Abstract
Rationale: African American women (AAW) have a higher incidence of triple negative breast cancer (TNBC), and higher mortality from breast cancer when compared to Caucasian women (CW). ...Epidemiological studies have shown that lack, or short duration, of breast-feeding, a more common practice among AAW than CW, may be one of the factors that increase the risk of TNBC. The pregnancy-lactation-involution cycle is a dynamic process where upon pregnancy, breast undergoes extensive proliferation and differentiation for milk production followed by apoptosis as it involutes to near pre-pregnant state. Prolonged breastfeeding results in gradual involution (GI) whereas no or short duration of breastfeeding leads to forced and abrupt involution (AI) of breast. We modeled GI and AI in wild-type FVB/N mice and reported that mammary glands of abruptly involuted mice had expansion of luminal progenitor (LP) cells over time and hyperplastic precancerous changes within 120 days postpartum1. In addition, there was increased Stat3 (Signal Transducer and Activator of Transcription 3) activation (pStat3Y705) in AI glands. Persistent Stat3 activation is linked to tumor cell proliferation, survival, invasion, and tumor-promoting inflammation2. In mice, Stat3 is required for the initiation and acute phase response during mammary gland involution and is crucial for the proliferation of LP cells3-5. We hypothesized that Stat3 activation plays a key role in the development of hyperplasia and fibrosis observed following AI.Methods: We bred Stat3Fl/Flmice with MMTV-Cre mice to induce mammary epithelial specific deletion of Stat3. Experimental (MMTV-Cre+;Stat3Fl/Fl) and control females (Stat3Fl/Fl) were bred once at 8 weeks of age and litter sizes were normalized to 6pups/dam within 24 hours of partum. With day of partum as day0, all 6 pups were removed on day7 and AI was initiated. Mammary glands were harvested on postpartum day28, day56, and day120. Florescence activated cell sorting (FACS) was performed to determine distribution of mammary epithelial subpopulations. Histological effects of Stat3 deletion on mammary gland involution was assessed via staining using haematoxylin and eosin (H&E), Masson’s Trichrome and immunostaining using anti-Ki67 and anti-Stat3 antibodies. Results: Stat3 deletion failed to abrogate the hyperplasia and collagen deposition we initially observed in our AI mice with intact Stat3 as determined by H&E and Trichrome stains. In addition, collagen deposition was further increased following Stat3 deletion, when compared to control cohort. FACS analysis demonstrated that Stat3 deletion resulted in reduction of LP cell population only at early timepoint (day28) but this population rebounded in glands by later timepoints. Stat3 deletion temporarily increased cell proliferation by Ki-67 staining at day28 and 56, with no difference observed between controls at day120. Conclusion: This is the first study showing results of mammary epithelial specific Stat3 deletion on long-term effect of AI. Contrary to our hypothesis, Stat3 deletion did not reduce the hyperplastic changes we observed following abrupt involution of mammary glands. Our findings indicate that Stat3 signaling may limit collagen formation within the mammary gland during abrupt involution. Stat3 is important for the maintenance of LP cells at early timepoints. Further studies are underway to determine the critical downstream events following Stat3 activation that limits long-term effects of abrupt involution. 1. Basree et. al. 2019, in press, Breast Cancer Research 2. Yu et. al. 2014 (PMID: 25342631) 3. Chapman et. al. 1999 (PMID: 10521404) 4. Hughes et. al. 2012 (PMID: 22081431)5. Staniszewska et. al. 2012 (PMID: 23285109)
Citation Format: Allen Zhang, Neelam Shinde, Christopher S Koivisto, Mustafa M Basree, Resham S Mawalkar, Hee K Kim, Gustavo Leone, Sarmila Majumder, Bhuvaneswari Ramaswamy. Mammary gland specific Stat3 deletion during involution results in distinct histological changes and higher collagen deposition 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 P5-07-11.
