Outcomes Of Pregnancy-associated Breast Cancer Research Articles

Systematic Review of Survival Outcomes of Pregnancy-Associated Breast Cancer in Asian Countries.

Pregnancy-associated breast cancer (PABC) is a rare type of gestational cancer. It poses a significant challenge in diagnosis and management, especially in Asian countries with limited resources. We carried out a systematic literature review and narrative synthesis to identify survival outcomes for women with PABC in Asia. We searched MEDLINE, PubMed, Cochrane Library and the reference lists of the included English language articles for those conducted between January 2010 and August 2022. The search terms were pregnancy-associated breast cancer, breast cancer AND pregnancy, survival of PABC and prognosis of PABC patients. PABC is defined as breast cancer diagnosed either during pregnancy or 1 year-5 years postpartum. This review included observational studies conducted in Asian countries. The final 11 articles met the selection criteria and were analysed. Five of the studies had high quality methods as assessed using the Joanna Briggs Institute (JBI) checklist. We reported study design, year of diagnosis, country, definition of PABC, control group, age of participants, median follow-up time, survival outcomes and pregnancy as prognostic factors. Only five studies reported that PABC patients had a poor overall or disease-free survival rate compared to the control. Pregnancy was a significant independent prognostic factor of breast cancer in only two studies. This review highlights that pregnancy has an unconfirmed association with breast cancer survival in Asia. Most studies that found a non-significant association had small samples, thus there is a need for large-scale multinational epidemiological studies in Asia to establish the survival outcomes in PABC patients.

Abstract 6852: Immune microenvironment profiling of pregnancy associated breast cancer: A transcriptomic and multiplex immunohistochemical analyses

Abstract Background: Pregnancy-associated breast cancer (PABC) is BC diagnosed during pregnancy or within 2 years after pregnancy. Although PABC is a rare subgroup of BC, the outcome of PABC is worse than BC developed in the same age group unrelated to pregnancy. The proliferation and involution of mammary gland during and after pregnancy create a unique immune microenvironment in the breast. Comprehensive profiling of the tumor immune microenvironment in PABC is important but lacking. Methods: We retrospectively identified PABC patients from electronic medical records and their tumor blocks from pathology department in our institution. Age- and stage-matched BC patients were selected as control group. NanoString Breast Cancer 360 Gene Expression panel and Opal Polaris 7 color immunohistochemical (IHC) were utilized to profile PABC from transcriptome and protein levels. Result: PABC (N=26), BC developed 2 years (BC>2Y, N=54) after pregnancy, and matched non-pregnant BC patients (NPBC, N=27) were included in the final analysis respectively. Samples from BC>2Y (remote influence from pregnancy) and NPBC (pregnancy did not contribute to BC) both served as control groups for PABC patients in our study. PAM50 subtyping categorized patients into luminal A(N=42), luminal B(N=26), basal(N=12), and HER2 (N=25) enriched subgroups. In multiplex IHC analysis, CD4+ cells, CD8+ cells, CD20+ cells, and CD68+/CD163+ (M2) cells were all statistically higher in the tumor samples from PABC and BC>2Y than from NPBC. This suggests a potential contribution of pregnancy in the immune microenvironment. In the luminal A subgroup, CD8+ cells, CD20+ cells, and CD68+/CD163+ cells remain statistically higher in the PABC than in the NPBC samples. In NanoString BC360 transcriptomic profiling, immune cell abundance was evaluated from representative gene signatures. Mast cells were significantly lower in the PABC group than in the NPBC group. Cytotoxic T cells are significantly higher both in the PABC and BC>2Y groups than in the NPBC group. Conclusion: We are the first study to profile immune microenvironment using both transcriptomic and IHC methods. Our study is also unique in using NPBC and BC>2Y patients as control groups for PABC patients. CD8+ T cells are statistically higher in PABC patients than in NPBC patients using either transcriptomic profiling or multiplex IHC analysis. M2 macrophages, which promote tumor growth, are abundant in all the PABC and the luminal A PABC samples. Citation Format: I-Chun Chen, Ching-Hsuan Chen, Chia-Lang Hsu, Tzu-Pin Lu, Yen-Shen Lu, Ching-Hung Lin. Immune microenvironment profiling of pregnancy associated breast cancer: A transcriptomic and multiplex immunohistochemical analyses [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 6852.

