Impact of radiographic findings on for prognosis skin cancer with perineural invasion

Objectives: Update our experience using radiotherapy (RT) for head-and-neck squamous or basal cell carcinoma with clinical perineural invasion (PNI) and correlate radiographic findings with outcomes. Materials and Methods: We treated 65 patients with cT4N0 head-and-neck skin cancers with clinical PNI from 1965 to 2009 (N0 disease, 59; N1 disease, 6). Treatment included RT alone (N=18), RT with concurrent chemotherapy (N=14), surgery and postoperative RT (N=26), or postoperative RT with concurrent chemotherapy (N=5), and preoperative RT and surgery (N=2). Patients were stratified by imaging-negative disease (N=11), minimal or moderate peripheral disease (N=18), and macroscopic and/or central disease (N=36). Median RT dose was 72.6 Gy (50.4 to 79.2 Gy). Median follow-up overall and for living patients was 5.4 and 11.6 years, respectively. Results: Five-year outcomes for imaging-negative disease versus minimal/moderate peripheral disease versus macroscopic/central disease were: local control, 81% versus 60% versus 47% (P=0.23); local-regional control, 80% versus 54% versus 47% (P=0.22); neck control, 100% versus 89% versus 93% (P=0.45); and distant metastasis-free survival, 89% versus 100% versus 93% (P=0.57), respectively. Five-year survival rates for imaging-negative disease versus minimal/moderate peripheral disease versus macroscopic/central disease were: overall survival, 82% versus 50% versus 52% (P=0.26), and cause-specific survival, 100% versus 58% versus 65% (P=0.08). Twenty-two (34%) patients had 1 or more severe (grade ≥3) late complications. Conclusions: There is a nonsignificant trend towards improved local control for imaging-negative patients and patients with minimal/moderate peripheral disease compared with macroscopic/central disease. Although survival appears better for imaging-negative patients, extent of imaging-positive PNI did not impact overall or cause-specific survival.