Small cell architecture--a histological equivalent of EGFR amplification in glioblastoma multiforme?

Although there is much written about the molecular definitions of "primary" glioblastomas (GBM), there is little known about the histological features of this predominant subtype. We hypothesized that the "small cell architecture" would represent a histological feature of most primary GBMs. This was tested by comparing the presence of the small cell phenotype with the presence or absence of amplification of the epidermal growth factor receptor (EGFR), a common event in primary GBMs. After a pilot study that found a correlation between this small cell phenotype and EGFR amplification, we selected 9 pure small cell GBMs (SCGBM) and 12 non-SCGBMs to be studied for EGFR amplification by fluorescence in situ hybridization (FISH). In this set of 21 cases, 8 of 9 SCGBMs and 5 of 12 non-SCGBMs were amplified for EGFR. We then correlated the EGFR status of 79 GBMs unselected for their histological features from a set that had been previously characterized in regard to EGFR amplification. Fourteen of 21 (67%) exclusively small cell neoplasms, 8 of 25 (32%) GBMs with both small cell and non-small cell areas, and 3 of 33 (9%) non-small cell GBMs were amplified for EGFR (p = 0.0004 with an exact test). We conclude that EGFR amplification is associated with a small cell phenotype in GBMs and that SCGBMs are an important component of "primary" GBMs.

PTEN mutation, EGFR amplification, and outcome in patients with anaplastic astrocytoma and glioblastoma multiforme.

BACKGROUND: Survival of patients with anaplastic astrocytoma is highly variable. Prognostic markers would thus be useful to identify clinical subsets of such patients. Because specific genetic alterations have been associated with glioblastoma, we investigated whether similar genetic alterations could be detected in patients with anaplastic astrocytoma and used to identify those with particularly aggressive disease. METHODS: Tissue specimens were collected from 174 patients enrolled in Mayo Clinic Cancer Center and North Central Cancer Treatment Group clinical trials for newly diagnosed gliomas, including 63 with anaplastic astrocytoma and 111 with glioblastoma multiforme. Alterations of the EGFR, PTEN, and p53 genes and of chromosomes 7 and 10 were examined by fluorescence in situ hybridization, semiquantitative polymerase chain reaction, and DNA sequencing. All statistical tests were two-sided. RESULTS: Mutation of PTEN, amplification of EGFR, and loss of the q arm of chromosome 10 were statistically significantly less common in anaplastic astrocytoma than in glioblastoma multiforme (P =.033, P =.001, and P<.001, respectively), and mutation of p53 was statistically significantly more common (P<.001). Univariate survival analyses of patients with anaplastic astrocytoma identified PTEN (P =.002) and p53 (P =.012) mutations as statistically significantly associated with reduced and prolonged survival, respectively. Multivariate Cox analysis of patients with anaplastic astrocytoma showed that PTEN mutation remained a powerful prognostic factor after adjusting for patient age, on-study performance score, and extent of tumor resection (hazard ratio = 4.34; 95% confidence interval = 1.82 to 10.34). Multivariate classification and regression-tree analysis of all 174 patients identified EGFR amplification as an independent predictor of prolonged survival in patients with glioblastoma multiforme who were older than 60 years of age. CONCLUSION: PTEN mutation and EGFR amplification are important prognostic factors in patients with anaplastic astrocytoma and in older patients with glioblastoma multiforme, respectively.

Lenercept (p55 tumor necrosis factor receptor fusion protein) in severe sepsis and early septic shock: a randomized, double-blind, placebo-controlled, multicenter phase III trial with 1,342 patients.

