Short-term treatment for acute myelogenous leukaemia

Research progress on the role and mechanism of Sirtuin family in doxorubicin cardiotoxicity

BACKGROUND

Doxorubicin (DOX) is a widely utilized anthracycline chemotherapy drug in cancer treatment, yet its efficacy is hindered by both short-term and long-term cardiotoxicity. Although oxidative stress, inflammation and mitochondrial dysfunction are established factors in DOX-induced cardiotoxicity, the precise molecular pathways remain elusive. Further exploration of the pathogenesis and identification of novel molecular targets are imperative. Recent studies have implicated the Sirtuins family in various physiological and pathological processes, suggesting their potential in ameliorating DOX-induced cardiotoxicity. Moreover, research on Sirtuins has discovered small-molecule compounds or medicinal plants with regulatory effects, representing a notable advancement in preventing and treating DOX-induced cardiac injury.

PURPOSE

In this review, we delve into the pathogenesis of DOX-induced cardiotoxicity and explore the therapeutic effects of Sirtuins in mitigating this condition, along with the associated molecular mechanisms. Furthermore, we delineate the roles and mechanisms of small-molecule regulators of Sirtuins in the prevention and treatment of DOX-induced cardiotoxicity.

STUDY-DESIGN/METHODS

Data for this review were sourced from various scientific databases (such as Web of Science, PubMed and Science Direct) up to March 2024. Search terms included "Sirtuins," "DOX-induced cardiotoxicity," "DOX," "Sirtuins regulators," "histone deacetylation," among others, as well as several combinations thereof.

RESULTS

Members of the Sirtuins family regulate both the onset and progression of DOX-induced cardiotoxicity through anti-inflammatory, antioxidative stress and anti-apoptotic mechanisms, as well as by maintaining mitochondrial stability. Moreover, natural plant-derived active compounds such as Resveratrol (RES), curcumin, berberine, along with synthetic small-molecule compounds like EX527, modulate the expression and activity of Sirtuins.

CONCLUSION

The therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity represents a potential molecular target. However, further research is urgently needed to elucidate the relevant molecular mechanisms and to assess the safety and biological activity of Sirtuins regulators. This review offers an in-depth understanding of the therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity, providing a preliminary basis for the clinical application of Sirtuins regulators in this condition.

Pretreatment leukaemia cell drug resistance is correlated to clinical outcome in acute myeloid leukaemia

In 85 adult patients diagnosed with acute myeloid leukaemia (AML) and treated at the same institution during a 5-yr period, the clinical significance of in vitro cellular drug resistance to the anthracyclines aclarubicin (Acla) and daunorubicin (Dau) as well as the nucleoside analogue cytarabine (Ara-C) was investigated using a 4-d MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay. In 59 patients of whom 40 were treated by the combination of Acla and Ara-C we found that leukaemia cell drug resistance towards Acla was higher (by a factor 2.80) in patients who failed to enter complete remission (CR) after the first cycle of induction chemotherapy as compared to patients who entered complete remission. The relationship was significant in univariate as well as multivariate analysis (p=0.02 and 0.03, respectively). By contrast, no in vitro single drug resistance values were consistently correlated to other parameters of clinical outcome (overall CR rate, overall survival (OS), or continuous complete remission (CCR)), whereas the combined Acla and Ara-C drug resistance profile (Acla/Ara-C DRP) was of prognostic significance to overall survival of all 85 patients (p=0.004) as well as to the CCR of 39 complete responders (p=0.04). These findings remained statistically significant in multivariate analyses correcting for other variables influencing clinical outcome including patient age, leukocyte count, karyotype, FAB-subtype, and presence/absence of secondary AML. We conclude that the in vitro drug resistance of leukaemia cells at time of disease presentation appears to be independent of prognostic significance to short- and long-term clinical outcome in AML.

