Experiences in the treatment of refractory chylothorax associated with lymphoproliferative disorders.

BACKGROUND: Chylothorax is a rare condition which can be associated with malignant lymphoproliferative disorders (LPDs). We retrospectively analyzed the results of the conservative treatment of 10 patients with persistent non-traumatic malignant chylothorax. RESULTS: Conservative treatment lead to a decline of chylothorax after mean of 66 days and consisted of the treatment of the underlying disease and of simultaneous long-term supportive care (drainage of the thoracic cavity, dietary measures and nutrition management). In most cases (80%), chylothorax disappeared only after a successful therapeutic response of the underlying disease. Low-dose radiotherapy had very good effects in two patients. CONCLUSION: Conservative treatment of malignant chylothorax can be considered a suitable method. Based on our results, successful treatment of the lymphoproliferative disorder seems to be a very important factor for the disappearance of chylothorax.

Profound radiosensitivity in "leukemic" T-cell lines and T-cell-type acute lymphoblastic leukemia demonstrated by sodium [51Cr]chromate labeling.

Radiation sensitivity was determined by measuring spontaneous release from 51Cr-labeled cells in various lymphoid cell populations. Among six leukemia T-cell lines originating from acute lymphoblastic leukemia, four such lines were found to be highly radiosensitive. In contrast, two of the leukemic T-cell lines and four normal control B-cell lines were not radiosensitive. Thymocytes from six patients and leukemia T-cell blasts from three patients with T-cell leukemia were likewise found to be highly radiosensitive, whereas leukemic blasts from six patients with null-cell (non-T, non-B-cell) acute lymphoblastic leukemia were not radiosensitive. Normal peripheral blood lymphocytes and mitogen-induced normal lymphoblasts were found not to be radiosensitive. The results indicate that measurement of the radiation sensitivity of acute leukemic blasts may have a therapeutic significance in coping with the heterogeneous nature of individual leukemia cases.

Cytogenetic studies of long-term survivors of childhood acute lymphoblastic leukemia.

Ten long-term survivors of childhood acute lymphoblastic leukemia were studied to determine if cytogenetic abnormalities were present in lymphocytes following discontinuation of therapy. The study included patients diagnosed between 1969 and 1974 who had received radiation therapy and a minimum of 3 years systemic chemotherapy. At study, the patients had been off all therapy from 1.3 to 6.5 years (median, 4 years). Peripheral blood lymphocytes were examined for spontaneous chromosome breakage and sister chromatid exchanges. In addition, G-banded metaphase and prometaphase chromosomes were analyzed. Chromosome breakage was found to be within normal limits for all patients. Likewise, there was no significant difference between patients and controls with respect to sister chromatid exchange frequency. However, seven of the ten patients were found to have one or more cells with nonclonal karyotypic abnormalities. Our results indicate that although long-term survivors of childhood acute lymphoblastic leukemia treated with intensive radiation and combination chemotherapy do not demonstrate chromosome instability or DNA damage as measured by breakage and sister chromatid exchange, a majority of these patients have a subpopulation of lymphocytes with nonclonal chromosome abnormalities years after stopping therapy.

Failure of late intensification therapy to improve a poor result in childhood lymphoblastic leukemia.

This clinical study, begun in 1975, tested the efficacy of early and delayed intensification treatments in children with acute lymphoblastic leukemia. Regardless of presenting features, all patients received 4 weeks of conventional induction therapy with daily prednisone and weekly vincristine and daunorubicin. One-third were randomized to receive, in addition, two doses of asparaginase during induction therapy, while another one-third received four doses of both asparaginase and cytarabine after remission induction. Preventive central nervous system therapy uniformly included 2400 rads cranial irradiation and five doses of intrathecal methotrexate. Remissions were maintained with daily p.o. mercaptopurine and weekly i.v. methotrexate. Of the 277 assessable patients, 254 (92%) entered complete remission, and 102 (37%) remain clinically free of leukemia for 4.6 to 8.0 years (median, 6.3 years). The three treatment groups showed no significant differences in either remission induction rate or outcome, even when the analysis was based on risk assignment. A "late intensification" phase of therapy, added to the maintenance protocol for 65 patients who had been in continuous complete remission for 14 to 30 months, failed to extend remission durations, as judged from statistical comparison with matched controls (p = 0.84). When tested as a time-dependent covariate in the Cox proportional-hazards model, delayed intensification again showed no important effect on duration of complete remission. We conclude that limited early or aggressive late intensification of therapy, as described here, does not improve outcome in childhood acute lymphoblastic leukemia.

