Impact of the COVID-19 Outbreak-Delayed Referral of Colorectal and Lung Cancer in Primary Care: A National Retrospective Cohort Study

The Coronavirus disease 2019 (COVID-19) outbreak impacted health care. We investigated its impact on the time to referral and diagnosis for symptomatic cancer patients in The Netherlands. We performed a national retrospective cohort study utilizing primary care records linked to The Netherlands Cancer Registry. For patients with symptomatic colorectal, lung, breast, or melanoma cancer, we manually explored free and coded texts to determine the durations of the primary care (IPC) and secondary care (ISC) diagnostic intervals during the first COVID-19 wave and pre-COVID-19. We found that the median IPC duration increased for colorectal cancer from 5 days (Interquartile Range (IQR) 1-29 days) pre-COVID-19 to 44 days (IQR 6-230, < 0.01) during the first COVID-19 wave, and for lung cancer, the duration increased from 15 days (IQR) 3-47) to 41 days (IQR 7-102, < 0.01). For breast cancer and melanoma, the change in IPC duration was negligible. The median ISC duration only increased for breast cancer, from 3 (IQR 2-7) to 6 days (IQR 3-9, < 0.01). For colorectal cancer, lung cancer, and melanoma, the median ISC durations were 17.5 (IQR (9-52), 18 (IQR 7-40), and 9 (IQR 3-44) days, respectively, similar to pre-COVID-19 results. In conclusion, for colorectal and lung cancer, the time to primary care referral was substantially prolonged during the first COVID-19 wave. In such crises, targeted primary care support is needed to maintain effective cancer diagnosis.