Cancers médullaires de la thyroïde : hyperthyrocalcitoninémie persistante après chirurgie, réinterventions-résultats

Abstract

In the situation of persistant hypercalcaemia after cervicotomy for medullary carcinoma of the thyroid (CMT), the concerns are radically different depending on whether the initial operation has been adequate or not. If it has been inadequate, it is necessary to reoperate via cervicotomy and facilitate, in all cases, a total thyroidectomy and a bilateral and central neck dissection. If the cervicotomy has been adequate, it is necessary to have a high index of suspicion for a locoregional recurrence and systemic disease, but the indications for reintervention must be respected. The essential problem is the difficulty in staging residual or recurrent disease. In this situation all the imagery available should be utilised, including laparoscopy to rule out the possibility of miliary metastatic liver disease. There is no hope of cure in the setting of systemic disease, but it is necessary to recall that an extremely elevated calcitonin can be well tolerated and compatible with a survival for several decades. The overall prognosis lies not in the level of elevation of the tumoral marker but the extent of local invasion and systemic disease. There is no hope of cure when the calcitonin level is superior to 1000 pg/ml. There is also no chance of localising recurrent disease when the calcitonin level is inferior to 50 pg/ml. Therefore, one should only utilise the various available localisation techniques when the level of calcitonin is between 50 and 1000 pg/ml. A mediastinal disssection via sternotomy is only indicated in the absence of distal metastases and in the setting of nodal involvement just caudal to the initial cervicotomy, and only after a laparoscopy to exclude hepatic metastases. The future hopes lie with radio-immunoguided surgery in cases of local invasive disease and radiolabelled immunochemotherapy for systemic disease.