OBJECTIVE: Phase III study to confirm a trend observed in a previous phase II study showing that a single dose of lenercept, human recombinant p55 tumor necrosis factor receptor-immunoglobulin G1 (TNFR55-IgG1) fusion protein, decreased mortality in patients with severe sepsis or early septic shock. DESIGN: Multicenter, double-blind, phase III, placebo-controlled, randomized study. SETTING: A total of 108 community and university-affiliated hospitals in the United States (60), Canada (6) and Europe (42). PATIENTS: A total of 1,342 patients were recruited who fulfilled the entry criteria within the 12-hr period preceding the study drug administration. INTERVENTION: After randomization, an intravenous dose of 0.125 mg/kg lenercept or placebo was given. The patient was monitored for up to 28 days, during which standard diagnostic, supportive, and therapeutic care was provided. MEASUREMENTS AND MAIN RESULTS: The primary outcome measure was 28-day all-cause mortality. Baseline characteristics were as follows: a total of 1,342 patients were randomized; 662 received lenercept and 680 received placebo. The mean age was 60.5 yrs (range, 17-96 yrs); 39% were female; 65% had medical admissions, 8% had scheduled surgical admissions, and 27% had unscheduled surgical admissions; 73% had severe sepsis without shock, and 27% had severe sepsis with early septic shock. Lenercept and placebo groups were similar at baseline with respect to demographic characteristics, simplified acute physiology score II-predicted mortality, profiles of clinical site of infection and microbiological documentation, number of dysfunctioning organs, and interleukin-6 (IL-6) plasma concentration. Lenercept pharmacokinetics were similar in severe sepsis and early septic shock patients. Tumor necrosis factor was bound in a stable manner to lenercept as reflected by the accumulation of total serum tumor necrosis factor alpha concentrations. There were 369 deaths, 177 on lenercept (27% mortality) and 192 on placebo (28% mortality). A one-sided Cochran-Armitage test, stratified by geographic region and baseline, predicted 28-day all-cause mortality (simplified acute physiology score II), gave a p value of .141 (one-sided). Lenercept treatment had no effect on incidence or resolution of organ dysfunctions. There was no evidence that lenercept was detrimental in the overall population. CONCLUSION: Lenercept had no significant effect on mortality in the study population.

Detection of 1p and 19q loss in oligodendroglioma by quantitative microsatellite analysis, a real-time quantitative polymerase chain reaction assay.

The combined loss of chromosomes 1p and 19q has recently emerged as a genetic predictor of chemosensitivity in anaplastic oligodendrogliomas. Here, we describe a strategy that uses a novel method of real-time quantitative polymerase chain reaction, quantitative microsatellite analysis (QuMA), for the molecular analysis of 1p and 19q loss in oligodendrogliomas and oligoastrocytomas in archival routinely processed paraffin material. QuMA is performed on the ABI 7700 and based on amplifications of microsatellite loci that contain (CA)n repeats where the repeat itself is the target for hybridization by the fluorescently labeled probe. This single probe can therefore be used to determine copy number of microsatellite loci spread throughout the human genome. In genomic DNA prepared from paraffin-embedded brain tumor specimens, QuMA detected combined loss of 1p and 19q in 64% (21 of 32) of oligodendrogliomas and 67% (6 of 9) of oligoastrocytomas. We validate the use of QuMA as a reliable method to detect copy number by showing concordance between QuMA and fluorescence in situ hybridization at 37 of 45 chromosomal arms tested. These results indicate that QuMA is an accurate, high-throughput assay for the detection of copy number at multiple loci; as many as 31 loci of an individual tumor can be analyzed on a 96-well plate in a single 2-hour run. In addition, it has advantages over standard allelic imbalance/loss of heterozygosity assays in that all loci are potentially informative, paired normal tissue is not required, and gain can be distinguished from loss. QuMA may therefore be a powerful molecular tool to expedite the genotypic analysis of human gliomas in a clinical setting for diagnostic/prognostic purposes.

Pharmacokinetics of recombinant human interferon-alpha 2a combined with 5-fluorouracil in patients with advanced colorectal carcinoma.

We evaluated the pharmacokinetics of 5-fluorouracil (5-FU) combined with recombinant human interferon (IFN)-alpha 2a in 10 previously untreated patients with advanced colorectal carcinoma. 5-FU was administered as a continuous i.v. infusion, 750 mg/m2/day for 5 days during week 1. One s.c. injection of IFN-alpha 2a, 9 x 10(6) IU, was administered during week 2. Beginning with week 3, a continuous i.v. infusion of 5-FU 750 mg/m2/day for 5 days was administered in combination with IFN-alpha 2a, 9 x 10(6) IU s.c. three times per week. The combination of 5-FU and IFN-alpha 2a was continued every other week until either 3 months after complete remission or tumor progression. No grade 4 toxicity was observed. Granulocytopenia (two patients), leukopenia (one patient), thrombocytopenia (one patient), stomatitis (two patients), fatigue (one patient) and hand-foot syndrome (one patient) were the major (grade 3) toxic reactions encountered. Overall, one complete and six partial responses were noted. The results of the paired t-test showed no statistically significant differences between the means of the two treatments, 5-FU and 5-FU plus IFN-alpha 2a, with respect to the steady-state plasma concentration, area under the concentration-time curve, total body clearance, or steady-state volume of distribution of 5-FU, or the serum concentration of IFN. We conclude that 5-FU and IFN-alpha 2a do not interact pharmacokinetically at the doses and schedules in the regimen studied.

