Who merits a neck dissection after definitive chemoradiotherapy for N2-N3 squamous cell head and neck cancer?

BACKGROUND: The role of neck dissection (ND) after definitive chemoradiotherapy for squamous cell head and neck cancer is incompletely defined. We retrospectively reviewed 109 patients with N2-N3 disease treated with chemoradiotherapy to identify predictors of a clinical complete response in the neck (CCR-neck), pathologic complete response after ND (PCR-neck), and regional failure.

METHOD: All patients were given 4-day continuous infusions of 5-fluorouracil (1000 mg/m2/d) and cisplatin (20 mg/m2/d) during the first and fourth weeks of either once daily (n = 68) or twice daily (n = 41) radiation therapy. ND was considered for all patients after completion of chemoradiotherapy and was performed in 32 of the 65 patients achieving a CCR-neck after chemoradiotherapy and in all 44 patients with residual clinical evidence of neck disease. CCR-neck, PCR-neck, and regional failure were then correlated with potential predictors, including T, N, largest lymph node size (<3 cm, > or =3 cm), primary tumor site, and radiation fractionation schedule.

RESULTS: Achievement of a CCR-neck was predicted by N, N2 vs N3 (53 of 80 vs 12 of 29, p =.019) and by largest lymph node size, <3 cm vs > or =3 cm (19 of 25 vs 46 of 84, p =.06). Achievement of a PCR-neck could not be predicted by any clinical parameter. Regional failure occurred both in patients undergoing ND and those not dissected (5 of 76 vs 4 of 33, p =.33) and proved more likely only in the ND patients with residual positive pathology compared with those achieving a PCR-neck (5 of 25 vs 0 of 51, p <.001). Primary site was not a useful predictor of CCR-neck, PCR-neck, or regional failure. Most importantly, CCR-neck (vs
CONCLUSIONS: After chemoradiotherapy, clinical parameters do not identify those patients with residual neck node disease or those at risk for regional failure, suggesting that ND be considered for all N2-N3 patients.