Survie prolongée et régression tumorale spontanée au cours d’un mélanome de stade IV : rôles possibles de la surrénalectomie et de la libération massive d’antigènes tumoraux

Abstract

Mean survival for stage IV melanoma patients is 6 to 8 months. Long-term survival is rare and spontaneous regression even more unusual. A 46-year-old woman underwent amputation of the left thumb for subungual melanoma in 1997. In 2002, lobectomy was performed for a single pulmonary metastasis. In June 2006, a seemingly isolated adrenal metastasis was detected, and was rapidly complicated by acute abdominal symptoms due to metastatic rupture that required emergency adrenalectomy. During surgery, peritoneal metastases were observed macroscopically and confirmed histologically. One month later, then every six months until July 2009, clinical and laboratory tests, and in particular positron emission tomodensitometry (PET) scans, revealed no further tumoural lesions. No treatment was given. Screening for signs of autoimmunity revealed isolated appearances of anticardiolipin antibodies starting in June 2006. This rare case suggests the existence of specific factors resulting in tumour control. The favourable prognostic value of autoimmune signs has been discussed in stage III and IV melanoma. A number of studies have also suggested a link between prolonged survival and adrenalectomy for single and multiple adrenal metastases, with rare cases of complete regression of residual tumour following non-oncological surgery, as occurred in our patient. Other possible mechanisms include massive release of tumour antigens following metastatic rupture possibly resulting in massive stimulation of antitumour immune response, as suggested in certain animal models. Laboratory tests to validate these hypotheses have been indicated and could open up fresh therapeutic horizons.