The purpose of this study is to analyze the treatment results of patients with medullary thyroid cancer,focusing on surgical complications, biochemical cures, and survival. It is a retrospective analysis of 18 patients with advanced disease treated in a tertiary, teaching referral hospital in a developing country. Ten patients underwent only a initial surgery, of them, 7 developed surgical complications, 2 of them major. Five patients required a second procedure after the first surgery elsewhere, 2 of them developed complications, one major. Three denied further treatment after diagnosis was made. After a median follow-up of 35.5 months (1-108), 7 (39%) patients are alive without disease, 4 (22%) are alive with disease, and 7 (39%) died. From fifteen patients after surgery with curative puposes, 4 reached normal calcitonin levels and are still without evidence of recurrence after a mean follow-up of 47 months (3-86 months); 11 persisted with disease, of them, five patients needed a second surgery, two of them reached normal calcitonin levels, one of them is still under remission after 36 months, and one died 60 months later. Three patients denied more treatment. Nine patients did not reach normal calcitonin levels after first surgery or reoperation, but on postoperative images there were not evidence of residual disease and 6 of them are alive after a mean follow up of 55 (12-108) months. In conclusion, a biochemical cure
for the advanced disease is rare after surgery, however, long term survival is possible when judicious surgery produces no evidence of residual disease by imaging.