Pregnancy-associated breast cancer: clinicopathological characteristics of 20 cases with a focus on identifiable causes of diagnostic delay

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 multicenter study comparing clinicopathological factors, diagnosis and treatment outcomes with non-pregnant patients

PURPOSE

Pregnancy-associated breast cancer (PABC), defined as breast carcinoma diagnosed during pregnancy or in the first post-partum year, is one of the most common gestation-related malignancies with reported differences in tumor characteristics and outcomes. This multicenter study aims to review cases of PABC in Singapore, including their clinicopathological features, treatment, and clinical outcomes compared to non-PABC patients.

METHODS

Demographic, histopathologic and clinical outcomes of 93 PABC patients obtained from our database were compared to 1424 non-PABC patients.

RESULTS

PABC patients presented at a younger age. They had higher tumor and nodal stages, higher tumor grade, were more likely to be hormone receptor negative and had a higher incidence of multicentric and multifocal tumors. Histological examination after definitive surgery showed no significant difference in tumor size and number of positive lymph nodes suggesting similar neoadjuvant treatment effects. Despite this, PABC patients had worse outcomes with poorer overall survival and disease-free survival, OS (P < 0.0001) and DFS (P < 0.0001). Termination of pregnancy did not improve survival.

CONCLUSION

Patients with PABC present at a higher stage with more aggressive disease and have poorer outcomes compared to non-PABC patients. Reducing delay in diagnosis and treatment may help improve survival.

Breast cancer treatment and ovarian function

The aim of this study was to provide an update on ovarian function and the mechanisms of gonadal damage after exposure to chemotherapy in breast cancer survivors. The alkylating agents are toxic to both primordial and growing follicles. However, anti-metabolite drugs are more likely to destroy preantral and antral follicles. Younger patients are more likely to have a higher ovarian reserve, and therefore, more likely to retain some residual ovarian function after exposure to gonadotoxic regimens. However, there can be significant variability in ovarian reserve among patients of the same age. Furthermore, patients with critically diminished ovarian reserve may continue to menstruate regularly. Therefore age and menstrual status are not reliable indicators of good ovarian reserve and might give a false sense of security and result in an adverse outcome if the patient is consulted without considering more reliable quantitative markers of ovarian reserve (antral follicle count and anti-Müllerian hormone) and fertility preservation is not pursued. In contrast to well-documented ovarian toxicity of older chemotherapy regimens, data for newer taxane-containing protocols have only accumulated in the last decade and data are still very limited regarding the impact of targeted therapies on ovarian function.

Clinical Decision Making in the Management of Breast Cancer Diagnosed During Pregnancy: A Review and Case Series Analysis

Purpose: To highlight the various options available for the management of breast cancer diagnosed during pregnancy by describing the investigations, treatment, and outcomes in relation to these women. Methods: This is a narrative review of the literature to describe the issues related to pregnancy and obstetric management in patients with breast cancer. It incorporates a description of six cases of women (aged 29-39 years) with a first-time diagnosis of breast cancer during pregnancy to illustrate a number of issues that need to be considered during different trimesters. Results: Of the six cases, two were diagnosed in each pregnancy trimester. A painless breast mass was the presenting symptom in five cases (83%). In all cases, breast ultrasound was the primary diagnostic imaging procedure. Chest X-ray was performed in 3 (50%) and computed tomography in 2 (33%). A core needle biopsy was performed in all cases, and sentinel lymph node biopsy in 3 (50%) cases. Four women had grade 3 tumor; five had estrogen receptor-positive tumors. Four women had breast surgery during pregnancy. Five women gave birth after the induction of labor and/or cesarean section. In all six cases, a multidisciplinary team was involved in the delivery of health care. Conclusion: Regular breast examinations are needed for all pregnant woman during prenatal visits. Breast ultrasonography should be offered if a breast lump or other symptoms are detected. Breast surgery can be safely performed during all pregnancy trimesters, and some systemic therapeutic agents can be administered safely in the second and third trimesters.