Sanctuary therapy: a randomized trial of 724 children with previously untreated acute lymphoblastic leukemia: A Report from Children's Cancer Study Group.

Between 1972 and 1974, Childrens Cancer Study Group enrolled 724 children with newly diagnosed acute lymphoblastic leukemia on a single randomized clinical trial. Study CCG-101 was designed to test four types of presymptomatic central nervous system and sanctuary therapies consisting of (a) 2400-rad craniospinal radiation therapy (RT) plus 1200-rad extended-field RT, which included the liver, spleen, kidneys, lower abdomen, and gonads; (b) 2400-rad craniospinal RT; (c) 2400-rad cranial RT plus intrathecal methotrexate (i.t. MTX); and (d) i.t. MTX alone. Patients all received a 28-day induction course of vincristine, prednisone, and L-asparaginase and were maintained subsequently on a regimen consisting of daily 6-mercaptopurine, weekly MTX, and monthly pulses of vincristine and prednisone. Patients treated with six doses of i.t. MTX alone had a significantly higher incidence of central nervous system relapse than did patients treated with 2400-rad craniospinal RT plus 1200-rad abdominal RT, 2400-rad craniospinal RT, or 2400-rad cranial RT plus i.t. MTX. There was no significant differences in marrow remission duration or survival of the treatment groups. There appears to be a benefit with regard to length of bone marrow remission and survival for patients with initial white blood counts greater than or equal to 20,000/cu mm treated with cranial RT plus i.t. MTX. The majority of the patients remaining on study have now discontinued maintenance therapy. The 8-year overall estimated survival rate on this study is 56%, and the disease-free survival rate is 52%.

Serial observations on terminal deoxynucleotidyl transferase activity and lymphoblast surface markers in acute lymphoblastic leukemia.

Terminal deoxynucleotidyl transferase activity and cell surface markers were measured in peripheral lymphoid cells from 27 children with acute lymphoblastic leukemia in various phases of their disease. Lymphoblasts from untreated patients had smooth surface ultrastructure but heterogeneous surface receptors. Greater than 60% of lymphoblasts from 4 to 7 untreated patients formed rosettes with sheep red blood cells. Transferase activity was variable, ranging from 8 to 210 units/10(8) blasts, but it was consistently elevated at diagnosis and in relapse. Transferase levels did not correlate with the presence of lymphoblast surface receptors. During induction therapy transferase activity decreased rapidly, but it remained elevated in peripheral lymphoid cells even when blasts were not detectable in peripheral blood smears. Patients in remission had normal surface receptors and undetectable or minimally elevated levels of transferase. Terminal transferase activity may be a sensitive biochemical marker for a primitive cell population and may be important in the evaluation of therapeutic effectiveness in acute lymphoblastic leukemia.

Influence of intensive asparaginase in the treatment of childhood non-T-cell acute lymphoblastic leukemia.

Between June 1977 and December 1979, 72 evaluable patients with childhood non-T-cell acute lymphoblastic leukemia were induced into complete remission using vincristine, prednisone, and doxorubicin. All received asparaginase consolidation and central nervous system prophylaxis with cranial irradiation and intrathecal methotrexate. All patients then received prolonged intensification with vincristine, prednisone, and doxorubicin, and half of them were randomized to receive weekly high-dose asparaginase. Continuation therapy was with vincristine, prednisone, methotrexate, and 6-mercaptopurine. After a median follow-up of 57 months, there were four remission deaths and 25 relapses. Central nervous system relapse was the first event in 4% of patients. There were fewer treatment failures in the asparaginase-treated group [2-sided, p = 0.04 (0.07 controlling for standard and high-risk groups)]. Asparaginase toxicity occurred in six patients (8%) and was self-limited, but it precluded further use of the drug in those patients. The major toxicity of this treatment program was drug-induced cardiomyopathy which occurred in 10 patients (14%) and was fatal in three of them. In summary, we conclude that the intensive use of high-dose asparaginase has an important role in the treatment of children with acute lymphoblastic leukemia. The morbidity of multiple doses of doxorubicin outweighed its antileukemic advantage in standard-risk patients.

Medical Research Council leukaemia trial--UKALL V: an attempt to reduce the immunosuppressive effects of therapy in childhood acute lymphoblastic leukemia. Report to the Council by the Working Party on Leukaemia in Childhood.

