Do age and comorbidity impact treatment allocation and outcomes in limited stage small-cell lung cancer? a community-based population analysis

Abstract

Purpose The effects of age and comorbidity on treatment and outcomes for patients with limited stage small-cell lung cancer (L-SCLC) are unclear. This study analyzes relapse and survival in a community-based population with L-SCLC according to age and comorbidity. Methods A retrospective review was performed on 174 patients with L-SCLC referred to the British Columbia Cancer Agency, Vancouver Island Centre, between January 1991 and December 1999. Patient and treatment characteristics, disease response, relapse, and survival were compared among three age cohorts: <65 years ( n = 55, 32%), 65–74 years ( n = 76, 44%), and ≥75 years ( n = 43, 25%); and according to Charlson comorbidity scores 0, 1, and ≥2. Multivariate analysis was performed to identify independent prognostic factors associated with treatment response and survival. Results Patient factors that significantly differed with age were functional status classified by Eastern Cooperative Oncology Group performance status and number of comorbidities. Increasing age was significantly associated with fewer diagnostic scans. Combined modality chemoradiotherapy (CRT) was given in 86%, 66%, and 40% of patients ages <65, 65–74, and ≥75 years, respectively, ( p <0.0001). Thoracic irradiation use was comparable among the age cohorts ( p >0.05), but chemotherapy use varied significantly with less intensive regimens, fewer cycles, and lower total doses with advancing age ( p <0.05). Prophylactic cranial irradiation (PCI) was used in 41 patients, only 3 of whom were age >70 years. Overall response rates to primary treatment significantly decreased with advancing age: 91%, 79%, and 74% in patients ages <65, 65–74, and ≥75 years, respectively ( p = 0.014). Treatment toxicity and relapse patterns were similar across the age cohorts. Overall 2-year survival rates were significantly lower with advancing age: 37%, 22%, and 19% ( p = 0.003), with corresponding median survivals of 17, 12, and 7 months among patients ages <65, 65–74, and ≥75 years, respectively. On multivariate analysis, age and Charlson comorbidity scores were not significantly associated with treatment response and survival. Independent prognostic factors favorably associated with survival were good performance status, normal lactate dehydrogenase, absence of pleural effusion, and ≥four cycles of chemotherapy. Conclusion Increasing age was associated with decreased performance status and increased comorbidity. Older patients with L-SCLC were less likely to be treated with CRT, intensive chemotherapy, and PCI. Treatment response and survival rates were lower with advancing age, but this may be attributed to poor performance status and suboptimal treatment rather than age.