Histo-Morphologic Characteristics of Breast Cancer in Ghanaian Women and their Pathologic Response Patterns to Neoadjuvant Chemotherapy

Abstract

Abstract Background: Neoadjuvant chemotherapy (NACT) is an integral component of the management of locally advanced breast cancer. Preliminary studies on response assessment within the Ghanaian population have been conducted using clinical methods. The rate of pathological responses in patients with locally advanced breast cancer treated via NACT is yet to be studied in the Ghanaian patient population, as well as in the immunohistochemistry-based phenotypic subtypes. Materials and Methods: A retrospective-prospective cohort study at a single tertiary centre was undertaken between January 2018 and March 2019. A total of 56 patients with locally advanced breast cancers (stage III only) were managed by a multidisciplinary team at Komfo Anokye Teaching Hospital, Kumasi with chemotherapy, surgery and hormone therapy. Clinicopathologic staging was performed prior to the initiation of NACT, followed by mastectomy and axillary lymph node dissection. To evaluate the pathological response to chemotherapy, post-mastectomy specimens were compared with corresponding pre-treatment core biopsy samples. The assessment of response patterns was conducted using the Miller and Payne grading system, which quantifies changes in tumour cellularity within the breast tissue. Results: Grade 2 of the Miller–Payne criteria was the dominant pathological response in 18/56 (32.1%) of the specimens. Pathological complete response (pCR) occurred in 13/56 (23.2%) cases. Phenotypic subtyping was conducted for 31 out of 56 participants with available immunohistochemical data. Among these, the triple-negative breast cancer subtype demonstrated a pCR in 6/31 cases (19.4%), representing the highest response rate compared to other molecular subtypes. Conclusion: In this single-centre cohort, we describe the distribution of Miller–Payne grades and the rate of breast pCR after NACT. These findings provide preliminary, local response data and highlight the need for larger studies with standardised breast-and-nodal pCR endpoints and survival follow-up.