Long-Term Breast Cancer Outcomes of Pregnancy-Associated Breast Cancer (PABC) in a Prospective Cohort.

Simple SummaryThis study explored the characteristics, treatment, and survival outcomes of patients with pregnancy-associated breast cancer (PABC) in Korea. All patients of this study received standard treatments according to the National Comprehensive Cancer Network guideline. Compared to the non-PABC group, the PABC group had a lower percentage of hormone receptor positivity, increased HER2 overexpression, and higher Ki-67 levels. No maternal complications were observed in patients with PABC. In addition, the 5-year disease-free survival and overall survival rates were significantly poorer in the PABC group than in the non-PABC group. After adjusting for tumor characteristics, PABC was still associated with poor prognosis. This is the first report of the PABC population from a prospective cohort. Exploration to elucidate biologic relevance will follow.Background: Given that peak age of breast cancer (BC) is younger in Asians than in Western populations, relatively higher prevalence of pregnancy-associated breast cancer (PABC) has been reported. This study aimed to analyze the characteristics and clinical outcomes of PABC in Korea. Methods: We defined PABC as BC diagnosed during pregnancy or in the first postpartum year. We compared the clinicopathological characteristics and BC outcomes between patients with PABC and non-PABC patients in the prospective YBC cohort from Samsung Medical Center. Results: In total, 1492 patients were initially enrolled, and 1364 patients were included, of which 93 had PABC (6.8%). The median age of patients with PABC was 34 years. Hormone receptor expression was lower (64.6% vs 74.6%) and frequency of HER2 overexpression was higher (26.9% vs 17.6%) in patients with PABC than in non-PABC patients. The 5-year overall survival (OS) rates were 83.2% and 93.4% in patients with PABC and non-PABC patients, respectively (p < 0.001). The 5-year disease-free survival (DFS) rates were 72.2% and 83.8% in PABC and non-PABC patients. Conclusion: Compared to non-PABC patients, patients with PABC had poorer OS and DFS in this prospective cohort. Exploratory biomarker analysis for PABC is warranted.

Pregnancy associated breast cancer (PABC): Report from a gestational cancer registry from a tertiary cancer care centre, India

BackgroundPregnancy associated breast cancer (PABC) is a rare entity and defined as breast cancer diagnosed during pregnancy or one-year post-partum. There is sparse data especially from low and middle-income countries (LMIC) and merits exploration. MethodsThe study (2013–2020) evaluated demographics, treatment patterns and outcomes of PABC. ResultsThere were 104 patients, median age of 31 years; 43 (41%) had triple-negative disease, 31(29.8%) had hormone-receptor (HR) positive and HER2 negative, 14 (13.5%) had HER2-positive and HR negative and 16(15.4%) had triple positive disease. 101(97%) had IDC grade III tumors and 74% had delayed diagnosis. 72% presented with early stage (24, EBC) or locally advanced breast cancer (53, LABC) and received either neoadjuvant (n = 49) or adjuvant (n = 26) chemotherapy and surgery. Trastuzumab, tamoxifen, and radiotherapy were administered post-delivery. At a median follow up of 27 (IQR:19–35) months, the estimated 3-year event-free survival (EFS) for EBC and LABC was 82% (95% CI: 65.2–100) and 56% (95% CI: 42–75.6%) and for metastatic 24% (95% CI: 10.1%–58.5%) respectively.Of the 104 patients, 34 were diagnosed antepartum (AP) and 15 had termination, 2 had preterm and 16 had full-term deliveries(FTDs). Among postpartum cohort (n = 70), 2 had termination, 1 had preterm, 67 had FTDs. 83(including 17 from AP) children from both cohorts were experiencing normal milestones. ConclusionData from the first Indian PABC registry showed that the majority had delayed diagnosis and aggressive features(TNBC, higher grade). Treatment was feasible in majority and stage matched outcomes were comparable to non-PABCs.

