Patterns of local recurrence after curative resection and reconstruction for oropharyngeal and oral cancers: Implications for postoperative radiotherapy target volumes.

BACKGROUND: We aimed to determine the patterns of local recurrence after curative resection and reconstruction for oropharyngeal and oral cancers. METHODS: One hundred-fourteen patients with oropharyngeal and oral cancers underwent resection and reconstruction. The local recurrences were classified as "intra-flap" (the recurrent tumor was located in the flap tissue), "marginal" (</=5 mm from the flap anastomosis), and "outside" (in the original tissue and >5 mm from the anastomosis) recurrences. RESULTS: Twenty-seven patients (23.7%) experienced local recurrence, while 32 (28.1%) experienced regional, and nine (7.9%) recurred distantly. Among those who showed local recurrence, one developed "outside" recurrence and the remaining 26 developed "marginal" recurrences. Age >60 years and lymph node metastasis were associated with poor disease-free survival and overall survival (OS), while the perineural invasion was related to poor locoregional failure-free survival and OS. CONCLUSION: Most recurrences developed at the anastomosis marginal site, while none developed in the flap tissue.