Invasive lobular carcinoma (ILC) accounts for 10% to 15% of breast cancers in the United States, 80% of which are estrogen receptor (ER)‐positive, with an unusual metastatic pattern of spread to ...sites such as the serosa, meninges, and ovaries, among others. Lobular cancer presents significant challenges in detection and clinical management given its multifocality and multicentricity at presentation. Despite the unique features of ILC, it is often lumped with hormone receptor‐positive invasive ductal cancers (IDC); consequently, ILC screening, treatment, and follow‐up strategies are largely based on data from IDC. Despite both being treated as ER‐positive breast cancer, querying the Cancer Genome Atlas database shows distinctive molecular aberrations in ILC compared with IDC, such as E‐cadherin loss (66% vs. 3%), FOXA1 mutations (7% vs. 2%), and GATA3 mutations (5% vs. 20%). Moreover, compared with patients with IDC, patients with ILC are less likely to undergo breast‐conserving surgery, with lower rates of complete response following therapy as these tumors are less chemosensitive. Taken together, this suggests that ILC is biologically distinct, which may influence tumorigenesis and therapeutic strategies. Long‐term survival and clinical outcomes in patients with ILC are worse than in stage‐ and grade‐matched patients with IDC; therefore, nuanced criteria are needed to better define treatment goals and protocols tailored to ILC's unique biology. This comprehensive review highlights the histologic and clinicopathologic features that distinguish ILC from IDC, with an in‐depth discussion of ILC's molecular alterations and biomarkers, clinical trials and treatment strategies, and future targets for therapy.
Implications for Practice
The majority of invasive lobular breast cancers (ILCs) are hormone receptor (HR)‐positive and low grade. Clinically, ILC is treated similar to HR‐positive invasive ductal cancer (IDC). However, ILC differs distinctly from IDC in its clinicopathologic characteristics and molecular alterations. ILC also differs in response to systemic therapy, with studies showing ILC as less sensitive to chemotherapy. Patients with ILC have worse clinical outcomes with late recurrences. Despite these differences, clinical trials treat HR‐positive breast cancers as a single disease, and there is an unmet need for studies addressing the unique challenges faced by patients diagnosed with ILC.
Invasive lobular carcinoma is the second most common subtype of invasive breast cancer and presents unique challenges in detection and treatment. This review reports on the distinct morphological, molecular, and clinical features of invasive lobular carcinoma and highlights the challenges in the management of this cancer.
Abstract
Background: Epidemiological studies indicate that prolonged breast feeding reduces the risk of triple negative breast cancer (TNBC), which carries the worst prognosis. Prolonged ...breastfeeding allows gradual involution (GI) of the breast while lack of or short-term breast feeding leads to abrupt involution (AI). We developed a novel murine model mimicking AI and GI of breast, and found that GI offers better protection to mammary glands from tissue remodeling associated injuries. Our data showed that AI leads to the development of pro-tumorigenic microenvironment and ductal hyperplasia1. Tissue remodeling involves orchestrated cell death and repopulation, and is closely associated with metabolic reprogramming from mitochondrial oxidative phosphorylation (OXPHOS) to glycolysis. Such metabolic alterations can contribute to cellular changes aiding malignant transformation2. We used our murine model to evaluate whether AI affects cellular metabolism differentially when compared to GI. Methods: Wild-type mice of FVB background were used in all our experiments. Twelve to fourteen week old uniparous mice were allowed to nurse (6 pups/dam) for 7 days postpartum. All pups were removed on day7 postpartum from the dams in AI cohort and three each on day28 and day31 from dams in GI cohort. Whole mammary glands and sorted luminal progenitor (LP) cells harvested on postpartum day28 were subjected to Affymetrix microarray analysis. Gene Set Enrichment Analysis (GSEA) was used to compute pathway enrichments in AI vs. GI glands. Differentially expressed genes were validated using qRT-PCR. Mammary glands harvested on day28 postpartum were subjected to mass spectrometry based untargeted metabolic profiling using Agilent QTOF. Raw data were analyzed using XCMS to assess key metabolic networks altered in AI vs GI glands. Targeted analysis for lactate, pyruvate, succinate and palmitic acid were performed using C13 labelled internal standards to compare OXPHOS vs glycolysis reliance in the AI and GI glands. Results: We observed enrichment of mitochondrial OXPHOS pathway, fatty acid metabolism and Myc target genes in both whole mammary gland and LP cells of AI vs. GI mice. Adipogenesis and hypoxia related genes were enriched in AI-glands. We observed significant upregulation of genes involved in glucose transport and fatty acid synthesis in AI