Purpose: To evaluate the prognostic factors for the risk of distant metastases after postoperative radiotherapy for laryngeal cancer.
Material and methods: Medical records of 267 patients cancer treated between 1997 and 2003 were analyzed. All pts had locally advanced squamous cell laryngeal cancer treated with surgery and postoperative radiotherapy. Metastasis Free Survival was analyzed using Kaplan-Meier method. A multivariate Cox proportional hazard model and logistic regression model was used to evaluated influence of the following variables on MFS and the ultimate risk of metastases: age, sex, localization, TN stage, HGB before and at the end radiotherapy, total radiation dose, dose per fraction, overall treatment time, interval surgery-radiation time, pathological margins and positive nodes in surgical specimen.
Results: The crude incidence of distant metastases was 12% (33/267 pts). One year, 3-year, 5-year actuarial metastases free survival were 95%, 85% and 84% respectively. The lungs and bones were the most common sites of metastases (58% and 33% respectively), whereas metastases to liver (6%) and brain (3%) were rare. Localization of cancer (glottic vs. supraglottic) and number of positive lymph nodes at pathological staging significantly and independently affected MFS.
Conclusions: Number of positive lymph nodes in pathological specimen and site of primary cancer (glottic vs. supraglottic) significantly and independently predict a risk of distant metastases in combined modality treatment for laryngeal cancer.