Neoadjuvant Chemotherapy Response Among Patients with Locally Advanced Breast Cancer at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia

Abstract Background: Breast cancer is the most common diagnosed cancer and the leading cause of cancer death among females in Ethiopia and in many parts of the world. In sub-Saharan African countries including Ethiopia, a high proportion of breast cancer patients present with locally advanced breast cancer (LABC) or metastatic disease at the time of diagnosis. LABC is primarily treated by neoadjuvant chemotherapy (NACT) before surgery. There is, however no data on response rate and resectability of LABC after NACT in Ethiopia. Methods: A retrospective study was applied to assess response and resectability of locally advanced breast cancer after neoadjuvant chemotherapy. Among 141 breast cancer patients evaluated by breast surgeons and oncologists at a breast multidisciplinary team (MDT) clinic in Tikur Anbessa Hospital from September 2017 to August 2019, 63 patients were excluded because their tumors were resectable without down staging. Of these 78 patients with unresectable tumors, 27 patients were excluded from the study because they received <4 cycles of NACT or were lost to follow-up, leaving 51 patients for the final analysis. Patients were given either 4 cycles of NACT with doxorubicin (60mg/m2) + cyclophosphamide (600mg/m2) (AC) or 8 cycles of (4 cycles of AC + 4 cycles of paclitaxel (175mg/m2)) (AC – T) every 3 weeks. After chemotherapy patients were reevaluated at MDT for modified radical mastectomy. Demographic and clinical data were collected from patient charts and analyzed using SPSS 25 software. Results: Among the 51 patients with LABC who received NACT, eleven patients (21.6 %) had complete clinical response (cCR), 31 patients (60.8 %) had partial clinical response (cPR), 3 patients (5.9 %) had stable disease (SD), and 6 patients (11.8 %) had progressive disease (PD). Forty-one patients (80.4 %) underwent mastectomy, and margin status was negative in 23 patients (56.1 %), positive in 16 patients (39 %) and unknown in 2 patients (4.9 %). Only 4 patients (9.8 %) had complete pathologic response (pCR) after NACT. Patients who received AC – T (NACT) had slightly significant overall clinical response rate (p = 0.099) and cCR (p = 0.037) compared to patients who received AC NACT. Conclusion: Neoadjuvant chemotherapy for patients with LABC in Ethiopia setting has significantly reduced tumor size in most patients, allowing modified radical mastectomy with clear margin. Eight cycles of chemotherapy have a slightly higher overall response rate and complete clinical response rate than 4 cycles.