Surgical Timing and Safety of Breast Cancer Operations After COVID-19: A Prospective-Only Meta-Analysis of Cohort Studies.

Background: The COVID-19 pandemic raised uncertainties regarding the safe timing of breast cancer surgery after SARS-CoV-2 infection, and robust prospective evidence has remained limited. Methods: We conducted a systematic review and meta-analysis of prospective cohort studies (2020-2024) investigating postoperative outcomes in breast cancer patients with confirmed SARS-CoV-2 infection ≤90 days before surgery versus contemporaneous non-infected controls treated at the same institutions and in the same period. PROSPERO CRD420251174613. Random-effects models (DerSimonian-Laird with Hartung-Knapp adjustment) were used to pool odds ratios (ORs) and 95% confidence intervals (CIs). Study quality was assessed with the Newcastle-Ottawa Scale, and certainty of evidence was rated using GRADE. Results: Twelve prospective cohort studies, including 7812 patients, compared breast cancer surgery after recent confirmed SARS-CoV-2 infection over 90 days with contemporaneous non-infected controls treated at the same centres. Overall, recent infection was associated with higher 30-day postoperative complications (Clavien-Dindo ≥ II) compared to. non-infected patients (OR 2.01, 95% CI 1.44-2.81) and increased venous thromboembolism (3.6%vs. 1.2%; OR 3.12, 95% CI 1.29-7.55). Early surgery 14 days after infection carried the highest risk of complications (OR 4.38, 95 CI 2.31-8.30), whereas operations performed ≥6 weeks yielded outcomes comparable to non-infected controls (OR 1.03, 95 CI 0.81-1.31); 30-day mortality remained very low (0.3). Conclusions: Breast cancer surgery after SARS-CoV-2 infection is associated with excess perioperative risk only when performed within the first two weeks. Delaying surgery to approximately six weeks minimises complications and VTE without compromising short-term safety.