Impact of Diagnostic Delays on Lung Cancer Survival Outcomes

A Population Study of the US SEER-Medicare Database

Perrin E. Romine, MD, MSc; Qin Sun, MPA; Catherine Fedorenko, MMSc; Li Li, MA, MPA; Mariel Tang, BA; Keith D. Eaton, MD, PhD; Bernardo H.L. Goulart, MD; Renato G. Martins, MD, MPH

Disclosures

J Oncol Pract. 2022;18(6):e877-e885. 

In This Article

Results

Patient Characteristics

A total of 10,824 eligible patients were identified in the US SEER database and included in this study. Patient baseline characteristics are shown in Table 1. Patients were evenly distributed across age range and year of diagnosis, with females comprising 52.2% of the cohort. The majority of patients were White (86.5%) and from urban areas (60.2%). Stage I and IV patients made up the bulk of the cohort (with 42.9% and 35.6%, respectively). With a median follow-up of 808 days, there were 6,356 total deaths (58.7%). Median survival by stage was as follows: 706 days for stage I, 616 days for stage II, 460 days for stage III, and 262 days for stage IV.

Time to Diagnosis and Survival Outcomes

The median time to diagnosis for this cohort was 20 (range 0–363, standard deviation 52, interquartile range 5–48) days. Time to diagnosis varied across stage groups, with a longer median time seen in stage I patients (30 days) compared with stage II-IV patients (28, 19, and 7 days, respectively). In an unadjusted analysis, shorter time to diagnosis was significantly associated with worse survival outcomes for all stages combined (P < .0001). When stratified by stage, this trend held within stage IV patients but not earlier stage patients (Kaplan-Meier survival curve for stage IV patients shown in Figure 1).

Figure 1.

5-Year OS by time to diagnosis quartile in stage IV patients.

Multivariate survival analysis for all stages combined and by stage is shown in Table 2. In the entire cohort and within each stage, age, sex, diagnosis year, histology, and comorbidity index were statistically associated with OS. Longer time to confirmation was independently associated with improved survival outcomes for all patients combined, driven by the subset of patients with stage IV disease. In a secondary landmark analysis excluding patients deceased within 6 months after diagnosis, a shorter time to confirmation was no longer associated with worse survival outcomes in all comers or stage IV patients (P = .65 and .065, respectively, Table 3).

Sensitivity Analysis

In two separate sensitivity analyses, we analyzed the impact of delay in time to diagnosis on OS in stage IV patients with Medicare part D alone and in patients treated within 6 weeks of diagnosis. In both cases, the trend toward better survival outcomes in those with a longer time to diagnosis held although the association was not as large as in the original analysis (data not shown).

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