The effect of orlistat on the pharmacokinetics and pharmacodynamics of warfarin in healthy volunteers.

To assess the effect of orlistat on the pharmacokinetics and pharmacodynamics of warfarin, a third-party blind, placebo-controlled, randomized, two-way crossover study was performed in 12 healthy volunteers. Each participant received single 30-mg oral doses of racemic warfarin sodium (Coumadin; DuPont Pharma, Wilmington, DE) administered on the eleventh day of treatment with 120 mg orlistat (treatment A) and placebo (treatment B) three times a day for 16 days; the two treatments were separated by a 3-week washout period. Serial blood samples were collected before and at appropriate intervals after each dose of warfarin to determine plasma concentrations of R-warfarin and S-warfarin and blood prothrombin time (PT) and plasma Factor VII concentration. In addition, serum concentrations of vitamin K1 and its epoxide and of osteocalcin and its undercarboxylated form were measured before breakfast on days -7, 1, 4, 6, and 10. Equivalent results between treatments with orlistat and placebo were found with regard to all pharmacokinetic parameters of R- and S-warfarin (except for time to maximum concentration of R-warfarin). Pharmacodynamic parameters of warfarin (PT and Factor VII) and vitamin K nutritional status parameters (ratios of vitamin K1 to vitamin K1 epoxide and undercarboxylated osteocalcin to osteocalcin) also were unaltered by orlistat. Orlistat administered at doses of 120 mg three times daily did not significantly alter the pharmacokinetics and pharmacodynamics of a single 30-mg oral dose of warfarin in healthy volunteers.

The effect of probenecid on the pharmacokinetics of zalcitabine in HIV-positive patients.

PURPOSE: The purpose of this study was to determine the potential effect of probenecid on the pharmacokinetics of zalcitabine in HIV-positive patients. METHODS: Twelve patients received single oral 1.5 mg doses of zalcitabine alone and during probenecid treatment (500 mg at 8 and 2 hours before and 4 hours after zalcitabine dosing) in an open-label, randomized two-way crossover study with a one-week washout period between treatments. Serial blood and urine samples were collected over a 24 hour period and assayed for zalcitabine by a modified GC/MS method. RESULTS: Coadministration of probenecid with zalcitabine resulted in a decrease in mean (%CV) renal clearance of zalcitabine from 310 (28%) ml/min when zalcitabine was given alone to 180 (22%) ml/min with probenecid and a prolonged half-life from 1.7 hours to 2.5 hours. Mean AUCs increased from 59 ng.h/ml when zalcitabine was given alone to 91 ng.h/ml when given with probenecid. Considering the short half-life of zalcitabine (1-3 hours) relative to its dosing schedule, the pharmacokinetic changes observed in this study are not expected to result in significant accumulation during chronic dosing. CONCLUSIONS: The results of this study show that co-administration of probenecid with zalcitabine results in a moderate decrease in renal clearance of zalcitabine due to inhibition of renal tubular secretion and a 50% increase in drug exposure. Although well tolerated in this single-dose study, patients taking this combination should be monitored closely for signs of toxicity and dosage reduction should be considered if warranted.

The effect of food on pharmacokinetics of zalcitabine in HIV-positive patients.

PURPOSE: The purpose of this study was to determine the effect of food on the pharmacokinetics of zalcitabine in HIV-positive patients. METHODS: Twenty patients received single oral 1.5 mg doses of zalcitabine with and without a standard breakfast in an open-label, randomized crossover study with at least a one week washout period between treatments. Serial blood and urine samples were collected over 24 hours and assayed for zalcitabine by a modified GC/MS method. RESULTS: Administration with food delayed and prolonged absorption resulting in a decrease of approximately 39% in maximal plasma concentrations compared to dosing under fasting conditions. Comparison of plasma AUC values indicated a small (14%) reduction in bioavailability when given with food. Approximately 59% and 45% of the dose were excreted unchanged in the urine under fasting and fed conditions, respectively. CONCLUSIONS: The results of this study show that the administration of zalcitabine with food results in a mild reduction in bioavailability. Although these changes are not expected to be of clinical importance, further studies must be conducted for confirmation.

The influence of reduced dietary fat absorption induced by orlistat on the pharmacokinetics of digoxin in healthy volunteers.

