The relationship between post-surgery infection and breast cancer recurrence. A systematic review

Structured Summary Background Breast cancer is the second most prevalent form of cancer in women worldwide, with surgery remaining the standard treatment. The adverse impact of the surgery remains controversial. It has been suggested that systemic factors during the postoperative period may increase the risk of recurrence, specifically surgical site infection (SSI). Aim To critically appraise current published literature regarding the influence of SSIs, after primary breast cancer surgery, on breast cancer recurrence, and to delve into potential links between these. Methods This systematic review adopted two approaches; to identify the incidence rates and risk factors related to SSI after primary breast cancer surgery and, secondly, examine breast cancer recurrence following SSI occurrence. Findings 99 studies with 484605 patients were eligible in the SSI-focused searches, and 53 studies with 17569 patients for recurrence-focused. There was a 13.07% mean incidence of SSI. 638 Gram positive and 442 Gram negative isolates were identified, with methicillin-susceptible Staphylococcus aureus and Escherichia coli most commonly identified. There were 2077 cases of recurrence (10.8%), with 563 cases of local recurrence, 1186 cases of distant and 25 cases which recurred both locally and distantly. Five studies investigated the association between SSI and breast cancer recurrence with three concluding that an association did exist. Conclusions There is association between SSI and adverse cancer outcomes, but the cellular-link between them remains elusive. Confounding factors of retrospective study design, surgery type and SSI definition make results challenging to compare and interpret. A standardised prospective study with appropriate statistical power is justified.