Pregnancy-associated breast cancer: nationwide Dutch study confirms a discriminatory aggressive histopathologic profile

Purpose

Breast cancer is the most common type of malignancy in pregnant women, occurring approximately once in every 3000 pregnancies. Pregnancy-associated breast cancer (PABC) is commonly defined as breast cancer diagnosed during or within one year after pregnancy, and it accounts for up to 6.9% of all breast cancers in women younger than 45 years old. Whether these cancers arise before or during pregnancy, and whether they are stimulated by the high hormonal environment of pregnancy, is currently unknown. This study assesses the histopathological profile of PABC in a large Dutch population-based cohort.

Methods

We identified 744 patients with PABC (in this cohort defined as breast cancer diagnosed during or within 6 months after pregnancy) diagnosed between 1988 and 2019, in the nationwide Dutch Pathology Registry (PALGA). An age-matched PALGA cohort of unselected breast cancer patients (≤ 45 years), diagnosed between 2013 and 2016, was used as a control. Histopathologic features of both cohorts were compared.

Results

The median age of PABC patients was 34.3 years old (range 19–45 years) and most breast cancers were diagnosed during pregnancy (74.2%). As compared to age-matched controls, PABC patients had tumors of higher Bloom–Richardson grade (grade I: 1.5% vs. 12.4%, grade II: 16.9% vs. 31.3%, grade III: 80.3% vs. 39.5%, p < 0.0001). Furthermore, estrogen (ER)- and progesterone (PR)-receptor expression was less frequently reported positive (ER: 38.9% vs. 68.2% and PR: 33.9% vs. 59.0%, p < 0.0001), while a higher percentage of PABC tumors overexpressed HER2 (20.0% vs. 10.0%, p < 0.0001). The most observed intrinsic subtype in PABC was triple-negative breast cancer (38.3% vs. 22.0%, p < 0.0001), whereas hormone-driven cancers were significantly less diagnosed (37.9% vs. 67.3%, p < 0.0001).

Conclusion

This study, based on a large population-based cohort of 744 PABC Dutch patients, underlines the more aggressive histopathologic profile compared to age-matched breast cancer patients ≤ 45 years. Further in-depth genetic analysis will be performed to unravel the origin of this discriminating phenotype. It definitely calls for timely detection and optimal treatment of this small but delicate subgroup of breast cancer patients.

Supplementary Information

The online version of this article (10.1007/s10549-021-06130-w) contains supplementary material, which is available to authorized users.

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.

Maternal Mortality: 10 Year Experience of a Tertiary Center in Turkey

We retrospectively evaluated five maternal mortality cases that occurred in our institution within the last 10 years. Rate of maternal mortality was 24.5 per 100000 live births. Maternal mortality causes were cardiopulmonary failure secondary to veno-occlusive disease, septic shock secondary to osteosarcoma, pulmonary thromboembolism secondary to metastatic breast cancer, septic shock secondary to cholecystitis, and postpartum hemorrhage secondary to Niemann-Pick disease. Four out of five cases were evaluated as indirect maternal mortality cases. Three out of five cases ended up with a healthy newborn, while other cases ended up with abortus and postpartum exitus.

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.

Clinico-pathologic features, treatment and outcomes of breast cancer during pregnancy or the post-partum period

PURPOSE

Breast cancer during pregnancy (BC-P) or the first year post-partum (BC-PP) is rare and whether it differs from breast cancer (BC) in young women not associated with pregnancy is uncertain.

METHODS

We queried our institutional database for BC-P and BC-PP cases and matched controls with BC not associated with pregnancy diagnosed between January 1, 1985 and December 31, 2013. We performed two parallel retrospective cohort studies evaluating clinico-pathologic features, treatment and outcomes for BC-P and BC-PP cases compared to their controls.