glands, namely, Glut-5, Cidea, Acss2, Acsm3, Acly, Atp6v0d2, Acot11, and Elvol3. Several factors indicating a higher reliance on OXPHOS vs glycolysis, such as, Ppar-γ, Pgc1α, Cpt-2, Srebp1c and Chrebp were upregulated in AI glands. Upregulation of Cpt-2 and Srebp1c in the AI glands indicate higher flux through fatty acid oxidation and reliance on cholesterol synthesis. Metabolomic profiling revealed significant alteration in L-carnitine, GMP and XMP in AI glands which reflect mitochondrial fatty acid transport and nucleotide biosynthesis via guanine-guanosine salvage pathway. Pyruvate and lactate associated with glycolysis were increased in GI vs. AI glands. Conclusion: We show for the first time that in the abruptly involuting (AI) mammary glands following short-term breast feeding, there is a significant shift in the metabolic pathways towards mitochondrial OXPHOS and fatty acid oxidation compared to GI glands. Studies are underway to determine the effect of this metabolic shift on cellular transformation and tumorigenesis and the potential to target these pathways to reverse the detrimental effects of AI. 1. Basree MM, Shinde N, Koivisto C, et al. Breast Cancer Res. 2019; 21(1):80. 2. Ward PS, Thompson CB. Cancer Cell. 2012; 21(3):297.
Citation Format: Neelam Shinde, Kirti Kaul, Allen Zhang, Saba Mehra, Resham Mawalkar, Hee Kyung Kim, Ramesh Ganju, Sarmila Majumder, Bhuvaneswari Ramaswamy. Abrupt involution of lactating mammary gland induces metabolic reprogramming conducive to pro-tumorigenic changes 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 PS17-28.
Abstract
Objective: Epidemiological studies indicate a direct relation between length of breast feeding and protection against risk of triple negative breast cancer (TNBC), an aggressive subtype. ...While prolonged breastfeeding allows gradual involution (GI) of the breast, short-term or no breast feeding leads to abrupt involution (AI). We modelled AI and GI of breast in mice, and showed that mice subjected to GI have better protection from tissue remodeling associated injuries in the mammary gland. Our data revealed late development of ductal hyperplasia aided by pro-tumorigenic microenvironment in the AI glands1. Detailed mechanism of mammary gland involution immediately following cessation of lactation has been studied in the past, but only in the AI setting, that is after abrupt removal of pups at the peak of lactation2,3. The goal of this study is to conduct stepwise comparison of the mechanism of GI vs. AI early on to understand the protective effect of GI against breast cancer risk.Methods: Wild-type FVB mice were used in all our studies. Females were mated at 8 weeks of age and uniparous mice were allowed to nurse (6 pups/dam) for 7 days. Females were then assigned randomly to AI or GI cohort. All pups were removed from the AI dams on postnatal day7 (PND7). Three pups each were removed from GI dams on day28 and 31. Mammary glands were harvested intermittently between PND7 and PND35. H&E stained sections were used for histological studies. Unstained FFPE sections were used for immunohistochemistry and TUNEL assay. Total RNA and protein from whole mammary gland was used for qPCR and western blot respectively. Results: GI glands transitioned from fully active lactating to near involuted glands over a period of 8 days (PND17- PND25), while for AI glands it took < 4 days (PND8.5-PND12). The shrinkage and flattening of tall epithelia and loss of acini was gradual in GI glands as opposed to rapid breakdown of acini and adipocyte repopulation in AI gland. Apoptotic cell count peaked on PND11 (5%) in AI vs. PND25 (3%) in GI glands. The pStat3Y705+ cells were highest on PND8.5 (25%) in AI vs. on PND25 (11%) in GI glands. Macrophage infiltration (F4/80+) peaked on PND11 (35%) and remained elevated at ~24% till PND25, while in GI glands increase was gradual from PND17 through PND25 (27%). Expression of key genes identified in AI mice2,3 have markedly different expression pattern in GI mice (Table). While some peaked at a later time point in GI vs. AI coinciding with maximum cell death, expression of some are significantly low or undetectable in GI glands at both RNA and protein level. Conclusions: We show for the first time that kinetics of cell death, adipocyte repopulation, immune cell infiltration and inflammatory state of glands undergoing abrupt vs. gradual involution are markedly different. Several genes known to play a key role during AI are either not expressed or barely detectable in the GI glands at any time point during involution. These data suggests that not only the kinetics, but mechanism of GI and AI are not identical. We conclude that orchestrated cell death in GI protects from drastic lysosomal, and immune cell activities that predisposes mammary glands to higher risk of neoplastic changes.Significance: Epidemiological data highlights the benefits of prolonged breastfeeding in protecting against breast cancer, particularly, TNBC, an aggressive subtype prevalent in the African American women. Our study highlights the mechanism underlying the benefits of gradual involution of breast.