To assess the influence of an orlistat-induced reduction in dietary fat absorption on the pharmacokinetics of digoxin, an open-label, placebo-controlled, randomized, two-way crossover study was performed in 12 healthy volunteers. Each subject received single 0.4-mg doses of digoxin (soft gelatin capsules) administered orally on the fourth day of orlistat (120 mg three times daily for 6 days) and placebo (three times daily for 6 days) treatment, separated by at least an 11-day washout period. Serial blood samples were collected before and at appropriate intervals after each digoxin dose to determine plasma concentrations of unchanged digoxin. The 90% confidence intervals for the ratio of geometric least-squares means (for Cmax, AUC0-48, AUC0-t, and AUC) and for the difference of arithmetic least-squares means (for tmax and lambda z) indicate that the pharmacokinetics of digoxin was not altered by treatment with orlistat. This results suggests that a approximately 30% reduction in dietary fat absorption will not change the efficacy of digoxin in cardiac patients.

The effects of cimetidine and ranitidine on the pharmacokinetics of cifenline.

Twelve healthy subjects completed an open single dose study to evaluate the effect of co-administration of cimetidine and ranitidine on the pharmacokinetics of cifenline. Each subject received a single 160 mg dose of cifenline alone, in combination with cimetidine (300 mg four times daily), and with ranitidine (150 mg twice daily). The H2-receptor antagonists were given with breakfast 1 h prior to cifenline dosing and continuing for 48 h. Co-administration of cimetidine significantly increased Cmax (27%) and AUC (44%) and prolonged the half-life (30%) of cifenline. There were no differences in these parameters when ranitidine was co-administered with cifenline. The results of this study suggest that cimetidine, but not ranitidine, lowers the clearance of cifenline by inhibition of hepatic oxidative metabolism.

The effect of trimoprostil (trimethyldesoxy prostaglandin E2) on the intrauterine pressure in women.

Prostaglandin E2 is uterotonic. Trimoprostil, a prostaglandin E2 analog, is a gastric antisecretory and cytoprotective agent. The effects of single doses of 0, 0.125, 0.75, and 3.0 mg trimoprostil on intrauterine pressure were measured in a double-blind, crossover study in eight surgically sterile women. The 3 mg dose was not tolerated because of abdominal cramps. The other doses caused a dose-related increase in resting uterine tone and peak pressure with peak effect occurring between 30 and 60 minutes after administration with a duration of about 120 minutes. No effects on the frequency of uterine contractions occurred. Peak mean tone increased from 11.0 to 71.2 mm Hg (p less than 0.01) and peak pressure from 24.6 to 125.1 mm Hg (p less than 0.01) after placebo compared with the 1.5 mg dose. Adverse reactions included abdominal pain that correlated with an increase in intrauterine pressure and tone.

Evaluation of effect of levamisole on feline mammary cancer.

Seventy-three cats with untreated malignant mammary tumors (64 with adenocarcinoma, 9 with carcinoma in situ) were selected for study. All cats were clinically staged and stratified on the basis of tumor volume. Following radical mastectomy, the cats were randomized for treatment with either levamisole or placebo. There was no significant difference in either survival time or recurrence rate between the levamisole and placebo groups. The most significant prognostic factor was tumor volume: Cats with small tumors had a significantly enhanced survival time (p = 0.00006) and lower recurrence rate (p = 0.00004). Breed of cat was also an important prognostic factor; the domestic short-haired cats had a significantly (p = 0.038) longer survival time than the cats of other breeds.

Subacute and chronic myelomonocytic leukemia in children (juvenile CML). Clinical and hematologic observations, and identification of prognostic factors.