Leukaemia cell drug resistance and prognostic factors in AML

In 93 cases of acute myeloid leukaemia (AML) the extent to which prognostic factors mirrored the in vitro cellular chemotherapy resistance (to anthracyclines aclarubicin (Acla) and daunorubicin (Dau) as well as nucleoside analogue cytarabine (Ara-C)) was investigated using a 4-d MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay. We found that age at presentation and presence of secondary AML were significantly correlated to leukaemia cell Ara-C resistance. Thus, analysis of in vitro drug resistance data revealed that age at presentation and presence of secondary leukaemia were both independently correlated to cellular drug resistance, with older age being associated with higher Ara-C resistance in vitro (p=0.02 and 0.01 in univariate and multivariate analyses, respectively) and with secondary leukaemia being associated with higher Ara-C resistance (p=0.04 and 0.059 in univariate and multivariate analysis, respectively). Median LC-50 values (Ara-C) were: 178 ng/ml in paediatric cases, 356 ng/ml in younger adult cases, and 584 ng/ml in elderly (age > or = 60 yr) cases giving a resistance ratio between these age subgroups of 1:2.0:3.3. Median LC-50 values (Ara-C) was 381 ng/ml in de novo cases as opposed to 891 ng/ml (resistance ratio 1:2.3) in secondary cases. By contrast, cytogenetic findings, presenting leucocyte count, FAB-subtype, and gender were not consistently correlated to in vitro drug resistance to any of the three drugs. We conclude that at least two major adverse prognostic factors in AML (advanced age at presentation and presence of secondary leukaemia) are associated with increased leukaemia cell Ara-C resistance. High leucocyte count is not associated with increased cellular drug resistance towards Acla, Ara-C or Dau.

Post-remission therapy of adult acute myeloid leukaemia: one cycle of high-dose versus standard-dose cytarabine. Leukaemia Project Group of the Swiss Group for Clinical Cancer Research (SAKK)

BACKGROUND

Intensification of post-remission therapy improves the cure rate of acute myeloid leukemia (AML) but is often accompanied by unacceptable toxicity. From 1985 to 1992 the Swiss Group for Clinical Cancer Research (SAKK) performed a randomized phase III trial to evaluate the effectiveness of one single postremission course of high-dose cytarabine (HDAC) in terms of leukaemia-free and overall survival in adults with de novo AML.

PATIENTS AND METHODS

Adult (15-65 years) AML patients in remission after two induction courses were randomly assigned to one consolidation course either with standard (SDAC: 100 mg/sqm 24 hours infusion over seven days) or with high-dose cytarabine (HDAC: 3000 mg/sqm every 12 hours as one-hour-infusion for six days). In addition, both arms included daunorubicin (45 mg/sqm daily on days 1 to 3). Thereafter, patients were observed without maintenance until relapse.

RESULTS

After two induction courses 208/276 eligible patients achieved remission (CR: 169, 61%, PR: 39, 14%), 41 were resistant (15%) and 20 died early (7%). Seventy-one patients in remission were not randomized. One hundred thirty-seven were randomized in CR/PR (67 SDAC, 70 HDAC). 4/70 patients randomized to HDAC did not receive it. Treatment-related mortality in HDAC was 1.4% (1/66). WHO grade 3-4 toxicities occurred in 14/67 SDAC and in 38/66 HDAC patients (P < 0.0001). The median event free survival was 10.8 (SDAC) vs. 12.2 months (HDAC; P = 0.18). The median overall survival was 24.6 (SDAC) vs. 32.6 months (HDAC; P = 0.07). Although statistically uncertain, HDAC reduced the hazard of progression (hazard ratio: 0.69, P = 0.08) and of death (hazard ratio: 0.70, P = 0.13). For 112 patients stratified as CR the estimated four-year disease-free survival was 25% (+/-6%) with SDAC and 37% (+/-6%) with HDAC (P = 0.09). The overall survival rates at four years were 38% (+7%) and 48% (+7%), respectively (P = 0.10). In multivariate analysis HDAC significantly reduced the hazard of relapse by 39% compared to SDAC (hazard ratio = 0.61, 95% CI: 0.37-0.99; P = 0.049).

CONCLUSIONS

We conclude that early consolidation of adult AML in CR with a single course of HDAC is superior in terms of outcome to one cycle of SDAC. The results of our intensive, single course HDAC group compare favourably with less intensive, repetitive HDAC cycles, suggesting that Ara-C dose intensity may be more important than total dosage. In addition, our treatment strategy is much less toxic and less expensive.