GeneFold Change compared to PND7 (GI vs. AI) Peaked on (GI vs. AI)Stat34.0 vs. 5.9PND25 vs. PND8.5Ctsb2.8 vs. 3.4PND25 vs. PND8.5CD143.4 vs. 20PND25 vs. PND8.5Orm11.7 vs. 10PND25 vs. PND12Lrg130 vs. 216PND25 vs. PND12MMP215.8 vs. 27PND25 vs. PND12Chi3L11350 vs. 572, 859PND28 vs. PND11, 28Cebpδnone vs. 4.4None vs. PND8.5CtsLnone vs. 5.7None vs. PND8.5Orm2none vs. 370None vs. PND12Slpinone vs. 92None vs. PND8.5
Citation Format: Bhuvaneswari Ramaswamy, Neelam Shinde, Morgan Bauer, Maria Cuitino, Saba Mehra, Resham Mawalkar, Mustafa Basree, Allen Zhang, Kirti Kaul, Xiaoli Zhang, Ramesh Ganju, Sarmila Majumder. Mechanistic differences between abrupt and gradual involution of mouse mammary gland 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 P5-01-08.
Pulmonary lobectomy can result in intercostal nerve injury, leading to denervation of the rectus abdominis (RA) resulting in asymmetric muscle atrophy or an abdominal bulge. While there is a high ...rate of intercostal nerve injury during thoracic surgery, there are no studies that evaluate the magnitude and predisposing factors for RA atrophy in a large cohort.
A retrospective chart review was conducted of 357 patients who underwent open, thoracoscopic or robotic pulmonary lobectomy at a single academic center. RA volumes were measured on computed tomography scans preoperatively and postoperatively on both the operated and nonoperated sides from the level of the xiphoid process to the thoracolumbar junction. RA volume change and association of surgical/demographic characteristics was assessed.
Median RA volume decreased bilaterally after operation, decreasing significantly more on the operated side (−19.5%) versus the nonoperated side (−6.6%) (P < 0.0001). 80.4% of the analyzed cohort experienced a 10% or greater decrease from preoperative RA volume on the operated side. Overweight individuals (body mass index 25.5-29.9) experienced a 1.7-fold greater volume loss on the operated side compared to normal weight individuals (body mass index 18.5-24.9) (P = 0.00016). In all right-sided lobectomies, lower lobe resection had the highest postoperative volume loss (Median (interquartile range): −28 (−35, −15)) (P = 0.082).
This study of postlobectomy RA asymmetry includes the largest cohort to date; previous literature only includes case reports. Lobectomy operations result in asymmetric RA atrophy and predisposing factors include demographics and surgical approach. Clinical and quality of life outcomes of RA atrophy, along with mitigation strategies, must be assessed.
