Breast Implants and the Risk of Squamous Cell Carcinoma of the Breast: A Systematic Literature Review and Epidemiologic Study.

Squamous cell carcinoma may arise primarily from the breast parenchyma (PSCCB) or from the periprosthetic capsule in patients with breast implants (BIA-SCC). A systematic literature review was performed to identify all PSCCB and BIA-SCC cases, and estimate prevalence, incidence rate (IR) and risk. Using predefined keywords, studies since no time limit up to November 2023 were searched on PubMed, Web of Science, Google Scholar, and Cochrane Library. As the numerator for PSCCB and BIA-SCC we used the cases obtained from literature, while as the denominator for PSCCB the female population aged from 18 to 99, and for BIA-SCC the population with breast implants. Overall 219 papers were included, featuring 2,250 PSCCB and 30 BIA-SCC cases. PSCCB prevalence was 2.0 per 100,000 (95%CI 0.2:100,000 to 7.2:100,000) individuals with a lifetime risk of 1:49,509 (95%CI 0.2:10,000 to 5,6:10,000); and BIA-SCC prevalence was 0.61 per 100,000 (95%CI 0.2:100,000 to 1.3:100,000), with a lifetime risk of 1:164,884 (95%CI 0.2:100,000 to 5.6:100,000). BIA-SCC prevalence is 3.33-times lower than PSCCB, while BIA-ALCL prevalence is 3,84-times higher than Primary Breast ALCL. When comparing, BIA-SCC prevalence of 1:164,910 individuals with breast implants regardless of texture, to the BIA-ALCL prevalence of 1:914 patients with textured implants, the BIA-SCC risk is 180-times lower than BIA-ALCL. BIA-SCC occurs less frequently than PSCCB and considerably less than BIA-ALCL. The association between textured implants and BIA-SCC cases is relevant for patient education regarding uncommon and rare risks associated with breast implants, and ongoing vigilance, research, and strengthened reporting systems remain imperative.