The Medical Research Council UKALL V trial for children with standard-risk acute lymphoblastic leukemia (ALL) (aged 1 to 14 years, leucocyte count less than 20 X 10(9)/L) was designed to determine whether the immunosuppressive effects of treatment could be reduced without sacrifice of antileukemic effect by alterations in the type of continuing therapy or in fractionation of cranial irradiation. Remission was achieved in 496 children on standard induction therapy, and 309 children received 24 Gy of cranial irradiation in ten to 16 fractions over 21 days, and 174 received 21 Gy in five to nine fractions over 21 days. The type of radiotherapy administered had no influence on relapse at any site or rate of death in remission. All 496 children were randomized to receive chemotherapy for 2 or 3 years with 6-mercaptopurine and methotrexate either as a continuous (group C) or a semicontinuous (group G) regimen or as a five-day pulse every 3 weeks (group I). All groups also received vincristine and prednisolone every 6 weeks. With a minimum follow-up of almost 7 years, patients in group I had significantly fewer remission deaths (P = .025) but a much higher rate of bone marrow relapse than those in group C or G (P = .002). There was an overall benefit for 3 years of chemotherapy compared with 2 years, which in contrast to previous studies, was more apparent in girls and in patients in groups C and G. Testicular relapse occurred in 37 boys, including 19 patients off therapy, with a previously negative biopsy. The overall results confirmed the prognostic significance of initial leucocyte count, even among these standard-risk patients, while girls had a superior rate of disease-free survival, but not of hematologic remission. It is concluded that, even among standard-risk patients, the prognosis is influenced by the height of the initial leukocyte count. While alterations in the fractionation of cranial irradiation do not appear to have influenced disease-free survival, intermittent continuing chemotherapy, although less immunosuppressive, is less effective than conventional continuous therapy in the treatment of ALL. In this study, 3 years of chemotherapy appeared superior to 2 years.

Effects of radiation on ovarian function in long-term survivors of childhood acute lymphoblastic leukemia: a report from the Childrens Cancer Study Group.

The Childrens Cancer Study Group has assessed serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and pubertal development in 97 long-term female survivors of childhood acute lymphoblastic leukemia (ALL). All patients received identical induction and maintenance therapy with either 18 or 24 Gy of radiation therapy (RT) to one of the following fields: cranial, craniospinal, or craniospinal plus 12 Gy abdominal RT including the ovaries. Thirty-six percent (35 patients) were found to have above normal levels of FSH and/or LH. The percentages of elevated values for RT fields were 93% for craniospinal plus abdominal RT, 49% for craniospinal RT, and 9% for cranial RT (P less than .001). A dose-response relationship was observed between 18 Gy and 24 Gy in females receiving only craniospinal RT (P = .01). Craniospinal plus abdominal RT and abnormal FSH/LH levels were significantly associated with lack of pubertal development and delayed onset of menses. Duration of maintenance chemotherapy was not associated with abnormal gonadotropin levels or the development of secondary sexual characteristics. Additional follow-up of this cohort is needed to establish the ultimate pubertal development and fertility of these patients.

Memory function in disease-free survivors of childhood acute lymphocytic leukemia given CNS prophylaxis with or without 1,800 cGy cranial irradiation.

Previous studies have found that CNS prophylaxis of children with leukemia, especially young children receiving cranial irradiation, causes neuropsychologic deficits. In the present study, 40 children in continuous complete remission from acute lymphocytic leukemia (ALL) were given a battery of tests to assess memory functioning 5 years after CNS prophylaxis. All children were free of CNS disease at diagnosis and had been randomly assigned to receive CNS prophylaxis with either 1,800 cGy cranial irradiation (CRT) plus intrathecal (IT) methotrexate (MTX) or IT MTX plus intravenous (IV) high-dose MTX (HDMTX). No treatment- or age-related differences were seen on 16 standardized memory measures. However, scores of the combined sample were significantly lower than age-corrected norms on a test of visual-spatial memory and on four scales of verbal memory. Differences in methods or intensity of CNS prophylaxis and study group selection criteria are proposed to explain our findings and to resolve discrepancies with previous reports. The long-term neuropsychological sequelae in these survivors of ALL may be attributable to some common factor, such as the disease itself or systemic and IT chemotherapy.

Leydig cell function in boys following treatment for testicular relapse of acute lymphoblastic leukemia.

