Mortality among workers exposed to ethylene oxide

BACKGROUND

Ethylene oxide is a sterilant gas that causes leukemia and other cancers in animals. Studies in Sweden have shown an excess of leukemia and stomach cancer in humans exposed to ethylene oxide, but other studies have generally failed to confirm these findings.

METHODS

We conducted a study of mortality in 18,254 U.S. workers exposed to ethylene oxide at 14 plants producing sterilized medical supplies and spices. The subjects averaged 4.9 years of exposure to the gas and 16 years of follow-up. The exposure levels in recent years averaged 4.3 ppm (eight-hour time-weighted adjusted exposure) for sterilizer operators and 2.0 ppm for other workers. The levels in earlier years are likely to have been several times higher. Mortality in this cohort was compared with that in the general U.S. population.

RESULTS

Overall there was no significant increase in mortality from any cause in the study cohort. The standardized mortality ratios (SMRs) were 0.97 for leukemia (95 percent confidence interval, 0.52 to 1.67; 13 deaths observed), 1.06 for all hematopoietic cancers (95 percent confidence interval, 0.75 to 1.47; 36 deaths), and 0.94 for stomach cancer (95 percent confidence interval, 0.45 to 1.70; 11 deaths). Analyses according to job category and according to the duration of exposure showed no excess in cancers, as compared with the rate in the general population, but there was a significant trend toward increased mortality with increasing lengths of time since the first exposure for all hematopoietic cancers. The rate of death from hematopoietic cancer (especially non-Hodgkin's lymphoma) was significantly increased among men (SMR, 1.55; 27 deaths). Mortality from leukemia in recent years (1985 through 1987) was significantly increased among men (SMR, 3.45; 5 deaths).

CONCLUSIONS

For the entire cohort, there was no increase in mortality from hematopoietic cancer. There was a slight but significant increase among men, however. Among men and women combined, there was a trend toward an increased risk of death from hematopoietic cancer with increasing lengths of time since the first exposure to ethylene oxide.

Prophylaxis of graft-versus-host disease by administration of the murine anti-IL-2 receptor antibody 2A3

The efficacy of murine monoclonal IgG1 antibody 2A3 specific for the 55 kD chain of the human IL-2 receptor (CD25) was evaluated for prophylaxis of acute GVHD in patients with advanced leukemia transplanted with unmodified bone marrow from related HLA-haploidentical donors incompatible for two or three HLA loci of the nonshared haplotype. As GVHD prophylaxis, 36 patients (control) received standard cyclosporine and methotrexate (C + M) whereas 11 patients (study) received C + M plus antibody 2A3, 1.0 mg/kg on day -1, and 0.5 mg/kg daily from day 0 through day +19. Antibody administration was not associated with appreciable toxicity and did not adversely affect engraftment. During treatment, circulating CD25+ cells appeared saturated by the infused antibody. Patients receiving antibody 2A3 tolerated more cyclosporine than controls (p less than 0.001) with lower increase of serum creatinine (p less than 0.05) during the first month. Seven of 10 (70%) evaluable study patients developed acute GVHD of grade II-IV with onset at a median of 20 days compared to 27 of 31 (87%) control patients with onset at a median of 13 days (p = 0.11). Trough serum levels of antibody 2A3 ranged from 7.2 to 68.8 mg/l, and lower values correlated with occurrence of acute GVHD. A human anti-mouse immunoglobulin antibody response was detected in four patients but was not associated with lower levels of antibody 2A3 in the serum. Two study patients and two controls have survived more than 1 year (p = 0.92). These findings suggest that administration of antibody 2A3 suppressed and delayed activation of alloantigen-specific T cells but did not result in their elimination.

