Predicting Chemotherapy Toxicity in Older Patients with Cancer: A Multicenter Prospective Study.

BACKGROUND: Standard oncology tools are inadequate to distinguish which older patients are at higher risk of developing chemotherapy-related complications. MATERIALS AND METHODS: Patients over 70 years of age starting new chemotherapy regimens were prospectively included in a multicenter study. A prechemotherapy assessment that included sociodemographics, tumor/treatment variables, and geriatric assessment variables was performed. Association between these factors and the development of grade 3-5 toxicity was examined by using logistic regression. RESULTS: A total of 551 patients were accrued. Chemotherapy doses (odds ratio [OR] 1.834; 95% confidence interval [CI] 1.237-2.719) and creatinine clearance (OR 0.989; 95% CI 0.981-0.997) were the only factors independently associated with toxicity. Only 19% of patients who received reduced doses of chemotherapy and had a creatinine clearance ≥40 mL/minute had grade 3-4 toxicity, compared with 38% of those who received standard doses or had a creatinine clearance <40 mL/minute (p < .0001). However, no satisfactory multivariate model was obtained using different selection approaches. CONCLUSION: Chemotherapy doses and renal function were identified as the major risk factors for developing severe toxicity in the older patient. These factors should be considered when planning to initiate a new chemotherapy regimen and should also lead to a closer follow-up in these patients. IMPLICATIONS FOR PRACTICE: Older patients are more vulnerable to chemotherapy toxicity. However, standard tools are inadequate to identify who is at higher risk of developing chemotherapy-related complications. Chemotherapy doses (standard vs. reduced) and renal function were identified as the major risk factors for developing severe toxicity in the elderly. These factors should be considered when planning to initiate a new chemotherapy regimen and should also lead to a closer follow-up.

Phase II study of neratinib in older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer.

OBJECTIVE: The tolerability and efficacy of targeted therapy in older adults with cancer has not been adequately studied. Neratinib is a novel HER1, HER2, HER4 tyrosine kinase inhibitor that has recently been granted FDA approval for treatment of breast cancer. The major toxicity of neratinib is diarrhea, which affects up to 90% of patients. This phase II trial evaluates the safety and tolerability of neratinib in adults ≥60. METHODS: Patients aged 60 or older with histologically proven metastatic breast cancer and HER2 amplification (defined by ASCO/CAP guideline) or HER2/HER3 activating mutation were enrolled to receive neratinib at 240 mg daily in 28-day cycles. The association between tolerability, defined as dose reduction and number of completed courses, and log2 Cancer and Aging Research Group (CARG) toxicity risk score was assessed using a Student's t-test and linear regression, respectively. Response rate, progression free survival, and overall survival were also evaluated. RESULTS: 25 patients were enrolled with median age of 66 (range 60-79). Seventy-six percent of patients were white, 16% Asian, and 8% African-American. Seventy-six percent were patients with hormone receptor (HR) positive metastatic breast cancer (MBC) and 24% were patients with HR negative MBC. Median number of prior lines of metastatic therapy were 3 (range 0-11). 20/25 (80%) had worst grade toxicities ≥2. A total of 9/25 (36%) had grade 3 toxicities including 5/20 (20%) diarrhea, 2/20 (8%) vomiting, and 2/20 (8%) abdominal pain. There were no grade 4 or 5 toxicities. A total of 9/25 (36%) had dose reduction, and 2/25 (8%) discontinued therapy due to toxicity. The association between dose reductions and CARG toxicity score reached borderline statistical significance suggesting a trend with participants with higher CARG toxicity risk scores being more likely to require a dose modification (p = 0.054). 1/25 (4%) had a partial response, 11/25 (44%) had stable disease, 12/25 (48%) had progression of disease, and 1/25 (4%) was not assessed. Median progression free survival (PFS) was 2.6 months (95% CI [2.56-5.26]), and median overall survival (OS) was 17.4 months (95% CI [10.3, NA]). CONCLUSIONS: Neratinib was safe in this population of older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer (BC). Higher CARG toxicity risk score may be associated with greater need for dose adjustments. Future studies are needed to confirm this finding.