Paclitaxel efficacy and toxicity in older women with metastatic breast cancer: combined analysis of CALGB 9342 and 9840

Abstract

Two Cancer and Leukemia Group B (CALGB) studies were utilized to determine the efficacy and tolerability of paclitaxel (Taxol) in older patients with metastatic breast cancer. CALGB 9840 evaluated weekly paclitaxel (80 mg/m(2)) versus paclitaxel every 3 weeks (175 mg/m(2)); CALGB 9342 evaluated three doses of paclitaxel as follows: 175, 210 and 250 mg/m(2) each over 3 h every 3 weeks. Of the 1048 patients, paclitaxel was used first line in 57%. The groups: (i) <55 years (45%), (ii) 55-64 years (29%), and (iii) ≥65 years (26%). Tumor response was also similar among age groups. First-line therapy (P = 0.0001) and better performance status (PS) (P = 0.018) were significantly related to higher response. Age did not significantly relate to overall survival (OS) or progression-free survival (PFS). First-line therapy, better PS, estrogen receptor positive status and a fewer number of metastatic sites were significantly related to improved OS and PFS. The grade ≥3 toxic effects that increased linearly with age were leucopenia (P = 0.0099), granulocytopenia (P = 0.022), anorexia (P = 0.028), bilirubin elevation (P = 0.0035) and neurotoxicity (P < 0.0001). Patients over 65 years receiving second-line therapy had the shortest time to neurotoxicity. Older women with breast cancer derive similar efficacy from treatment with paclitaxel as younger women. Older women are at increased risk for specific toxic effects.