Background: Using 1998-2005 SEER-Medicare data, we examined the effect of diagnostic and treatment delays on all-cause and colorectal cancer (CRC)-specific death among US adults aged ≥ 66 years with invasive colon or rectal cancer. We hypothesized that longer delays would be associated with a greater risk of death.
Methods: We defined diagnostic and treatment delays, respectively, as days between (1) initial medical consult for CRC symptoms and pathologically confirmed diagnosis (maximum: 365 days) and (2) pathologically confirmed diagnosis and treatment (maximum: 120 days). Cases (CRC deaths) and controls (deaths due to other causes or censored) were matched on survival time. Logistic regression analyses adjusted for sociodemographic, tumor, and treatment factors.
Results: Median diagnostic delays were 60 (colon) and 40 (rectal) days and treatment delays were 13 (colon) and 16 (rectal) days in 10,663 patients. Colon cancer patients with the longest diagnostic delays (8-12 months vs. 14-59 days) had higher odds of all-cause (aOR: 1.31 CI: 1.08-1.58), but not CRC-specific death. Colon cancer patients with the shortest treatment delays (<1 vs. 1-2 weeks) had higher odds of all-cause (aOR: 1.23 CI: 1.01-1.49), but not CRC-specific death. Among rectal cancer patients, delays were not associated with risk of all-cause or CRC-specific death.
Conclusions: Longer delays of up to 1 year after symptom onset and 120 days for treatment did not increase odds of CRC-specific death. There may be little clinical benefit in detecting and treating existing symptomatic disease earlier. Screening prior to symptom onset must remain the primary goal to reduce CRC incidence, morbidity, and mortality.