Pregnancy-associated breast cancer: a case— control study in a young population with a high-fertility rate

Abstract

Pregnancy-associated breast cancer (PABC) is not a rare event. The association frequently imposes a management challenge. We intended to review the clinical features, therapy, and outcome of patients with PABC seen at a single institution over a five-year period and to compare those with that seen in a matched control group. Data of all patients with PABC diagnosed during pregnancy were retrospectively reviewed (Group I). For each patient in Group I, three matched controls with breast cancer without pregnancy were identified (matched for age, stage, and year of diagnosis, Group II). 72 patients in Group I and 216 in Group II were identified. Their median age was similar (34 vs 35 y, respectively). The median number of prior pregnancies for patients in Groups I and II was 5. Patients had shorter duration of symptoms prior to diagnosis as compared with their controls (5.6 vs 9.4 months, P < 0.0001). 3%, 31%, 40%, and 26% of patients had Stage I to IV, respectively. A pattern that was similar to that seen in our breast cancer population. Pregnancy was terminated in 34 patients (47%), while 38 (53%) had normal spontaneous vaginal delivery. 47 patients in Group I had surgery; 37 (52%) had modified radical mastectomy and 10 (14%) had conservative surgery. In 37 patients surgery was performed after termination of pregnancy and 10 had surgery performed during pregnancy. The median number of positive lymph nodes in Group I was 4 as compared with 2 for patients in Group II. No patients in Group I had systemic chemotherapy during first trimester, while only 4 (6%) and 3 (4%) received adjuvant or neoadjuvant during second and third trimester, respectively. No congenital malformation in the newborns was diagnosed. None of the patients in Group I received radiotherapy during pregnancy. Over a median of 47.5 months, 48 (67%) patients in Group I were alive as compared to 126 (58%) in Group II, with no difference in the median survival (P= 0.79). Comparing overall survival (OS) between the two groups stage for stage also showed no significant difference. Also there was no difference in progression-free survival between the two groups. Cox proportional hazard model identified advanced stage as the only independent adverse prognostic variable that influenced OS in Group I. Despite that this series included a relatively young population with a high fertility rate, the study confirmed the lack of a survival difference between patients with PABC and their matched controls.

Does Pregnancy-Associated Breast Cancer Imply a Worse Prognosis? A Matched Case-Case Study

“…Focusing on matched case-case studies, it is worth mentioning that our study is not in accordance with the study by Ibrahim et al [23] who pointed to a lack of survival difference between patients with PABC and their matched controls. Moreover, the majority of the large population-based studies have not found inferior survival for patients with PABC [10,11,12,13].…”

Prognosis for patients diagnosed with pregnancy-associated breast cancer: a paired case-control study

“…Hence, following published methodology, 6,8,11 the PABC patients were matched with corresponding controls based on the institution of registration, year of registration and patient's age (± two years). The year of registration was used as the criterion for the purpose of obtaining uniformity regarding the type of diagnostic tests, classification systems and treatment.…”

“…Multivariate analysis (using the Cox regression method) revealed that tumor size (≤ 3.0 cm versus > 3.0 cm), axillary lymph node involvement (0 versus 1-3 versus ≥ 4) and age (≤ 33 years versus > 33 years) each exerted an independent and significant influence on overall survival and on the emergence of metastasis. In contrast, Ibrahim et al 11 investigated 72 PABC patients together with their matching controls (216 non-pregnant women in the same condition), who were selected according to disease stage, year of diagnosis and age. Only disease stage was identified as significant with regard to overall survival according to the Cox model.…”

Epidemiology of Inflammatory Breast Cancer (IBC)1

“…Many reports have noted that IBC is associated with pregnancy and/or lactation [27,37,53,55,68,75,90], whereas other series suggest that IBC is no more common for pregnancy-related tumors than for other breast cancer types [52,66,82]. In their classic description of IBC in 1924 [56], Lee and Tannenbaum did not find a single IBC case during pregnancy.…”