1042 Background: Circulating tumor DNA (ctDNA) can overcome limitations of tissue biopsy (tbx) in patients with metastatic breast cancer (mBC). While tbx provides a snapshot of a tumor’s molecular ...profile from one site and time, ctDNA provides a more comprehensive landscape of the tumor genome. Serial liquid biopsies (lbx) can be easily obtained for monitoring clinical response and resistance over time. The Individualized Molecular Analyses Guide Efforts in Breast Cancer (IMAGE) II study evaluates tbx and serial lbx methods for tumor genomic profiling in mBC. Methods: IMAGE II (NCT02965755) is a prospective, multi-center trial to evaluate the clinical utility of lbx versus tbx. Eligible individuals had mBC of any subtype, with progression requiring therapy change. Tbx sequencing per standard of care was required unless biopsy was not technically feasible. Upon enrollment, we collected baseline plasma for tissue-agnostic comprehensive genomic profiling (CGP) by Foundation Medicine. Both lbx and tbx sequencing results were reviewed in real time by the Johns Hopkins Molecular Tumor Board to provide treatment recommendations. Clinical data was recorded. We collected serial lbx samples 1-2 weeks post initiation of next line of therapy, at first restaging, and at progression. Here we present the analysis of data collected at enrollment, and serial lbx results will be reported at a later date. Results: Total enrollment was 199 pts, of whom 194 were women (median age = 57 years, range 27-86 years). There were 140 HR+HER2-, 4 HR-HER2+, 20 HR+HER2+ and 35 triple negative (TNBC) cases. Metastases were found in bone only in 19 pts, or included lung in 99 pts, liver in 97 pts, and brain in 14 pts. Median prior lines of metastatic therapy was 2, with 44 pts (22.1%) having been on 4 or more, including antibody-drug conjugates (14 pts), immunotherapy (2), cytotoxic chemotherapy (74), endocrine (88), and targeted therapy (12). 9 pts were newly diagnosed with mBC at the time of enrollment. 110 pts (55%) had tbx sequencing. In lbx-based CGP results from 190 patients, the genes most frequently altered were TP53(90 patients), PIK3CA (63), ESR1 (54). Copy number amplifications were found in FGFR1 (21 patients) and FGFR3 (12), and copy number losses were found in PTEN in 3 patients. Of the 87 patients whose baseline lbx was profiled using FoundationOne Liquid CDx which allows calculation of ctDNA tumor fraction (TF), 69 (79.3%) pts had detectable ctDNA TF. 60 patients (69.0%) had ctDNA TF at least 1%. We will present the frequency of clinically actionable mutations detected via lbx vs tbx genomic profiling, accounting for sites of metastases, receptor subtype and prior therapy exposure, as well as the association between ctDNA TF and sites of disease. Conclusions: A high rate of ctDNA TF detection in pts with mBC highlights the value of lbx for CGP in this setting for detecting multiple alteration classes across mBC subtypes and metastatic sites. Clinical trial information: NCT02965755 .
Abstract Introduction: A meta-analysis of 47 global epidemiological studies highlights a higher breast cancer risk in women who did not breastfeed or breastfed for a short time. Further studies ...showed this is especially true for triple-negative breast cancer (TNBC) patients. Premenopausal AA women (AAW) have a lower prevalence of breastfeeding and a higher incidence of TNBC and mortality. Our previous study compares short-term breastfeeding, abrupt involution (AI) with prolonged breastfeeding called gradual involution (GI), revealing that AI alone induces ductal hyperplasia four months postpartum. Our current investigation delves into early events during AI versus GI, employing a comprehensive approach encompassing histology, gene expression, and myeloid cell involvement. Methods: Utilizing FVB female mice, we conducted a comparative analysis of AI and GI. AI involved early pup removal, while GI was achieved through staggered weaning. The evaluation included analysis of histomorphology, gene/protein expression, and myeloid cell infiltration. Sequential mammary gland (MG) changes were monitored through H&E staining, TUNEL assay, and DNA damage analysis. 3D-organoid cultures of luminal progenitors (LPs) were employed to assess the impact of AI versus GI. qRT-PCR, IHC, Western blot, and flow cytometry/multiplex imaging were employed for the differential expression analysis of molecular and cellular factors associated with AI/GI. Results: Our research showed that AI had early adipocyte repopulation, rapid cell death, DNA repair, and myeloid cell infiltration, resulting in a chronically inflamed microenvironment. In contrast, the GI triggers a controlled immune response and prolonged cell death, facilitating comprehensive remodeling of the MG. Our flow cytometric or multiplexing imaging analyses revealed that AI-affected glands exhibit an enrichment of CCL9-producing CD206+ M2-like macrophages and CD11b+Gr1+ myeloid-derived suppressor cells. Moreover, exogenous CCL9 treatment on LPs in 3D-organoid culture results in disorganized acinar-type organoids, mirroring morphological differences observed in LPs from AI mammary glands on day56 PPM. Further analysis of CCL9 treated organoids revealed the expansion of Esr1- LPs population in ex-vivo organoid culture which might indicate an increase in the putative cells of origin of TNBC. Conclusion: Our studies comparing AI and GI demonstrate that AI is producing a pro-tumorigenic environment in the breast. It is important to note that prolonged breastfeeding protects the breast, although this cannot be a singular risk factor for TNBC. Therefore, understanding the mechanism will lead to prevention strategies to improve outcomes for all women but, has the potential to have a significant benefit in AAW. Citation Format: Sanjay Mishra, Neelam Shinde, Maria Cuitino, Morgan Bauer, Dinesh Ahirwar, Vijaya Bharti, Kate Ormiston, Resham Mawalkar, Sara Alsammerai, Gautam Sarathy, Xiaoli Zhang, Anna Vilgelm, Ramesh Ganju, Sarmila Majumder, Bhuvaneswari Ramaswamy. Understanding the link between breastfeeding and the risk of breast cancer through comparative analysis of the murine-based model of mammary gland involution abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2138.
