OBJECTIVE: Non-Small Cell Lung Cancer (NSCLC) patient survival depends on a number of factors including initiation of treatment. Standard treatment options for NSCLC patients include surgery, radiation therapy, and chemotherapy. The objective of this study is to evaluate the effect of timeliness of recommended treatment initiation on survival at 1 year among a cohort of privately insured NSCLC patients in South Carolina (SC).
METHODS: Data for the study was retrospectively linked between the SC state cancer registry and the state health plan (SHP) Blue Cross & Blue Shield (BCBS) claims data. The SHP is the primary insurance payer for SC state employees. We examined treatment initiation within 1-year post diagnosis for each treatment type separately, based on National Comprehensive Cancer Network stage-specific treatment guidelines, and compared the median time to treatment with the RAND Corporation maximum time interval of 6 weeks. Using Kaplan Meier curves, we explored time to treatment initiation for each treatment type separately and overall. Finally, we conducted Cox Proportional Hazards Modelling in SAS Version 9.4 to investigate the time-to-event (death) as a function of covariates including stage, race, age at diagnosis, and treatment initiation.
RESULTS: The majority of the study sample (N=872) was white (77.2%) and male (55.1%). Almost half (46.7%) were diagnosed at the distant metastasis stage. The mean time from diagnosis to initiation of recommended treatment according to cancer stage for surgery, radiation therapy and chemotherapy was 92.2 days, 54.4 days and 52.9 days, respectively – all longer than the 6 week recommended interval proposed by RAND. Patients who initiated surgery, radiation, and chemotherapy within 1 year of diagnosis lived longer than their counterparts, HR=0.82, HR=0.79, and HR=0.66, respectively. Compared to patients with distant metastasis, those with localized (HR=0.50) and regional (HR=0.74) stages also lived longer. Compared to males, females had a longer time-to-event (HR=0.94), as did patients in younger age categories (<50, 50-64, 65-74 vs. 75+ years). Patients diagnosed with non-small cell carcinoma (HR=1.28) died earlier than their counterparts diagnosed with adenocarcinoma.
CONCLUSION: Initiation of all treatment types within 1 year post diagnosis may improve survival for NSCLC patients. Within 1 year of treatment initiation, patients in earlier stages and of younger age experience better survival outcomes.
