Age and comorbidity as independent prognostic factors in the treatment of non small-cell lung cancer: a review of National Cancer Institute of Canada Clinical Trials Group trials

Abstract

Purpose: This study analyzed patients enrolled in two large, prospectively randomized trials of systemic chemotherapy (adjuvant/palliative setting) for non-small-cell lung Cancer (NSCLC). The main objective was to determine if age and/or the burden of chronic medical conditions (comorbidity) are independent predictors of survival, treatment delivery, and toxicity.

Patients and methods: Baseline comorbid conditions were scored using the Charlson comorbidity index (CCI), a validated measure of patient comorbidity that is weighted according to the influence of comorbidity on overall mortality. The CCI score (CCIS) was correlated with demographic data,(ie, age, sex, race), performance status (PS), histology, cancer stage, patient weight, hemoglobin, alkaline phosphatase, lactate dehydrogenase, outcomes of chemotherapy delivery (ie, type, total dose, and dose intensity), survival, and response.

Results: A total of 1,255 patients were included in this analysis. The median age was 61 years (range, 34 to 89 years); 34% of patients were elderly (at least 65 years of age); and 31% had comorbid conditions at randomization. Twenty-five percent of patients had a CCIS of 1, whereas 6% had a CCIS of 2 or greater. Elderly patients were more likely to have a CCIS equal to or greater than 1 compared with younger patients (42% v 26%; P < .0001), as were male patients (35% v 21%; P < .0001) and patients with squamous histology (36% v 29%; P = .001). Although age did not influence overall survival, the CCIS appeared prognostic (CCIS 1 v 0; hazard ratio 1.28; 95%CI, 1.09 to 1.5; P = .003).

Conclusion: In these large, randomized trials, the presence of comorbid conditions (CCIS > or = 1), rather than age more than 65 years, was associated with poorer survival.