Pregnancy-associated Breast Cancer Group Research Articles

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.

Pregnancy-related breast cancer: 14-year experience in a tertiary institution in Hong Kong

BackgroundThe incidence of pregnancy-associated breast cancer (PABC) is increasing. Its tumor characteristics and overall survival compared with those in nonpregnant patients remain controversial. While there have been suggestions that PABC patients have a 40 % increase in the risk of death compared to non-pregnant patients, other studies suggested similar disease outcomes. This study aims to review our local experience with PABC. MethodsTwenty-eight patients diagnosed with PABC and twenty-eight patients diagnosed at premenopausal age randomly selected by a computer-generated system during the same period were recruited. Background characteristics, tumor features, and survival were compared. ResultsAmong the twenty-eight pregnant patients, seventeen were diagnosed during pregnancy, and eleven were diagnosed in the postpartum period. Compared to the non-pregnant breast cancer patients, they presented with less progesterone receptor-positive tumor (35.7 % vs. 64.2 %, p = 0.03). Although there was no statistically significant difference in tumor size (p = 0.44) and nodal status (p = 0.16), the tumor tended to be larger in size (2.94 +/− 1.82 vs 2.40 +/− 1.69 cm) and with more nodal involvement (35.7 % vs 25.0 %). There was also a trend of delayed presentation to medical attention, with a mean duration of 13.1 weeks in the PABC group and 8.6 weeks in the control group. However, the overall survival did not differ (p = 0.63). ConclusionPABC is increasing in incidence. They tend to have more aggressive features, but overall survival remains similar. A multidisciplinary approach is beneficial for providing the most appropriate care.

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

AimWe aimed to clarify tumor features and prognosis of pregnancy‐associated breast cancer (PABC) among Chinese women.MethodsPABC was defined as breast cancer diagnosed during pregnancy or within a year after delivery. Patients with PABC were selected from breast cancer cases of women ≤45 years treated at our institution between December 2012 and December 2017, and one non‐PABC control was matched for stage, age, and year of diagnosis for each case.ResultsForty‐one women with PABC were identified (22 diagnosed during pregnancy and 19 within 1 year of delivery). There were significantly more progesterone receptor (PR)‐ and triple‐negative tumors in the PABC (56.1% and 24.4%, respectively) than in the non‐PABC group (31.7% and 4.9%, respectively) (P = .045 and .026, respectively). Human epidermal growth factor receptor 2 positivity was the same in both groups (31.7%). Median disease‐free survival (DFS) was 29.0 months (95% confidence interval [CI], 6.5‐51.5 months) in the PABC and 40.9 months (95% CI, 22.8‐58.8 months) in the non‐PABC group (P = .167). Median overall survival (OS) was 82.8 months in the PABC (95% CI, 39.3‐126.5 months) versus 80.1 months (95% CI, 56.7‐103.6 months) in the non‐PABC group (P = .131).ConclusionHistological features were similar in both groups, except that PR‐ and triple‐negative tumors were more frequent in the PABC group. Survival analyses show similar OS for patients with PABC and non‐PABC. DFS tended to be shorter in the PABC group; however, this difference was not statistically significant.

Physiologic and hypermetabolic breast 18-F FDG uptake on PET/CT during lactation.