Therapy of acute myelogenous leukemia

Treatment of acute myelogenous leukemia (AML) is divided into remission induction and post-remission therapy. Remission induction is usually with cytarabine and an anthracycline. Daunorubicin is commonly used but recent data suggest idarubicin or mitoxantrone are equally effective, possibly better. High-dose cytarabine has also been used for remission induction but is not proven superior. Post-remission treatment is typically with two or more courses of drugs similar to those used for remission induction. Other studies use non-cross resistant drugs and/or high-dose cytarabine. Although some data favor use of high-dose cytarabine, no approach is clearly superior. There is considerable controversy whether persons in first remission and with an HLA-identical sibling should receive a bone marrow transplant immediately or after relapse. Although transplant results appear superior, especially in persons less than 20 years of age, the most effective strategy may be reserving transplants for persons failing chemotherapy. This strategy also applies to persons receiving autologous transplants or transplants from alternative donors, like HLA-matched related or unrelated persons.

The treatment of acute myeloid leukaemia preceded by the myelodysplastic syndrome

Most cases of acute myeloid leukaemia in the elderly and about 15% of the cases in younger patients follow a myelodysplastic disease. This disease may differ biologically from de novo AML making cure more difficult. Understanding post-MDS AML is difficult because of its preponderance in the elderly and the many complicating factors of treating old people. However, it is likely that post-MDS AML is more resistant to chemotherapy than de novo AML, that periods of pancytopenia last longer following chemotherapy and remissions are shorter. In younger patients high complete remission rates are achievable with aggressive chemotherapy and good supportive care. Such patients are best served by subsequent allogeneic bone marrow transplantation if possible, and if not then bone marrow autograft or a maintained remission should be considered. For older patients cure is unlikely and the choice between low-dose cytarabine and aggressive chemotherapy must be made if treatment is to be contemplated at all. The former leads to less hospitalisation and fewer side effects, but the latter gives a greater chance of a complete remission. This will not be long lasting.

Cell kinetics with in vivo bromodeoxyuridine and flow cytometry: clinical significance in acute non-lymphoblastic leukaemia

From 1986 to 1988, 54 consecutive previously untreated patients with acute non-lymphoblastic leukaemia (ANLL), median age 54 years, were treated for remission (CR) induction with vincristine and intravenous medium-dose cytarabine sequentially followed by daunomycin and infusion cytarabine. CR patients received intensive consolidation. Bone marrow blast kinetics was studied before therapy with in vivo bromodeoxyuridine and bivariate flow cytometry. CR rate was 70.2%, median CR was 13.2 months, responsive patient survival was 16.9 months and overall survival was 9.2 months. Besides lower median age, the 33 responsive patients also had shorter potential doubling time (Tpot) and greater cell production rate (PR) than the 14 unresponsive patients (mean values = 10.9 vs. 25.4 days, P less than 0.05, and 14.7 vs. 8.9 cells/100 cells/day, P less than 0.02, respectively), due to a higher mean labelling index (7.0 vs. 5.1%, P less than 0.05) and/or to a shorter mean DNA synthesis time (13.6 vs. 18.6 hours, P less than 0.05). Besides lower white blood cell count and bone marrow blast percentage, patients who experienced CR longer than 13.2 months had shorter Tpot (P less than 0.05) and a greater PR (P less than 0.02) than those who relapsed before this time. These data indicate that kinetic parameters have prognostic relevance in ANLL patients treated with sequential vincristine, cytarabine and daunomycin for inducing CR and with intensive consolidation after CR, a high proliferative activity being a favourable factor for both CR achievement and its duration.

