Microsurgery influences breast reconstruction and its timing in patients with breast cancer: A population-based multilevel analysis.

[BACKGROUND] The number of post-mastectomy breast reconstructions performed in patients with breast cancer varies widely. This study aimed to assess geographic and temporal variability and associated factors from 2018 to 2020, including the effect of the COVID-19 pandemic.

[METHODS] This population-based cohort study was conducted in women who underwent mastectomy for invasive breast cancer from 2018 to 2020 in the Catalan public healthcare system, with follow-up until November 2022. Data were drawn from the Catalan hospital discharge registry. Random-effects logistic regression was performed to identify individual, temporal, and center-based variables influencing breast reconstruction and to assess the associations with immediate versus delayed reconstruction.

[RESULTS] Among the 4315 included patients, 2173 (50.4%) underwent breast reconstruction (range by center 0% to 79%); 1750 (80.5%) surgeries were immediate and 423 (19.5%) were delayed. Significant, negative associations were older age, heart disease, kidney disease, and metastasis. Microsurgery and the R2 health region showed positive associations (odds ratio [OR] 4.67, 95% credible intervals [CrI] 1.73-13.63). Surgeries were immediate in 0% to 99% of the cases, according to center. Age was unrelated; however, microsurgery (OR 7.15, 95% CrI 1.92-29.34) and belonging to health region R5 (OR 47.88, 95% CrI 1.67-99.0) were related. Compared to 2018, rates of reconstructive surgery were similar to those in 2019 (OR 0.98, 95% CrI 0.81-1.18) and 2020 (OR 0.94, 95% CrI 0.77-1.14), whereas immediate reconstruction was more common (2019: OR 1.72, 95% CrI 1.30-2.27; 2020: OR 4.85, 95% CrI 3.44-6.84).

[CONCLUSIONS] Age, comorbidities, and microsurgery help explain between-center variability in breast reconstruction, while its timing appeared to be influenced by microsurgery alone. The pandemic may have accelerated the trend toward immediate surgery.