To investigate the patterns of breast cancer-related and lactation-related 18F-FDG uptake in breasts of lactating patients with pregnancy-associated breast cancer (PABC) and without breast cancer. 18F-FDG-PET/CT datasets of 16 lactating patients with PABC and 16 non-breast cancer lactating patients (controls) were retrospectively evaluated. Uptake was assessed in the tumor and non-affected lactating tissue of the PABC group, and in healthy lactating breasts of the control group, using maximum and mean standardized uptake values (SUVmax and SUVmean, respectively), and breast-SUVmax/liver-SUVmean ratio. Statistical tests were used to evaluate differences and correlations between the groups. Physiological uptake in non-breast cancer lactating patients' breasts was characteristically high regardless of active malignancy status other than breast cancer (SUVmax = 5.0 ± 1.7, n = 32 breasts). Uptake correlated highly between the two breasts (r = 0.61, p = 0.01), but was not correlated with age or lactation duration (p = 0.24 and p = 0.61, respectively). Among PABC patients, the tumors demonstrated high 18F-FDG uptake (SUVmax = 7.8 ± 7.2, n = 16), which was 326-643% higher than the mostly low physiological FDG uptake observed in the non-affected lactating parenchyma of these patients (SUVmax = 2.1 ± 1.1). Overall, 18F-FDG uptake in lactating breasts of PABC patients was significantly decreased by 59% (p < 0.0001) compared with that of lactating controls without breast cancer. 18F-FDG uptake in lactating tissue of PABC patients is markedly lower compared with the characteristically high physiological uptake among lactating patients without breast cancer. Consequently, breast tumors visualized by 18F-FDG uptake in PET/CT were comfortably depicted on top of the background 18F-FDG uptake in lactating tissue of PABC patients. • FDG uptake in the breast is characteristically high among lactating patients regardless of the presence of an active malignancy other than breast cancer. • FDG uptake in non-affected lactating breast tissue is significantly lower among PABC patients compared with that in lactating women who do not have breast cancer. • In pregnancy-associated breast cancer patients, 18F-FDG uptake is markedly increased in the breast tumor compared with uptake in the non-affected lactating tissue, enabling its prompt visualization on PET/CT.

380P - Clinico-pathological features and prognosis of patients with pregnancy associated breast cancer: A matched case control study

BackgroundThe impact of pregnancy on clinico-pathological features and prognosis of breast cancer remains controversial.We aimed to evaluate the impact of the association of pregnancy with breast cancer on tumor feature and prognosis- overall survival (OS) and disease free survival (DFS). MethodsWe defined Pregnancy Associated Breast Cancer (PABC) as breast cancer diagnosed during pregnancy or within a year following delivery. We enrolled PABC patients(pts) treated at our institution between December 2012 and December 2017 , and for each case, one non-PABC control was matched for stage, age, and year of diagnosis. Chis-quare and Fisher’s exact test, the Kaplan-Meier method, and Cox’s regression model were used. Univariate and multivariate analyses were performed to assess the parameters associated with prognosis. Results41 women with PABC were identified; 22 pts were diagnosed during pregnancy and 19 were diagnosed within one year of postpartum. There were more PR negative and triple negative tumors in the PABC(56.1% and 24.4%) than in the non-PABC(31.7% and 4.9%) (p=0.045 and 0.026 respectively). The HER2 positivity was the same in the two group, both 31.7%. Median DFS in PABC pts was 29.0 months (95% CI range 6.5-51.5 months ) compared with 40.9 months (95% CI range 22.8–58.8 months) in the non-PABC pts(p=0.167). Median OS in two groups were similar and even longer in PABC group, 82.8 months in PABC pts range(95% CI 39.3-126.5months) compared with 80.1 months (95% CI range 56.7-103.6months) in the non-PABC pts( p=0.131). ConclusionsThe results show histological features were similar in both groups, except that triple-negative tumors were more common in the PABC group. The survival analyses show similar OS for patients diagnosed with PABC compared with non-PABC patients, and DFS tends to be shorter for PABC but no significant difference was observed. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Pregnancy‐associated breast cancer in a contemporary cohort of newly diagnosed women