[Mortality due to cancers of the brain and lymphatic tissues and leukemia as a function of agriculture pesticide use in Quebec (1976-1985)]

Potential hazards associated with the use of agricultural pesticides are a growing concern for society. We describe the relationships between the mortality data for cancers of the brain, the lymphatic tissues and leukemia, and the spatial distribution of agricultural pesticide use for 34 drainage basins in Quebec, from 1976-1985. The basins were grouped into three categories (low, intermediate, and high exposure) according to the level of sales of pesticides. For cancers of the lymphatic tissues among women 35 to 64 years of age, a high relative risk (RR) was observed (RR = 1.91, 95% Confidence Interval = 1.14, 3.18) in basins highly exposed to pesticides compared to those with low exposure. Analysis of correlation for this cancer at 34 basins showed significant associations between geographical distributions of the Standardized Mortality Ratio (SMR) and those of numerous variables indicative of pesticide use in agriculture. Agreement between the results for mortality data in this exploratory study and the results from another study on cancer incidence data for 1982-1983, supports the hypothesis of a potential relationship between the use of pesticides in agriculture and cancer of the lymphatic tissues.

Mortality, neoplasia, and Creutzfeldt-Jakob disease in patients treated with human pituitary growth hormone in the United Kingdom

OBJECTIVE

To determine the cause of death and incidence of neoplasia in patients treated with human pituitary growth hormone.

DESIGN

A long term cohort study established to receive details of death certification and tumour registrations through the Office of Population Censuses and Surveys and NHS central register.

PATIENTS

All patients (1246 male, 662 female) treated for short stature with pituitary growth hormone under the Medical Research Council working party and health services human growth hormone committee.

MAIN OUTCOME MEASURES

Death or development of neoplasia.

RESULTS

110 patients died (68 male, 42 female; aged 0.9-57 years) from 1972 to 1990. Fifty three death were from neoplasia responsible for growth hormone deficiency (27 craniopharyngioma, 24 other intracranial tumour, two leukaemia); two from histiocytosis X; and 13 from pituitary insufficiency. Six patients died of Creutzfeldt-Jakob disease, six of other neurological disorders, and eight of acute infection. Other deaths were apparently unrelated to growth hormone deficiency or its treatment. Seventeen tumours (in 16 patients) were identified during or after growth hormone treatment. Four were in patients with previous intracranial neoplasia and two were after cranial irradiation. Thirteen were intracranial, the others being Hodgkin's lymphoma, osteosarcoma, carcinoma of colon, and basal cell carcinoma.

CONCLUSIONS

Recurrence or progression of intracranial tumours and potentially avoidable metabolic consequences of hypopituitarism were the main causes of death. Growth hormone treatment probably did not contribute to new tumour development. Creutzfeldt-Jakob disease after pituitary growth hormone treatment continues to occur in the United Kingdom. This cohort must remain under long term review.

Cytogenetics of infantile leukemias and its correlations with bio-clinical features. The "G. Gaslini" Children's Hospital experience over a 9-year period

BACKGROUND AND METHODS

Infantile leukemia is a rare disorder, and few cytogenetic studies have been performed on this condition.

RESULTS AND CONCLUSIONS

The authors present the cytogenetic analyses performed on 14 cases of infantile leukemia. The most frequent chromosomal changes are rearrangements involving 11q (4 cases) and gains of one or more chromosomes 21. Patients with chromosomal rearrangements show a worse prognosis than those with only hyperdiploidy or a normal karyotype, although the difference was not statistically significant due to the small size and short median follow-up.

Prevention of graft-versus-host disease by lymphocyte depletion of the bone marrow graft with use of counterflow centrifugation

