Evaluation of Rare Types of Breast Cancer among Indian Patients - a Retrospective Study from a Regional Cancer Center.

Abstract

Breast cancer (BC) is the most common cancer among Indian women and invasive duct cell carcinoma (IDCC) the most common histology (80-90%) followed by noninvasive duct cell carcinoma (non-IDCC) subtypes (about 10%). Most of the non-IDCC are rare (<1-2%), and literature on this topic is sparse. Age is an important prognostic factor and varies with ethnicity. The aim of our study is to evaluate the incidence and age at presentation of different types of BC. This is a single institute retrospective observational study evaluating BC over the last 7 years at our institute. We evaluated the demographic and pathological features. There were a total of 2725 patients, of these 89.7% had IDCC and 10.2% had non-IDCC. There were 13 subtypes of non-IDCC, the most common being sarcoma/phyllodes (2.4%) and lobular (2.3%). The other subtypes were very rare (<1.5% each). The non-IDCC male BC was very rare (0.07%). The median age at presentation was similar for IDCC and non-IDCC types (50years). The p value for age at presentation was significant for mucinous (0.0001), phyllodes (<0.0001), and sarcoma breast (0.009) when compared with IDCC. The incidence of IDCC, non-IDCC, and rare subtypes of non-IDCC are comparable to literature except lobular (lower) and phyllodes/sarcoma (higher). Indian patients presented a decade earlier for both IDCC and non-IDCC types. Tubular and papillary presented at an age comparable to IDCC, in contrast to the West. Given these differences, the prognosis of non-IDCC needs to be evaluated in future studies on Indian BC patients.