Pregnancy-associated breast cancer (PABC) refers to breast cancer (BC) diagnosed during pregnancy, lactation, or in the postpartum period. There is evidence that PABC is associated with a poorer prognosis, and that the development of the disease is influenced by the unique hormonal milieu of pregnancy. The purpose of this study was to investigate the clinicopathologic characteristics associated with PABC in a contemporary cohort of women with newly diagnosed BC. Our institutional Breast Cancer Database was queried for women diagnosed with BC between 2009-2018 who had at least one full-term pregnancy (FTP). Variables of interest included patient demographics and clinical and tumor characteristics. PABC was defined as breast cancer diagnosed within 24months of delivery. Statistical analyses included Pearson's chi-square and logistic regression. Out of a total of 2202 women, 46 (2.1%) had PABC. Median follow-up in the total cohort was 5.5years. After adjusting for age at first FTP, PABC was associated with younger age at diagnosis, older age at first FTP, non-Caucasian race, BRCA positivity, presentation with a palpable mass, higher pathologic stage, higher histologic grade, and ER-negative and triple-negative receptor status. The association of PABC with non-Caucasian race may be reflected in the increased proportion of triple-negative breast cancers in the PABC group. PABC was also associated with older age at first FTP. As more women delay childbearing, risk for PABC may increase. Our findings suggest that women who become pregnant at older ages should be followed carefully during pregnancy and the postpartum period, especially if they are BRCA mutation carriers. The optimal approach for monitoring older women during pregnancy and the postpartum period is unclear.

Abstract P4-10-11: Pregnancy-associated breast cancer in a contemporary cohort of newly diagnosed women

Abstract Introduction: Pregnancy-associated breast cancer (PABC) refers to breast cancer (BC) diagnosed during pregnancy, lactation, or in the postpartum period. There is evidence that PABC is associated with a poorer prognosis, and that the development of the disease is influenced by the unique hormonal milieu of pregnancy. The purpose of this study was to investigate the clinicopathologic characteristics associated with PABC in a contemporary cohort of women with newly diagnosed BC. Methods: Our institutional Breast Cancer Database was queried for women diagnosed with breast cancer between 2010-17 who had at least one full term pregnancy (FTP). Variables of interest included patient demographics and clinical and tumor characteristics. PABC was defined as breast cancer diagnosed within 24 months of delivery. Statistical analyses included Pearson's chi-square and logistic regression. Results: Out of a total of 1934 women, 42 (2.2%) had PABC. Median follow up in the total cohort was 4.5 years. After adjusting for age at diagnosis, PABC was associated with older age at first FTP, ethnic minority status, BRCA mutation carriers, presentation with a palpable mass, higher histologic grade, and ER-negative and triple negative receptor status. Variables that were not significantly different between PABC and non-PABC cases included tumor histology, multifocality, presence of lymphovascular invasion, and family history of breast cancer. Table:Selected Characteristics of Women with PABCVariableNon-PABC (n=1892)PABC (n=42)P-value*Age at first full term pregnancy &amp;lt;0.001&amp;lt;35 years1610 (85%)28 (66.7%) ≥35 years277 (15%)14 (33.3%) Race 0.001White1397 (73.8%)23 (54.8%) Black181 (9.6%)8 (19%) Asian175 (9.2%)10 (23.8%) Hispanic131 (6.9%)1 (2.4%) Other8 (0.4%)0 (0%) BRCA 1,2 Positive56 (3%)9 (21.4%)&amp;lt;0.001Method of Presentation 0.002Breast Exam579 (30.6%)30 (71.4%) Mammography1137 (60.1%)10 (23.8%) Ultrasound87 (1.6%)2 (4.8%) MRI67 (3.5%)0 (0%) Other22 (1.2%)0 (0%) Invasive Grade 0.014Low213 (15%)0 (0%) Intermediate763 (53.8%)12 (37.5%) High442 (31.2%)20 (62.5%) Estrogen Receptor 0.034Positive1572 (83.9%)29 (69%) Negative301 (16.1%)13 (31%) Triple Negative135 (7.1%)7 (16.7%)0.041*P-values are age-adjusted. Conclusions: The association of PABC with ethnic minority status in our cohort is interesting and may be reflected in the increased proportion of triple negative breast cancers in the PABC group. In our contemporary cohort, PABC was associated with older age at first FTP. As more women delay childbearing, risk for PABC may increase. Our findings suggest that women who become pregnant at older ages should be followed carefully during pregnancy and in the postpartum period, especially if they are BRCA mutation carriers. The optimal approach for monitoring older women during pregnancy and the postpartum period is unclear. Clinical breast exam may play an important role, especially for those women known to be at increased risk for breast cancer. Citation Format: Gooch JC, Chun J, Jubas T, Guth A, Schnabel F. Pregnancy-associated breast cancer in a contemporary cohort of newly diagnosed women [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 P4-10-11.