Postremission chemotherapy in adult acute non-lymphoblastic leukaemia including intensive or non-intensive consolidation therapy

From October 1983 to December 1988, 84 consecutive adult patients with acute non-lymphoblastic leukaemia (ANLL; median age = 51 yr) were uniformly treated to induce remission (CR) with intravenous vincristine and cytarabine sequentially followed by daunomycin and infusion cytarabine. From October 1983 to December 1985 consolidation was non-intensive (2 courses with the same drugs used for induction) (protocol ANLL83: 27 patients, median age = 45). From January 1986 to December 1988 consolidation was intensive (4 courses of vincristine and cytarabine sequentially followed by etoposide plus thioguanine or amsacrine) (protocol ANLL86: 57 patients, median age = 57). Excluding early deaths, the CR rate was 71.6%. Median CR, responsive patient survival and overall survival were 11.1, 15.3 and 8.5 mo, respectively. For protocol ANLL83 and ANLL86, median CR was 8.7 and 13.2 mo (P less than 0.05) and median survival was 13.1 and 16.9 mo (P less than 0.05) for responders and 8.0 and 9.2 mo (P not significant) for all patients. Intensive consolidation including drugs not previously used for induction seems to prolong CR duration and responder survival in adult ANLL.

Acute myeloid leukemia in elderly adults

One hundred and fifteen previously untreated adults aged over 60 years were referred to St Bartholomew's Hospital between 1978 and 1986 for management of acute myeloid leukemia (AML). Twenty-seven patients received symptomatic or palliative treatment only because combination chemotherapy was considered inappropriate. Eighty-eight patients received intensive chemotherapy with curative intent. There was a 48 per cent 'early death' rate and a 24 per cent incidence of resistant disease; complete remission (CR) was achieved in 25/88 patients (28 per cent). By multivariate analysis, a blast count less than 50 x 10(9)/l at presentation was the only factor predictive for achievement of CR whilst the latter and a presentation blast count less than 50 x 10(9)/l predicted for superior survival. Treatment was often curtailed on account of unacceptable toxicity; only 2/88 patients received the planned six cycles of treatment. Two patients died in CR. Four patients are alive in first CR at 3-9 years from treatment; one is alive in second CR following meningeal relapse. Overall survival was significantly worse than that of a contemporaneous group of adults aged 15-59 years treated at this hospital, but duration of CR was comparable. There are great difficulties involved in the intensive treatment of AML in elderly adults, but the major survival benefit gained by achieving CR should stimulate the search for better tolerated but still curative regimens.

The frequency of long-term remission in patients with acute myelogenous leukaemia treated with conventional maintenance chemotherapy: a study of 760 patients with a minimal follow-up time of 6 years

Remission duration associated with the administration of conventional maintenance chemotherapy to patients with acute myelogenous leukaemia was evaluated. The records of 760 patients who entered remission between 1974 and 1979 were reviewed. The median duration of remission was 1.1 years with 16% of patients remaining in remission at 8 years. The relapse curve was biphasic with a high rate of relapse during the first 2 1/2 years of remission followed by a much lower relapse rate thereafter. Leukaemic relapses were noted through 8 years of remission. A plateau phase indicating freedom from the risk of leukaemic recurrence is not clearly apparent yet but may exist after the eighth year of remission.

[Post-remission treatment of acute leukemia in adulthood: allogeneic bone marrow transplantation or chemotherapy?]

The impact of bone marrow transplantation and chemotherapy on remission duration and survival in acute leukemia is controversial. Most studies on either procedure deal with selected patients and lack randomized or concurrent controls; many exclude high-risk subgroups. There are only a few preliminary reports on the direct comparison between bone marrow transplantation and intensive chemotherapy. Considerable controversy remains as to whether patients with AML in first remission who have an HLA identical sibling should receive a bone marrow transplant at that time or whether the transplant should be delayed until relapse or second remission. In patients under the age of 25 years, results of bone marrow transplantation are considered to be equivalent or superior to those achieved with chemotherapy. Because of a high lethality rate few results suggest that survival of patients transplanted during first remission is not superior to that obtained by intensified chemotherapy; however, the relapse incidence is decreased. In recent years, results in adult ALL, treated with various intensified programs, have improved considerably and are nearly comparable to those obtained in childhood ALL. Therefore, allogeneic bone marrow transplantation is usually performed in standard risk patients during second remission and, if relapse occurs within the first three years. It is not clear at present whether ALL high-risk patients will benefit from bone marrow transplantation during first remission.

