Relative dose intensity and therapy efficacy in different breast cancer molecular subtypes: a retrospective study of early stage breast cancer patients treated with neoadjuvant chemotherapy

To investigate the relationship between chemotherapy dose intensity and therapy efficacy of different molecular subtypes. Clinical and pathological features of the patients with breast cancer were retreived from the hospital records. 315 patients were analyzed (251 showed clinical response, 38 acquired pCR). Patients with positive ER status, negative PR status, higher Ki67 level and higher RTDI had better therapy response. 13.5 and 84.5 % were identified the benchmark of Ki67 and RTDI, respectively. As the result of interior-subgroup comparison, luminal subgroups acquired better response rate when RTDI ≥ 84.5 %. In patients of luminal breast cancer, tumor size change arose from increasing of dose intensity and finally showed reached a plateau after RTDI ≥ 95 % (r ² = 0.303, p < 0.001). As the result of intersubgroup comparison, TNBC patients were more likely to acquired better clinical and pathology response when RDTI < 84.5 %. Ki67 change arose sharply from increasing of dose intensity when RDTI < 84.5 % (r ² = 0.656, p < 0.001), whereas the regression curve showed a terminal plateau in patients of RDTI ≥ 84.5 % (r ² = 0.427, p < 0.001). Given lower RTDI, luminal patients are less likely to achieve response, and TNBC patients are associated with higher response rate. Dissimilar of therapy efficacy between luminal subtype and TNBC becomes inconspicuous as RTDI rises. Chemosensitivity may associate with dose intensity, especially in luminal subtypes, and tailored therapeutic strategies should be considered.