The clinical and hematologic characteristics of 38 children with subacute and chronic myelomonocytic leukemia (S & CMMOL) are described, and the prognostic significance of these characteristics as recorded at diagnosis is reported. The common and distinctive feature of these children was the excessive proliferation of cells of neutrophilic and monocytic series. The disease predominated in younger children, 95% were younger than 4 years, and boys were more affected than girls (22/16). The onset of the disease was heralded most often by acute or subacute symptoms. Splenomegaly was the most common physical finding at diagnosis. Leukocytosis was usually under 100 X 10(9)/l. Monocytosis and granulocytosis were often associated with normoblastosis, and, in some cases, with moderate blastosis (less than or equal to 30%). Severe anemia and marked thrombocytopenia were found in about one third of patients, increased fetal hemoglobin levels in 53%, and increased gamma-globulin levels in 50% of cases. The Philadelphia chromosome was absent in all blood and marrow cell karyotypes. Thirty-three of 38 patients were treated with moderate or intensive chemotherapy, and in all cases treatment never resulted in a complete remission. Terminal acute leukemia occurred in 11 cases. Of the 38 patients, 29 have died (median survival time, 16 months). Initial characteristics predicting a short survival (log-rank test) included: older age (greater than or equal to 2 years) (P less than 0.001), hepatomegaly (P less than 0.05), bleeding (P less than 0.001), thrombocytopenia (P less than 0.01), high counts of blasts and normoblasts in peripheral blood (P less than 0.01, P less than 0.01). Sex, infections, cutaneous manifestations, lymphadenopathy, degree of splenomegaly, hemoglobin levels, fetal hemoglobin, leukocyte counts, percent of blasts in bone marrow, and serum gamma-globulin levels were of no prognostic value. When survival was plotted on a semilogarithmic scale, a change in death rate was evident at the second year of survival suggesting that there may be two subgroups of patients with myelomonocytic picture, one with very rapid, and another with a slower rate of mortality. A stepwise discriminant-function analysis was performed in an attempt to distinguish between those children who lived less than or equal to 2 years and those who lived longer. A linear combination of variables which best discriminated between these two subgroups was found. Nearly all patients could be classified as a short-survivor or long-survivor on the basis of age and platelet, blast, and normoblast counts in peripheral blood.(ABSTRACT TRUNCATED AT 400 WORDS)

Prognostic factors for feline mammary tumors.

The case records of 100 cats with malignant mammary tumors were reviewed. All cats were staged clinically according to the staging system of the World Health Organization. The following information was obtained from the medical records: age at time of diagnosis, breed, tumor size, date of surgery, type of surgical procedure performed, histologic type of tumor, disease-free interval, survival time, and cause of death. Factors of no prognostic value were age (less than or equal to 10 years vs greater than 10 years) and breed. Tumor size was the most significant prognostic factor (P less than 0.0001). Cats with small tumors (1 cm3 to 8 cm3) had the best prognosis. The type of surgery, conservative vs radical, was significantly (P less than 0.01) related to disease-free interval, but was of no significance in prolonging survival time.

Philadelphia chromosome-positive chronic myelocytic leukemia in children. Survival and prognostic factors.

The survival and the prognostic significance of the diagnostic characteristics of 39 children with Philadelphia chromosome-positive chronic myelocytic leukemia (Ph1-positive CML), seen between 1963-1976 at the Hôpital Saint-Louis of Paris, have been analyzed. The disease predominated in children older than age 4 years (95%), with girls being more affected than boys (24 versus 15). The clinical and hematological picture at presentation was similar to that observed in adults with Ph1-positive CML. Most children of this series were treated with busulfan which, as in adults, led to reduction of leucocytosis and organomegaly but did not prevent the occurrence of blastic crisis. Well-documented blastic crisis was observed in 78% of cases. Of 39 children, 12 were still alive, all in the chronic phase. Twenty-seven have died, 21 of them after blastic crisis, 4-156 months after diagnosis (median survival, 53 months). The effect of each diagnostic characteristic on survival was evaluated using the log-rank test. Of the 14 characteristics studied, only the degree of blood and marrow blastosis was associated with a shorter survival. Age, sex, bleeding, lymphadenopathy, hepatomegaly, degree of splenomegaly, hemoglobin level, total leucocyte, immature granulocyte (promyelocytes + myelocytes + metamyelocytes), eosinophil, basophil, and platelet counts in the peripheral blood were of no prognostic significance. The failure to attain a level of statistical significance for some characteristics found to be of prognostic value for adults, could be due to the small sample size and/or to the disease homogeneity. The results of this study, however, stress the importance of the initial blastic infiltration in determining the duration of survival, which is ultimately determined by the occurrence of terminal acute leukemia. In conclusion, this study shows that the Ph1-positive CML of childhood exhibits the same course, incidence of blastic crisis, and survival as the disease of adults. It also indicates that treatment with moderate chemotherapy, such as busulfan, has no effect on the duration of survival. Therefore, new therapeutic approaches are urgently needed for the treatment of this disorder in children.

Acute nonlymphoblastic leukemia: prognostic factors in adults with long-term follow-up.

