Analysis of risk factors predictive of distant failure after targeted chemoradiation for advanced head and neck cancer.

BACKGROUND Distant metastasis (DM) is the most common mode of recurrence among patients with advanced head and neck carcinoma treated with intra-arterial cisplatin and radiotherapy (RADPLAT). OBJECTIVE To identify which patients are at greatest risk for DM and would benefit the most from new strategies designed to treat occult metastases. METHODS Between 1993 and 1999, 250 patients with advanced head and neck cancer were treated by RADPLAT. Excluded from the analysis were 10 patients who either did not complete the protocol or were unavailable for follow-up and 39 patients with persistent disease or local recurrence. The incidence and the risk factors for DM in these patients were evaluated in a model that included the following factors: age, T and N classification, site of tumor, histologic grade, number (0, 1, or >1) and position (high vs low) of neck levels involved, and bilateral nodal disease. Multiple stepwise logistic regression was used for the analysis. RESULTS In a univariate analysis, the following variables correlated to DM: N classification (P =.02), site of tumor (P =.01), lower neck nodes (P =.002), number of neck levels involved (P =.001), and bilateral nodal disease (P =.02). In a multivariate analysis, the most significant risk factors for DM were the number of neck levels involved and the site of the primary tumor (P<.001). The highest odds ratios for DM were among patients with multiple levels of nodal involvement (3.17) and patients with hypopharyngeal carcinoma (2.8). CONCLUSIONS Patients with more than 1 level of clinical nodal involvement and patients with hypopharyngeal carcinoma have the highest risk of developing DM as the initial site of failure and would benefit most from treatment strategies that address occult distant disease.