A gene required for class II-restricted antigen presentation maps to the major histocompatibility complex.

We have previously described a set of mutants (16.23-selected mutants) of a B lymphoblastoid cell line that are defective in the presentation of intact proteins to class II-restricted T cells, but effectively present immunogenic peptides. The mutations in these mutants are recessive in somatic cell hybrids and are not in Class II structural genes. Here, we report on a unique mutant, 5.2.4, in which a similar defect in class II-restricted antigen presentation has occurred in association with a one-megabase homozygous deletion in the class II region of the major histocompatibility complex (MHC). The defects in class II presentation among three of the 16.23-selected mutants, and between these mutants and 5.2.4, are noncomplementary in somatic cell hybrids. This suggests that the class II presentation-defective phenotype in all four mutants results from lesions in a single MHC-linked gene, a conclusion strengthened by the finding that in a hybrid made with a second, unrelated MHC deletion mutant, T2, the class II presentation defect in a 16.23-selected mutant is also not complemented. Mutant 5.2.4, in addition to its class II presentation defect, is also defective in surface expression of MHC class I molecules, most likely because its deletion encompasses the peptide supply factor 1 gene, whose function is known to be required for normal abundance of cell surface class I molecules. However, the surface abundance of class I molecules is normal in the 16.23-selected mutants, suggesting that the lesions affecting class I surface abundance and class II presentation result from mutations in different genes.

Molecular basis of the cauliflower phenotype in Arabidopsis.

Genetic studies demonstrate that two Arabidopsis genes, CAULIFLOWER and APETALA1, encode partially redundant activities involved in the formation of floral meristems, the first step in the development of flowers. Isolation of the CAULIFLOWER gene from Arabidopsis reveals that it is closely related in sequence to APETALA1. Like APETALA1, CAULIFLOWER is expressed in young flower primordia and encodes a MADS-domain, indicating that it may function as a transcription factor. Analysis of the cultivated garden variety of cauliflower (Brassica oleracea var. botrytis) reveals that its CAULIFLOWER gene homolog is not functional, suggesting a molecular basis for one of the oldest recognized flower abnormalities.

Chronic myelogenous leukemia: in vitro studies of hematopoietic regulation in a patient undergoing intensive chemotherapy.

A patient heterozygous for the X-linked enzyme glucose-6-phosphate dehydrogenase and with Philadelphia chromosome-positive chronic myelogenous leukemia (CML) was treated with combination chemotherapy and had a partial loss of Philadelphia chromosome accompanied by partial restoration of nonclonal hematopoiesis as determined by glucose-6-phosphate dehydrogenase. Studies of in vitro hematopoiesis were performed after chemotherapy to evaluate the influences of neoplastic stem cells on normal cells and to determine whether there were physical and cell kinetic differences between leukemic stem cells and their normal counterparts. The data revealed the following: (a) The frequencies of normal committed granulocytic stem cells (CFU-C) and erythroid stem cells (BFU-E) in blood did not differ from the frequencies in marrow. (b) Normal late erythroid progenitors (CFU-E) were found at a significantly lower frequency that the more primitive BFU-E. Calculations indicated that not only was there a decrease in CFU-E production by normal BFU-E, but there was also abnormal clonal expansion of CML BFU-E (CFU-E:BFU-E ratio for normal progenitors was 1.1, whereas for the CML clone it was 11.5). (c) No increase in frequency of normal CFU-C was found after marrow cells were exposed to high specific activity tritiated thymidine. (d) Normal CFU-C and those from the CML clone were not separable on the basis of density. (e) The frequency of normal BFU-E was consistently greater than that of CFU-C, suggesting that regulatory differences influence the commitment of normal progenitors to the two pathways.

4-demethoxydaunorubicin (idarubicin) in combination with 1-beta-D-arabinofuranosylcytosine in the treatment of relapsed or refractory acute leukemia.