RESULTS

In our population of 65 BC-P cases, 135 controls for BC-P cases, 75 BC-PP cases and 145 controls for BC-PP cases, high grade and estrogen receptor-negativity were more frequent in both case groups than their controls. Among those with stage I-III BC, patterns of local therapy were similar for both case groups and their controls, with the majority undergoing surgery and radiation. Over three-fourths of those with stage I-III BC received chemotherapy. BC-P cases tolerated chemotherapy well, with the majority receiving doxorubicin/cyclophosphamide every 3 weeks. On multivariate analyses of those with stage I-III BC, BC-P cases had non-significantly higher hazards of recurrence and death compared to their controls, while BC-PP cases had non-significantly lower hazards of recurrence and death compared to their controls.

CONCLUSION

BC-P and BC-PP were associated with adverse clinic-pathologic features in our population. However, we did not observe inferior outcomes for BC-P or BC-PP compared to controls, likely due to receipt of aggressive multi-modality therapy.

Atypical Lesions of the Breast and Lobular Carcinoma in Situ in Pregnancy - Surgeons' Practice

Objective

Approach to precancerous and high-risk breast lesions occurring in pregnancy has received little attention in the literature. We carried out a study to investigate the practice of surgeons in the management of these cases.

Materials and Methods

A short survey was sent to surgeons, including a multiple-choice questionnaire about their practice for atypical hyperplasia or lobular carcinoma in situ presenting in each trimester of pregnancy or at time of breastfeeding. Answer options included observation, immediate vacuum biopsy, immediate surgery, surgery in next trimester, surgery after delivery, and surgery after end of breastfeeding; based on the time of presentation.

Results

Out of the 671 practitioners invited, 97(14.5 %) responded to the survey. Participants were from 23 countries. Answers showed that management of gestational Atypical Ductal Hyperplasia (ADH) and Lobular Neoplasia (LN) was readily postponed by surgeons in favor of fetus safety while being cautious about risks of conservative management alone.

Conclusion

Various methods of treatment are selected by surgeons for managing high-risk breast lesions during pregnancy. In the absence of relevant literature, decision making in a multidisciplinary team would be the best approach in these cases.

Location and Frequency of Residual Breast Tissue after Mastectomy

Introduction

Residual breast tissue after mastectomy is a problem since breast cancer can arise from it. The aim of this study was to investigate the incidence and location of residual breast tissue following modified radical mastectomy.

Methods

111 consecutive breast cancer patients who underwent mastectomy were enrolled in this study. During surgery, after removal of the breast tissue and before skin closure, a 1-cm² tissue sample was obtained from each quadrant under the skin flaps. These samples were evaluated histopathologically for the presence of any residual breast tissue.

Results

Residual breast tissue was detected in the tissue samples of 12/111 (10.8%) patients. 4 of these patients had residual breast tissue in all 4 quadrants. 6 patients had residual tissue in a single quadrant. With 9 positive biopsy results, the upper medial quadrant was the most frequently involved location. The other quadrants had 6 positive biopsy results each. At the end of a median of 20 months of follow-up, none of these patients developed breast cancer recurrences.

Conclusion

Mastectomy has a high probability of residual breast tissue being left behind. Physicians should be aware of this and act accordingly when planning surgical or follow-up treatment.

Identification of core genes and clinical roles in pregnancy-associated breast cancer based on integrated analysis of different microarray profile datasets