Prognosis of patients receiving intensive care for lifethreatening medical complications of haematological malignancy

The mortality of patients admitted to intensive care units with haematological malignancy is high. A humane approach to the management of the critically ill as well as efficient use of limited resources requires careful selection of those patients who are most likely to benefit from intensive care. To delineate more accurately the factors influencing outcome in these patients the records of 60 consecutive admissions to the intensive care unit (37 male, 23 female) with haematological malignancy were reviewed retrospectively. Fifty patients were in acute respiratory failure, most commonly (34 patients) with a combination of pneumonia and septicaemic shock. The severity of the acute illness was assessed by the APACHE II (acute physiology and chronic health evaluation II) score and number of organ systems affected. Thirteen patients survived to leave hospital. The mortality of patients with haematological malignancy was consistently higher than predicted from a large validation study of APACHE II in a mixed population of critically ill patients. Moreover, no patient with an APACHE II score of greater than 26 survived. Mortality among the 22 patients with relapsed malignancy (21 deaths), was significantly higher than among the 35 patients at first presentation (26 deaths). On discharge from the intensive care unit all survivors had responded well to chemotherapy and had normal or raised peripheral white cell counts. They included seven patients who had recovered from leucopenia (white cell count less than 0.5 X 10(9)/l). In contrast, 36 of the 47 patients who died were leucopenic at the time of death. The overall mortality of critically ill patients with haematological malignancy is higher than equivalently ill patients without cancer. The dysfunction of an increasing number of organ systems, an APACHE II score of greater than 30, failure of the malignancy to respond to chemotherapy, and persistent leucopenia all point to a poor outcome.

Acute myeloblastic leukaemia in the elderly

Acute myeloblastic leukaemia (AML) is a disease of the elderly with a median age at presentation in the seventh decade and a peak incidence in the U.K. of greater than 20 patients per 100,000 population per yr between the ages of 80 and 84. Most major AML trials are carried out on a younger population of patients with low recruitment of the elderly. The results in older patients are much worse than younger patients and often no better than the natural history of the disease. These poor results may be partly due to poor tolerance of treatment in the elderly, but are also due to intrinsic differences between AML in the elderly and AML in younger patients. These problems all justify randomised, prospective trials designed specifically for elderly patients to test prognostic scoring and various levels of intensity of therapy.

Idarubicin in combination with etoposide and cytarabine in adult untreated acute non lymphoblastic leukemia

Thirty-one unselected patients with untreated acute non lymphoblastic leukemia (ANLL) ranging in age from 15 to 76 years received two courses of a new high-dose induction regimen consisting of idarubicin, etoposide and cytarabine. Patients who entered complete remission (CR) were then allocated to post-remission intensification (PRI). Patients under 40 years of age with a HLA-compatible donor were given bone marrow transplantation (BMT); those without an HLA identical donor received either autologous BMT (ABMT) or no subsequent therapy. Twenty-five out of 31 patients (80.6%) achieved CR (93.3% in young and 68.7% in old patients) and 14 (56%) after the first cycle. Six patients (five out six greater than 40 years) died of cerebral hemorrhage and/or infection during the induction phase and four additional patients (three elderly) died on the PRI for the same cause without recurrent disease. Eleven out 25 patients are disease-free survivors 2-34 months (median 10 months) after achievement of CR. In conclusion, this intensive chemotherapy regimen is effective both in young and older patients but the post-remission intensification is too aggressive in elderly patients.

The role of intensive remission induction and consolidation therapy in patients with acute myeloid leukaemia

Sixty-one patients with AML, 59 adults and two children, were treated with intensive remission induction and consolidation therapy. The median age was 36 years. Forty-four (72%) patients entered complete remission (CR); 11 patients received a bone marrow transplantation. The median survival of complete remitters was 26.5 months; the probability of remaining in CR at respectively 1 and 2 years was 75% and 62%. The only factor significantly correlated with the outcome of remission induction, survival and duration of CR was age. Patients less than 30 years fared significantly better than those 30 years or older; no difference in outcome was observed between patients aged 30-50 and those over 50 years. In patients less than 30 years the CR rate was 95%; 75% of them were still alive at 2 years and only one (5%) has relapsed. In contrast, in patients 30 years or older the CR rate was 60% and the median survival only 11.5 months, 50% of the complete remitters in this age group have relapsed. Morbidity from intensive consolidation therapy was considerable; more than 50% of consolidation courses were complicated by high fever, needing urgent admission; only four (3%) courses had a fatal event. It is concluded that intensive consolidation therapy may be considered as a major advance in the treatment of younger patients with AML, while its role in older individuals remains questionable. A possible explanation for the completely different outcome in younger and older patients with AML is discussed.

