Surgery Alone (Without Adjuvant Radiation) Adequately Treats Histologic Perineural Basal Cell Carcinomas: A Systematic Review With Meta-Analysis.

BACKGROUND: Histologic perineural invasion (PNI) in basal cell carcinomas (BCC) lacks evidence-based treatment guidelines.

OBJECTIVE: Systematically review and analyze treatment outcomes of BCC with histologic PNI (PNBCC).

MATERIALS AND METHODS: PubMed, Embase, and Cochrane Reviews were searched through June 25, 2021. Thirteen eligible cohort studies were meta-analyzed.

RESULTS: 502 of 713 PNBCC were treated with Mohs Surgery (MMS), wide local excision (WLE), or surgery (MMS or WLE) with adjuvant radiation (Surg + RT). Overall 5-year local control (LC) was 97.2% and cancer-specific survival (CSS) was 99.6%. Surg and Surg + RT did not differ in recurrence (2.1% vs 4.7%; p-value 0.56; RR 1.51 [0.37, 6.20]), LC (97.9% vs 96.2%; p-value 0.19; RR 0.98 [0.96, 1.01]) or CSS (100% vs 99.1%; p-value 0.40; RR 0.99 [0.95, 1.02]).

LIMITATIONS: No randomized controlled trials were found. Outcome data were often lacking.

CONCLUSION: Overall LC and CSS were high at median 5-year follow-up for surgery alone and Surg + RT. Surgery alone and Surg + RT demonstrated statistically equivalent outcomes. We do not recommend adjuvant radiation therapy for solely histologic PNBCC if clear margins are achieved.