More women are delaying child-birth. Thus, the diagnosis of pregnancy-associated breast cancer (PABC) will continue to increase. The aim of this study was to identify core candidate genes of PABC, and the relevance of the genes on the prognosis of PABC. GSE31192 and GSE53031 microarray profile datasets were downloaded from the Gene Expression Omnibus database and differentially expressed genes were analyzed using the R package and GEO2R tool. Then, Gene Ontology and Kyoto Encyclopedia of Gene and Genome pathway enrichment analyses were performed using the Database for Annotation, Visualization, and Integrated Discovery. Moreover, the Search Tool for the Retrieval of Interacting Genes and the Molecular Complex Detection Cytoscape software plug-in were utilized to visualize protein–protein interactions and to screen candidate genes. A total of 239 DEGs were identified in PABC, including 101 up-regulated genes mainly enriched in fatty acid activation and the fibroblast growth factor signaling pathway, while 138 down-regulated genes particularly involved in activation of DNA fragmentation factor and apoptosis-induced DNA fragmentation. Fourteen hub genes with a high degree of connectivity were selected, including CREB1, ARF3, UBA5, SIAH1, KLHL3, HECTD1, MMP9, TRIM69, MEX3C, ASB6, UBE2Q2, FBXO22, EIF4A3, and PXN. Overall survival (OS) analysis of core candidate genes was performed using the Gene Expression Profiling Interactive Analysis and UALCAN websites. High ASB6 expression was associated with worse OS of PABC patients. Molecular subtypes and menopause status were also associated with worse OS for PABC patients. In conclusion, ASB6 could be a potential predictor and therapeutic target in patient with PABC.

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.

Pregnancy-associated breast cancer in rural Rwanda: the experience of the Butaro Cancer Center of Excellence

BACKGROUND

Breast cancer is the most common malignancy encountered during pregnancy. However, the burden of pregnancy-associated breast cancer (PABC) and subsequent care is understudied in sub-Saharan Africa (SSA). Here, we describe the characteristics, diagnostic delays and treatment of women with PABC seeking care at a rural cancer referral facility in Rwanda.

METHODS

Data from female patients aged 18-50 years with pathologically confirmed breast cancer who presented for treatment between July 1, 2012 and February 28, 2014 were retrospectively reviewed. PABC was defined as breast cancer diagnosed in a woman who was pregnant or breastfeeding. Numbers and frequencies are reported for demographic and diagnostic delay variables and Wilcoxon rank sum and Fisher's exact tests are used to compare characteristics of women with PABC to women with non-PABC at the alpha = 0.05 significance level. Treatment and outcomes are described for women with PABC only.

RESULTS

Of the 117 women with breast cancer, 12 (10.3%) had PABC based on medical record review. The only significant demographic differences were that women with PABC were younger (p = 0.006) and more likely to be married (p = 0.035) compared to women with non-PABC. There were no significant differences in diagnostic delays or stage at diagnosis between women with PABC and women with non-PABC women. Eleven of the women with PABC received treatment, three had documented treatment delays or modifications due to their pregnancy or breastfeeding, and four stopped breastfeeding to initiate treatment. At the end of the study period, six patients were alive, three were deceased and three patients were lost to follow-up.

CONCLUSIONS

PABC was relatively common in our cohort but may have been underreported. Although patients with PABC did not experience greater diagnostic delays, most had treatment modifications, emphasizing the potential value of PABC-specific treatment protocols in SSA. Larger prospective studies of PABC are needed to better understand particular challenges faced by these patients and inform policies and practices to optimize care for women with PABC in Rwanda and similar settings.

Pregnancy-associated breast cancer: the risky status quo and new concepts of predictive medicine

The paper is motivated by severe concerns regarding currently applied care of the pregnancy-associated breast cancer (PABC) characterised by particularly poor outcomes of the disease. Psychological and ethical aspects play a crucial role in PABC: the highest priority not to damage the foetus significantly complicates any treatment generally, and it is quite usual that patients disclaim undergoing any breast cancer treatment during pregnancy. Although, due to global demographic trends, PABC is far from appearing rarely now, severe societal and economic consequences of the disease are still neglected by currently applied reactive medical approach. These actualities require creating new strategies which should be better adapted to the needs of the society at large by advancing the PABC care based on predictive diagnostic approaches specifically in premenopausal women, innovative screening programmes focused on young female populations, targeted prevention in high-risk groups, and optimised treatment concepts. The article summarises the facts and provides recommendations to advance the field-related research and medical services specifically dedicated to the PABC care.

Association of the Timing of Pregnancy With Survival in Women With Breast Cancer

Importance

Increasing numbers of women experience pregnancy around the time of, or after, a diagnosis of breast cancer. Understanding the effect of pregnancy on survival in women with breast cancer will help in the counseling and treatment of these women.

