Thrombotic microangiopathy syndromes and oncology
Thrombotic microangiopathy syndromes (TMA) are characterized by the association of mechanical hemolytic anemia (supported by the presence of schizocytes with a negative Coombs test), peripheral thrombocytopenia, and single or multiple organ failure. Cancer related TMA (CRTMA) are known since the 1950’s. Differences between the two forms of TMA (hemolytic and uremic syndrome or thrombotic thrombocytopenic purpura) is difficult to establish in routine practice. Levels of ADAMTS13 are extremely variable and of poor value for the diagnosis and treatment. Around 5 to 6% of cancers are complicated with CRTMA. The mucinous carcinomas, mainly gastric, breast, and prostate ones are the most frequent. Most of them are metastatic and often localized in the medulla. CR-TMA patients usually present characteristic features including significant weight loss and dyspnea but less frequent neurological symptoms. Low fibrinogen levels and erythromyelemia, sometimes associated with myelofibrosis, are the most common biological particularities. Classical TMA therapies like plasma exchange and immunomodulatory treatments appear to be almost ineffective. The most effective management is probably blood pressure control and administration of appropriate chemotherapy. However, prognosis often remains dramatic, mostly due to the underlying disease. Several antineoplastic drugs are responsible for TMA in cancer patients with drug-depending final outcome. The level of intensive care should be decided by the intensivists and oncologists, taking into account the patient’s wishes, TMA cause of and the underlying pathology.