Evaluation of the severity of screened colorectal cancer in the context of the health crisis linked to COVID19 in Ile-de-France region

Background

After the announcement in March 2020 of the COVID-19 pandemic, colorectal cancer (CRC) screening programs were suspended in several countries. Compared to the lesions detected during previous campaigns, this study aims to assess the severity of CRC detected during the 2020 screening campaign in Île-de-France, the French region most affected by the 1^st wave of the pandemic.

Methods

The descriptive and etiological study included all faecal immunochemical test (FIT) results carried out between January 2017 and December 2020 on people aged 50–74, living in Île-de-France. First, the proportion of colonoscopies performed within one month (One-month-colo) following FIT; the yield of colonoscopy (proportion of colonoscopies with a neoplasm lesion among those performed) and CRC severity (TNM Classification, Level-0: T0/N0/M0, Level-1: T1/T2/N0/M0, Level-2: T3/T4/N0/M0; Level-3: T3/T4/N1/M0; Level-4: M1) were described in 2020 compared to previous campaigns (2017, 2018, and 2019). Subsequently, the link between the level of CRC severity and the predictive factors, including campaign year and time to colonoscopy, was analysed using polytomous multivariate regression.

Results

The one-month-colo (2017: 9.1% of 11,529 colonoscopies; 2018: 8.5% of 13,346; 2019: 5.7% of 7,881; 2020: 6.7% of 11,040; p < 0.001), the yield (65.2%, 64.1%, 62.4%, 60.8% respectively, p < 0.001) were significantly different between campaigns. The proportion of CRC level-4 (4.8% in 2017 (653 CRC); 7.6% in 2018 (674 CRC); 4.6% in 2019 (330 CRC) and 4.7% in 2020 (404 CRC); p < 0.29) was not significantly different between campaigns. The probability of having CRC with a high severity level was inversely related to the time to colonoscopy but not to the campaign year. Compared to patients having undergone colonoscopy within 30 days, the odds were significantly reduced by 60% in patients having undergone colonoscopy after 7 months (adjusted Odds-Ratio: 0.4 [0.3; 0.6]; p < 0.0001).

Conclusions

The French indicators were certainly degraded before the first wave of the COVID-19. The delay in access to colonoscopy as well as its extension induced by the COVID-19 crisis had no impact in terms of cancer severity, due to a discriminatory approach prioritizing patients with evident symptoms.