast Cancer, 2017). Neoadjuvant chemotherapy (NAC) increases TMEM score in breast carcinoma in animal models and humans, indicating a previously unrecognized mechanism of resistance to cytotoxic therapy (Karagiannis et al. Science Trans Med 2017). Intravasation at TMEM sites may be inhibited using agents that block release of VEGF from TMEM-associated TIE2-hi, VEGF-hi macrophages (Harney et al. Mol Cancer Ther, 2017). Here we investigated whether TMEM score in post-NAC treated breast carcinoma is prognostic of distant recurrence in localized breast cancer after NAC, and thus provides a foundation for testing agents that block TMEM function in combination with NAC.

Methods: We determined TMEM score in 80 evaluable patients' post-NAC specimens with residual invasive ductal carcinomas of at least 0.5 cm. Approximately 60% of patients had ER+/HER2-negative, 28% had triple negative and 12% had HER2+ disease. Most of the patients received doxorubicin/cyclophosphamide + taxane and an anti-HER2 therapy if applicable. Tissue sections from residual tumors were stained for TMEM using triple immunohistochemistry for Mena-expressing cancer cells, CD31-expressing endothelial cells and CD68-expressing macrophages. The stained slides were scanned, and the images were analyzed by three pathologists, blinded to outcome, who independently determined the tissue areas appropriate for TMEM scoring. TMEM was scored within these areas using an automated algorithm.

Results: TMEM score was significantly higher in patients with distant recurrence (average TMEM=106), compared to patients without distant recurrence (average TMEM=71) (p<0.01, two-sided t-test). Moreover, in a Cox proportional hazards model that included TMEM score (upper tertile vs. lower 2 tertiles), age (>50 yrs. vs. <50), race (black vs non-black), tumor stage (T 1-3), estrogen receptor (ER) status (+ vs -), high TMEM score was associated with a increased risk of distant recurrence (HR=2.2, 95% CI=1.0 to 4.9, p=0.05)

Conclusion: TMEM score may provide independent prognostic information for distant recurrence in patients with residual invasive carcinoma after NAC. These results support the use of agents that block TMEM function in combination with NAC, as planned in the I-SPY2 trial.

Citation Format: Oktay MH, D'Alfonso T, Ginter P, Lanjewar S, Entenberg D, Pastoriza JM, Wang Y, Lin Y, Karagiannnis GS, Lin J, Ye X, Anampa J, Xue X, Rohan TE, Sparano JA, Condeelis JS. Tumor microenvironment of metastasis (TMEM) score in residual breast carcinoma post-neoadjuvant chemotherapy as an independent prognosticator of distant recurrence [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 P2-08-18.

Abstract 67: Chemotherapy induced pro-metastatic changes in the primary breast tumors of racially diverse patients

Neoadjuvant chemotherapy (NAC) induces influx of bone marrow-derived proangiogenic Tie2hi monocytes into the primary tumor, resulting in increased density of perivascular Tie2hi macrophages (1). Perivascular Tie2hi/Vegfhi macrophages in physical contact with Mena expressing cancer cells create micro-anatomic sites of transient vascular permeability called TMEM, which mediate cancer cell intravasation and dissemination (2). Cancer cells capable of intravasation via TMEM sites express high level of MenaINV, an isoform of Mena, induced by macrophage contact, which renders tumor cells intravasation-competent (3, 4). Consequently, breast cancers from mice and patients treated with NAC have increased density of TMEM sites and show increased expression of MenaINV (1) Moreover, in PyMT mouse mammary carcinoma and patient derived xenografts, NAC increases the number of circulating tumor cells and lung metastasis (1). The Tie2-inhibitor rebastinib, which inhibits TMEM function, can reverse chemotherapy-induced increases in the number of CTCs and lung metastasis in mouse mammary carcinoma (1, 5). Although NAC induces pro-metastatic changes in breast cancer microenvironment, large randomized prospective studies did not find significant differences in distant-recurrence free survival (DRFS) and overall survival (OS) between breast cancer patients treated with adjuvant and neoadjuvant chemotherapy in predominantly white populations. Since the breast cancer microenvironment in black women has higher microvascular density and density of Tie2hi macrophages, suggesting that black women may be more prone to develop TMEM-associated pro-metastatic changes in response to NAC, we questioned if there is a difference in DRFS in black women treated with NAC compared to AC. We evaluated DRFS in 1,211 racially diverse patients with localized or regionally advanced breast cancer treated with neoadjuvant or adjuvant chemotherapy between January 2000 and December 2016 and found that black patients with localized breast cancer treated with systemic neoadjuvant chemotherapy not only have inferior DRFS compared to white patients, but also worse DRFS when compared to black patients treated with adjuvant chemotherapy, after adjustment for clinical covariates in multivariate analysis. The biologic factors contributing to this finding, in particular TMEM-mediated pro-metastatic changes have been evaluated and will be discussed. 1. Karagiannis et al, Sci Transl Med. 2017;9:397. 2. Harney et al, Cancer discovery. 2015;5:932. 3. Pignatelli J et al, Sci Rep. 2016;6:37874. 4. Pignatelli J et al, Sci Signal. 2014;7:353. 5. Harney et al, Mol Cancer Ther. 2017;16:2486.