Role of maintenance chemotherapy in acute promyelocytic leukemia

The effect of maintenance chemotherapy on remission duration was analyzed in 39 of 70 patients (56%) with acute promyelocytic leukemia (APL) who achieved complete remission on induction chemotherapy. Overall, the median remission duration was 26 months, with a 3-year remission rate of 42%. The 3-year remission rate was significantly higher in patients who received 6-mercaptopurine and methotrexate (POMP) during maintenance, compared with those who did not (56% versus 30%; P less than 0.01), and in patients who received long-term maintenance therapy (P less than 0.01). A multivariate regression analysis selected maintenance therapy with POMP to be the only statistically significant factor associated with long-term remission duration. The type of maintenance chemotherapy is important in overall prognosis of patients with APL, and should be investigated further.

Cytosine arabinoside in the management of recurrent leukaemia

A Phase II study of high dose cytosine arabinoside (ara-C) with different schedules in patients with recurrent acute myelogenous leukaemia (AML) and myeloid blast crisis of chronic myeloid leukaemia has been conducted at St. Bartholomew's Hospital. Ara-C was infused continuously for seven days at a dose of 100-200 mgs/m2 daily from day 1 with 1-2 g/m2 (3 h infusions) twice daily from day 2 for six days. Nineteen patients with acute myelogenous leukaemia and four patients with myeloid blast crisis of chronic myeloid leukaemia (CML) were treated. Complete remission was achieved in 4/19 patients with AML and in a further four patients an antileukaemic effect was observed. There were eight early deaths and three patients failed to show any response to therapy. All four patients with myeloid blast crisis of CML failed to respond to the treatment. Toxicity was considerable with gastro-intestinal and hepatotoxicity being the most serious problems. Pharmacokinetic studies revealed that mean basal levels achieved with continuous infusion prior to high-dose ara-C were 10(2) ng/ml and peak levels were of the order of 10(4) ng/ml. The considerable toxicity of the regimen, without clinical advantage over less intensive programmes, resulted in its termination.

Early intensification and short-term maintenance chemotherapy does not prolong survival in acute myelogenous leukemia

Forty-one previously untreated patients with a diagnosis of acute myelogenous leukemia (AML) were entered on a study using early intensification followed by a short-term maintenance chemotherapy. Induction and early intensification consisted of three to four cycles of doxorubicin, vincristine, cytosine arabinoside (Ara-C) and prednisone (ADOAP) in escalating dosages. Maintenance therapy used three cycles of Ara-C thioguanine (AT), followed by three cycles of cyclophosphamide and rubidazone with vincristine and prednisone (CROP). Median total duration of therapy was 9 months. The overall complete remission (CR) rate was 73%. Tolerance to chemotherapy and dose escalation were better for patients who received their induction and early intensification in the protected environment. The overall median survival was 75 weeks. Compared to a historical control group treated with long-term maintenance chemotherapy, patients achieving CR on the current study had similar median remission (52 versus 65 weeks; P = 0.3) and survival durations (94 versus 98 weeks). This regimen using early intensification and short-term maintenance chemotherapy did not improve the overall prognosis of this AML population.

Intensive therapy for life-threatening medical complications of haematological malignancy

The medical records of 22 consecutive adult admissions to an intensive care unit (ICU) with life-threatening complications of haematological malignancy, or its treatment, are reviewed. Twenty patients (91%) were in acute respiratory failure, and 17 of the 22 patients required intermittent positive pressure ventilation (IPPV). The in-unit mortality was 55%, but only 4 patients (18%) survived to leave the hospital. Although the unit mortality appeared to be related to the acute physiology score (APS), this small series did not demonstrate a clear relationship between the APS and long-term survival (discharge from hospital). There were, however, significant differences in the number of organ systems involved between those who died on the ICU and those who returned to the ward, as well as between those who survived to leave hospital and those who died. No patient with more than three systems involved became a long-term survivor. All long-term survivors had either reasonable peripheral white cell counts throughout or their bone marrow showed significant recovery prior to discharge from the ICU. Unresponsive malignant disease and a failure to recover bone marrow function were major factors in those patients who died shortly after discharge from the ICU. Although long-term survival rates are low and are probably largely determined by the progress of the underlying malignancy, intensive care was life-saving in four patients, three of whom are alive several years after discharge.

