Implant-associated malignancies in the genitourinary system: a comprehensive review of evidence and gaps.

[BACKGROUND] The relationship between foreign material implantation and cancer development has been investigated since the 1940s, yet many questions remain regarding the mechanisms and risks associated with these interactions. This scoping review examines the potential oncogenic effects of foreign material implantation within the genitourinary system (GUS), focusing on neoplasms linked to chronic mucosal irritation from medical devices.

[METHODS] A systematic literature search of PubMed and Embase screened 15,925 studies for malignancies linked to implants (final search July 2023). Inclusion criteria involved clinical studies, cohort studies, case control studies, case reports and case series of human subjects with a history of genitourinary foreign devices or prosthesis implantation and de novo malignancies at the site of implantation or metastases of any tumor that were found adjacent to or near the prosthesis. Meta-analyses, systematic reviews, practice guidelines, narrative reviews, and studies with non-human subjects or benign masses were excluded. There were no date or language restrictions.

[RESULTS] Twenty-six case reports and series (46 cases) and 21 cohort studies were identified. GU implants identified included transurethral and suprapubic catheters, transvaginal mesh, midurethral slings, and ureteral stents. The mean duration of implant exposure before malignancy diagnosis was 16.8 years. Chronic irritation from indwelling catheters was frequently linked to malignancies, including squamous cell carcinoma (54.5%) and transitional cell carcinoma (38.6%), with the bladder as the most common tumor site (68.2%). However, materials used in catheters were rarely documented, underscoring a critical gap in reporting. Smoking, a significant bladder cancer risk factor, was often undocumented, complicating risk attribution.

[CONCLUSION] Our findings underscore the need for robust data on implant material and smoking history to refine our understanding of carcinogenesis. Clinicians should maintain vigilance for malignancy in patients with prolonged implant exposure, particularly in high-risk populations like those with spinal cord injuries. This review highlights the importance of balancing implant benefits with risks and provides guidance for future research and clinical practice.