Time to initial cancer treatment in the United States and association with survival over time: An observational study

Abstract

Background: Delays in time to treatment initiation (TTI) for new cancer diagnoses cause patient distress and may adversely affect outcomes. We investigated trends in TTI for common solid tumors treated with curative intent, determinants of increased TTI and association with overall survival.

Methods and findings: We utilized prospective data from the National Cancer Database for newly diagnosed United States patients with early-stage breast, prostate, lung, colorectal, renal and pancreas cancers from 2004-13. TTI was defined as days from diagnosis to first treatment (surgery, systemic or radiation therapy). Negative binomial regression and Cox proportional hazard models were used for analysis. The study population of 3,672,561 patients included breast (N = 1,368,024), prostate (N = 944,246), colorectal (N = 662,094), non-small cell lung (N = 363,863), renal (N = 262,915) and pancreas (N = 71,419) cancers. Median TTI increased from 21 to 29 days (P<0.001). Aside from year of diagnosis, determinants of increased TTI included care at academic center, race, education, prior history of cancer, transfer of facility, comorbidities and age. Increased TTI was associated with worsened survival for stages I and II breast, lung, renal and pancreas cancers, and stage I colorectal cancers, with hazard ratios ranging from 1.005 (95% confidence intervals [CI] 1.002-1.008) to 1.030 (95% CI 1.025-1.035) per week of increased TTI.

Conclusions: TTI has lengthened significantly and is associated with absolute increased risk of mortality ranging from 1.2-3.2% per week in curative settings such as early-stage breast, lung, renal and pancreas cancers. Studies of interventions to ease navigation and reduce barriers are warranted to diminish potential harm to patients.

Fig 1. Trends in time to treatment initiation over study period.

TTI increased significantly for all cancers from an overall median of 21 days in 2004–2005 to a median of 29 days in 2013–2014 (P<0.001).

Fig 2. Overall survival by prolonged treatment delay in stages I and II non-small cell lung and pancreas cancers.

Five-year overall survival for National Cancer Database patients with time to treatment initiation of six weeks or less was substantially higher when compared to patients with time to treatment initiation greater than six weeks for stage I (A) and stage II (B) non-small cell lung cancer and stage I (C) and stage II (D) pancreas cancers (P<0.001 for each).