Current practice for achieving local control of testicular relapse in males with acute lymphoblastic leukemia (ALL) includes the use of 2,400-rad testicular radiation. Although this therapy is known to cause germ cell depletion, it has been assumed that it does not alter testicular secretion of testosterone. To test this assumption, we measured gonadotropin and testosterone levels in seven boys with ALL who had been treated with radiation for clinically apparent testicular relapse. In four of seven boys, testicular relapse was bilateral with overt involvement of one testicle and microscopic involvement of the other. Three of these four boys demonstrated delayed sexual maturation, and in addition to elevated follicle-stimulating hormone (FSH) concentrations, testosterone levels were low and luteinizing hormone levels were elevated compared with controls. These data indicate that boys with overt testicular leukemia who are treated with 2,400-rad testicular radiation are at risk for Leydig cell dysfunction. However, the relative contributions of radiation, prior chemotherapy, and leukemic infiltration to this dysfunction remain to be clarified.

Abnormal computed tomography brain scans in children with acute lymphoblastic leukemia: serial long-term follow-up.

In a previous study we reported the occurrence of computed tomographic (CT) brain-scan abnormalities in a group of asymptomatic children with acute lymphoblastic leukemia (ALL) who had received prophylactic cranial irradiation and maintenance intrathecal chemotherapy. One or more of four types of CT-scan abnormalities were observed: ventricular dilatation (VD), subarachnoid space dilatation (SAD), areas of parenchymal decreased attenuation coefficient (DAC), and intracerebral calcifications (CALs). To study the natural history of these findings, serial CT scans were obtained on 24 of the original 32 patients who were available for long-term follow-up. CT scanning was performed for a minimum of seven years from the initiation of CNS preventive therapy. Review of the CT scans showed that VD (n = 5) and SAD (n = 7) were stable over the time of follow-up. DAC, originally observed in two patients, was no longer present on follow-up scans. In contrast, five patients developed CALS from five to seven years after initiation of CNS preventive therapy. All occurred in children who were less than 8 years of age at the time of diagnosis (P less than .01). These data indicate that CALs may develop many years after the cessation of CNS preventive therapy and suggest that long-term CT-scan follow-up should be considered in children who have received CNS preventive therapy.

Acute lymphoblastic leukemia in infants less than one year of age: a cumulative experience of the Children's Cancer Study Group.

A retrospective review of all 115 infants less than 1 year of age with acute lymphoblastic leukemia (ALL) entered on a consecutive series of recent Children's Cancer Study Group (CCSG) leukemia protocols was undertaken to examine in detail the outcome and clinical course of a large group of similarly treated infants. In comparison to the 4,392 children older than 1 year, entered on the same studies, infants had a significantly (P = .0001) increased incidence of leukocytosis, hepatosplenomegaly, meningeal leukemia at presentation, hypogammaglobulinemia, and failure to achieve complete remission (CR) status by day 14 of induction therapy. In contrast, lymphadenopathy, non-L1 French-American-British (FAB) morphology, mediastinal mass, and T cell leukemia were not more frequently observed. Ninety percent of these infants successfully completed the induction phase of therapy. With a median follow-up of 35 months, life table estimate of disease-free survival is only 23% at 4 years. Identical disease-free survival rates for infants were observed in each of the individual studies reviewed. Excessive toxicity resulting in limitation of therapy delivered was not a causative factor for the disappointing outcome of these patients. Rather, early disease recurrence, characterized by bone marrow relapse (55%) and CNS (22%) relapse, was the major factor responsible for the extremely poor prognosis of this patient group. Identical CNS relapse rates were observed in those patients who received cranial irradiation as part of CNS prophylaxis (21.8%) and in those patients who did not receive cranial radiotherapy (24%). Results of salvage therapy for patients who experienced systemic or extramedullary relapse were dismal. Debilitating neuropsychologic sequellae, presumably related to CNS irradiation, have been observed in 50% of the small number of long-term survivors. Infants less than 1 year of age with ALL present with a constellation of features which predict a poor outcome and constitute the group of children with ALL at greatest risk for treatment failure.

Outcome following late marrow relapse in childhood acute lymphoblastic leukemia.