Seventy-nine adult patients with acute nonlymphoblastic leukemia (ANLL) were treated on the L-6 protocol at Memorial Sloan-Kettering Cancer Center between May 1970 and January 1974. Forty-two patients achieved a complete remission (CR) and nine of these are still disease free, with a minimum of seven years of follow-up. An extensive statistical analysis has been carried out on a large number of pretreatment and treatment characteristics to identify factors related to CR and remission duration. Multivariate regression techniques yielded as favorable characteristics associated with CR, in order of importance: young age at diagnosis, the presence of Auer rods at diagnosis, and treatment with Pseudomonas vaccine. A regression model for remission duration identified as favorable prognostic factors for long-term remission: at most two courses of induction therapy, an intermediate age range, and a low platelet count at diagnosis.

Multidisciplinary treatment of advanced Hodgkin's disease by an alternating chemotherapeutic regimen of MOPP/ABDV and low-dose radiation therapy restricted to originally bulky disease.

Ninety-one evaluable patients with advanced Hodgkin's disease (patients with stages IIB, IIIB, or IV disease and patients with IIIA disease who were greater than 35 years old or had mixed cellularity or lymphocyte depletion histology) received chemotherapy with MOPP and ABDV given in alternating months; radiation therapy (RT) (2000 rad in 2 weeks) was given during Month 5 of therapy to the previously untreated patients through ports that were limited to the originally bulky disease. The complete remission rates observed were: 88% in previously untreated patients, 69% in patients who had had prior RT but minimal chemotherapy, and 50% in patients who had had prior heavy chemotherapy. The actuarial relapse-free survival rates at 4 years, for patients who had complete remission, are: previously untreated, 84%; prior RT, 70%; and prior heavy chemotherapy, 30%. The total actuarial survival rates at 5 years for all 118 patients, evaluable and nonevaluable, who were entered in the study, are: previously untreated, 80%, prior RT, 57%; and prior heavy chemotherapy, 40%.

Treatment of advanced diffuse histiocytic lymphoma: an analysis of prognostic variables.

Sixty-five patients with Stages III and IV diffuse histiocytic lymphoma (DHL) were treated with two different and successive combination chemotherapy protocols. Twenty-seven patients were treated with the cyclophosphamide (CTX) L2 protocol, which included maintenance chemotherapy for three years. Thirty-eight patients received the NHL-3 program. Both protocols included radiotherapy (1350--4000 rad) to areas of initial bulky disease or persistent tumor, as well as central nervous system prophylaxis with intrathecal methotrexate or cytosine arabinoside in patients with bone marrow involvement. Two-year survival rates were 44 and 56%, respectively, for the CTX-L2 and NHL-3 protocols. Of the 65 patients, 59 were evaluable for response to therapy. The CTX-L2 produced a 58% total response (TR) rate, 39% complete (CR), and 19% partial (PR). The patients on NHL-3 achieved a TR rate of 82%, 33% CR, and 48% PR. The difference in TR was significant (P = 0.05), but in CR was not. Prior chemotherapy (P = 0.077) and serum lactic dehydrogenase (LDH) level above 500 U/liter (P = 0.01) significantly lessened the chances for achievement of a CR. However, sex, age, the presence of systemic symptoms, stage (III vs. IV), and prior RT were not found to be significantly related to CR rate. This analysis suggests that a high level of serum LDH characterizes a subgroup of patients with particularly aggressive DHL that requires a more intensive modality of treatment.

Treatment of acute nonlymphocytic leukemia in adults: response to 2,2-anhydro-1-B-D-arabinofuranosyl-5-fluorocytosine and thioguanine on the L-12 protocol.

Fifty-one adult patients with acute nonlymphocytic leukemia (excluding acute promyelocytic leukemia) were treated on the L-12 protocol. The L-12 differed from the preceding L-6 in that 2,2-anhydro-1-B-D-arabinofuranosyl-5-fluorocytosine (AAFC), replaced arabinosylcytosine (ara-C) together with 6-thioguanine (TG) for remission induction. Achievement of remission was followed by an extended 14-week multi-drug consolidation program. With this more intense regimen, an overall complete remission rate of 49% and a median remission duration of 23.7 months were achieved; these results were not significantly better than the 57% complete remission rate and 8.6 months median remission duration obtained with the L-6 regimen. Four year disease-free survival was 22% on the L-12 compared with 16% on the L-6 protocol. No relationship between prognosis and FAB classification was found on either the L-6 or the L-12 protocol.