Delayed regional metastases, distant metastases, and second primary malignancies in squamous cell carcinomas of the larynx and hypopharynx

OBJECTIVE: To determine the impact of delayed regional metastases, distant metastases, and second primary tumors on the therapeutic outcomes in squamous cell carcinomas of the larynx and hypopharynx. STUDY DESIGN: Chart review and statistical analysis. METHODS: A retrospective tumor registry analysis was made of patients with squamous cell carcinomas of the larynx and hypopharynx who were treated with curative intent in the Department of Otolaryngology-Head and Neck Surgery and the Radiation Oncology Center of the Washington University School of Medicine (St. Louis, MO) between January 1971 and December 1991 and developed delayed regional metastases (2 y after treatment), distant metastases, and second primary malignancies. RESULTS: In 2550 patients, the mean age (59.8 y), sex (8.5 male patients and 1 female patient), and tumor differentiation did not affect the incidence of delayed distant, regional, or second primary malignancies. The overall incidence of delayed regional metastases was 12.4% (317/2550 patients); distant metastases, 8.5% (217/2550); and second primary tumors, 8.9% (228/2550), with a 5-year disease-specific survival of 41%, 6.4%, and 35%, respectively. Second primary malignancies were not statistically related to the origin of the primary tumor, tumor staging, or delayed regional and distant metastases (P =.98). Delayed regional metastases and distant metastases were related to advanced primary disease (T4 stage), lymph node metastases (node positive [N+]), tumor location (hypopharynx), and locoregional tumor recurrence (P < or =.028). Advanced regional metastases at initial diagnosis (N2 and N3 disease) increased the incidence of delayed and distant metastases threefold (P =.017). These two metastatic parameters were significantly greater in hypopharyngeal tumors than in laryngeal tumors (P =.037). The incidences of delayed regional metastases by anatomical location of the primary tumor were as follows: glottic, 4.4%; supraglottic, 16%; subglottic, 11.5%; aryepiglottic fold, 21.9%; pyriform sinus, 31.1%; and posterior hypopharyngeal wall, 18.5%. The incidences of distant metastases were as follows: glottic, 4%; supraglottic, 3.7%; subglottic, 14%; aryepiglottic fold, 16%; pyriform fossa, 17.2%; and posterior hypopharyngeal wall, 17.6%. Seventeen hypopharyngeal tumors (2%) presented with M1 disease. Delayed regional metastases to the ipsilateral treated neck had a significantly worse survival prognosis than delayed metastases to the contralateral nontreated neck (P =.001). CONCLUSIONS: Conclusions are as follows: 1) The incidence of second primary tumors is independent from the primary tumor staging and distant and delayed regional metastases. The highest incidence occurred in patient groups with the highest disease-free survival rates (P =.0378). 2) Highest incidence of delayed and distant metastases occurred in hypopharyngeal tumors and was three times greater than in laryngeal cancers (P =.028). 3) Salvage therapeutic rates were poor for delayed metastases to the ipsilateral treated nodes and distant metastases as compared with contralateral neck metastases and second primary tumors (P =.001). 4) Delayed and distant lymph node metastases were significantly higher in advanced primary disease (T4 stage), locoregional recurrences, and regional disease (N2 and N3) (P =.028) in both the larynx and hypopharynx. 5) The higher incidence of delayed and distant metastatic disease was related to more advanced initial tumor presentation in hypopharyngeal cancer as compared with laryngeal cancer (P =.039). 6) Incidence of distant metastases was greatest between 1.5 and 6 years after initial treatment with a mean incidence being less than or equal to 3.2 years.