Triple negative breast cancer in South Africa
There were 275 patients with triple negative breast cancer identified out of 1898 patients (14.4%). The prevalence at Milpark Breast Care Unit was 13.9% and 16.1% at Helen Joseph Hospital. 135 patients were further analysed. Stage at presentation was IIa and IIb in approximately half (47.23%) of the patients. Patients presented with large tumours - 57.78% greater than two centimeters, and lymph node positive disease (55.55%). The majority (72.73%) of patients had high-grade, poorly differentiated tumours. This is consistent with studies showing that triple negative breast cancers present with more advanced tumours. There was a non-significant trend for younger patients to present with more advanced tumours with more aggressive histology. The triple negative breast cancer is challenging to manage due to its lack of response to steroid blockade and lack of biological therapy. This was reflected in the number of patients treated with multimodality therapy. 94.81% of patients had chemotherapy, 59.26% as neoadjuvant and 40.74% as adjuvant treatment. There were 93 (68.89%) patients treated with radiation therapy. There was a recurrence in 22.96% of patients, with preponderance to lymph node and visceral metastases. Recurrences occurred early, the median was 23.1 months and all had occurred within eight years. Younger patients had more recurrences (32.35%) and all occurred within six years. Stage at presentation and lymph node involvement were significantly associated with recurrence. Complete pathological response to neoadjuvant chemotherapy is associated with improved outcomes. The recurrence rate was 1.25% if there was a complete pathological response in both the breast and lymph nodes. The mortality rate was 19.26% and was greater in younger patients, 23.53% for women 40 years old and younger and 31.82% for women 35 years old and younger. Mortality was significantly associated with stage at presentation and lack of surgery but not lymph node positivity. Conclusion The prevalence of triple negative breast cancer in two South African breast care units was similar to some studies but less than studies in West and East Africa. Patients in these units, similar to other units, presented at a more advanced stage and had poorer outcomes than luminal breast cancers. Younger patients showed a trend to more advanced presentation and poorer outcomes than older patients within the triple negative subtype. This suggests than the outcomes of young patients cannot be explained by preponderance to aggressive subtypes alone.
MBChB FCS (SA) Cert GIT Department of Surgery University of the Witwatersrand