The Effects of Comorbidity and Age on RTOG Study Enrollment in Stage III Non–Small Cell Lung Cancer Patients Who Are Eligible for RTOG Studies

Abstract

To determine the influence of measured comorbidity in Radiation Therapy Oncology Group (RTOG) combined modality therapy (CMT) study enrollment in Stage III non-small cell lung cancer (NSCLC). One hundred and seventy-one patients with a Karnofsky Performance Score ≥70 and clinical Stage III NSCLC were analyzed retrospectively for comorbidity, RTOG study eligibility, and enrollment at initial consultation. Effect of comorbidity scores (Cumulative Illness Rating Scale) were tested on patient selection for CMT, RTOG enrollment, and overall survival. Comorbidity (Grade 4; p < 0.005) and use of radiation only (p ≤ 0.001) were associated with inferior survival independent of other factors. Patient selection for CMT was affected by age (≥70, p < 0.001), comorbidity (severity index [SI] > 2, p = 0.001), and weight loss (>5%, p = 0.001). Thirty-three patients (19%) were enrolled in a CMT RTOG study (Group 1). Forty-nine patients (29%) were eligible but not enrolled (Group 2), and 57 (33%) were ineligible (Group 3). The most common ineligibility reasons were weight loss (67%) and comorbidity in the exclusion criteria of the RTOG studies (63%). Group 1 patients were the youngest (p = 0.02), with the lowest comorbidity scores (p < 0.001) and SI (p < 0.001) compared with Groups 2 and 3. Group 3 patients were the oldest with the most unfavorable comorbidity profile. Comorbidity scores (SI >2; p = 0.006) and age (≥70; p = 0.05) were independent factors influencing RTOG study enrollment in patients meeting study eligibility requirements (Groups 1 and 2). Comorbidity scales could be useful in stratification of patients in advanced lung cancer trials and interpretation of results particularly regarding the elderly population.