Adjuvant radiation halves recurrence risk in cutaneous squamous cell carcinoma

Adjuvant radiation (ART) after a clear margin surgery reduces the risk of local recurrence and locoregional recurrence in patients with high T-stage cutaneous squamous cell carcinomas, reports a recent study.

This 20-year retrospective cohort study was conducted at two academic centres for high T-stage cutaneous squamous cell carcinomas (Brigham and Women’s Hospital T2b or T3) with negative histologic margins postresection. The authors compared local recurrence and locoregional recurrence in tumours that received ART or observation.

Of the 508 tumours included, 96 underwent ART (ART+). The 5-year cumulative incidence of local recurrence was lower with ART+ (3.6 percent, 95 percent confidence interval [CI], 1.6‒7.7) compared to no ART (ART-; 8.7 percent, 95 percent CI, 6.3‒12.0), as was locoregional recurrence (ART+: 7.5 percent, 95 percent CI, 4.4‒11.9 vs ART-: 15.3 percent, 95 percent CI, 11.9‒22.1).

The authors classified recurrent tumours ≥6 cm or Brigham and Women’s Hospital T3 tumours as high-risk because of an increased 5-year cumulative incidence of locoregional recurrence (26.3 percent, 95 percent CI, 19.0‒35.7).

High-risk tumours that underwent ART had a lower 5-year cumulative incidence of locoregional recurrence than those that did not (ART+: 17.2 percent, 95 percent CI, 11.9‒26.4 vs ART-:31.0 percent, 95 percent CI, 26.1‒40.8).

This study was limited by its retrospective design, heterogenous population, and variations in radiation protocols, according to the authors.