Thirty-four children with acute lymphoblastic leukemia, who developed bone marrow relapse after treatment was electively stopped, received reinduction, consolidation, continuing therapy, and intrathecal (IT) methotrexate (MTX). Sixteen children who relapsed within six months of stopping treatment had a median second-remission duration of 26 weeks; all next relapses occurred in the bone marrow. In 18 children who relapsed later, the median duration of second remission was in excess of two years, but after a minimum of four years' follow-up, 16 patients have so far relapsed again (six in the CNS). CNS relapse occurred as a next event in four of 17 children who received five IT MTX injections only and in two of 14 children who received additional regular IT MTX. Although children with late marrow relapses may achieve long second remissions, their long-term out-look is poor, and regular IT MTX does not afford adequate CNS prophylaxis. It remains to be seen whether more intensive chemotherapy, including high-dose chemoradiotherapy and bone marrow transplantation, will improve the prognosis in this group of patients.

Treatment of meningeal relapse in childhood acute lymphoblastic leukemia. I. Results of craniospinal irradiation.

Fourteen children were treated for isolated meningeal relapse occurring seven to 44 months (median, 14 months) after prophylactic cranial irradiation (2,400 rad/12 fractions) and intrathecal methotrexate (IT MTX, 12 mg/m2 for four doses during cranial irradiation). Eight had "high-risk" acute lymphocytic leukemia with age less than 2 years, white blood cell counts greater than 20,000, or T cell markers. Treatment for central nervous system leukemia included IT MTX (12 mg/m2 twice weekly until clearance of spinal fluid cytology) followed by craniospinal irradiation (CSI, 3,000 rad/20 fractions to the cranium and 1,800 rad/12 fractions to the spine). No maintenance IT MTX was given. Systemic chemotherapy was continued or reinstituted for a minimum of one year after CSI. No instance of second meningeal relapse has occurred. Five patients remain in secondary complete remission 66+, 54+, 36+, 26+, and 24+ months after meningeal relapse. Disease-free survival was limited by marrow relapse in eight patients (2-20 months after CSI) and testicular relapse in one. No acute toxicities were noted with CSI. Myelosuppression occurred in seven patients. Infections within two months of CSI were noted in five. No neurologic sequelae are apparent. Serial neuropsychometric studies in 10 patients revealed a significant decline in mean values on Global IQ scales. Long-term survival with acceptable toxicity is possible following aggressive, prompt treatment of meningeal relapse occurring after prophylactic cranial irradiation. Hematologic relapse remains the major obstacle to long-term disease-free survival.

Serial cranial computed-tomography scans in children with leukemia given two different forms of central nervous system therapy.

Cranial computed tomography (CT) was used to estimate the frequency and permanence of brain abnormalities in 108 consecutive children with acute lymphoblastic leukemia (ALL). Fifty-five patients received cranial irradiation (1,800 rad) with intrathecal methotrexate (RT group) and 53 patients received intravenous and intrathecal methotrexate without irradiation (IVIT group). Continuation treatment included sequential drug pairs for the RT group and periodic IVIT methotrexate for the other group. After 12 to 24 months of serial evaluation, five (9%) of the 55 patients in the RT group have had CT scan abnormalities, compared to 10 (19%) of 52 in the IVIT group (p = 0.171). Fourteen of the 15 patients with CT scan abnormalities had focal or diffuse white-matter hypodensity; these have reverted to normal in most cases, reflecting a dynamic process. While such CT findings are of concern and may be an early indicator of central nervous system toxicity, this remains to be proven. Therapy should not be altered on the basis of abnormal CT scans alone but in the context of the entire clinical situation.

Therapy of CNS leukemia with intraventricular chemotherapy and low-dose neuraxis radiotherapy.

Successful treatment of CNS leukemic relapse has been frustrated by frequent local recurrence and eventual marrow relapse. We describe the treatment of meningeal leukemia in 39 children with intrathecal remission induction followed by the placement of an Ommaya reservoir to facilitate the administration and distribution of chemotherapeutic agents into the CSF. Six hundred or 900 rad of craniospinal radiation and maintenance intraventricular and intrathecal chemotherapy was then administered. Systemic reinduction therapy was added in the later cases. Sixteen children (41%) experienced no further events, with 17+ months to 13+ years (median, 25 months) follow-up . Eleven patients (28%) had CNS recurrence, nine (23%) bone marrow (BM) relapse, and two (5%) testicular relapse as the next adverse event. The course of patients with first isolated CNS relapse differed from that of the others. Eleven (69%) of 16 patients treated for first isolated CNS relapse are alive and 9 are event free, while only 35% of patients whose CNS relapse occurred simultaneously or after recurrent disease at other sites are alive (P = .04). Seven of 23 in the later group are event free. The difference is due to the increased incidence of BM relapse in the later group (30% v 6%; P = .04). For patients with first isolated CNS relapse, the life-table median CNS remission duration is 42 months. The projected CNS relapse-free survival and event-free survival 8 to 10 years after CNS relapse are 40% and 32%, respectively. Headache, nausea, and emesis of short duration were frequent during therapy. In three patients, the reservoir had to be removed for infection. No patient suffered neurologic deficit related to the reservoir. The therapy described can reduce the CNS relapse rate with manageable toxicity. Systemic relapse is still a major problem after multiple CNS relapse and in those in whom the CNS relapse follows or is simultaneous with relapse at other sites.