A combination of density flotation centrifugation and counterflow centrifugation (elutriation) allows the elimination of 98% of the T-lymphocytes, present in a marrow aspirate. This reduces substantially the occurrence of graft versus host disease (GvHD) after transplantation without loss of the repopulation capacity. A limitation of the traditional Beckman elutriator rotor is the relatively small size of the elutriation chamber, which makes five to six runs, of one hour each, necessary to process the whole bone marrow graft. We developed a new elutriator rotor, containing four disposable elutriator chamber (Dijkstra BV, Amsterdam, The Netherlands), which allows to complete the lymphocyte elimination from the bone marrow graft within 2 hours. Ninety-nine consecutive patients were transplanted with elutriated MLC-negative bone marrow grafts from histocompatible siblings. Indications for transplantation were: AML (n = 32), ALL (n = 34) and CML (n = 33). The grafts contained after counterflow centrifugation a mean of 12.1 (+/- 2.4)% of the nucleated cells, 1.9 (+/- 1.4)% of the T-lymphocytes, and 93.5 (+/- 59.4)% of the CFU-GM, originally present in the collected bone marrow. Immunoprophylaxis post grafting was given to 97 BMT recipients. Primary graft failure occurred in 5 of 95 evaluable patients (5%). The probability of acute GvHD greater than grade 1 at day 100 after BMT was 16%. The projected 3-year estimate of extensive chronic GvHD was 13%. The low incidence of GvHD was associated with a relatively low transplant related mortality in patients above the age of 40 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Leukaemia mortality among relatives of cystic fibrosis patients

A total of 219 families of patients with cystic fibrosis living in Wales were studied for the occurrence of other diseases and for cause of death, and the findings in relation to leukaemia are reported. There were eight deaths due to leukaemia, five of the myeloid type, in first and second degree relatives; this is significantly more than the expected on the basis of national age specific mortality rates. In comparison, mortality among siblings, parents, aunts and uncles, and grandparents from all causes was within the expected. Screening the five patients with myeloid leukaemia for the delta F508 mutation showed that four were carriers of this mutation. It is concluded that carriers of the delta F508 mutation may have an increased risk of developing acute myeloid leukaemia. This could happen through the direct effect of the cystic fibrosis gene itself, or through its influence on another gene, such as the met oncogene, or gene(s) involved in granulocyte function on the long arm of chromosome 7.

[Therapy studies in medical oncology. Analysis of progress-- Usefulness for the individual patient]

Since the end of the nineteen-forties, medical oncologists have been using cytostatic drugs and, in the case of some tumors, hormone-active substances. To these have been added in recent years, although only for a few indications, the so-called biological response modifiers (BRM substances) such as interferons and interleukins. New substances and methods are accepted into routine practice only after well-documented clinical trials. This development is, however, far from being complete; there continues to be a requirement for new standards and an optimisation of indications, dosages, drug combinations, modes of administration, and intervals between dosages. On the basis of a number of studies, it is shown how, building on the experience obtained in earlier trials, the curative and palliative effects of such treatments can be improved. In the palliative situation, in particular, the indication and nature of chemotherapy must be reconsidered since most earlier studies failed to document the factor "quality of life".

Methotrexate combined with cyclosporin A decreases graft-versus-host disease, but increases leukemic relapse compared to monotherapy

Forty patients with leukemia receiving HLA-identical sibling marrow and treated with four doses of methotrexate (MTX) in combination with cyclosporin A (CSA) for prevention of graft-versus-host disease (GVHD) were compared with retrospective controls consisting of 57 patients treated with MTX alone and 30 patients treated with CSA alone. Follow-up time ranged from 2.6 to 6.7 years after bone marrow transplantation. Patients in the MTX + CSA group were older and received a smaller marrow cell dose, but were otherwise comparable regarding disease status, donor/recipient sex match and seropositivity for cytomegalovirus (CMV) and other herpes viruses. Engraftment was slowest in the MTX + CSA group and fastest in the CSA group (p = 0.005 vs MTX and p less than 0.001 vs CSA). The incidence of moderate to severe acute GVHD (grade II-IV) was 8% among patients on MTX + CSA and 26% and 47% in the MTX (p = 0.028) and CSA (p = 0.0001) groups respectively. The corresponding figures for chronic GVHD were 25, 42 and 40% (n.s.). The incidence of CMV interstitial pneumonia was 0% in patients treated with MTX + CSA compared to 23% in the MTX treated patients (p = 0.01) and 11% in the CSA treated patients (p = 0.05). The actuarial 3-year survival in the three groups was similar, 56% for the MTX + CSA patients and 53% for both the MTX and CSA patients (n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)

