More Frequent Screening of the Contralateral Breast is Warranted After Treatment of Primary Node-Positive Breast Cancer

Abstract

Purpose: Mammographic screening of the contralateral breast is often advocated during follow-up of women previously treated for primary operable breast cancer; however most guidelines state the yearly contralateral mammogram as a universal recommendation without stratifying for the risk status of the breast primary, we are trying to challenge this concept through this retrospective analysis. Method(s): Breast cancer patients treated at Cairo Oncology Centre (Cairo, Egypt) in the period between 2000-2008 were reviewed. Eligible patients were those who had no evidence of metastasis at diagnosis, and complete information on date of diagnosis, treatment, estrogen receptor (ER), progesterone receptor (PR) and HER2 status. We compared the difference in systemic adjuvant therapy and pathological parameters between cases that later developed contralateral relapse and cases that did not. We investigated the impact of different clinico-pathological parameters on contralateral disease-free survival in a Cox regression model adjusted for tumor size (pT), nodal status (pN), grade, ER, PR, HER2 and treatment. Result(s): 2068 patients were included in the analysis. Contralateral breast cancer was diagnosed in 92patients. At a median follow up period of 11.8 months, the median contralateral DFS for the whole group was 96 months. The median CDFS for the different subgroups was 54.,71,145., 14 Months for HR + /Her2-, HR + /Her2 + , HR-/ Her2 + , Triple -ve subgroup, respectively. Factors associated with higher risk of developing contralateral breast cancer were ER -ve/PR -ve phenotype (8.4%vs. 3.3%; p = 0.001) and development of local recurrence (10.1%vs. 4.2%; p = 0.002); while adjuvant radiotherapy to the ipsilateral side seems protective against contralateral relapse (5.7% vs. 3.1%; p = 0.012), no particular chemotherapy regimen seems particularly protective against contralateral relapse. Based on univariate analysis, the only variable associated with shorter time to develop contralateral recurrence (shorter contralateral DFS) is nodal involvement (p = 0.03, HR = 1.77). Conclusion(s): Our data suggests that high risk breast cancer, particularly node positive and ER/PR -VE disease, warrants more frequent screening of the contralateral breast. However, this hypothesis needs to be further explored in prospective randomized studies.