Tumor host interactions may be important in the prognosis of head and neck cancer. The manner and extent to which the immune system responds to cancer is of interest. The more eosinophilic infiltration of the tumor, the better the prognosis. Presumably, this indicates a greater host response to tumor. Perineural invasion at the tumor site has been associated with more extensive local and regional disease, and therefore a worse prognosis.
Vascular invasion is an important step in the development of metastasis.
Although most circulating tumor cells do not develop into metastasis, the greater the number released into the vascular system, the higher the likelihood. Specific head and neck tumors often have a distinctive history at presentation. Vocal changes lasting more than two weeks in a smoker should elicit an examination for laryngeal carcinoma. Given this early symptom, patients tend to present earlier with laryngeal carcinoma than with other lesions of the head and neck, and therefore often have a better prognosis. Moreover, the lymphatic supply to the larynx is not as great as in other head and neck regions, and therefore regional metastasis may occur later.