We conducted a Phase I-II trial of 4-demethoxydaunorubicin (idarubicin, IDR) in combination with 1-beta-D-arabinofuranosylcytosine (ara-C) in 51 patients with relapsed or refractory acute nonlymphocytic leukemia, acute lymphocytic leukemia, or chronic myelogenous leukemia in blast crisis. Only 1 of 12 patients treated at the first dose level (idarubicin, 10 mg/m2/day for 3 days and ara-C, 25 mg/m2 i.v. bolus followed by 200 mg/m2 continuous infusion daily for 5 days) achieved aplasia and complete remission. The dose of idarubicin was subsequently increased to 10 mg/m2/day for 4 days with the ara-C dose held constant. Complete remission incidence for this dose schedule was: 7 of 31 patients with acute nonlymphocytic leukemia, 0 of 5 patients with acute lymphocytic leukemia, 0 of 1 patient with chronic myelogenous leukemia in blast crisis, and 1 of 2 patients with biphenotypic leukemia. Nonhematological toxicity included nausea, vomiting, mucositis, and abnormal liver function tests. Detailed pharmacological studies were performed to determine whether ara-C altered IDR metabolism or that of its main metabolite, 13-hydroxyidarubicinol or IDR clearance. A high degree of variability among patients was apparent and no consistent effect could be demonstrated. In summary, 9 of 37 patients (24%) with relapsed or refractory ANLL, including 1 patient with biphenotypic leukemia, achieved remission. We conclude that idarubicin in combination with ara-C is an active combination in patients with relapsed or refractory leukemia.

Phase I and II clinical and pharmacological study of 4-demethoxydaunorubicin (idarubicin) in adult patients with acute leukemia.

Fifty-two adults treated previously with either acute leukemia (43 patients) or blastic-phase chronic myelogenous leukemia (nine patients) received 4-demethoxydaunorubicin (20 to 45 mg/sq m) i.v. over 2 to 3 days. Three of the ten patients with acute lymphocytic leukemia achieved a complete remission (CR) lasting 5 to 7 weeks. Five of the 28 patients with acute nonlymphocytic leukemia achieved a CR lasting 5 to 80 weeks. All remissions were induced with one course of treatment with a median time to CR of 28 days (range, 22 to 40 days). None of the patients with blastic chronic myelogenous leukemia or secondary leukemia achieved a CR. The drug was well tolerated; mucositis (36%), nausea and vomiting (35%), and hepatic dysfunction (26%) were the most common side effects. Pharmacokinetic observations on five patients demonstrated multiphasic clearance of 4-demethoxydaunorubicin and extensive formation and prolonged retention of 4-demethoxy-13-hydroxydaunorubicin; that metabolite accumulated in plasma on repeated daily dosing. 4-Demethoxydaunorubicin has sufficient antileukemic activity in both acute lymphocytic leukemia and acute nonlymphocytic leukemia to warrant a prospective comparison, in combination regimens, against the conventional anthracyclines, daunorubicin and/or doxorubicin.

Phase I and II trial of 4'-(9-acridinylamino)methanesulfon-m-anisidide in patients with acute leukemia.

Patients with acute leukemia in relapse were given 5'-(9-acridinylamino)methanesulfon-m-anisidide at a dosage of 75 to 200 mg/sq m as a daily bolus infusion of 5 consecutive days. None of the 11 patients treated at 75 to 150 mg/sq m daily for 5 days achieved remission. Ten patients with acute lymphoblastic leukemia and 21 with acute nonlymphoblastic leukemia were given treatment at 200 mg/sq m daily for 5 days. Six of these patients achieved complete remission, three with acute lymphoblastic leukemia and three with acute nonlymphoblastic leukemia. Neutropenia and thrombocytopenia were seen in all patients and in the responders lasted a median of 39 and 41 days, respectively. Stomatitis was the most significant nonhematopoietic toxicity noted. occurring in 80% of the patients. Hyperbilirubinemia was seen in 25% of the patients treated. Since 4'-(9-acridinylamino)methanesulfon-m-anisidide will induce remission in heavily pretreated patients with acute leukemia, consideration should be given to exploring its use in combination with other active drugs.

