Contralateral Breast Cancer: a Clinico-pathological Study of Second Primaries in Opposite Breasts after Treatment of Breast Malignancy

Background: Breast cancer is by far the most frequent cancer of women (23 % of all cancers), ranking secondoverall when both sexes are considered together. Contralateral breast cancer (CBC) is becoming an importantpublic health issue because of the increased incidence of primary breast cancer and improved survival. The presentcommunication concerns a study to evaluate the role of various clinico-pathological factors on the occurrenceof contralateral breast cancer. Materials and
Methods: A detailed analysis was carried out with respect to age,menopausal status, family history, disease stage, surgery performed, histopathology, hormone receptor status,and use of chemotherapy or hormonal therapy. The diagnosis of CBC was confirmed on histopathology report.Relative risk with 95%CI was calculated for different risk factors of contralateral breast cancer development.
Results: CBC was found in 24 (4.5%) out of 532 patients. Mean age of presentation was 43.2 years. Family historyof breast cancer was found in 37.5% of the patients. There was statistically significant higher rate (83.3%) ofCBC in patients in age group of 20-40 years with RR=11.3 (95% CI: 1.4, 89.4, p=0.006) seen in 20-30 years andRR=10.8 (95% CI:1.5-79.6, p=0.002) in 30-40 years as compared to older age of 60-70 years. Risk of developmentwas higher in premenopausal women (RR=8.6, 95% CI: 3.5-21.3, p≤0.001). Women with family history ofbreast cancer had highest rate (20.9%) of CBC (RR=5.4, 95% CI: 2.5-11.6, p≤0.001). Use of hormonal therapyin hormone receptor positive patients was protective factor in occurrence of CBC but not significant (RR=0.7,95% CI: 0.3-1.5, p=0.333).
Conclusions: Younger age, premenopausal status, and presence of family history werefound to be significant risk factors for the development of CBC. Use of hormonal therapy in hormone receptorpositive patients might be protective against occurrence of CBC but did not reach significance.