Citation Format: George S. Karagiannis, Jessica M. Pastoriza, Sonali Lanjawar, Yarong Wang, David Entenberg, Esther Cheng, Timothy M. Dalfonso, Joan G. Jones, Jesus Anampa, Thomas E. Rohan, Joseph A. Sparano, John S. Condeelis, Maja H. Oktay. Chemotherapy induced pro-metastatic changes in the primary breast tumors of racially diverse patients [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 67.

Anthracycline Use for Early Stage Breast Cancer in the Modern Era: a Review

OPINION STATEMENT

Anthracycline-based regimens have been an important treatment component for patients with breast cancer. As demonstrated in the last Early Breast Cancer Trialists' Collaborative Group (EBCTCG) meta-analysis, anthracycline-based regimens decrease breast cancer mortality by 20-30%. Anthracycline toxicities include the rare-but potential morbid-cardiotoxicity or leukemogenic effect, and the almost universal-but very distressing-alopecia. Due to potential toxicities, and large number of patients being exposed, several worldwide trials have re-examined the role of anthracycline-based regimens in the management of breast cancer. Current literature supports that anthracyclines are not required for all patients with breast cancer and should be avoided in those with high cardiac risk. Recent results from the ABC trials suggest that anthracyclines should not be spared for patients with triple negative breast cancer (regardless of axillary node involvement) or HER2-/ER+ with significant node involvement. Based on current literature, for HER2-negative patients with low-risk breast cancer, anthracyclines could be spared with regimens such as cyclophosphamide, methotrexate, and fluorouracil (CMF) or docetaxel and cyclophosphamide (TC). Patients with intermediate or high-risk breast cancer should be considered for anthracycline-based regimens based on other factors such as age, comorbidities, tumor grade, lymphovascular invasion, and genomic profiling. Patients with HER2-positive breast cancer with low risk could be treated with paclitaxel and trastuzumab. For the remaining patients with HER2 overexpression, while docetaxel, carboplatin, and trastuzumab (TCH) has demonstrated to improve disease-free survival (DFS), anthracycline-containing regimens should be discussed, especially for those with very high-risk breast cancer. Although several biomarkers, such as topoisomerase II (TOP2A) and chromosome 17 centromeric duplication (Ch17CEP) have been proposed to predict benefit from anthracycline regimens, further research is required to delineate their proper utility in the clinical setting.

