Histological classification, grading, staging, and prognostic indexing of female breast cancer in an African population: A 10-year retrospective study

BACKGROUND: Breast cancer (BC) is a heterogeneous disease characterized with diverse genetic and ethnic/racial variations that may influence tumor characteristics and prognosis. We studied different histological types of BC and their prognostic indicators in part of Southwestern Nigeria. MATERIALS AND METHODS: A 10-year retrospective study of archival tissue-paraffin blocks and records of surgical cases (documented as BCs) between January 2005 and December 2014 was done. Tumor classification was made after the World Health Organization guidelines. Modified Bloom-Richardson score and TNM staging system were used in grading and staging the tumors. Nottingham prognostic index was employed in scoring the prognosis. RESULTS: The mean age was 49.7 years (20–89 years). The age group from 50 to 59 years was most affected. Out of 343 total cases, the most common histological type was invasive ductal carcinoma of no special type (88.9%). The majority (51.9%) had tumor sizes ranging 2–5 cm (pT2) and some (39.1%) with >5 cm (pT3) were all at palpable stages. The tumors were mostly Grades II and III types. Observation for lymph node metastasis confirmed that 261 (76.1%) were pN0 (negative), 77 (22.4%) were pN1, and 5 (1.5%) were pN2. Prediction of a chance of survival showed moderate prognosis in the majority (48.7%) of the cases. CONCLUSION: Although early detection of BC in this region was considerably poor, there was a better outcome compared with some other black populations. Clinical presentation, histological type, and prognostic indices varied from existing reports in many ethnic/racial groups. Indexing of BC pattern on a regional standpoint may serve a new direction toward better management considering the associated geographic disparity.