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 (breast implant-associated squamous cell carcinoma [BIA-SCC]). A systematic literature review was performed to identify all PSCCB and BIA-SCC cases, and to estimate prevalence, incidence rate (IR), and risk. Studies up to November 2023 were searched on PubMed, Web of Science, Google Scholar, and Cochrane Library for predefined keywords. The numerator for PSCCB and BIA-SCC was the number of cases obtained from the literature; the denominator for PSCCB was the female population aged from 18 to 99, and the denominator for BIA-SCC was the population with breast implants. Overall, 219 papers were included, featuring 2250 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). The prevalence of BIA-SCC is 3.33 times lower than that of PSCCB, while the prevalence of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is 3.84 times higher than that of primary breast ALCL. When comparing the 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 the BIA-ALCL risk. 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.