Outcomes in Pregnancy Associated Breast Cancer: A Single Centre Experience


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Sreedevi Kumar1, Louise Murray2, Zakeea Sher2, Mark Teo1, Ada Keding1, Joji Joseph1
1St James's Institute of Oncology, Leeds, UK, 2University of Leeds, Leeds, UK

Background

Women with pregnancy-associated breast cancer (PABC) have a worse prognosis than non-pregnant women of a similar age. it is not clear whether pregnancy is an independent risk factor for poor outcomes in breast cancer. To analyse outcomes in PABC and assess if pregnancy is an independent poor prognostic factor.

Method

We conducted a retrospective case control audit of women treated with PABC between 2002 and 2008 at our centre. We identified 50 women with PABC and 149 age-matched non-PABC patients diagnosed in the same period. Clinical data and outcomes were obtained from electronic records. T-test and Chi-square test were used to compare cohort demographics. Relapse-free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meir method. We used log-rank and Cox Proportional methods to assess associations between survival and collected variables.

Results

Median follow up was 62·6 months There was no difference in age at diagnosis (median age-33years) tumour stage or molecular markers between the two groupsThe PABC cohort had significantly higher N stage (P=0·03) thus a greater proportion presenting with AJCC stage III+ cancers compared with non-PABC (38·0% v 21·5% respectively, p<0·01). More PABC patients underwent mastectomy (68·0% v 45·6% respectively, p=0·03). 90% of patients in both groups received chemotherapy with anthracycline +/- taxane. On univariate analysis, PABC patients had significantly worse RFS than non-PABC patients (5-year: 54·4% v 76·4% respectively, log-rank p=0·025). This difference was reflected in the 5- year OS though not statistically significant (71·5% v 81·5% respectively, log-rank p=0·09). However, multivariate analysis showed no independent contribution of PABC on RFS ( HR 0·93, 95% CI 0·47-1·87, p=0·84) or OS (HR 0·58, 95%CI 0·26-1·30, p=0·19).

Conclusion

PABCwas not found to independent risk factor. PABC patients tend to present at a later AJCC stage which may account for the difference in survival between the two groups