thioguanine-anhydrous and Esophageal-and-Gastric-Varices

6-Thioguanine (TG) was recently studied to determine whether TG in maintenance therapy achieves better event free survival than 6-mercaptopurine (MP) for standard risk acute lymphoblastic leukemia (ALL) on the clinical trial, CCG-1952 (5/1996-1/2000). Veno-occlusive disease was previously recognized as a complication of TG on CCG-1952. We report a newly recognized pediatric complication of TG: splenomegaly and portal hypertension (PH) developing during maintenance or after completion of therapy.. Twelve patients (3-10 years) had been randomized to receive a targeted dose of 50 mg/m(2)/day of TG during maintenance phases. Actual TG dose ranged from 25 to 77 mg/m(2)/day (median 34 mg/m(2)/day).. The initial patient, a boy who had marked thrombocytopenia and intermittent splenomegaly during maintenance therapy, was evaluated for persistent pancytopenia and progressive splenomegaly 3 months after completion of therapy. Dilated splenic vein and collaterals consistent with PH were documented by MRI/MRA. Esophagogastroduodenoscopy found esophageal varices. Liver biopsy showed periportal fibrosis and marked dilatation of veins and venules. Of the other 12 patients, 9 patients studied had abnormal MRI/MRAs with evidence of varices in 4. Eight patients had splenomegaly on physical examination. Liver biopsies in a girl after 3.3 courses of TG and a boy after 4.6 courses of TG showed periportal fibrosis and dilatation of venules and sinusoids and minimal focal fatty changes. Subsequent MRI/MRAs have been stable or improved.. The evaluations of these 12 patients suggest that treatment with TG causes injury to the liver leading to PH and that thrombocytopenia and splenomegaly are clinical hallmarks of this toxicity.

Topics: Administration, Oral; Antimetabolites, Antineoplastic; Child; Child, Preschool; Esophageal and Gastric Varices; Female; Humans; Hypertension, Portal; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Male; Mercaptopurine; Pancytopenia; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Splenomegaly; Thioguanine; Thrombocytopenia

Portal hypertension with varices developed in 18/675 patients with chronic myeloid leukaemia (CML) in a randomized trial comparing busulphan with busulphan and thioguanine. All 18 had received the drug combination and none busulphan alone (P less than 0.0001). Ascites was also seen significantly more often in the combination arm (P less than 0.05). These results strongly suggest that the addition of thioguanine was responsible for the development of portal hypertension. The histological features were predominantly those of non-cirrhotic portal hypertension--either idiopathic portal hypertension with minimal morphological abnormalities, nodular regenerative hyperplasia or in two cases leukaemic infiltration only was noted. Cirrhosis was present in 3/16 cases studied. Both treatment groups developed abnormal liver function tests during the chronic phase, but particularly with progression of the disease. During chronic phase abnormalities were significantly more frequent in those receiving busulphan and thioguanine-alkaline phosphatase (P less than 0.02), transaminases (P less than 0.04), bilirubin (P less than 0.05), multiple abnormalities (P less than 0.01). The development of portal hypertension was often associated with abnormalities of these tests; however, lack of specificity precludes their use as a predictor of subsequent clinical problems. Thioguanine confers no survival advantage in this disease. In view of its hepatotoxicity it should not be used routinely for maintenance of control in chronic phase CML.

Topics: Alkaline Phosphatase; Ascites; Bilirubin; Busulfan; Chemical and Drug Induced Liver Injury; Esophageal and Gastric Varices; Humans; Hypertension, Portal; Jaundice; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Thioguanine; Transaminases

Topics: Antimetabolites; Colitis, Ulcerative; Esophageal and Gastric Varices; Female; Gastrointestinal Hemorrhage; Humans; Hyperplasia; Liver; Middle Aged; Thioguanine

6-Thioguanine treatment in childhood acute lymphoblastic leukaemia (ALL) has been shown to cause hepatic veno-occlusive disease, but this usually resolved with drug withdrawal. Recent reports suggested that treatment of ALL with 6-thioguanine can lead to chronic hepatotoxicity and portal hypertension. We describe our experience from 2 UK centres of chronic hepatotoxicity in children receiving maintenance 6-thioguanine for ALL in the national leukaemia protocol ALL 97/99.. Retrospective review of children who were referred with liver disease secondary to 6-thioguanine treatment of ALL was performed. A paediatric pathologist blinded to the clinical features reviewed liver histology slides.. Ten of 75 children (13%) treated with 6-thioguanine in both centres were referred at a median of 6 months (range, 2-29) after discontinuation of chemotherapy. In 8 cases, referral was due to persistent thrombocytopenia and splenomegaly. Two children presented with acute variceal bleeding. All had thrombocytopenia at referral, and ultrasonography showed coarse hepatic echo texture and splenomegaly in all. Endoscopy showed oesophageal varices in 7 and gastric varices in 1. Nine underwent liver biopsy that showed features compatible with nodular regenerative hyperplasia in 5 cases. After a median follow-up of 36 months, a further child has had a variceal haemorrhage and all but 2 children remain thrombocytopenic.. 6-Thioguanine-induced chronic hepatotoxicity is a significant complication in children treated with this agent for ALL. Children may present several months to years after discontinuation of 6-thioguanine. All children given maintenance treatment of ALL with this agent should be screened, and affected children require long-term surveillance.

Topics: Adolescent; Antimetabolites, Antineoplastic; Chemical and Drug Induced Liver Injury, Chronic; Child; Esophageal and Gastric Varices; Female; Gastrointestinal Hemorrhage; Humans; Male; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Retrospective Studies; Thioguanine

5 patients receiving continuous busulphan and 6-thioguanine for chronic myeloid leukaemia (CML) were found to have oesophageal varices associated with abnormal liver function tests. 3 of these cases presented with gastrointestinal haemorrhage and 1 patient died. The 2 other cases had varices discovered at endoscopy. Nodular regenerative hyperplasia (NRH) of the liver was identified as the cause of portal hypertension in the 4 patients on whom liver biopsies were done. The administration of busulphan and thioguanine in combination is likely to be associated with the development of NRH, with portal hypertension and oesophageal varices occurring in a substantial proportion of cases.

Topics: Adult; Aged; Aged, 80 and over; Busulfan; Drug Therapy, Combination; Esophageal and Gastric Varices; Female; Gastrointestinal Hemorrhage; Humans; Hyperplasia; Leukemia, Myeloid; Liver; Male; Middle Aged; Thioguanine