Long-term Outcomes of Pregnancy-Associated Breast Cancer: A Single Institution Experience

Background: The incidence of pregnancy-associated breast cancer (PABC) is increasing, especially in the developed countries. Herein, we report the long-term outcomes of PABC from a single institution in an Arab country. Methods: Consecutive patients diagnosed to have PABC between 2005 and 2012 at a tertiary referral hospital from a Gulf cooperation council country were the subjects of the study. Long-term outcomes are reported, with a minimum follow-up of 8 years. Results: A total of 16 patients were evaluable for long-term survival analysis. The median age at the time of diagnosis was 31.5 (26-40) years. Nine (56%) patients were multiparous (&gt; 5 previous pregnancies). The mean gestational age at diagnosis was 19.7±7.4 weeks. Immunohistochemistry revealed the following phenotypes: Luminal A 3 (18.8%); HER-2 enriched 8 (50%); triple-negative 5 (31.2%). Three patients underwent modified radical mastectomy as the initial treatment, of which 2 received adjuvant chemotherapy during pregnancy. For patients who received neoadjuvant or palliative chemotherapy, the response rate was 75% (pCR 2; CR 1; PR 6). After a median follow-up of 60 months, median progression-free survival was 36 months (95%CI 24.2 to 47.8), while the overall survival was 59 months (95%CI 31.6 – 86.4). Age, marker status, Ki-67 score, clinical stage and differentiation grade did not affect the PFS or OS on univariate analysis. Conclusions: Fifty percent of the patient with PABC expressed HER-2/neu protein, and 1/3rd had triple-negative disease. The rate of response to chemotherapy, and long-term survival may help to set a benchmark for studies from the region. Larger cohort studies may help to draw firm conclusions.

Abstract 4914: Pregnancy and breast cancer outcomes

Abstract Background: Pregnancy-associated breast cancer (PABC) poses a unique challenge as hormonal changes occurring in pregnancy potentially interact with breast cancer outcomes. However, reports on prognosis of PABC have been rare and inconsistent, and most of these studies were from Western countries with only few from Asia. We investigated the outcome of PABC linking a large hospital-based database and the nationwide claims database of Korea. Patients and methods: We retrospectively studied a cohort of 3687 female patients of reproductive age (&amp;lt;50 years old) who had undergone surgery for breast cancer at Seoul National University Hospital from 2008 to 2015. Data on stage distribution and tumor characteristics were reviewed from the institutional database, and history of delivery or abortion from the nationwide claims database of Korea for comprehensive identification. Breast cancer during pregnancy was defined as delivery within 9 months of the diagnosis of breast cancer, and postpartum breast cancer as breast cancer diagnosis within 12 months of delivery, with both being counted as PABC. Results: Among 3687 patients, 18 and 45 patients were classified as having breast cancer during pregnancy and postpartum breast cancer, respectively, comprising 63 cases of PABC. Patients with PABC were significantly more likely to have advanced stage and/or hormone receptor negative tumor, and be younger than 35 years old at diagnosis of breast cancer than those without it (P value for T stage, .0001; N stage, .0011; ER negativity, &amp;lt;.0001; PR negativity, &amp;lt;.0001; age at breast cancer diagnosis &amp;lt;35, &amp;lt;.0001). Similar distribution pattern of clinical characteristics was observed with postpartum breast cancer compared to their counterparts (P value for T stage, &amp;lt;.0001; N stage, .0001; M stage, .0421; ER negativity, &amp;lt;.0001; PR negativity, &amp;lt;.0001; age at breast cancer diagnosis &amp;lt;35, &amp;lt;.0001), whereas these characteristics were comparable between patients with and without breast cancer during pregnancy. PABC and postpartum breast cancer were seemingly associated with worse survival with univariate hazard ratio (HR) of 4.53 (95% confidence interval, CI, 2.53-8.13; P value &amp;lt;.0001) and 5.34 (95% CI, 2.91-9.82; P value &amp;lt;.0001), multivariate HR of 1.52 (95% CI, .82-2.83; P value .1841) and 1.57 (95% CI, .82-2.99; P value .1708), respectively. Breast cancer during pregnancy was not associated with worse survival. Conclusions: PABC and postpartum breast cancer tended to be associated with higher stage, hormone receptor negativity, and thus worse survival, but breast cancer during pregnancy had no adverse effect on survival in patients with breast cancer. Note: This abstract was not presented at the meeting. Citation Format: Mihong Choi, Jiyeon Han, Bo Ram Yang, Myoung-jin Jang, Miso Kim, Tae-Yong Kim, Seock-Ah Im, Han-Byoel Lee, Hyeong-Gon Moon, Wonshik Han, Dong-Young Noh, Kyung-Hun Lee. Pregnancy and breast cancer outcomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4914.