Neoadjuvant chemotherapy induces breast cancer metastasis through a TMEM-mediated mechanism

Breast cancer cells disseminate through TIE2/MENA^Calc/MENA^INV-dependent cancer cell intravasation sites, called tumor microenvironment of metastasis (TMEM), which are clinically validated as prognostic markers of metastasis in breast cancer patients. Using fixed tissue and intravital imaging of a PyMT murine model and patient-derived xenografts, we show that chemotherapy increases the density and activity of TMEM sites and Mena expression and promotes distant metastasis. Moreover, in the residual breast cancers of patients treated with neoadjuvant paclitaxel after doxorubicin plus cyclophosphamide, TMEM score and its mechanistically connected MENA^INV isoform expression pattern were both increased, suggesting that chemotherapy, despite decreasing tumor size, increases the risk of metastatic dissemination. Chemotherapy-induced TMEM activity and cancer cell dissemination were reversed by either administration of the TIE2 inhibitor rebastinib or knockdown of the MENA gene. Our results indicate that TMEM score increases and MENA isoform expression pattern changes with chemotherapy and can be used in predicting prometastatic changes in response to chemotherapy. Furthermore, inhibitors of TMEM function may improve clinical benefits of chemotherapy in the neoadjuvant setting or in metastatic disease.

Phase I Trial of Veliparib, a Poly ADP Ribose Polymerase Inhibitor, Plus Metronomic Cyclophosphamide in Metastatic HER2-negative Breast Cancer

BACKGROUND

Poly-ADP-ribose-polymerase is an essential nuclear enzyme, involved in base-excision repair of damaged DNA. Poly-ADP-ribose-polymerase inhibition sensitizes tumor cells to cytotoxic agents, which induce DNA damage, including cyclophosphamide (C), and metronomic dosing of C may optimize potential for synergy.

METHODS

The primary objective of this phase I trial was to determine the safety and identify the recommended phase II dose of the combination of low-dose oral C (50, 75, 100, and 125 mg) once daily in combination with veliparib (V) (100, 200, and 300 mg) administered twice a day (BID) for 21-day cycles using a standard 3 + 3 design in patients with metastatic human epidermal growth factor receptor 2/neu-negative breast cancer. Dose-limiting toxicity was defined as any grade 3 non-hematologic toxicity or grade 4 thrombocytopenia/neutropenia occurring during cycle 1.

RESULTS

A total of 31 patients were enrolled; 19 were treated with 50 mg of C and 12 were treated at higher doses (75, 100, or 125 mg), with V doses ranging from 50 to 300 mg BID. The recommended phase II dose of the combination was V 200 mg orally BID plus C 125 mg orally daily, with nausea and headache dose-limiting at higher V dose levels. Objective response or stable disease for at least 24 weeks occurred in 3 (43%) of 7 patients with known deleterious germline BRCA mutations and 2 (11%) of 19 patients with negative/unknown mutation status (P = .1).

CONCLUSION

The combination of oral continuous dosing of V (200 mg orally BID) with metronomic C (50, 75, 100, and 125 mg daily) is well-tolerated and shows antitumor activity in patients with BRCA-mutation-associated metastatic human epidermal growth factor receptor 2/neu-negative breast cancer.

Abstract 3963: Neoadjuvant chemotherapy promotes prometastatic changes in the primary breast tumor microenvironment in mice and humans

