[Invasive differentiated thyroid cancers: discussion of therapeutics, multidisciplinary approach]

Although well differentiated treated thyroid cancers have generally an indolent course, some of those tumors present with an aggressive pattern, invading locoregional structures in the neck (mainly in the central compartment of the neck). Patients are usually older than 50 years. Initial treatment should imply large resections including the pharynx, a portion of the esophagus and sometimes the larynx, reconstruction may be necessary, with the use of flaps (free or pedicled). Those major operations have to be balanced with the quality of life and the length of expected survival, especially for older people whose adaptation to this pattern of survival may be an overwhelming situation (informed consent of the patient is necessary, a detailed information about the expected results is mandatory). Recent studies at the Mayo Clinic and at the Memorial Sloan Kettering Cancer Center have shown that intraluminal invasion of the esophagus or of the trachea are indicators of a poor prognosis. Multivariate studies have demonstrated that the age of the patient at presentation remains the predominant prognostic factor: for patients younger than 45 years, safe margins of excision allow a similar survival to that of patients without extrathyroidal extension. Whereas, after stratification for age, for older patients, the survival seems not to be affected by the size of the tumor or by the uncompleteness of the resection, this may be explained, at least partially, by the poor prognosis of the disease in those older patients. External beam radiation seems to be useful for patients for whom resection with close margins or shave-excision are performed. Two recent publications show that external radiation improves the survival of patients for whom complete resection of the tumor was not possible.