Abstract P4-10-10: Assessment of short inter-pregnancy interval in breast cancer diagnosed during pregnancy

Abstract Background: The relationship between pregnancy and breast cancer (BC) risk is not fully understood. Most of the literature has described this interaction in terms of the age at first pregnancy and the number of full-term pregnancies. During the prospective accrual of the “Joven &amp; Fuerte” young women with BC program in Mexico, we identified patients with pregnancy-associated BC (PABC) that experienced a short inter-pregnancy interval (SIPI) (&amp;lt;18 months between a live birth and the beginning of a following pregnancy). To our knowledge, there are no descriptions of the interaction between SIPI and PABC. Objective: We aim to assess the occurrence of SIPI in patients with PABC, as well as describe their clinical features at presentation. Results: We included patients accrued in the “Joven &amp; Fuerte” program from August 2014 and June 2018 at three Mexican cancer centers. A total of 375 patients ≤40 years-old with newly-diagnosed BC were assessed. 37 patients were diagnosed with PABC (10%), 21 during pregnancy and 16 after pregnancy. 6/37 (16%) patients with PABC experienced a SIPI, all diagnosed during pregnancy (28% of 21). The main clinicopathological features are described in the table 1. Table 1.Clinicopathological features of patients with PABC and SIPICaseAge at BC diagnosis (years)IPI (months)Pregnancy trimester at diagnosisStageBC subtype131183rdIIBNot available23262ndIIIAHR neg, HER2 pos337143rdIIAHR neg, HER2 pos436152ndIVHR pos, HER2 neg53142ndIIIAHR pos, HER2 neg63142ndIIICNot available Conclusion: According to the phenomena seen in this cohort of young BC patients, we hypothesize that SIPI may increase the incidence and/or modify the clinical outcomes of PABC. The evidence from clinical and laboratory data suggest that the mechanisms that could alter the interaction include, but are not limited to, the prolongation of the exposure to high concentrations of estrogens or their genotoxic metabolites, interaction with the effect of progesterone and other pregnancy-associated hormones on breast tissue, and immunologic factors. To date, to our knowledge there is no evidence about the effect of SIPI in PABC. Thus, research in this area should be encouraged, particularly in vulnerable women in limited-resource settings, where SIPI is, unfortunately, a common occurrence, and might represent a risk factor for BC/PABC. Citation Format: Diaz-Perez H, Del Toro-Mijares R, Lopez-Martinez EA, Muñoz-Lozano JF, Fonseca A, Platas A, Martinez-Cannon BA, Barragan-Carrillo R, Castro-Carrasco J, Limon-Gomez S, Villarreal-Garza C. Assessment of short inter-pregnancy interval in breast cancer diagnosed during pregnancy [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 P4-10-10.

Clinicopathological features, treatment, and outcome of pregnancy-associated breast cancer in Ahmadu Bello University Teaching Hospital, Zaria, Northwestern Nigeria