Chemotherapy induces influx of bone marrow-derived proangiogenic Tie2hi monocytes in primary tumors. Tie2hi perivascular macrophages specifically induce the prometastatic Mena isoforms in tumor cells and can assemble specialized microanatomical sites called “tumor microenvironment of metastasis” (TMEM), structures that may serve as doorways for intravasation of tumor cells in mammary tumors. Both TMEM and MenaINV are required for tumor cell intravasation and dissemination. Thus, we hypothesized that chemotherapy may increase the density of TMEM sites and MenaINV-expressing, intravasation-competent tumor cells, resulting in increased tumor cell invasion and metastasis. We studied these potential pro-metastatic effects of chemotherapy in a neoadjuvant setting (NAC) by either administering paclitaxel or a combination of doxorubicin and cyclophosphamide in several mammary carcinoma mouse and human breast cancer models. As expected, chemotherapy delayed tumor growth, yet it significantly increased the recruitment of TMEM-forming, perivascular Tie2hi/Vegfhi macrophages and TMEM density. Using high-resolution multiphoton intravital imaging in live tumor-bearing mice, we observed that paclitaxel also increased the activity of TMEM sites, visualized as endothelial cell tight-junction disruption around TMEM and subsequent intravasation of the migratory cancer cell subpopulation. Indeed, paclitaxel-treated mice have higher numbers of circulating tumor cells, single cell seeding in lungs and incidence and number of micrometastatic foci, all associated with increased TMEM activity, as demonstrated by high-resolution imaging techniques. Tie2 inhibitors reversed paclitaxel-induced pro-metastatic phenotypes without affecting the assembly of TMEM, indicating that Tie2-mediated signaling is required for paclitaxel-mediated cancer cell dissemination via TMEM. Paclitaxel also caused a significant increase in the expression of MenaINV at both the gene and protein levels. Furthermore, paclitaxel treatment in Mena-/- breast tumor-bearing mice resulted in failure to assemble TMEM and to increase circulating-tumor cells and cancer cell metastasis despite the fact that Tie2hi macrophages are attracted to perivascular niches as a result of paclitaxel treatment. This indicated that Mena is involved in the paclitaxel-mediated increase in cancer cell dissemination but not required for Tie2hi macrophage recruitment. These pre-clinical data are further supported by findings from a cohort (N=20) of breast cancer patients, who received pre-operative paclitaxel-based chemotherapy and demonstrated significant increases in TMEM density and MenaINV expression. Together, our data provide solid evidence that NAC leads to metastasis in rodents via TMEM/ MenaINV-mediated mechanisms, and to cancer cell dissemination in certain clinical scenarios in humans.

Citation Format: George S. Karagiannis, Jessica Pastoriza, Jeanine Pignatelli, Yarong Wang, Allison S. Harney, David Entenberg, Ved P. Sharma, Emily Xue, Esther Cheng, Timothy M. D'Alfonso, Joan G. Jones, Jesus Anampa, Thomas E. Rohan, Joseph A. Sparano, John S. Condeelis, Maja H. Oktay. Neoadjuvant chemotherapy promotes prometastatic changes in the primary breast tumor microenvironment in mice and humans [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3963. doi:10.1158/1538-7445.AM2017-3963

Breast cancer in patients with Li-Fraumeni syndrome - a case-series study and review of literature

Background

Li–Fraumeni Syndrome (LFS) is a rare disease with autosomal dominant inheritance linked to germline mutations of tumor suppressor gene TP53. These patients are predisposed to malignancies such as sarcoma, breast cancer, leukemia, and other malignancies. Breast cancer, the most common malignancy in adult patients with LFS, has an early-onset presentation and is usually treated as per the guidelines for the general population due to the limited literature about breast cancer in LFS. We aimed to describe our institutional experience treating patients with breast cancer and LFS to contribute to literature about this entity.

Design

Retrospective single-institution case-series study. We searched for cases with LFS and breast cancer from 01/01/2000 to 12/31/2015 with treatment received at our institution.

Results

We identified 4 cases (2 African Americans, 1 Indian, and 1 Hispanic) in 4 different families, who were diagnosed with LFS after presenting with breast cancer. Three cases were triple-negative disease and 1 case was ER+, HER2 positive disease. They were treated with mastectomy and a third-generation breast chemotherapy regimen and/or trastuzumab-containing regimen. Radiation therapy was used in 2 patients. Breast cancer recurrence was seen in 1 patient, while three other malignancies were identified after breast cancer treatment (1 breast sarcoma, 1 leiomyosarcoma, and 1 myelodysplastic syndrome). A patient, who underwent surveillance with a positron emission tomography-computed tomography scan, was found to have a stage I leiomyosarcoma and was treated with surgical resection, but then developed metastatic disease requiring cytotoxic chemotherapy.

Conclusion

Breast cancer among patients with LFS needs a multidisciplinary treatment approach. Surgical management follows the guidelines for the general population. Risk–benefit assessment of chemotherapy and radiotherapy needs to be performed carefully in a case-by-case approach. Patients should undergo multimodality cancer surveillance, preferably in the context of a clinical trial.

