Immunosuppression and the development of malignancies of the upper airway and related structures

In the general population, 90% of the malignancies developing in the upper respiratory tract are squamous cell carcinomas. Analysis of 1081 neoplasms in 1023 renal transplant patients reported to the Denver Transplant Tumor Registry indicates that squamous cell carcinoma remains the predominant malignancy which develops in the upper respiratory tract of immunosuppressed individuals. Comparing the incidence of cancers of the oral cavity (excluding lip cancers) in the immunosuppressed population with the general population it is rather similar (3.5% vs. 4%). When lip cancers are included, one sees a great excess of tumors developing in transplant patients (15% vs. 4.6%). Thus the excess of head an neck epithelial malignancies among these patients is confined to neoplasms of the lip. Examination of the 25 patients reported in this study reveals an unusually young age of the patients, the average age being 41.8 years compared with the general population where most head an neck tumors occur in the 55-65 age group. The average time post-transplantation when cancer developed was 5.3 years, supporting the concept that the more effective the immunosuppressive regimen for prevention of graft rejection, the greater the susceptibility for the development of cancer. Since 90% of transplant patients have serological or clinical evidence of active herpes virus infection, it is possible that this microorganism may play a role in the development of certain head and neck malignancies, especially those involving the lips.