Prognostic significance of terminal deoxynucleotidyl transferase activity in acute nonlymphoblastic leukemia.

Bone marrow and/or peripheral blood samples from 133 (75%) of a total of 177 consecutive previously untreated protocol patients with acute nonlymphoblastic leukemia (ANLL) were analyzed for terminal deoxynucleotidyl transferase (TdT) activity at the time of presentation. Twenty-nine (22%) were found to exhibit TdT activity (greater than or equal to 0.10 U/10(8) cells, TdT+) as measured in a biochemical microassay. There were no differences between TdT+ as compared with TdT-negative (TdT-) patients with respect to age, sex, French-American-British (FAB) classification, or the presence of Auer's rods. Remission induction rates were higher for the TdT- patients, with 68% v 48% for the TdT+ patients (P = .05). TdT- patients also experienced longer remissions (P = .003) than TdT+ patients, especially in the Auer's rod-positive subgroup (P = .002). None of five patients with TdT+ ANLL treated with vincristine and prednisone as initial therapy achieved complete remission; all required induction regimens containing daunorubicin or amsacrine in combination with cytosine arabinoside and 6-thioguanine. It is concluded that TdT activity in ANLL indicates biphenotypia or lineage infidelity and is associated with a poor prognosis on chemotherapy protocols currently used for the treatment of ANLL.

Lymphoblastic lymphoma in adults.

Fifty-one patients with lymphoblastic lymphoma (LBL) treated with one of five successive intensive chemotherapy protocols for acute lymphoblastic leukemia (ALL) since 1971 were reviewed. The patients were divided into leukemic and nonleukemic groups, and their clinical and laboratory parameters compared. The projected 5-year survival rate for all patients treated with the L10/17 protocols was 45% for both leukemic and nonleukemic LBL. The response to treatment was compared with that of 111 patients with ALL and was nearly identical. Poor prognostic factors were age beyond 30, WBC greater than 50,000/microL, failure to achieve a complete response (CR), and a late CR during induction. Leukemia at presentation, T cell surface markers, and the presence of a mediastinal mass did not adversely affect survival. The use of intensive chemotherapy protocols has proven to be a significant advance in the treatment of LBL.

Leukemia following treatment of germ cell tumors in men.

We investigated the incidence of leukemia occurring subsequent to the treatment of germ cell tumors in men at our institution over a 30-year interval and found four patients with acute nonlymphocytic leukemia (ANLL) and one patient with chronic myelomonocytic leukemia. The relative risk (observed/expected cases) estimates for the development of leukemia ranged from 13.7 (P = .0005) in the total population to 50.1 (P = .0001) in the group treated with cytotoxic agents alone. All three patients with ANLL treated with contemporary antileukemic therapy had complete responses, with survivals of 7, 29, and 133 + months. In a review of the literature, 14 additional cases of germ cell tumors were found in which the men subsequently developed leukemia. It is concluded that leukemia following germ cell tumors is increased in incidence and is likely to be treatment induced. Complete responses and long-term survival are possible in secondary leukemia and aggressive antileukemic therapy should be given.

Philadelphia chromosome and terminal transferase-positive acute leukemia: similarity of terminal phase of chronic myelogenous leukemia and de novo acute presentation.

Twenty-eight patients with Philadelphia chromosome (Ph1)--positive and terminal transferase (TdT)--positive acute leukemia (AL) were treated with intensive chemotherapy used for adult acute lymphoblastic leukemia (L-10 and L-10M protocols). Fifteen patients had a documented chronic phase of Ph1-positive chronic myelogenous leukemia preceding the acute transformation (TdT + BLCML) while the remaining 13 patients did not (TdT + Ph1 + AL). An overall complete remission (CR) rate of 71% was obtained with a median survival of 13 months in the responders. Clinical presentation, laboratory data, cytogenetics, response to treatment, and survivals of the two groups of patients are compared. These results appear to be similar, suggesting a common or closely related origin. Since the overall survival of those receiving chemotherapy maintenance is poor, three patients underwent allogeneic bone marrow transplantation (BMT) from histocompatibility leukocyte antigen--matched siblings after they achieved CR. One of them is a long-term survivor (35 + months) with a Ph1-negative bone marrow. New techniques such as BMT should be considered in young patients with a histocompatibility leukocyte antigen--compatible sibling once a CR has been achieved.