Abstract PD6-05: A prospective evaluation of clinical outcomes in women with pregnancy-associated breast cancer (PABC)

Abstract Background: Many studies suggest that women with PABC- breast cancer (BC) diagnosed during pregnancy or within 12 months post partum- have adverse outcomes compared to age matched women whose BC is not associated with pregnancy (non-PABC). However, it is unclear whether this is due to diagnostic delay alone or biological differences. Hence, we investigated whether PABC is independently prognostic for disease-free survival (DFS) and overall survival (OS) in a prospective database of young BC patients. Methods: A prospective database of women ≤40 years of age diagnosed with BC between February 2008 and January 2015 was analyzed. Data regarding, stage at diagnosis, pathology, treatment, and clinical outcomes were available. Statistically significant differences in baseline characteristics and administered therapies in women with and without PABC were evaluated using the chi-square or Fisher's Exact tests. Kaplan-Meier curves for DFS and OS in the PABC and non-PABC cohorts were compared using the log-rank test. A multivariate Cox proportional hazards model adjusted for age, nodal involvement and tumor size. Results: Of 224 women in the database who provided consent for research, 32 (12%) had PABC. Mean age of the PABC and non-PABC patients respectively was 34 (range 27 to 39) and 37 (range 21 to 40) and the median follow-up was 40 months in both groups. PABC was more likely to be locally advanced at diagnosis (44% vs. 22%, p&amp;lt;0.01) and less likely to be hormone receptor positive (75% versus 85%; p &amp;lt;0.01). There was no significant difference in age at diagnosis, tumor grade, lymphovascular invasion, HER2 expression or administered treatments between the two groups. Among the 166 women with early stage BC (not locally advanced), PABC was associated with positive lymph node status in a univariate model [OR 3.2 (95%CI 1.2-8.4), p=0.02] but just missed significance in a multivariate analysis that adjusted for age and tumor size (p=0.06). Eight patients (22%) in the PABC group and 19 (10%) in the non-PABC group experienced local or distant disease recurrence; 3 patients (8%) in the PABC group and 11 (6%) in the non-PABC group died. The 3-year DFS in the PABC and non-PABC cohorts was 79% vs. 90% (p=0.22) and the 3-year OS was 97% in both groups. Conclusion: Diagnostic delay could account for the higher rate of locally advanced disease in the PABC group. However, the lower hormone receptor expression and strong trend toward greater lymph node involvement independent of size suggest that women with PABC may have intrinsically worse disease biology. Event rates may still be too low to detect a statistically significant difference in recurrence risk. Further research is necessary to identify unique molecular features of PABC that may be amenable to targeting. Citation Format: Jerzak KJ, Zhu S, Li N, Mandel R, Warner E. A prospective evaluation of clinical outcomes in women with pregnancy-associated breast cancer (PABC) [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 PD6-05.

Clinicopathologic Characteristics of Pregnancy-Associated Breast Cancer: Results of Analysis of a Nationwide Breast Cancer Registry Database

