Survival after bilateral breast cancer: results from a population-based study

Abstract

Background Controversy exists on the impact of bilaterality of breast cancer on survival. We used population-based data to compare survival of women with unilateral versus bilateral breast cancer. Patients and methods At the Geneva cancer registry, we identified all 7,912 women diagnosed with invasive breast cancer between 1970 and 2002. Breast cancers were categorized as unilateral, synchronous bilateral (contralateral tumour diagnosed within six months after the first tumour) and metachronous bilateral (contralateral tumour diagnosed over six months after the first tumour). With multivariate modelling we compared characteristics and survival between women with unilateral and bilateral disease.Results Patients with synchronous bilateral tumours (n = 155, 2.0%) had more often lobular histology and less frequently stage I disease than women with unilateral disease. Women with metachronous breast cancer (n = 219, 2.8%) received less often chemotherapy or hormone therapy for their first tumours. Ten-year disease-specific survival was similar (66%) after unilateral and metachronous bilateral breast cancer, but worse after synchronous bilateral cancer (51%). After adjustment, breast cancer mortality risks were not significantly increased for women with either synchronous or metachronous bilateral disease (Hazard ratios 1.1 (0.8-1.5) and 0.8 (0.5-1.4), respectively). Conclusion This large population-based study indicates that bilaterality of breast cancer is not associated with impaired survival.

Clinicopathological Features in Bilateral Breast Cancer

“…BBC tumor pathology is not presented as different ratios and types from UBC. The grade distribution in our study in descending order is grade 2,3, and 1, significant difference between groups was observed (p=0.045), there is no contradiction with literature data (Beckmann et al, 2001;Verkooijen et al, 2007). The HER2 over expression ratio in UBC is 25-30% (Slamon et al, 1989).…”

“…In a study, the presence of hormone receptor was detected lower than UBC in metachronous 2nd breast, and the difference was significant (Kheirelseid et al, 2011), in another study, metachronous and synchronous status of HR, significant difference between UBC and BBC have not determined (Beckmann et al, 2001). In another study, in the synchronous BBC and UBC, OR for ER positivity was 1, while for adjusted OR identified as 1.4 (Verkooijen et al, 2007). However, the ratio of sub-group of ER receptor status unspecified in this study is considerably higher (for both of the group 70%) and reduces the value of this data.…”

“…When compared with UBC historical data (70-80% IDC), the histopathology is similar in BBC patients (SC 81% and 76%; MC 70% and 76%; p=0.9) (Beckmann et al, 2001;Takahashi et al, 2005;Verkooijen et al, 2007;Vuoto et al, 2010 ). In a study comparing BBC and UBC the IDC ratio was reported as 66% (SC) and 63% (MC), respectively (Verkooijen et al, 2007).…”

“…The difference between groups is due to both tumor size and the mean number of lymph node metastasis, as against the MC. In studies comparing UBC and BBC, stage was determined as, significantly higher in BBC than UBC and in MC than SC (Beckmann et al, 2001;Hartman et al, 2007;Verkooijen et al, 2007;Kheirelseid et al, 2011).…”

Incidence of metachronous contralateral breast cancer in the Canton of Zurich: a population-based study of the cancer registry

“…2008; Verkooijen et al 2007;Vichapat et al 2011a). In the Canton of Vaud, the age incidence pattern of CBC was examined as it was not comparable to the pattern of incidence for most cancers or breast cancer.…”