2ND HEAD AND NECK CANCERS FOLLOWING RADIATION-THERAPY OF T1 AND T2 CANCERS OF THE ORAL CAVITY AND OROPHARYNX

The risk of second cancer in the head and neck region following definitive radiation therapy was evaluated among 600 patients who were treated for T1 and T2 cancers of the oral cavity and oropharynx at the Henri Mondor hospital between January 1970 and March 1987. Seventy-five patients (12.5%) were managed with external irradiation only, 243 (40.5%) with RT and Iridium 192, and 282 (47%) with Iridium 192 alone. One hundred fifteen patients (19%) developed a second cancer from 3 to 183 months after initial therapy (median: 32 months), including 69 patients (11.5%) in whom the second malignancy was diagnosed in the head and neck region. An increased and constant actuarial risk of development of second head and neck cancer was found (2.7%/year of observation). Univariate analysis showed that age, sex, stage, and modality of the initial treatment did not influence the risk of second head and neck cancer; there was a greater risk of second head and neck malignancy for those patients with soft palate carcinoma (p < 0.05). Multivariate analysis revealed that the only group of patients who developed a second head and neck cancer more frequently were those who were irradiated with Iridium 192 only (p = 0.0076). There was a trend toward a greater risk of second head and neck malignancy for those with soft palate carcinoma (p = 0.059). Radical treatment of the second head and neck malignancy by surgery and/or re-irradiation was performed for 67% of patients. Patients initially treated by Iridium 192 only could undergo salvage treatment more often than those who previously received external beam radiotherapy (79% vs 53%, p = 0.02). The overall 2-year and 5-year survivals after the diagnosis of the second head and neck cancer were 32% and 10%, respectively.