PurposeThis study aimed to evaluate the clinicopathological characteristics of pregnancy-associated breast cancer (PABC) in comparison with non-pregnancy associated breast cancer (non-PABC).MethodsA total of 344 eligible patients with PABC were identified in the Korean Breast Cancer Society Registry database. PABC was defined as ductal carcinoma in situ, invasive ductal carcinoma, or invasive lobular carcinoma diagnosed during pregnancy or within 1 year after the birth of a child. Patients with non-PABC were selected from the same database using a 1:2 matching method. The matching variables were operation, age, and initial stage.ResultsPatients with PABC had significantly lower survival rates than patient with non-PABC (10-year survival rate: PABC, 76.4%; non-PABC, 85.1%; p=0.011). PABC patients had higher histologic grade and were more frequently hormone receptor negative than non-PABC patients. Being overweight (body mass index [BMI], ≥23 kg/m2), early menarche (≤13 years), late age at first childbirth (≥30 years), and a family history of breast cancer were more common in the PABC group than in the non-PABC group. Multivariate analysis showed the following factors to be significantly associated with PABC (vs. non-PABC): early menarche (odds ratio [OR], 2.165; 95% confidence interval [CI], 1.566–2.994; p<0.001), late age at first childbirth (OR, 2.446; 95% CI, 1.722–3.473; p<0.001), and being overweight (OR, 1.389; 95% CI, 1.007–1.917; p=0.045).ConclusionEarly menarche, late age at first childbirth, and BMI ≥23 kg/m2 were more associated with PABC than non-PABC.

Abstract P5-08-21: Expression of EZH2 and its downstream effectors pEZH2 and H3K27 in pregnancy associated breast cancer (PABC)

Abstract Background: Pregnancy associated breast cancer (PABC) arises during or after pregnancy, is typically triple negative, and is associated with a poor prognosis. Enhancer of Zeste Homolog 2 (EZH2), a core protein of the polycomb-repressive complex, plays a vital role in the epigenetic maintenance of histone H3 lysine (H3K27) repressive chromatin mark and has been found to be aberrantly expressed in various cancers including the breast. EZH2 is involved in stem cell renewal and is involved the initiation, progression and maintenance of cancer cells. EZH2 has been reported to be highly expressed in triple negative breast cancers and to be associated with poor prognosis. In this study, we assessed expression of EZH2 and its downstream markers phosphorylated EZH2 (pEZH2) and H3K27 and correlated their expression with clinicopathologic characteristics in this aggressive type of breast carcinoma. Design: 23 patients diagnosed with PABC within 2 years of pregnancy (mean age=35.8, range=26-48) and control age-/stage-matched nulliparous women (mean age=37.5, range=29-51) were evaluated. Slides were reviewed and pathologic tumor characteristics were noted. Immunohistochemical stains for EZH2, pEZH2, H3K27 and the cancer stem cell marker ALDH1 were performed on 23 PABC and 15 control cases. Extent (1=1-25% positive tumor cells, 2=26-50%, 3=51-75% or 4=76-100%) and intensity (1=weak, 2=moderate or 3=strong) of staining were assessed. A composite score (CS) was calculated by multiplying the extent by intensity (range=0-9; weak=1-3; moderate=4-6 and strong=7-9). Results: PABCs were more likely than controls to have moderate to strong immunoreactivity for EZH2 (69.6% vs. 33.3%, p=0.04). All PABC and control cases expressed EZH2 and pEZH2, while 60.9% of PABC and 40% of control cases expressed H3K27. Within the PABC group, moderate to strong EZH2 expression was seen more frequently in grade 3 tumors (86.7% in grade 3 tumors vs. 37.5% in grades 1-2, p=0.03). Of interest, all triple negative (TN) PABC cases had moderate to strong EZH2 (100% vs. 43.8%, p=0.02). All five PABC cases with the strongest EZH2 (CS=9) were grade 3 tumors (3 TN, 1 HER2+ and 1 luminal B), 60% of which had positive lymph node metastasis. Although 83.3% of ALDH1+ cases also had moderate to strong EZH2, no significant correlation was observed. Conclusions: 1. PABCs express EZH2 and pEZH2 consistently. 2. PABCs are more likely than controls to have moderate to strong immunoreactivity for EZH2. 3. Within the PABC group, all triple negative tumors and the majority of grade 3 tumors have high EZH2 expression. 4. PABC cases with the strongest EZH2 are grade 3 tumors that have positive lymph nodes. Increased expression of EZH2 in PABC may contribute to the poor prognosis in these cases. Our findings add to the understanding of the molecular pathways that operate in different subtypes of breast carcinomas. Citation Format: Blanco Jr LZ, Parini V, Dhamne SA, Siziopikou KP. Expression of EZH2 and its downstream effectors pEZH2 and H3K27 in pregnancy associated breast cancer (PABC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-21.