Autologous bone marrow transplantation for patients with poor-prognosis lymphoma.

Review of prognostic factors at Memorial Hospital in New York City has shown that adult patients with large-cell lymphoma (diffuse histiocytic lymphoma by Rappaport classification) who have high lactic dehydrogenase (LDH) and/or bulky mediastinal or abdominal disease are destined to do poorly with conventional combination chemotherapy, with a 2-year disease-free survival of about 20%. Patients who relapse after conventional combination chemotherapy have a similar poor prognosis. Thirty-one such patients with lymphoma were studied to evaluate the efficacy of intensive radiotherapy (hyperfractionated total body irradiation [TBI] [1,320 rad]), and cyclophosphamide (60 mg/kg/d for two days) followed by autologous bone marrow transplantation (ABMT). Our results show a disease-free survival advantage (P = .002) for 14 patients who underwent ABMT immediately after induction of remission with 79% surviving at a median follow-up 49.2+ months, compared with a median survival of 5.2 months for 17 patients administered ABMT while in relapse and/or after failing conventional treatment. Our results support the use of aggressive therapy as early treatment for patients with poor prognostic features.

A cause-specific hazard rate analysis of prognostic factors among 199 adults with acute lymphoblastic leukemia: the Memorial Hospital experience since 1969.

Results of a multivariable analysis of prognostic factors are reported for 199 previously untreated adults with acute lymphoblastic leukemia (ALL). These patients have long-term follow-up, and the probability of cure is estimated at approximately 35%. The cause-specific hazard rate analysis found lower rates of achieving complete remission (CR) in patients with WBC greater than 10,000/microL, AUL (undifferentiated) morphology, and older age. Since these patients required additional time to respond, fewer of them actually achieved CR. Characteristics directly associated with a higher rate of death during induction therapy due to severe bone marrow suppression were low serum albumin concentration (less than or equal to 3.5 g/dL), age greater than 50 years, acute undifferentiated leukemia (AUL) morphology, low Karnofsky performance status, and weight loss greater than 5%. Factors associated with a higher rate of relapse were WBC greater than 20,000/microL, non-T cell ALL, age greater than 60 years, Ph' + ALL, and time to achieve CR greater than 5 weeks. These criteria were used to identify patients at high risk of relapse. In addition, the predictive value of high WBC was found to disappear by 18 months of continuous CR. Finally, the rate of death following first relapse was higher in patients with a short first remission duration, high percentage weight loss at initial diagnosis, and older age. In summary, factors associated with a higher rate of death during attempted induction (ie, low albumin, high percent weight loss, and poor performance status) had no association with the patient's ability to remain relapse-free. Conversely, factors correlating with more extensive or resistant disease (ie, high WBC, null or B cell ALL, or Ph' + ALL) showed no association with the ability to tolerate therapy. Thus, a less toxic but more effective induction regimen is needed for patients with a poor clinical status, whereas a more intensive form of therapy appears warranted for patients presenting with more extensive or resistant disease.

Treatment of acute lymphoblastic leukemia in adults: results of the L-10 and L-10M protocols.

Two successive protocols (L-10 and L-10M) employing multidrug induction therapy with vincristine, prednisone, and doxorubicin (Adriamycin) plus an intensive consolidation phase and maintenance program have led to a significant improvement in the prognosis of adult acute lymphoblastic leukemia (ALL). The complete remission (CR) rates for the 34 patients entered on the L-10 protocol and the 38 patients entered on the L-10M protocol were 85% and 84%, respectively. The median duration of remission has not yet been reached for either the L-10 (median follow-up, 5.5 years; range, 3.5-7.5 years) or the L-10M protocol (median follow-up, 2.5 years; range, 1-3.5 years). The median survival time has not yet been reached for the L-10M protocol. Central nervous system prophylaxis with intrathecal methotrexate alone was effective in preventing central nervous system relapse. An analysis of possible prognostic factors indicated that patients less than 25 years of age had a higher CR rate than older patients (p = 0.02). Patients with an initial leukocyte count below 15,000/microL experienced longer remissions than patients with a leukocyte count above 15,000/microL (p = 0.008), and patients who achieved CR within the first month of therapy were in remission longer than those requiring a longer time to achieve CR (p = 0.04). Patients with T cell ALL did not have a poorer prognosis than other patients treated on these protocols. The L-10 and L-10M protocols were well tolerated with minimal morbidity.