Meningeal involvement in patients with acute nonlymphocytic leukemia. Incidence, management, and predictive factors

Between 1977 and 1983, symptomatic meningeal leukemia was diagnosed in 9 of 93 adult patients with acute nonlymphocytic leukemia (10%). All cases occurred after complete remission had been achieved (46 patients), either as the only site of relapse (3 patients), or together with a first bone marrow relapse (3 patients), or after a bone marrow relapse (3 patients). Extramedullary involvement at initial diagnosis was the only independent predictive factor (P = 0.005), the number of patients with initial hyperleukocytosis being too small (three) for evaluation. Remission of the meningeal leukemia was obtained after treatment in four of eight patients. The presence of meningeal leukemia and the response to therapy had no influence on survival. However, the morbidity and therapy related toxicity of meningeal leukemia were impressive. Some recommendations for prophylactic treatment are suggested.

Low dose cytosine arabinoside in the treatment of acute non-lymphocytic leukaemia

Complete remissions were obtained with low dose cytosine arabinoside (ARA-C) in 8 of 21 previously untreated patients with ANLL above 60 years of age and in 2 of 4 previously treated patients below 60 years of age. 7 of the patients remain in remission after 1-26 months. The results demonstrate that low dose ARA-C with rather low toxicity may induce remissions in elderly patients with ANLL.

Prolonged survival in acute myelogenous leukaemia without maintenance chemotherapy

46 adults with previously untreated acute myelogenous leukaemia who achieved complete remission with 6-thioguanine, cytarabine, and daunorubicin (TAD) received two courses of intensive consolidation chemotherapy. The first cycle consisted of 5-azacytidine and doxorubicin followed by a second consolidation cycle with TAD. Maintenance chemotherapy was not administered. Median remission duration was 14 months and 26% (95% confidence interval, 11%-41%) remained in continuous remission at 5 years. Actuarial 5 year survival was 31% (+/- 15%). Results were most favourable in patients who achieved complete remission within 60 days of chemotherapy being initiated. These data indicate that prolonged disease-free survival can be achieved in patients treated with intensive induction and consolidation treatment alone without maintenance chemotherapy.

Acute myelogenous leukaemia: maintenance chemotherapy after early consolidation treatment does not prolong survival

To investigate the value of maintenance chemotherapy after early consolidation treatment, an attempt was made to induce remission in 162 previously untreated patients, age-range 7-65 years (median 43). The 74 patients who were still in remission after early consolidation treatment (given for 3-5 months) were assigned to either maintenance chemotherapy every 8 weeks for 2 years or to observation only. After a median observation period of 44 months there was no difference between the groups in duration of remission or survival. Surprisingly, patients above 40 survived longer after early consolidation (median 4 years) than did patients aged 40 and below (median 1.6 years, p = 0.0002).

A comparison of two schedules of cytosine arabinoside used in combination with adriamycin and 6-thioguanine in the treatment of acute myelogenous leukemia

The most effective schedule of cytosine arabinoside (Ara-C) administration remains controversial and is further confused by the use of combination chemotherapy. Two remission induction regimens comprising adriamycin, Ara-C, and 6-thioguanine have been compared in patients with acute myelogenous leukemia. Administration of Ara-C by continuous intravenous infusion resulted in faster clearing of leukemic blasts from the peripheral blood and bone marrow than after administration of the same dose by twice daily intravenous injection. Myelosuppression and gastrointestinal toxicity were, however, more pronounced when Ara-C was given by infusion. The complete remission rate was higher in the patients treated with intravenous infusions. It is too early to assess the duration of remission in the infusion study; however, despite the relatively low remission rate, 80% of patients under the age of 60 in the intravenous bolus study remain in remission with a minimum follow-up of two years.