Risk Factors for Chemotherapy-Related Toxicity and Adverse Events in Elderly Thai Cancer Patients: A Prospective Study

Abstract

Objectives: To assess factors predisposing to severe chemotherapy-related toxicity and adverse events (AEs) and dose modification in aging cancer patients. Methods: Cancer patients aged ≥70 years scheduled to receive the first cycle of a new chemotherapy regimen were enrolled. On the day of starting chemotherapy, demographic data, performance status (PS), and geriatric parameters were recorded. AEs and chemotherapy modification were recorded. Quality of life (QOL) was assessed at baseline and 3 months after starting chemotherapy or at the end of chemotherapy. Results: We included 151 patients (mean age, 76.4 years) with gastrointestinal (47%), lung (24%), breast (9%), or genitourinary (6%) cancer. All-grade and severe AEs occurred in 83 and 42% of patients, respectively; 51.6% of patients required chemotherapy modification due to toxicities. A higher incidence of severe AEs (71% vs. 39%, p = 0.01) and poorer QOL was found in patients with PS 2 than in those with PS 0-1. Patients with PS 2 or who received palliative-intent chemotherapy or had multiple comorbidities were more likely to discontinue chemotherapy because of toxicity. Conclusions: PS remains a key predictor of chemotherapy-related toxicity in elderly patients. PS 2 was correlated with higher incidence of severe AEs, premature treatment discontinuation, and worsening QOL after treatment.