Evaluation of Pattern of Relapse in Luminal Breast Cancer

Background: The most common molecular subtype of breast cancer worldwide is luminal breast cancer. It has shown a good prognostic profile compared to other types. Despite the immense development of adjuvant treatment in the past years, around 20% of patients with early-stage disease relapse. Aim of the study: To evaluate the relapse pattern in luminal breast cancer and the correlation between luminal types and (AJCC 8th edition). Subject and Methods: A total of 230 luminal breast cancer patients treated at Al-Hussein University Hospital between 2013 and 2018 were analyzed. Patients have been divided into the following groups: luminal A (31%) and B (32.6%), luminal B HER2+ve (18.6%), and luminal UC (17.3%). Results: The median follow-up was 66.7 months, and the relapse rate of luminal breast cancer was 27.8%. Although statistically not significant, luminal A had the lowest relapse rate (19.4%), while luminal B (36%), HER2 positive luminal B (23.2%), and luminal UC (32.5%) (p=0.117). The predominant organ relapse was bone (29.6%) mainly observed in luminal A and B, 35.7% and 32.3% of patients respectively (p=0.048). Luminal Correlation with the AJCC staging system was significant, luminal A was most often observed in early stages with 81.9% presented in Stages I to II (p=0.008). Conclusions: Luminal breast cancer has a wide discrepancy in relapse rate and pattern. Luminal A seems to have the best prognosis for DFS. Ki-67 % and HER2 testing would give a prognostic factor in luminal subcategorization and could be beneficial in the intensification of adjuvant therapy.