Objectives: To define rates of occult metastases in salvage oral cavity and oropharyngeal cancer resection requiring free flap, to examine the location of occult metastases, and to determine associations between occult metastasis and survival.
Study design: Retrospective cohort study.
Setting: Two tertiary care referral centers.
Methods: We identified previous cases of irradiation with recurrent or second primary oral cavity or oropharyngeal squamous cell carcinoma that had no evidence of regional metastasis and required free tissue transfer reconstruction of the primary site. Patients who underwent elective neck dissection or exploration were reviewed. The main outcome measures were the presence and location of occult nodal metastasis. Disease-free survival and overall survival were measured. Odds ratios and hazard ratios were used for analysis.
Results: A total of 83 patients were included: 52 with oral cavity primary tumors and 31 with oropharynx. An overall 78 (94%) underwent elective salvage neck dissection. Occult metastases were found in 9 (11.5%) patients. The most common nodal station for occult metastasis was level 2. Neither elective neck dissection nor the presence of occult metastasis was significantly associated with regional disease-free or overall survival. Oropharyngeal primary tumors were associated with higher risk of occult metastasis (odds ratio, 1.38; P < .01) and worse overall survival (hazard ratio, 2.09; P = .01).
Conclusion: There is a low incidence of occult metastasis in postradiated recurrent or second primary oral cavity and oropharyngeal tumors. Elective neck dissection and occult nodal metastases were not associated with regional or overall survival. This series may help surgeons make decisions regarding the extent of neck surgery after prior radiation, especially when free flap reconstruction is required.
Keywords: head and neck cancer; neck dissection; neck radiation; occult metastasis; salvage surgery; squamous cell carcinoma.