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Background: Surgical-site infection (SSI) is a well known complication after breast cancer surgery and has been reported to be associated with cancer recurrence. The aim of this study was to investigate the association between SSI and breast cancer recurrence, adjusting for several known confounders. The secondary aim was to assess a possible association between any postoperative infection and breast cancer recurrence.

Method: This retrospective cohort study included all patients who underwent breast cancer surgery from January 2009 to December 2010 in the Uppsala region of Sweden. Data collected included patient, treatment and tumour characteristics, infection rates and outcome. Association between postoperative infection and oncological outcome was examined using Kaplan-Meier curves and Cox regression analysis.

Results: Some 492 patients (439 with invasive breast cancer) with a median follow-up of 8.4 years were included. Mean(s.d.) age was 62(13) years. Sixty-two (14.1 per cent) of those with invasive breast cancer had an SSI and 43 (9.8 per cent) had another postoperative infection. Some 26 patients had local recurrence; 55 had systemic recurrence. Systemic recurrence was significantly increased after SSI with simple analysis (log rank test, P = 0.035) but this was not observed on adjusted analysis. However, tumour size and lymph node status remained significant predictors for breast cancer recurrence on multiple regression. Other postoperative infections were not associated with recurrence.

Conclusion: Neither SSI nor other postoperative infections were associated with worse oncological outcome in this study. Rather, other factors that relate to both SSI and recurrence may be responsible for the association seen in previous studies.

Background; Surgical site infection (SSI) is a well-known complication after breast cancer surgery. The primary aim was to assess risk factors for SSI. Risk factors for other wound complications were also studied.

Materials and Methods: In this prospectively registered cohort study, patients who underwent breast-conserving surgery (BCS) or mastectomy between May 2017 and May 2019 were included. Data included patient and treatment characteristics, infection, and wound complication rates. Risk factors for SSI and wound complications were analyzed with simple and multiple logistic regression.

Results: The study cohort consisted of 592 patients who underwent 707 procedures. There were 66 (9.3%) SSI and 95 (13.4%) wound complications. "BMI > 25, " "oncoplastic BCS, " "reoperation within 24 hour, " and "prolonged operative time " were risk factors for SSI with simple analysis. BMI 25-30 and > 30 remained as significant risk factors for SSI with adjusted analysis. Risk factors for "any wound complication " with adjusted analysis were "mastectomy with/without reconstruction " in addition to "BMI 25-30 " and "BMI > 30. "

Conclusion: The only significant risk factor for SSI on multivariable analysis were BMI 25-30 and BMI > 30. Significant risk factors for "any wound complication " on multivariable analysis were "mastectomy with/without reconstruction " as well as "BMI 25-30 " and "BMI > 30. "

Background

There is conflicting evidence regarding whether postoperative complications after breast cancer surgery are associated with worse oncological outcome. This study aimed to assess the risk of systemic breast cancer recurrence after surgical site infection and also the impact of surgical site infection on locoregional recurrence, breast cancer-specific survival and overall survival.

Methods

This nationwide cohort study included patients who underwent surgery for primary breast cancer in Sweden between January 2008 and September 2019. The study cohort was identified in the Breast Cancer Database Sweden 3.0, a database linking the National Breast Cancer Quality Register to national population-based healthcare registers held by the National Board of Health and Welfare and Statistics Sweden. The primary exposure was surgical site infection within 90 days from surgery, and the primary outcome was systemic recurrence of breast cancer. Secondary outcomes included locoregional recurrence, overall survival and breast cancer-specific survival. Multivariable Cox regression analysis was performed to assess the association between exposure, predictors and outcomes.

Results

Of 82 102 patients included in the study, 15.7% experienced a surgical site infection within 90 days of surgery. Surgical site infection was not significantly associated with systemic recurrence, locoregional recurrence or breast cancer-specific survival after adjustment for confounding variables. Surgical site infection was significantly associated with worse overall survival, but the significant association disappeared in a sensitivity analysis excluding all patients with any kind of malignancy before breast cancer diagnosis.

Conclusion

Surgical site infection after breast cancer surgery does not significantly increase the risk of systemic recurrence. All possible actions should nevertheless be taken to reduce complication rates.