The use of recombinant human granulocyte-macrophage colony stimulating factor in autologous bone marrow transplantation

To examine the effects of recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) in patients undergoing autologous bone marrow transplantation (ABMT), a series of phase I, II, and III trials was done. rhGM-CSF was given to patients undergoing ABMT for lymphoid neoplasia beginning 2 h after marrow infusion. The results indicate that rhGM-CSF is well tolerated and stimulates early neutrophil and platelet recovery. rhGM-CSF did not affect relapse or survival. Patients who received rhGM-CSF had fewer infections, less marrow transplant-related toxicity, and shorter hospital stays than control patients.

Adult leukemia and farm practices: an alternative approach for assessing geographical pesticide exposure

Many studies have attempted to show a significant relationship between leukemia and farm practices, and some of them mention the potential responsibility of pesticide exposure. In this study, a pesticide exposure index (PEI) is established for geographical units at a small scale. It measures, as accurately as possible, the exposure of the farming population to pesticides, taking into account differential practices in the treatment of different crops as well as an estimate of the time per inhabitant spent cultivating each crop. This approach was developed in southern Normandy, an area of France exhibiting strong contrasts of agricultural activities, and where the necessary agricultural surveys at a small geographical level were available. Statistically significant increasing trends between leukemia mortality of males over 15 on one hand and the PEI and the proportion of agricultural land growing cereals on the other hand were found.

Use of ofloxacin in prevention and treatment of secondary infections in hematological malignancies

We evaluated the effectiveness of ofloxacin (OFX) administered for prophylactic purposes during 77 episodes of neutropenia (less than 500/mm3) in 54 patients with hematological malignancies and to combat infection in 17 patients with both hematological malignancies and secondary infections. The prophylactic effect of OFX was demonstrated by the absence of febrile episodes in 73.3% of patients during the neutropenic phase. Of 16 patients who developed secondary infections, 13 showed good responses with other antibiotics. The overall efficacy rate of OFX in secondary infections was 64.7%. Although 4 patients developed elevated SGOT and SGPT levels and 1 showed an elevated BUN level, OFX was generally well tolerated.

Occupation and leukemia mortality among men in 16 states: 1985-1987

The relationship between leukemia and occupation was investigated in a case-control study using death certificates of 5,147 men who died of leukemia (ICD-9 codes 204-208) and 51,470 who died of other causes in 16 U.S. states from 1985 to 1987. Of six occupational activities identified previously as potentially increasing the risk of leukemia, only petroleum refining and rubber manufacturing had excess deaths for all leukemias combined (odds ratios (ORs) = 1.3, 95% confidence intervals (CI) = 0.6-2.8 and 0.9-1.8, respectively). Meat workers and wood workers had elevated mortality from acute lymphocytic leukemia (OR = 2.2, 95% CI = 0.7-7.0 and OR = 1.3, 95% CI = 0.8-2.2, respectively). There was no leukemia excess among farmers or auto mechanics. A survey of 43 other occupational groups indicated a widespread excess of leukemia among white collar occupations, primarily managers and professionals, but none among blue collar workers. This pattern was most pronounced for men under 65 years of age, and existed for all leukemia subtypes and among both blacks and whites. Despite the lack of specific exposure information and other limitations of death certificate data, these results encourage further examination of occupational causes of leukemia.

Effect of pulsed magnetic fields on leukemia-prone AKR mice. No-effect on mortality through five generations

Leukemia-prone AKR mice were exposed twice a week to a 6 mT, 12 Hz or 460 Hz pulsed magnetic field for 30 min. If we take into account the five consecutive generations of mice, the above exposure actually took place in utero and, or during their life span. There was no difference in the incidence of leukemia or in the actuarial survival curves or in the average spleen or thymus weights.

