Despite extensive research on cancer care during the COVID-19 pandemic, evidence on the impact on prediagnostic time intervals is lacking. To better understand how COVID-19 changed the pathway to diagnosis of cancer, we examined the length of intervals from symptom onset to diagnosis for 13 common cancer types with known clinical stage over 1-year nonpandemic period (March 2019 to March 2020; N = 844) and three biannual COVID periods (March 2020 to September 2021; N = 1172). We analyzed the patient interval (from first symptoms to presentation to a physician), the primary care/emergency department interval (from presentation with relevant symptoms to a primary care or emergency department physician to referral to a hospital-based diagnosis center) and the hospital interval (from referral to diagnosis). Compared to nonpandemic data, there were significant changes across COVID periods. The pandemic mostly impacted patient intervals for cancers diagnosed over the first 6 months after onset in March 2020. Overall median patient intervals were longest in the early COVID period (39 [IQR 22-64] days) and shortest in the nonpandemic period (20 [IQR 13-30] days; Kruskal-Wallis test [χ2 ], P < .0001). Differences in clinical stage between periods were relevant, with cancers from the mid-period (September 2020 to March 2021) showing the most advanced stage. A shift to later stage was plausibly a result of delayed intervals in the early COVID period. Since intervals are eventually relevant to prognosis, our results provide a baseline against which the impact of improvement strategies to minimize the negative outcomes of COVID-19-associated cancer delays can be assessed and implemented.
Keywords: COVID-19; diagnostic interval; patient interval; primary care interval; stage.
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