Background: Pregnancy-associated breast cancer (PABC) is breast cancer diagnosed during pregnancy or within 1 year of delivery. It is the most frequent malignancy diagnosed during pregnancy or lactation. There is a paucity of information on PABC in our hospital. Aim: The aim of the study is to highlight the clinicopathological features, treatment, and outcome of PABC in the center. Materials and Methods: It was a 6-year prospective study of PABC from January 2007 to December 2012 at our hospital. Information documented included patient's biodata, clinical features, pathological types, receptor status, staging, treatment, and outcome of PABC patients. Results: A total of 1344 patients had breast cancer during the study period. 31 patients (2.3%) had PABC. Age ranged 20–43 years, median 31 years. Common clinical features were: breast lump/mass – 27 (87.1%) patients, skin thickness – 10 (32.3%), nipple retraction – 9 (29.0%), and inflammation – 6 (19.4%). 19 (61.3%) patients were diagnosed in pregnancy: first trimester – 4 (12.9%), second trimester – 7 (22.6%), third trimester – 8 (25.8%), while 12 (38.7%) were within 1 year of delivery. Twenty-two patients (71.0%) had advanced disease. Twenty-four (77.4%) patients had invasive ductal carcinoma. Thirteen (59.1%) patients were ER/PR positive, 6 (27.3%) were triple negative, and 3 (13.6%) were HER2 positive. Twenty-four patients (77.4%) had vaginal delivery. Three patients (9.7%) had spontaneous abortion and 1 patient (3.2%) had still birth. 25 babies (80.6%) were alive and well. 17 patients (54.8%) had modified radical mastectomy (2 patients in second trimester and 15 patients after delivery), 25 (80.6%) had chemotherapy, 14 (45.2%) had radiotherapy, and 1 (3.2%) received trastuzumab. Mortality was 8 (25.8%). Conclusion: PABC constituted 2.3% of all breast cancer patients in our hospital. Majority (71%) presented with advanced disease. 3 out of every 4 were invasive ductal carcinoma, while 1 in 4 were triple negative. The mortality was 25.8%.

Outcome of Pregnancy-Associated Breast Cancer in Primigravid Women: A Report of 3 Cases

Incidence of Pregnancy-Associated Breast Cancer is increasing due to delay in child bearing. Management during pregnancy is challenging for the treating physicians as options like chemotherapy may put the foetus at risk. Therapeutic approach involving a multidisciplinary team, integrating surgery and chemotherapy along with patient preferences may yield a good outcome. We report the short- and long-term outcome in three women who were diagnosed to have breast cancer during their pregnancy and were managed with surgery and chemotherapy. Of the three cases, two of them are under remission at 8 and 9 years of follow-up, whereas the third lady had recurrence and died after 2 years of diagnosis. All three babies were normal without any delay in milestones on follow-up. Multidisciplinary team of specialists, integrating the various approaches with labour management, may help to optimise the outcome for the mother and her baby.

A single-institution study of 117 pregnancy-associated breast cancers (PABC): Presentation, imaging, clinicopathological data and outcome

This retrospective single-institution study was designed to describe the main clinical, radiological and histological features, as well as the outcome of pregnancy-associated breast cancer (PABC), with a special emphasis on imaging and diagnostic difficulties. We reviewed all breast cancers diagnosed during pregnancy or during the 12 months following delivery at our institution, between 1993 and 2009. Out of a total of 16,555 new cases of breast cancer observed during this period, 117 PABC (0.7%) were diagnosed. Mean age at diagnosis was 33.7 years. Most cancers (81.2%) were diagnosed after delivery. Intermediate or high family risk was frequent (27.5%). The most common mode of presentation was a palpable mass (89.7%). Mean time to diagnosis was 5.8 months. Sensitivity for mammography was 80.9% and for ultrasound 77%. Most prognostic factors were unfavourable: frequent lymph node involvement (51.8%), high-grade tumours, hormone receptor negativity (45.9%) and HER2 positivity (38.7%). Treatments generally included surgery (61.7% mastectomies), radiotherapy (96%) and chemotherapy (79.6%). Overall 5-year survival was 81.8%. PABC is an uncommon but aggressive form of breast cancer and must be considered in the presence of any breast abnormality during pregnancy or the months following delivery. Mammography and ultrasound should both be performed at the slightest clinical suspicion. Radiologists must be aware that masses may lack typical malignant ultrasound characteristics. Biopsies should be largely performed.

Pregnancy associated breast cancer: an institutional experience.

