Abstract
Objective and Subjects: To clarify the clinical features of multiple primary cancers (MPC) in the Ryukyu Islands, we investigated 218 head and neck squamous cell carcinoma cases newly and histologically diagnosed from February 2005 to August 2008 at our clinic.
Methods: Medical records were retrospectively reviewed for MPC development.
Results: 1. MPC were observed in 48 of 218 patients and consisted of 25 synchronous and 23 metachronous cancers during a mean follow-up period of 16.4 months. 2. MPC development was observed in 50.0% of middle ear cancer, 28.8% of mesopharyngeal cancer, 23.9% of hypopharyngeal cancer, 18.0% of laryngeal cancer, and 17.3% of oral cavity cancer cases. 3. The most common site for synchronous MPC development was the esophagus (16 lesions), followed by head and neck (4), lung (3), stomach (1) and rectum (1). 4. Metachronous MPC were divided into two groups according to the location of the first cancer, i.e. head and neck group (9 cases) and other cancer group (14 cases). The period between detection of first cancer and development of second cancer was significantly shorter in the head and neck group (40 months) than in the other cancer group (98 months). 5. Treatment results in patients with MPC were not significantly different from those in patients without MPC. 6. Significant risk factors in MPC development included a high alcohol intake, and mesopharynx and hypopharynx as tumor locations.
Conclusions: These results demonstrated the high incidence of multiple primary cancers in patients with head and neck squamous cell carcinoma, especially mesopharyngeal cancer. Long-term regular and repeated examinations of high-risk areas, i.e. the esophagus, head and neck, stomach, and lung, are important to detect MPC in the early clinical stage.