Abstract
Background: Triple negative breast cancer (TNBC) is associated with poor survival, particularly affecting African American women (AAW). Epidemiological studies indicate prolonged breast ...feeding reduces breast cancer (BC) risk, including TNBC. AAW have significantly lower rates of breast feeding compared to Caucasian women. To understand this link we developed a mouse model mimicking abrupt (AI) and gradual involution (GI). AI led to increased estrogen signaling, cell proliferation and chronic inflammation, which was followed by hyperplasia and squamous metaplasia in mammary glands1. There was an increase in the luminal progenitor (LP) cell population, the cells of origin of TNBC, and a decrease in mature luminal (ML) cells in AI glands. In this study, we sought to determine if blocking estrogen signaling with tamoxifen (TAM) could revert the negative effects of AI, and if so, could be a prophylactic option to reduce BC risk in women who do not breast feed.
Methods: Uniparous FVB/N mice (~8 weeks) were allowed to nurse six pups per dam at partum. To induce AI, all pups were removed on postpartum (PP) day 7 (d7). For TAM treatment, 5mg sustained release TAM citrate pellet or placebo was implanted in the subscapular region on PP d8. Mammary glands were harvested on PP d28 and d120. FFPE sections were used for histology and immunohistochemistry. Single cell suspensions were analyzed for mammary epithelial subpopulations using Fluorescence Activated Cell Sorting. Affymetrix and qPCR were used for gene expression analysis. Mass cytometry was performed on mammary glands harvested at PP d120.
Results: TAM treatment for 21 days completely abrogated hyperplastic and metaplastic changes in AI glands harvested on d120. Treatment initiation on PP d8, d15 and d35 had the same effect. TAM treatment reduced the cell proliferation and collagen deposition in AI glands. De-enrichment of estrogen signaling pathways and decrease in Elf5 expression, a luminal progenitor marker, were observed upon TAM treatment in d28 glands. Mass cytometry revealed a marked reduction in LP population and a significant increase in ML population in TAM treated AI glands on d120, restoring to the levels in age matched virgin mice. Significant increases in progenitor-like markers TSPAN8, Ly6D, CD200 and decreases in CD49f and CD47 expression in LP cells were observed, indicating return to a normal uniparous LP state. Expression of Ly-6D in ML cells, a ML cell marker, was also rescued upon TAM treatment.
Conclusion: Using our mouse model of AI and GI, we show that suppression of estrogen signaling after initiation of AI offered marked protection against precancerous changes. TAM restored the balance of epithelial lineages and normalized the LP and basal cells in AI glands to the post-involution phenotype. Our data provide a rationale for considering short-term TAM treatment for women who do not breastfeed to reduce risk of BC. 1. Basree et.al. PMID 31315645
Citation Format: Bhuvaneswari Ramaswamy, Neelam Shinde, Gary K. Gray, Resham Mawalkar, Allen Zhang, Mustafa Basree, Xiaoli Zhang, Ramesh Ganju, Gina M. Sizemore, Joan S. Brugge, Sarmila Majumder. Prophylactic use of tamoxifen could reduce the risk of breast cancer in women who do not breast feed postpartum abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 11.