In 1983, the Northern California Oncology Group (NCOG) instituted a randomized trial of intravenous (IV) versus intraarterial (IA) floxuridine (FUDR) administered via an implantable pump for patients with colorectal cancer metastatic to the liver. The study objectives were to compare the hepatic response rate, time to hepatic progression, and toxicity for the two treatment arms. The study design, which allowed patients failing IV FUDR to crossover to the IA arm, prevents a meaningful comparative analysis of survival. Patients with liver-only metastases (N = 143) were randomized, 76 to the IV arm and 67 to the IA arm, and 115 patients (65 IV, 50 IA) were fully evaluable. Of the 65 patients in the IV arm, 28 crossed over to IA treatment after failing IV FUDR. The dose-limiting toxicity of IV FUDR was diarrhea, whereas biliary toxicity limited both the dose and duration of IA FUDR therapy. Of the first 25 patients treated with IA FUDR at a dose of .3 mg/kg/day, 10 developed radiographically evident biliary strictures, and three developed permanent jaundice. With reduction of the initial IA FUDR dose to .2 mg/kg/day, and adoption of a policy of early dosage reduction, treatment interruption, or termination of therapy for persistent elevations in alkaline phosphatase, only two further cases of serious biliary toxicity occurred. However, 26 of the 50 IA FUDR patients ultimately had therapy terminated because of drug toxicity rather than disease progression. When compared with systemic infusion, infusion into the hepatic artery greatly enhanced the antitumor activity of FUDR against colorectal liver metastases. Although biliary toxicity is the most serious limitation of this form of therapy, biliary stricture and jaundice usually can be averted through careful monitoring of liver enzymes and early dosage reduction.
Since the introduction of antineoplastic chemotherapy, lasting clinical remissions have been obtained for many patients with acute lymphoblastic leukemia, Hodgkin's disease, gestational trophoblastic tumors, and other malignancies. With this therapeutic success there have been concerns about persistent or delayed toxicities of cancer chemotherapy that may become clinically significant for long-term survivors. Gonadal toxicity and infertility occur in many men, women, and children treated with antineoplastic drugs. In this paper we review the clinical syndromes of chemotherapy-related gonadal toxicity and discuss how particular drug classes, doses, or combinations correlate with the degree of gonadal injury and with the potential for recovery of function. Further, we examine how drug effects on germ cell production and endocrine function vary with the age of the patient at the time of treatment. Finally, we comment on the need for long-term prospective studies of fertility, teratogenesis, and mutagenesis in patients receiving cancer chemotherapy.
High response rates have been reported with hepatic intra-arterial infusions of floxuridine in patients having colorectal carcinoma metastatic to the liver. The major toxicity of this therapy has been described as "chemical hepatitis." In a randomized trial of intravenous v intra-arterial floxuridine, we observed that all 35 patients receiving intra-arterial therapy developed significant increases in alkaline phosphatase and, in some cases, serum glutamic oxaloacetic transminase and/or bilirubin. Seven patients receiving intra-arterial therapy were studied with cholangiography which, in all cases, demonstrated sclerosis of the intrahepatic and/or extrahepatic bile ducts. In addition, liver biopsies showed cholestasis and pericholangitis with minimal hepatocyte damage. These findings suggest that "biliary sclerosis" rather than "chemical hepatitis" is the predominant toxicity associated with hepatic intra-arterial infusions of floxuridine.
Hepatic intra-arterial (HIA) infusion of floxuridine (FUDR) via an implanted pump has shown promise in the treatment of colorectal cancer metastasized to the liver. However, the potential benefit of this therapy may be offset by the high incidence of treatment-limiting biliary toxicity. Although weekly HIA bolus of fluorouracil (5-FU) is effective against metastatic colorectal cancer to the liver with no biliary toxicity, it is limited by systemic side effects. In December 1986, we began a phase II trial of alternating HIA FUDR and 5-FU via the implanted pump in an attempt to extend the duration of treatment by obviating the limiting biliary (FUDR) and systemic (5-FU) drug toxic effects. Patients received continuous HIA FUDR at 0.1 mg/kg of body weight per day on days 1 through 8 followed by an HIA bolus of 5-FU at 15 mg/kg given via the pump sideport on days 15, 22, and 29, with the cycle repeated every 35 days. Sixty-eight patients were enrolled in this trial, and 64 were fully evaluable. Of the 64 patients, 30 (47%) previously had received chemotherapy. Major response (complete response plus partial response) was observed in 32 (50%) of 64 patients, and the median survival from pump implantation in all patients was 22.4 months. In contrast to the experience with the single-agent HIA FUDR regimen, no patient had treatment terminated because of drug toxicity. Alternating HIA FUDR and 5-FU has efficacy similar to that of HIA FUDR given alone, but when closely monitored and adjusted appropriately, is not associated with toxic effects requiring treatment termination.
DNA polymerase III is an enzyme activity in eukaryotic cells which under certain conditions shows strong preference for polyadenylic acid as template when primed by oligodeoxythymidylate. Its first complete separation from other DNA polymerases in human lymphoblasts is reported. This enzyme is biochemically and immunologically distinct from DNA polymerase I and from viral reverse transcriptase from a primtate type C virus.
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