Pregnancy-associated breast cancer (PABC) has been defined as breast cancer diagnosed during pregnancy or within 1 year of delivery. There is a paucity of data on PABC from India. The aim of our study was to assess the clinical-pathological parameters and outcome of PABC at Institute Rotary Cancer Hospital, All India Institute of Medical Sciences. We screened approximately 3,750 cases registered from January 2001 to December 2012 and found 26 cases of PABC. Patients' records were obtained from the computer database using International Classification of Diseases code (C-50). The median age was 26 years (range 20-35). The median duration of symptoms was 11.5 months. The American Joint Committee on Cancer stage distribution was Stage I - 1, Stage II - 3, Stage III - 14 and in Stage IV - 8 patients. Median clinical tumor size is 5.5 cm. Four patients were presented with the inflammatory breast cancer. Positive family history was elicited in three patients. Twenty-one patients were diagnosed after delivery, two patients in the first trimester, two patients in the second trimester and three patients in the third trimester. Estrogen receptor (ER), progesterone receptor (PR) negativity and human epidermal growth factor receptor 2 (HER2/neu) positivity was 56% and 38%, respectively. Nearly, 40% of patients had a high-grade tumor and 70% had pathological node positivity. With a median follow-up of 33 months, 3 years relapse free survival and overall survival was 40% and 50% respectively. Bone was the most common site for systemic relapse. PABC constituted 0.7% of all breast cancer patients. It is associated with advanced stage at presentation. Half of them were ER/PR negative and one-third was HER2/neu positive.

Postpartum diagnosis demonstrates a high risk for metastasis and merits an expanded definition of pregnancy-associated breast cancer

Previous studies report conflicting data on outcomes of pregnancy-associated breast cancer (PABC). Our aim was to examine the effect of a postpartum diagnosis on maternal prognosis in a young women’s breast cancer cohort. We conducted a retrospective cohort study of women age ≤45 years, diagnosed with breast cancer (n = 619) during 1981–2011 at the University of Colorado Hospital and The Shaw Cancer Center in Edwards, CO. Breast cancer cases were grouped according to time between giving birth and diagnosis: nulliparous (n = 125), pregnant (n = 24), < 5 years postpartum (n = 136), >5—<10 postpartum (n = 130), and ≥10 years postpartum (n = 147), to examine the clinicopathologic features and the risk of distance recurrence and death. Cases diagnosed after pregnancy, but within five-years postpartum, had an approximate three fold increased risk of distant recurrence (HR 2.80, 95 % CI: 1.12–6.57) and death (HR 2.65, 95 % CI: 1.09–6.42) compared to nulliparous cases. Postpartum cases diagnosed within five years of last childbirth demonstrated a higher five-year distant recurrence probability (31.1 %) and a markedly lower five-year overall survival probability (65.8 %) compared to nulliparous cases (14.8 and 98.0 %, respectively). A diagnosis of breast cancer during the first five-years postpartum confers poorer maternal prognoses after adjustment for biologic subtype, stage, and year of diagnosis. We propose that the definition of PABC should include cases diagnosed up to at least five-years postpartum to better delineate the increased risk imparted by a postpartum diagnosis. Based on emerging preclinical and epidemiologic data, we propose that pregnant and postpartum cases be researched as distinct subsets of PABC to clarify the risk imparted by pregnancy and the events subsequent to pregnancy, such as breast involution, on breast cancer. Further, we highlight the importance of postpartum breast cancer as an area for further research to reduce the increased metastatic potential and mortality of PABC.Electronic supplementary materialThe online version of this article (doi:10.1007/s10549-013-2437-x) contains supplementary material, which is available to authorized users.

P1-08-17: Pregnancy-Associated Breast Cancer Does Not Have a Worse Outcome in the 4912 Women with Breast Cancer of the AMAZONA Project.