Clinical pharmacology of recombinant human tumor necrosis factor in patients with advanced cancer.

Twenty-six patients with advanced cancer refractory to standard therapy were treated with recombinant human tumor necrosis factor (rTNF) in a study aimed at determining the toxicity and tolerance of rTNF and at seeking evidence of antitumor activity. The study design involved two treatments per week for 4 weeks with alternating subcutaneous and intravenous (IV) administration, and weekly dose escalation through four levels in each patient. The dose range was 1 to 200 micrograms/m2 for IV bolus injection, and 5 to 250 micrograms/m2 for subcutaneous injection. Thirteen patients completed the full course. Early discontinuation of treatment was related to rTNF toxicity in seven cases. The major side effects were rigors, fever, headache, fatigue, and hypotension. Acute changes in granulocyte, lymphocyte, and monocyte counts, changes in serum zinc levels and plasma cortisol levels consistent with an acute phase response, and inflammation at the site of subcutaneous injection were also seen. At doses of 125 to 250 micrograms/m2, inflammation at the subcutaneous injection site was unacceptably severe. Minor changes were seen in hemostatic parameters. Hypotension was corrected by fluid administration and did not require treatment with vasopressors. Initial serum concentrations of rTNF were measured at five minutes after IV administration and were found to range from 2.5 ng/mL after a dose of 35 micrograms/m2 to 80 ng/mL after a dose of 200 micrograms/m2. The half-life of rTNF in the blood was 20 minutes. A decrease in lymph node size was observed in a patient with B cell lymphoma.

Randomized phase III trial of liposomal daunorubicin versus doxorubicin, bleomycin, and vincristine in AIDS-related Kaposi's sarcoma.

PURPOSE: To compare the safety and efficacy of liposomal daunorubicin (DaunoXome; NeXstar Pharmaceuticals, Inc, Boulder, CO) with a reference regimen of doxorubicin, bleomycin, and vincristine (ABV) in advanced AIDS-related Kaposi's sarcoma (KS). PATIENTS AND METHODS: In a prospective randomized phase III trial, 232 patients were randomized to receive DaunoXome 40 mg/m2 or a combination regimen of doxorubicin 10 mg/m2, bleomycin 15 U, and vincristine 1 mg, administered intravenously every 2 weeks. Treatment was continued until complete response (CR), disease progression, or unacceptable toxicity. RESULTS: Of 232 patients randomized, 227 were treated: 116 with DaunoXome and 111 with ABV. The overall response rate (CR or partial response [PR]) was 25% (three CRs and 26 PRs) for DaunoXome and 28% (one CR and 30 PRs) for ABV. The difference in response rates was not statistically significant. The median survival time was 369 days for DaunoXome patients and 342 days for ABV patients (P = .19). The median time to treatment failure was 115 days for DaunoXome and 99 days for ABV (P = .13). ABV patients experienced significantly more alopecia and neuropathy (P < .0001). DaunoXome patients experienced more grade 4 neutropenia (P = .021). Cardiac function remained stable, with no instances of congestive heart failure on either treatment arm. CONCLUSION: In this large phase III trial, the efficacy of DaunoXome was comparable to that of ABV. Response rates, time to treatment failure, and overall survival were similar on both treatment arms. DaunoXome is a safe and effective primary therapy for advanced AIDS-related KS.

Concomitant administration of chlorambucil limits dose intensity of fludarabine in previously treated patients with chronic lymphocytic leukemia.

