In a Surveillance, Epidemiology, and End Results (SEER)-Medicare Database analysis reported in JCO Oncology Practice, Romine et al found that longer time from suspicion to histologic diagnosis of non–small cell lung cancer (NSCLC) was associated with better overall survival; however, this effect was no longer apparent when patients dying within 6 months of diagnosis were excluded from the analysis.
As stated by the investigators, “Time from diagnosis to treatment has been associated with worse survival outcomes in NSCLC. However, little is known about the impact of delay in time to diagnosis. We aimed to evaluate the impact of time from radiographic suspicion to histologic diagnosis on survival outcomes….”
Study Details
The study involved patients from the SEER-Medicare data set diagnosed with any-stage NSCLC between January 2011 and December 2015 who received stage-appropriate treatment and had a computed tomography scan within 1 year of diagnosis. Time to confirmation was defined as the interval between most recent computed tomography imaging and date of histologic diagnosis.
Key Findings
Among the total of 10,824 patients included in the analysis, median time to confirmation was 20 days (range = 0–363 days).
In multivariate analysis, longer time to confirmation was associated with improved overall survival among all patients after adjustment for age, sex, year of diagnosis, area of residence, histology, and comorbidity index. Compared with the quartile of shortest time to confirmation (Q1), hazard ratios for death were 0.89 (95% confidence interval [CI] = 0.83–0.95, P < .001) for Q2, 0.85 (95% CI = 0.79–0.91, P < .001) for Q3, and 0.78 (95% CI = 0.73–0.84, P < .001) for Q4.
The overall effect was driven by findings in patients diagnosed with stage IV disease (n = 3,996). Among these patients, compared with Q1, hazard ratios were 0.86 (95% CI = 0.78–0.94, P = .001) for Q2, 0.81 (95% CI = 0.74–0.89, P < .001) for Q3, and 0.71 (95% CI = 0.65–0.78, P < .001) for Q4. No significant differences by quartile were observed among 4,773 patients diagnosed with stage I disease or 1,310 diagnosed with stage II disease. Among 1,094 diagnosed with stage III disease, patients in Q4 had poorer survival vs Q1 (HR = 0.76, 95% CI = 0.62–0.94, P = .012).
In multivariate analysis excluding patients who died within 6 months of diagnosis, no significant difference in overall survival for any quartile vs Q1 was observed among all 9,518 patients or among 2,749 diagnosed with stage IV disease.
The investigators concluded, “Time to confirmation of NSCLC was inversely associated with overall survival in this U.S. SEER population study. This association was lost when patients deceased within 6 months of diagnosis were excluded, suggesting that retrospective registry-claims databases may not be the optimal data source to study time to diagnosis as a quality metric because of the unaccounted confounding effects of tumor behavior. Prospective evaluations of clinically enriched data sources may better serve this purpose.”
Perrin E. Romine, MD, MSc, of the Division of Medical Oncology, Seattle Cancer Care Alliance/University of Washington, Seattle, is the corresponding author for the JCO Oncology Practice article.
Disclosure: The study was supported by the National Cancer Institute. For full disclosures of the study authors, visit ascopubs.org.
