PURPOSE Neoadjuvant chemotherapy followed by mastectomy is the treatment of choice in patients with inflammatory breast cancer (IBC) or locally advanced breast cancer (LABC), but it is considered less effective in these diseases than in operable breast cancer (OBC). We report a prospective comparison of the GeparTrio trial of patients with IBC (cT4 days) or LABC (cT4a-c or cN3; stage IIIB or IIIC) and patients with OBC (cT2-3). PATIENTS AND METHODS Participants were stratified by stage and were randomly assigned to six or eight cycles of docetaxel/doxorubicin/cyclophosphamide (TAC) or to two cycles of TAC followed by four cycles of vinorelbine/capecitabine. We present results of a secondary aim of the study, which was to compare pathologic complete response (pCR; ie, no remaining invasive/noninvasive tumor in breast and lymph nodes) in different stage groups. Results A total of 287 patients with IBC (n = 93) or LABC (n = 194) and 1,777 patients with OBC were entered onto the trial. At baseline, parameters were as follows for the three types of cancer, respectively: median tumor sizes: 8.0 cm, 7.0 cm, and 4.0 cm (P < .001); multiple lesions: 31.2%, 27.3%, and 19.6% (P < .001); nodal involvement: 86.6%, 71.2%, and 51.6% (P < .001); grade 3: 44.4%, 30.4%, and 39.9% (P = .178); lobular-invasive type: 7.5%, 17.5%, and 13.3% (P = .673); negative hormone receptor status: 38.0%, 20.0%, and 36.4% (P = .008); and positive human growth factor receptor 2 status: 45.1%, 38.9%, and 35.7% (P = .158). Response rates for IBC, LABC, and OBC, respectively, were 8.6%, 11.3%, and 17.7% for pCR (P = .002); 71.0%, 69.6%, and 83.4% for overall response by physical or sonographic examination (P < .001); and 12.9%, 33.0%, and 69.9% for breast conservation (P < .001). All P values were for IBC and LABC versus OBC. However, tumor stage itself was not an independent predictor for pCR in multivariable analysis (odds ratio, 1.51; 95% CI, 0.88 to 2.59; P = .13). CONCLUSION No evidence of a difference in response to neoadjuvant chemotherapy was found by tumor stage when analysis was adjusted for baseline characteristics.