Abstract P5-10-05: Time differences in breast cancer diagnosis among minorities in a large referal academic center

Background: Breast cancer (BC) is the most common malignancy and leading cause of cancer death in women. BC incidence is lower in Hispanic (H) (91.9/100,000) compared to non-Hispanic Whites (NHW -128.1/100.000) and Non-Hispanic Black (NHB - 124.3/100,000) population; however, mortality rate is higher in NHB (31/100,000) compared to NHW (21.9/100,000) and H (14.5/100,000). Diagnosis delay is a plausible factor that may explain differences in BC clinical outcomes among different race/ethnicity subgroups.

Objective: To compare time to diagnosis (TTD) by race/ethnicity in women with breast cancer diagnosed at Montefiore Medical Center from 2004 to 2012.

Methods: Patients with breast cancer and available race/ethnicity information diagnosed between 2004 and 2012 were categorized into 4 race/ethnicity groups: NHB, NHW, H or Asian. Dates of screening mammogram, diagnostic mammogram and biopsy were obtained. TTD was defined as the time difference between abnormal mammogram and biopsy dates.

Results: 919 patients had ethnicity information, 302 (32.8%) were H. TTD was longer in H compared to non-Hispanics (35 vs 31 days, z=2.2, p=0.02). Race and ethnicity information was available for 834 patients with a mean age of 62 years (SD:12.4). Of these, 252 (30.2%) were H and 387 (46.4%) were NHB. NHW had the shortest TTD (30 days), the highest frequency of Stage I (70%) and lowest frequency of high-nuclear grade (15.6%). NHB had a TTD of 31 days and higher frequency of triple negative disease (18.9%). TTD was significantly longer in H compared to NHW (35 vs 30 days, z=2.3, p=0.02), and there was a non-significant longer TTD when comparing H versus NHB (35 vs 31 days, z=1.9, p=0.0574). TTD between NHB and NHW was not different (31 vs 30 days, z=1.4, p=0.14).

Conclusions: The longer TTD in H vs Non-Hispanics was driven by the TTD in NHW. NHW had shorter TTD and more favorable pathological features which could lead to lower mortality rate. There was no difference in TTD between NHW and NHB but the latter had higher frequencies of triple negative disease. Correlation between TTD and mortality in our population will help to clarify the clinical effect of TTD differences among race/ethnicity subgroups.

 Total (n= 834)Not Hispanic Black (n=387)Not Hispanic White (n=180)Hispanic (n=302)Asian (n=15)Age (SD)62 (12.4)62.965.261.6 (11.9)53.2Stage*     I613 (65.7)239 (61.6)126 (70)202 (67.3)10 (66.7)II242 (25.9)121 (31.3)36 (20)71 (23.7)3 (20)III56 (6)19 (4.9)12 (6.7)20 (6.7)3 (15.3)IV21 (2.3)8 (2.1)6 (3.3)7 (2.3)1 (1)Histology*     IDC697 (75.1)292 (75.5)121 (67.2)224 (74.7)13 (86.7)ILC81 (8.7)34 (8.8)23 (12.8)21 (7)2 (13.3)Mixed140 (15.1)57 (14.7)33 (18.3)49 (16.3)0 (0)Grade*     High253 (28.4)138 (35.7)28 (15.6)73 (24.3)4 (26.7)Moderate426 (48)155 (40.1)86 (47.8)151 (50.3)9 (60)Low210 (23.6)83 (21.5)49 (27.2)62 (20.7)1 (6.7)Receptor status*     ER positive762 (81.8)286 (73.9)162 (90)258 (86)12 (80)PR positive632 (67.8)229 (59.2)137 (76.1)219 (73)11 (73.3)HER-2 positive143 (15.4)70 (18.1)14 (7.8)49 (16.3)5 (33.3)Triple negative115 (12.3)73 (18.9)14 (7.8)21 (7)1 (6.7)Times     Time to diagnosis33 (20-52)31 (19-52)30 (19-44.5)35 (21-58.5)42 (21-72)Screening to Diagnostic22 (14-36)22 (13-36)21 (13-32)23 (14-14)26 (17-37)Diagnostic to Biopsy7 (0-13)7 (0-13)6 (0-14)7 (1-13)5 (0-9)

Citation Format: Acuna A, Gligich O, Khan H, Xue X, Lin J, Sparano J, Anampa J. Time differences in breast cancer diagnosis among minorities in a large referal academic center [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-10-05.