Objective

To compare the overall survival of women diagnosed with breast cancer during pregnancy or in the postpartum period with that of women who had breast cancer but did not become pregnant.

Design, Setting, and Participants

This population-based, retrospective cohort study linked health administrative databases in Ontario, Canada, comprising 7553 women aged 20 to 45 years at the time of diagnosis with invasive breast cancer, from January 1, 2003, to December 31, 2014.

Exposures

Any pregnancy in the period from 5 years before, until 5 years after, the index date of the diagnosis of breast cancer. Women were classified into the following 4 exposure groups: no pregnancy (the referent), pregnancy before breast cancer, pregnancy-associated breast cancer, and pregnancy following breast cancer.

Main Outcomes and Measures

Five-year actuarial survival rates for all exposure groups, age-adjusted and multivariable hazard ratios [HRs] of pregnancy for overall survival for all exposure groups, and time-dependent hazard ratios for women with pregnancy following breast cancer.

Results

Among the 7553 women in the study (mean age at diagnosis, 39.1 years; median, 40 years; range, 20-44 years) the 5-year actuarial survival rate was 87.5% (95% CI, 86.5%-88.4%) for women with no pregnancy, 85.3% (95% CI, 82.8%-87.8%) for women with pregnancy before breast cancer (age-adjusted hazard ratio, 1.03; 95% CI, 0.85-1.27; P = .73), and 82.1% (95% CI, 78.3%-85.9%) for women with pregnancy-associated breast cancer (age-adjusted hazard ratio, 1.18; 95% CI, 0.91-1.53; P = .20). The 5-year actuarial survival rate was 96.7% (95% CI, 94.1%-99.3%) for women who had pregnancy 6 months or more after diagnosis of breast cancer, vs 87.5% (95% CI, 86.5%-88.4%) for women with no pregnancy) (age-adjusted HR, 0.22; 95% CI, 0.10-0.49; P < .001).

Conclusions and Relevance

Pregnancy did not adversely affect survival in women with breast cancer. For breast cancer survivors who wish to conceive, the risk of death is lowest if pregnancy occurs 6 months or more after diagnosis.

Breast Cancer in Pregnancy: Avoiding Fetal Harm When Maternal Treatment Is Necessary

The management of breast cancer during pregnancy poses unique challenges and requires a multi-disciplinary approach. In this review, we discuss the treatment of breast cancer in pregnancy and recent updates regarding the safety of surgical and chemotherapeutic treatments, including both oncologic and fetal outcomes. The treatment of breast cancer during pregnancy mirrors that outside of pregnancy, with a few important differences dictated by the balance of maternal versus fetal health. Overall, surgical treatment, neo-adjuvant chemotherapy, and/or adjuvant chemotherapy are feasible in most women during pregnancy. Further research to determine the safety of these therapies in pregnancy-associated breast cancer is warranted.

Pregnancy Associated Breast Cancer: Awareness is the Key to Diagnosis -A Case Report

Pregnancy-associated breast cancer (PABC) is defined as breast cancer that occurs during pregnancy or within one year of delivery. PABCs are typically found at advanced stage and are reported to have higher recurrence and mortality rates as compared to non PABC. Although it is said to be rare its incidence is increasing. Very little data is available on PABC among Indian women. Delay in diagnosis is one of the major causes of aggressive presentation of PABC. This is due to the fact that most of the lesions presenting during this period are benign and lactational changes hamper the detection of mass clinically as well as by various investigative methods. Paget's disease of breast, usually reported in elderly woman, when occurs in lactating breast may mimic benign eczematous lesion. Increased awareness among patients as well as clinicians is required to detect this highly aggressive form of breast cancer at an early and treatable stage. Treatment is by multidisciplinary approach and depends upon the gestational stage. Here we report a case of PABC in a lactating woman presenting with Paget's disease because such case may be under diagnosed as breast feeding related lesion leading to delayed diagnosis.

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.