Intellectual and academic achievement status after CNS relapse: a retrospective analysis of 40 children treated for acute lymphoblastic leukemia.

We determined the intellectual and academic status of 40 children with acute lymphoblastic leukemia who had experienced a primary isolated relapse in the CNS by analyzing the results of psychoeducational tests administered a median of 6.1 years after the relapse. Mean scores for full-scale IQ (87.5), verbal IQ (86.7), performance IQ (90.3), as well as academic achievement in reading (89.8), spelling (83.9), and mathematics (83.5) were significantly below normal expectations for age. Twenty percent of the group were mentally retarded and were receiving special educational assistance. The best clinical predictors of full-scale IQ were the number of radiation therapy courses, age, and the presence or absence of cerebral pathology as measured by computed tomography (CT). Children who were younger at the time of treatment, who received two courses of radiation therapy, and who had clinical seizures and structural abnormalities of the brain as detected by CT had the poorest psychological outcome. Although the psychoeducational consequences of CNS relapse and its attendant treatment are significant, these must be balanced by consideration of the relatively low probability of long-term survival without aggressive therapy. Recognition of this type of delayed morbidity with systematic surveillance and prompt attempts at rehabilitation may decrease or at least minimize these sequelae.

Long-term evaluation of a CNS prophylaxis trial--treatment comparisons and outcome after CNS relapse in childhood ALL: a report from the Childrens Cancer Study Group.

The current status of children with acute lymphoblastic leukemia (ALL) who had developed CNS disease while being treated on protocol CCG-101 was investigated. Seven hundred thirty-six eligible patients were entered into the study between June 1972 and July 1974. All children who were greater than 18 months of age were eligible for randomization to a CNS prophylaxis trial for which one regimen gave only a short course of intrathecal methotrexate (IT MTX) as prophylaxis. All other regimens included radiation therapy as prophylaxis. Current follow-up (median, greater than 10 years) shows no significant difference by standard life-table analysis for ultimate survival, although a substantial excess of CNS episodes occurred on the IT MTX regimen. Of the 675 patients who completed induction therapy and achieved remission in the study, 100 (14.8%) developed CNS disease as the first evidence of relapse. Fifty-five of these 100 had no subsequent CNS episodes. Only 17 of these 55 patients are surviving without further relapses since the CNS episode. The median time to isolated CNS relapse was 457 days. Time to the initial CNS relapse was found to be the most important factor for predicting outcome. Thirty-five of the 55 patients with isolated relapse subsequently relapsed in the bone marrow, and of these, 32 have died. Twenty patients of the 100 with CNS disease as the first evidence of relapse developed two episodes of CNS involvement and 17 of these 20 patients subsequently relapsed in the bone marrow; only one patient survived. Twenty-five patients of the 100 have shown a pattern of chronic CNS disease with multiple CNS relapses. The overall disease-free survival for the 100 patients who developed one or more relapse was only 16%. These data demonstrate that the occurrence of a CNS relapse is an indicator of poor subsequent outcome. Comparison of results of groups receiving different CNS prophylaxis required careful consideration of the entire pattern of relapses and mortality.

Staging and therapy of chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is a heterogeneous disease. Some patients require no therapy and have prolonged survival. Others have brief survival despite intensive treatment. Several staging systems have been developed. These are useful in predicting outcome and need of therapy, but controversies exist. Additional prognostic factors have been identified such as cytogenetics, lymphocyte levels or doubling time, bone marrow morphology, and others. Patients with low-stage CLL have not been shown to benefit from treatment. In patients with intermediate disease, combination chemotherapy with cyclophosphamide, vincristine, and prednisone (CVP) has not been shown to be superior to chlorambucil with or without prednisone. The therapy of high stage CLL is controversial; therapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) may be superior to CVP. Future directions of therapeutic research include the treatment of patients with low stage disease, more precise identification of patients requiring therapy, and more precise definition of therapeutic response.