Abstract PD5-02: Paclitaxel induced mena- and TMEM-mediated pro-metastatic changes in the breast cancer microenvironment

Background: Breast cancer cell intravasation and dissemination occurs specifically at microanatomical structures that we call tumor-microenvironment of metastasis (TMEM), representing direct physical contact between a tumor cell expressing the actin-regulatory protein Mammalian-enabled (Mena), a perivascular Tie2hi/Vegfhi-expressing macrophage, and an endothelial cell (Harney et al. Cancer Discovery 2015). TMEM sites have been identified in mouse and human mammary carcinomas, and both TMEM density (Rohan et al. JNCI 2014) and invasive Mena isoform expression (Agarwal et al. Breast Cancer Res, 2012; Forse et al. BMC Cancer, 2015]) correlates with metastasis in early stage breast cancer. Since cytotoxic agents such as PTX induce influx of bone marrow-derived progenitors that differentiate into Tie2hi/VEGFhi macrophages in the primary tumor, we hypothesized that PTX may potentiate tumor cell invasion and metastasis by inducing the formation of TMEM sites and/or function.

Methods and Results in humans: We analyzed the effect of chemotherapy on TMEM and invasive Mena isoforms in 10 patients with localized breast cancer who had residual disease after neoadjuvant chemotherapy (NAC: weekly paclitaxel followed by dose-dense doxorubicin-cyclophosphamide [AC]), of whom 7 had more than 2-fold increase in TMEM density in residual disease compared with pretreatment. In a separate cohort of 5 patients, NAC produced an acute increase of up to 150-fold in invasive Mena isoforms after 1-2 doses of NAC.

Methods and Results in mice: After our preliminary data in humans, we evaluated effects of PTX in 4 different models, including 2 mouse models (PyMT-spontaneous & transplantation) and 2 patient-derived xenograft (PDX) triple negative models (HT17, HT33). Although PTX delayed primary tumor growth, tumors in PTX-treated mice had significantly more TMEM sites, circulating tumor cells (CTCs) and metastatic foci when compared to vehicle-treated animals. Using intravital imaging of MMTV-PyMT-Dendra2/Cfms-CFP mice, PTX induced influx of macrophages into primary tumors and intravasation of cancer cells at TMEM sites. Furthermore, PTX treatment significantly increased expression of Mena at the gene and protein levels, including invasive Mena isoforms. Deletion of the Mena gene completely abolished dissemination and metastasis in all cases, including those treated with PTX.

Conclusions: We show in mammary carcinoma mouse models and PDX models that although PTX delays tumor growth, it induces invasive Mena isoform expression and significantly increases the density of TMEM sites that are responsible for cancer cell intravasation, dissemination and metastasis. Thus, our data indicate that PTX paradoxically induces dissemination of breast cancer cells by promoting invasive Mena isoforms and TMEM-mediated cancer cell intravasation, suggesting that blockade of TMEM assembly and/or function could enhance the effectiveness of PTX and possibly other cytotoxic agents commonly used to treat early and advanced stage breast cancer.

Citation Format: Karagiannis GS, Pastoriza JM, Wang Y, Harney AS, Entenberg D, Pignatelli J, Jones JG, Anampa J, Sparano JA, Rohan TE, Condeelis JS, Oktay MH. Paclitaxel induced mena- and TMEM-mediated pro-metastatic changes in the breast cancer microenvironment [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD5-02.