Fifteen patients with chronic lymphocytic leukemia (CLL) were treated in a phase I-II study of chlorambucil with an escalating dose of fludarabine. The study was designed to identify a maximum tolerated dose (MTD) of fludarabine given in conjunction with a constant dose of chlorambucil. Patients were eligible for study if they had Rai intermediate or high-risk disease which had relapsed from or was refractory to conventional treatment. The initial cohort of patients received fludarabine 10 mg/m2/d days 1-5 and chlorambucil 20 mg/m2 days 1 and 15. Cycles were repeated every 28 days. Unacceptable toxicity was encountered in this cohort. The protocol was then modified to give chlorambucil 20 mg/m2 on day 1 (only). At this chlorambucil dose, cohorts of three patients were treated with fludarabine 10, 15, and 20 mg/m2/d x 5 days. The predominant toxicity was thrombocytopenia with 73% experiencing grade > or = 3 toxicity. The dose-limiting non-hematologic toxicity was infection. We identified an MTD of fludarabine of 15 mg/m2/d x 5 days when given with chlorambucil 20 mg/m2 for this group of patients. One patient achieved a CR and three patients achieved a PR for a total response rate of 27%. We conclude that concomitant administration of chlorambucil limits the dose intensity of fludarabine which can be administered to previously treated patients with CLL.

Comparative trial of cytarabine and thioguanine in combination with amsacrine or daunorubicin in patients with untreated acute nonlymphocytic leukemia: results of the L-16M protocol.

Ninety-six patients with de novo acute nonlymphocytic leukemia (ANLL) were randomized to receive either daunorubicin (50 mg/m2, IV) on days 1-3; cytarabine (Ara-C) (25 mg/m2, IV) bolus, followed by 160 mg/m2 as a continuous IV infusion daily for 5 days and 6-thioguanine (6-TG) (100 mg/m2 po) every 12 hr daily for 5 days (DAT); or amsacrine (190 mg/m2, IV) on days 1-3 with Ara-C and 6-TG at the above doses (AAT). Patients achieving complete remission (CR) then received two courses of consolidation therapy with the same combination that had induced remission but at slightly reduced total doses. Patients less than or equal to age 40 with an HLA-identical sibling donor underwent allogeneic transplantation, usually after consolidation therapy. The remaining patients were then randomized to receive either maintenance therapy (alternating cycles of vincristine/methotrexate, cyclophosphamide/6-TG, daunorubicin/hydroxyurea and Ara-C/6-TG) or no further treatment. Ninety-two patients were evaluable for response. Twenty-five of the 46 patients (54%) who received DAT and 32 of the 46 patients (70%) who received AAT achieved CR (p = 0.13). When patients were stratified by age, however, remission induction advantage with AAT became statistically significant (p = 0.03). Additionally, more patients achieved CR following one course of AAT than following one course of DAT (48% vs 28%, p = 0.03). Overall survival in the AAT group was improved as well (p = 0.01). Too few patients were randomized on the maintenance arm of the protocol to make interpretation meaningful. Non-hematologic toxicity was generally comparable in both arms. In conclusion, patients with de novo ANLL who received AAT had a higher remission incidence and slightly longer survival compared to patients who received DAT. Further investigation of this drug combination in untreated patients with ANLL is warranted.

Severe toxicity limits intensification of induction therapy for acute lymphoblastic leukemia.

Fourteen adult patients with newly-diagnosed acute lymphoblastic, leukemia (ALL), and lymphoblastic lymphoma, were treated with a dose-intense induction regimen. This regimen was designed to increase the fraction of patients achieving an early complete remission, in an attempt to increase the fraction of patients who are long-term disease-free survivors. The induction regimen included vincristine, prednisone, intermediate-dose cytarabine (Ara-C), and idarubicin, all given during the first week of therapy. This combination led to significant hepatic, gastro-intestinal, infectious, and neurologic toxicity. There was unacceptable treatment-related mortality (29%). After the first eight patients, the study was modified, omitting the Ara-C from the induction phase. Gastrointestinal morbidity was less in the cohort treated without Ara-C; however, infectious morbidity persisted at unacceptable levels and this program was terminated as too toxic to administer. There were nine complete remissions, three early deaths, and two patients with resistant disease. There have been six relapses, three of which occurred in patients who, because of protracted grade III/IV toxicity, were no longer receiving chemotherapy. With a minimum follow-up of 20 months, only three patients are still alive. We conclude that this combination of vincristine, prednisone, Ara-C, and idarubicin, is too toxic to be used as induction therapy for adult patients with ALL and lymphoblastic lymphoma.