Pregnancy-associated breast cancer in Taiwanese women: potential treatment delay and impact on survival.

This study investigated the clinicopathologic characteristics and survival of women diagnosed with pregnancy-associated breast cancer (PABC) in Taiwan. PABC is defined as breast cancer diagnosed during pregnancy or within 1 year after obstetric delivery. Our sample of PABC patients (N = 26) included all patients diagnosed at a major medical center in northern Taiwan from 1984 through 2009. Among these patients, 15 were diagnosed during pregnancy and 11 were diagnosed within 1 year after delivery. The comparison group included 104 patients within the same age range as the PABC patients and diagnosed with breast cancer not associated with pregnancy from 2004 through 2009 at the same hospital. Patients' initiating treatment delayed, 5-year and 10-year overall survival were delineated by stratified Kaplan-Meier estimates. Patients' characteristics were associated with initiating treatment delayed was evaluated with multivariate proportional hazards modeling. Antepartum PABC patients were younger and had longer time between diagnosis and treatment initiation than postpartum PABC patients. The predictor of treatment delayed was including birth parity, cancer stage, and pregnancy. The PABC group had larger tumors, more advanced cancer stage, and tumors with less progesterone receptor than the comparison group. The antepartum PABC patients had higher mortality than postpartum PABC and comparison groups within 5 years after diagnosis. Based on these results, we confirmed that pregnant women with breast cancer were more likely to delay treatment. Therefore, we recommend that breast cancer screening should be integrated into the prenatal and postnatal routine visits for early detection of the women's breast problems.

Breast cancer and pregnancy: a comparative analysis of a Chilean cohort.

IntroductionRecent reports show that pregnancy-associated breast cancer (PABC) survival is similar to that of non-pregnant young patients. We evaluate the characteristics and prognosis of PABC patients treated in our cancer centre.Patients and methodsWe identified patients with invasive PABC who were treated between 1999 and May 2013 and compared their characteristics with a no PABC cohort of similar age.ResultsThe prevalence of PABC was 1% (n = 17). The median age was 35 years (range: 29– 42 years). The initial tumour was suspected clinically in 93% of the cases. Total mastectomy rates were higher in women with PABC (78.6% versus 40.5%, p = 0.02), and more tumours in the PABC group were triple negative, epidermal growth factor type 2 (HER2)–positive, and at advanced stages; however, these differences were not statistically significant. While estimated overall survival at ten years was higher in the non-PABC group (75.5% versus 80.5%, p = 0.043), disease-specific survival (DSS) rate at ten years was not statistically different between groups (83.9% for PABC and 75.5% for unrelated pregnancy BC, p = 0.37).ConclusionsPABC is a rare event. In our cohort, it tended to be more aggressive. Compared with a similar age cohort, the DSS was not worse.

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

Pregnancy Associated Breast Cancer (PABC) manifests during pregnancy or within a year following delivery. We sought to investigate differences in management, outcome, clinical, histopathology and immunohistochemistry (IHC) characteristics of PABC and matched controls in a retrospective case control study. PABC and control patients were selected from breast cancer cases of women ≤45 years, diagnosed in the 2nd Department of Pathology, Semmelweis University, Budapest, Hungary between 1998 and 2012. Histopathology information on tumor type, grade, size, T, N, lympho-vascular invasion (LVI), Nottingham Prognostic Index (NPI), associated in situ lesions and IHC charcteristics: ER, PgR, HER2, Ki67, p53 were recorded, IHC-based subtype was assessed, clinical, management and outcome data were analysed. Thirty-one breast cancer cases were pregnancy related. Clinical management data did not differ in cases and controls. Histopathology of disease at presentation was not significantly different, but NPI assessed the PABC group as having poor, whereas controls as having intermediate prognosis. Associated in situ lesion was more often high grade Extensive Intraductal Carcinoma Component (EIC) in PABC. Triple negative and LuminalB prol tumors predominated in PABC. Disease-free and overall survival was inferior compared to controls. PABC patients with LuminalB prol and Triple negative tumors had inferior outcomes. On multivariate analysis inferior prognosis of PABC was associated with pregnancy. Our study has demonstrated inferior outcome of PABC. Difference in tumor biology is reflected by the predominance of triple negative and LuminalB tumors in PABC. The strength of the study is the analysis of complete pathology and IHC data.

