P2-19-02: Multidisciplinary Treatment of Pregnancy-Associated Breast Cancer.

Abstract

Abstract Background: Breast cancer complicates pregnancy in a significant minority of younger breast cancer (BC) patients (pts). Application of standard treatment algorithms is limited by the lack of randomized data to support safety and efficacy. A multidisciplinary approach attempts to maximize treatment efficacy for a pt while minimizing fetal toxicity. We sought to describe contemporary multidisciplinary BC treatment in an academic setting and explore early maternal and fetal outcomes. Methods: A search of the Dana-Farber/Harvard Cancer Center clinical database was performed to find BC pts self-identified as pregnant at presentation with >2 visits at our institution. Information available within the database along with complementary chart review provided sociodemographic, disease, staging, pregnancy and treatment information as well as short-term maternal and fetal outcomes. Results: 55 pts diagnosed between 1996–2011 were identified. The median age at diagnosis was 34 years. 25.5% were stage I, 49.1% stage II, 20% stage III, and 5.4% stage IV. 63.6% had hormone receptor positive disease, 36.3% HER2 positive, and 18.1% triple negative. 71% underwent testing for germline BRCA1/2 mutations, with 9% of all pts testing positive. 29% were diagnosed in the first trimester (T1), 29% in T2, and 42% in T3. 89% underwent ultrasound imaging for staging, 49% X-ray imaging, 16.3% MRI, and 0% CT. 67% underwent surgery during pregnancy: 43.2% mastectomy, 48.6% lumpectomy, and 8.1% lumpectomy with subsequent mastectomy during pregnancy. 18.9% underwent surgery in T1, 45.9% in T2, and 37.8% in T3. 27.2% underwent sentinel lymph node biopsy. 51% received chemotherapy (C) during pregnancy: of those, 100% received anthracycline/cyclophosphamide (2-4 cycles), 11% paclitaxel, and 0% trastuzumab. 28.5% received C on a dose-dense schedule, with 25% supported by growth factors (14.2% filgrastim, 10.8% pegfilgrastim). 28.5% received neoadjuvant C. C was initiated during T1 for 0%, T2 for 64.3%, and T3 for 35.7%. Two pts terminated pregnancy in T1, one spontaneously miscarried at 12 weeks (wks), and two are currently in the third trimester of pregnancy; therefore, a total of 50 pts had delivered at the time of this analysis. The median time of delivery was 36 wks. 50% delivered prior to 37 wks and were considered preterm; of those, 76% were inductions or Caesarian sections planned to facilitate cancer therapy. Only 12% delivered prior to 34 wks. For the 25 infants for whom Apgar scores were available, 76% had scores of ≥ 8 at delivery, and 100% had scores of ≥ 8 at 5 minutes. For the 25 infants for whom birth weights were available, the median birth weight was 6lbs 1oz. Only 4 were less than 5lbs at the time of delivery. A total of 4 fetal abnormalities were noted: cleft palate (2), club foot (1), and ventricular septal defect (1). Conclusions: Within a multidisciplinary academic center, treatment of pregnancy-associated BC using contemporary treatment algorithms, including taxane chemotherapy, growth factor support, and sentinel lymph node biopsy, has been pursued without significant adverse effect on fetal outcomes when compared to other published series. A considerable number of preterm deliveries have been observed. Further data collection is ongoing for confirmation of initial observations. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-19-02.