Abstract 244: Paclitaxel increases the assembly and function of the tumor microenvironment of metastasis in breast cancer

Chemotherapy induces influx of bone marrow-derived progenitors such as mesenchymal stem cells, endothelial progenitors and proangiogenic monocytes into the primary tumor to promote angiogenesis. Thus it is feared that chemotherapy may potentiate tumor cell invasion and metastasis. Here, we show that paclitaxel delays tumor growth in several mammary carcinoma mouse and human breast cancer models, yet it significantly increases the density of microanatomical sites called “tumor microenvironment of metastasis” (TMEM) that are responsible for tumor cell intravasation and dissemination of breast cancer. The TMEM site consists of a Mena-overexpressing cancer cell in direct contact with a Tie2hi/VEGFhi macrophage and an underlying endothelial cell. Mice treated with paclitaxel have significantly more circulating tumor cells (CTCs) and metastatic foci when compared to vehicle-treated animals indicating that the chemotherapy-induced TMEM are active in assisting tumor cell intravasation. Moreover, syngeneic transplantation of Dendra2+/PyMT tumors into FVB recipients showed significantly higher incidence of Dendra2+ cells in the lung, following paclitaxel administration. In parallel experiments, paclitaxel induced the influx of macrophages and intravasation of cancer cells as observed using intravital imaging of MMTV-PyMT-Dendra2/Cfms-CFP mice, in which blood vessels were visualized with Quantum dots. Furthermore, paclitaxel treatment in experimental mice caused a significant increase in the expression of Mena at the gene and protein levels. PCR assays for total Mena (PanMena) or specific Mena isoforms (MenaINV, Mena11a) revealed that this increase was particularly attributed to the invasive Mena isoforms [i.e. MenaINV and MenaCalc (Menacalc = PanMena - Mena11a)]. These pre-clinical data are supported by the findings from a cohort of 10 breast cancer patients who received neoadjuvant dose-dense paclitaxel followed by doxorubicin/ cyclophosphamide. Of these tumors, 7/10 patients had more than 2-fold increase in TMEM density following neoadjuvant chemotherapy regimen. Moreover, chemotherapy produced an acute increase of up to 150-fold in MenaINV expression in 3/7 and up to 5.5-fold in MenaCalc in 3/4 patients who underwent serial fine needle aspiration (FNA) biopsy before and after 1-2 doses of either neoadjuvant paclitaxel or doxorubicin-cyclophosphamide. This is provocative because an increase in either MenaCalc score or TMEM density are independently associated with increased risk of distant recurrence in breast cancer patients. In conclusion, our data indicate that paclitaxel treatment induces intravasation-mediated dissemination of breast cancer cells in rodents and in certain clinical scenarios in humans by promoting increases in MenaCalc expression and TMEM intravasation sites.

Citation Format: George S. Karagiannis, Allison H. Harney, Yarong Wang, Jessica Pastoriza, Jeanine Pignatelli, Jesus Anampa, Joseph A. Sparano, Joan G. Jones, David Entenberg, John S. Condeelis, Maja H. Oktay. Paclitaxel increases the assembly and function of the tumor microenvironment of metastasis in breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 244.

Progress in adjuvant chemotherapy for breast cancer: an overview

Breast cancer is the most common cause of cancer and cancer death worldwide. Although most patients present with localized breast cancer and may be rendered disease-free with local therapy, distant recurrence is common and is the primary cause of death from the disease. Adjuvant systemic therapies are effective in reducing the risk of distant and local recurrence, including endocrine therapy, anti-HER2 therapy, and chemotherapy, even in patients at low risk of recurrence. The widespread use of adjuvant systemic therapy has contributed to reduced breast cancer mortality rates. Adjuvant cytotoxic chemotherapy regimens have evolved from single alkylating agents to polychemotherapy regimens incorporating anthracyclines and/or taxanes. This review summarizes key milestones in the evolution of adjuvant systemic therapy in general, and adjuvant chemotherapy in particular. Although adjuvant treatments are routinely guided by predictive factors for endocrine therapy (hormone receptor expression) and anti-HER2 therapy (HER2 overexpression), predicting benefit from chemotherapy has been more challenging. Randomized studies are now in progress utilizing multiparameter gene expression assays that may more accurately select patients most likely to benefit from adjuvant chemotherapy.