Survival Outcomes in Pregnancy Associated Breast Cancer: A Retrospective Case Control Study

Pregnancy-associated breast cancer (PABC) has been defined as breast cancer diagnosed during pregnancy or within one year of delivery. It is believed that after adjusting for age and stage, the 5-year survival rates are the same in both pregnant and nonpregnant women. We conducted a retrospective case-control study among patients treated at our institution between 1990 and 2005 to compare the 5-year survival outcomes for PABC with women treated for breast cancer who were not pregnant. Overall survival (OS) and disease-free survival (DFS) were estimated by the Kaplan-Meier method, and log rank tests were used to assess the associations between OS, DFS and pregnancy status, HER-2 status, ER/PR status, and family history. The median age was 33 years (range 24-42) for both groups. Twenty-two (55%) patients with PABC were ER/PR receptor positive compared with 20 (50%) for the controls. Ninety percent of patients with PABC received chemotherapy compared with 87.5% in the nonpregnant group. 91.5% of patients with PABC had breast-conserving surgery and 8.5% had mastectomies compared with 86% and 14%, respectively, for the control group. The median OS was 4.9 years in the PABC group compared with 6 years for the controls (p = 0.02). The median DFS was 2.7 years for the PABC group compared with 5.1 years for the controls (p = 0.01). The most common site of relapse was bone for the PABC group (27%) and local recurrence (33%) for the controls. Univariate analysis revealed that OS and DFS were associated with pregnancy status, family history, ER/PR status, and stage. After adjusting for age and stage, PABC patients had higher risk of both death (p = 0.01) and recurrence (p = 0.02) compared with nonpregnant controls. Women with PABC had significantly shorter OS and DFS compared with nonpregnant age and stage-matched controls.

Presentation, Management and Outcome of 32 Patients with Pregnancy-Associated Breast Cancer: A Matched Controlled Study

Pregnancy-associated breast cancer (PABC) is a rare and challenging problem. We sought to describe epidemiology, management and outcome of women in whom breast cancer was diagnosed during pregnancy or within one year after delivery. Thirty-two women with PABC were referred to two European Union oncology centers between 1995 and 2007, 16 during pregnancy and 16 within 1 year after delivery. Data concerning diagnosis, management, delivery and fetal and maternal outcome were recorded. A group of 32 patients (matched controls) presenting with nonpregnancy-associated breast cancer (non-PABC) was matched for age at diagnosis, tumor size and stage to each PABC patient. Differences in outcome between the PABC and non-PABC groups were then assessed. Histological features were similar in both groups, except that estrogen receptor-negative tumors were more common in the PABC group. Three patients received chemotherapy and two others underwent surgery during pregnancy, with no excess toxicity or severe maternal/fetal adverse effects. All children in the PABC group were healthy, except for one exposed to epirubicin in utero and born with rectal atresia. Overall survival was similar in PABC and non-PABC patients (p = 0.449). The subgroup of patients with breast cancer diagnosed within one year after delivery showed a shorter time to relapse than controls or patients with gestational cancer (p = 0.0178). PABC is a special situation, necessitating individualized, multi-disciplinary management. Prognosis is similar for women with nongestational cancer matched for age and stage though poorer outcome postpartum should be further investigated.