Abstract Introduction: Pregnancy traditionally is considered a protective factor for breast cancer. Recent data suggests that pregnancy-associated breast cancer (PABC), a distinct biologic variant possibly related to breast involution, can occur up to 10 years post-partum and may carry a worse prognosis than that of age matched sporadic or nulliparous breast cancer. The Amazona project is a retrospective cohort of 4,912 Brazilian women with breast cancer that has previously reported on worse outcomes of patients according to type of institution where treatment was received (San Antonio 2009 abstr. 3082). We have assessed the outcomes of PABC in the Amazona cohort. Objectives: 1- To identify whether women who were diagnosed with breast cancer up to 10 years after their first pregnancy had worse disease free survival (DFS) and overall survival (OS) than nulliparous women (NW); 2- to assess if age at first pregnancy is related to age of breast cancer diagnosis and worse DFS or OS; 3- to assess whether number of pregnancies is associated with worse DFS or OS; 4- to assess whether time from first pregnancy to diagnosis or age of first pregnancy are associated with histological grade, clinical stage or tumor expression of ER, PR, and HER2. Methods: We analyzed 4836 women for whom parous history was available, in respect to DFS, OS, tumor clinical stage, histological grade, expression of ER, PR and HER2, according to age of first pregnancy, diagnosis up to 5 and 10 years after first pregnancy, and number of pregnancies, using NW as controls. Analysis of DFS and OS was done by Cox regression modeling adjusted for institution type, stage, ER, PR, HER2 and grade. Results: Our cohort had 1996 nulliparous women and 2840 parous women. The median follow up was 28 months and there were 318 deaths and 735 recurrences. We did not find any correlation between PABC with DFS (5 year interval HR 1.15, 95%CI 0.43−3.07; 10 year interval HR 1.01, 95%CI 0.57−1.81) or OS (5 year interval HR 1.88, 95%CI 0.6−5.94; 10 year interval HR 0.5, 95%CI 0.73−3.09), nor was there a correlation between age at first pregnancy with age of breast cancer diagnosis. We also did not see any difference between age of first pregnancy and DFS or OS. Women with 3 or more pregnancies had worse OS (HR 0.71, 95%CI 0.54−0.93) but not worse DFS (HR 0.93, 95%CI 0.76−1.13).Tumors diagnosed within 5 or 10 years from first pregnancy did not differ by grade, ER, PR, HER2, and clinical stage from those of NW. Women who had their first pregnancy after age 20 tended to have more ER positive (OR 1.99, 95%CI 1.49−2.65), PR positive (OR 1.40, 95%CI 1.06−1.87), and HER2 positive (OR 1.85, 95%CI 1.22−2.79) tumors than NW. Conclusions: In this large cohort of breast cancer patients from the diverse geographic and socioeconomic spectrum of Brazil we did not find any association between PABC or age of first pregnancy to DFS or OS. The association with worse OS but not DFS for women with 3 or more pregnancies might be due to confounding factors. PABC was not associated with worse clinical prognostic factors. Women who had their first pregnancy after age 20 were more likely to have ER+, PR+ and HER2 + tumors than nulliparous patients. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-08-17.

Pathologic features and outcomes of pregnancy-associated breast cancer (PABC): A case control study.

1589 Background: PABC may be defined as breast cancer (BC) diagnosed during pregnancy or within one year of giving birth. Conflicting data exist regarding the impact of pregnancy on clinical features and prognosis of BC. Methods: We performed a single institution retrospective chart review of 99 patients (pts) diagnosed with PABC between 1992 and 2007, identified through our institutional database. Pts with non-invasive BC, prior BC or metastases at diagnosis were excluded. Non-PABC controls were matched 2:1 to PABC cases by year of diagnosis and age at diagnosis. Tumor features including T stage, N stage, grade, estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status were recorded. Details of obstetric history, treatment and outcomes were also recorded. Results: The median age at diagnosis for cases was 35 (range 24-48) and for controls was 36 (range 25-48). Of the PABC pts, the diagnosis was made during pregnancy in 36, and after delivery in 63. 9 pts received chemotherapy during pregnancy, consisting of doxorubicin with or without cyclophosphamide. PABC cases were more likely than controls to be ER negative (59% vs. 31%, p < 0.0001) and PR negative (72% vs. 40%, p < 0.0001). Cases were also more likely to have advanced T stage (p = 0.0496) and N stage (p = 0.017) and higher grade tumors (p = 0.0137). Overall survival (OS) did not differ between cases and controls (p = 0.9584). The median follow-up for cases was 6.3 years and for controls was 4.7 years. After adjustment for ER, PR, HER2, T stage, N stage or grade, the presence of PABC vs non-PABC was not prognostic for survival. ER status, T stage and N stage were prognostic for OS after adjustment for PABC vs. non-PABC. On multivariate analysis, independent prognostic factors for OS were ER status (p = 0.0019) and N stage (p = 0.0001). The diagnosis of PABC was not an independent prognostic factor (p = 0.0999). Conclusions: PABC is associated with a higher incidence of ER and PR negative tumors, higher grade tumors and a more advanced disease stage at diagnosis than controls matched for age and year of diagnosis. While PABC is associated with less favorable tumor features, the diagnosis of PABC in itself is not an adverse prognostic factor for survival. No significant financial relationships to disclose.