Importance: COVID-19 has had a major effect on health care activities, especially surgery. At first, comparisons were proposed using 2019 activities as the highest standard. However, while such an approach might have been suitable during the first months of the pandemic, this might no longer be the case for a longer period.

Objective: To examine approaches that may better assess the use of cancer surgeries.

Design, setting, and participants: In a cross-sectional design, the nationwide French hospital facility data (Medicalised Information System Program) were used to assess cancer surgery for 6 cancer site categories in adults from January 1, 2010, to December 31, 2021.

Exposure: Estimated cancer surgery activity during the COVID-19 pandemic.

Main outcomes and measures: Three models were proposed to assess the expected number of surgical procedures between 2020 and 2021 and make a comparison with those observed in earlier years.

Results: In France, cancer removal surgeries account for approximately 7000 hospitalizations per year for liver cancer; 4000 for pancreatic cancer; 7700 for ovarian cancer; 1300 for esophagus cancer; 23 000 for ear, nose, and throat (ENT) cancer; 78 000 for breast cancer; and 16 600 for thoracic cancers. For most cancer sites, the number of surgical procedures increased from 2010 to 2019: liver, 14%; pancreas, 38%; ovary, 14%; esophagus, 18%; breast, 8%; and thoracic, 29%. Assuming stability, these values underestimate the gap in activity observed in 2020-2021. For other procedures, a decrease was observed: stomach, -10%, and ENT, -6%. Assuming stability, these values overestimate the gap in activity observed in 2020-2021. At the end of 2021, according to the model, the gap in activity observed in 2020-2021 was estimated at between -1.4% and 1.7% for breast, -6.6% and -7.3% for thoracic, -3.1% and -2.5% for ovarian, -4.2% and -1.7% for pancreas, -6.7% and 5.9% for stomach, and -13.0% and -13.9% for esophageal cancers. For ENT, liver, and urologic cancers, because the trend was different before and after 2015, it was necessary to opt for modeling using only the most recent period. The cumulative gap in activity observed in 2020-2021 was estimated at -1.0% for ENT cancers, -5.3% for liver cancers, and -2.9% for urologic cancers.

Conclusions and relevance: The findings of this study suggest that short- and medium-term trends must be considered to estimate COVID-19 cancer surgery activities. Breast cancer is the site for which the activity showed the smallest decrease during the pandemic, with almost full recovery in 2021.