Current status of treatment of acute leukemia in adults: an overview of the Memorial experience and review of literature.

The results of treatment of 629 previously untreated adults with acute leukemia at Memorial Hospital are reviewed. During the past 14 years, 135 adults (greater than 15 years) with acute lymphoblastic leukemia (ALL) have been treated with one of three successive multidrug-intensive treatment protocols (L2, L10/10M, and L17/17M), each calling for 2.5 to 3 years of systemic chemotherapy and prophylactic intrathecal methotrexate without cranial irradiation. The complete remission (CR) rates were L2 (n = 22) = 77%; L10/10M (n = 69) = 86%; L17/17M (n = 44) = 77%. The median durations of survival and remission were, respectively, L2 = 33 and 30 months; L10/10M = 62 months and not reached; and L17/17M = not reached. Almost all relapses occurred within the first 3 years while still continuing treatment, and there were only rate late relapses after stopping treatment. It appears that approximately half of the patients may have been cured with the latest two protocols. During the last 17 years, 494 adults aged 15 to greater than 70 with acute nonlymphoblastic leukemia (ANLL) were treated with one of five successive multiple drug treatment protocols of varying intensity (arabinosylcytosine + 6-thioguanine [n = 36]; L6 [n = 101]; L12 [n = 104]; L14/14M [n = 121]; and L16/16M [n = 132]). Patients with myelodysplastic syndromes generally were not treated until they developed acute leukemia, but were then entered and included in the results. Secondary leukemias following treatment of other neoplastic diseases were not included. The complete remission rates were fairly constant between 47 and 64% and the median durations of remissions were between 9 and 21 months. The intensive treatment L14 and L16 protocols were associated with more early deaths and did not result in a significantly improved remission incidence or duration or survival. With all protocols, the majority of relapses occurred within the first 2 years, but relapses continued to occur at a decreasing rate for 4 years and occasionally even later. Whereas a small fraction (approximately 10 to 15%) of adults with ANLL are now apparently being cured with combination chemotherapy, despite intensive efforts there has been little improvement during the last decade and more selective and effective forms of treatment are urgently needed.

The acute monocytic leukemias: multidisciplinary studies in 45 patients.

The clinical and laboratory features of 37 patients with variants of acute monocytic leukemia are described. Three of these 37 patients who had extensive extramedullary leukemic tissue infiltration are examples of true histiocytic "lymphomas." Three additional patients with undifferentiated leukemias, one patient with refractory anemia with excess of blasts, one patient with chronic myelomonocytic leukemia, one patient with B-lymphocyte diffuse "histiocytic" lymphoma and one patient with "null" cell, terminal deoxynucleotidyl transferase-positive lymphoblastic lymphoma had bone marrow cells with monocytic features. Another patient had dual populations of lymphoid and monocytoid leukemic cells. The true monocytic leukemias, acute monocytic leukemia (AMOL) and acute myelomonocytic leukemia (AMMOL), are closely related to acute myelocytic leukemia (AML) morphologically and by their response to chemotherapy. like AML, the leukemic cells from the AMMOL and AMOL patients form leukemic clusters in semisolid media. Cytochemical staining of leukemic cells for nonspecific esterases, presence of Fc receptor on the cell surface, phagocytic ability, low TdT activity, presence of surface "ruffles" and "ridges" on scanning EM, elevations of serum lysozyme, and clinical manifestations of leukemic tissue infiltration are features which accompanied monocytic differentiation in these cases.