Long-term outcomes of polycythemia vera patients treated with pipobroman as initial therapy.

From 1968 to 1993, 179 newly diagnosed patients with polycythemia vera (PV) were enrolled in a prospective study using pipobroman as first chemotherapy. Among them, 140 fulfilled the Polycythemia Vera Study Group criteria for PV, and 39 patients (22%) can be considered as idiopathic erythrocytosis (IE). Vascular events occurred in 10% of IE and 20% of PV patients and solid tumors in 7.