Prognostic factors in major salivary gland cancer

To identify features of major salivary gland cancers that are prognostic for disease-free survival.

A retrospective study of 78 patients with major salivary gland cancer (64 parotid and 14 submandibular gland) who underwent surgery for definitive treatment from 1976 to 1996. A select group of patients also received adjuvant radiation (56%) and/or chemotherapy (13%).

Clinical and pathological risk factors were obtained from patients' charts and pathology reports. Age, gender, tumor site, T-stage, facial paralysis, histologic neck involvement, perineural invasion, and cancer grade were analyzed with respect to disease-free survival. The role of adjuvant treatment in terms of clinical outcome was also investigated.

In our series, the 5-year disease-free survival was 65%. Examining clinical and histologic features one at a time, we found poorer prognosis was associated with submandibular tumors compared with parotid (P =.02), higher T-stage (P =.001), positive cervical nodes (P <.001), perineural invasion (P =.002), and high-grade or adenoid cystic tumors (P =.002). A multivariable analysis indicated that positive lymph nodes (P =.07) and perineural invasion (P =.03) were important histologic predictors of shorter disease-free survival. Receipt of both adjuvant radiation and cisplatin-based chemotherapy (P =.05) was an independent predictor of longer disease-free survival.

Our study indicated that the presence of positive lymph nodes and perineural invasion is important independent predictors of disease-free survival. Our limited data also suggest that adjuvant chemotherapy and radiation therapy may improve disease-free survival.