High-dose ara-C and etoposide in refractory or relapsing acute leukemia

A total of 32 patients (15 men and 17 women) presenting with relapsing or refractory acute leukemia were treated with a 3-h infusion of 3 g/m2 cytosine arabinoside (ara-C) twice daily on days 1-6 and a 1-h infusion of 100 mg/m2 etoposide on days 1-5. In all, 6 subjects had acute lymphocytic leukemia (ALL); 25 had acute myeloid leukemia (AML) of types M1 (n = 6), M2 (n = 10), M4 (n = 5), and M5 (n = 4); and 1 had mixed-type leukemia. The median age was 35 years (ranges, 16-62 years). Of the patients presenting with AML, 11 were primarily refractory and 3 became refractory after their first relapse. Six subjects had an early first relapse following a complete remission (CR) that lasted less than 6 months and five, a second relapse. Another patient underwent a primary relapse after greater than 6 months but had been heavily pretreated. In all, 5 subjects with refractory AML achieved a CR (36%; 95% confidence interval (CI), 10%-62%) as did 7 patients exhibiting relapsing AML (58%; CI, 30%-86%). Three patients who had relapsing or resistant ALL achieved a CR. Side effects consisted of severe hematotoxicity associated with granulocytopenia of less than 500/mm3 that lasted for a mean of 23.6 days and thrombocytopenia of less than 20,000/mm3 whose mean duration was 20.8 days. Marked gastrointestinal toxicity and infections were also prevalent. Cutaneous and ocular toxicity as well as allergic, pulmonary and cerebellar side effects were observed in a few cases. We conclude that the combination of high-dose ara-C and etoposide is a powerful but toxic induction regimen for refractory or relapsed acute leukemia.

The role of the professional nurse in a bone marrow transplantation programme

Two different methods of transplantation are available. The allogeneic procedure is the transfer of bone marrow between compatible siblings, whereas in autografting the patient's own haematopoietic stem cells are collected, stored, and subsequently reinfused. Both forms have become established in the treatment of the leukaemias, aplastic anaemia, the malignant lymphomas, myeloma and certain immunologic diseases. Similarly, these techniques are being used in solid tumour oncology to reconstitute bone marrow function after high doses of chemotherapy, which would otherwise result in irreversible myelotoxicity. The success of such programmes depends upon a well developed multidisciplinary approach, prominently involving experienced and dedicated nursing staff. The latter individuals will establish contact with the patient typically during the first admission for chemotherapy and this will be consolidated during subsequent outpatient visits. Then follows the highly specialised care of central venous lines and management of radiation or chemotherapy-related side effects, often with intensive care needed for safe reversal of sepsis that may, however, be associated with renal or cardiorespiratory dysfunction. Most importantly, and again centrally involving the professional nurse, is responsibility for all aspects of maintaining and operating the protected environment, together with laminar air-flow rooms. Additional interaction is also necessary with dieticians, social workers, liaison psychiatrists, occupational therapists and frequently the infectious disease, cardiovascular, respiratory and renal services. Furthermore, achievement of optimal results presupposes the availability of a dedicated cell support section, as well as the competence to cryopreserve haematopoietic stem cells and monitor the safety of this step with in vitro bone marrow culture--another role for the specialised or academic nurse.(ABSTRACT TRUNCATED AT 250 WORDS)

Double-blind test of human urinary macrophage colony-stimulating factor for allogeneic and syngeneic bone marrow transplantation: effectiveness of treatment and 2-year follow-up for relapse of leukaemia

A randomized, double-blind placebo-controlled phase III clinical trial was performed to study the effects of human urinary macrophage colony-stimulating factor (hM-CSF) after allogeneic and syngeneic bone marrow transplantation (BMT) in 60 hM-CSF treated and 59 placebo control patients. HM-CSF was administered at a daily dose of 2 x 10(5) units/kg from day 1 to day 14 after BMT. Significant differences between hM-CSF and control patient were found in the recovery time to greater than 0.5 x 10(9) granulocytes/l and the survival rate during the initial 120 d without retransplantation. There was no difference in the incidence or grade of graft-versus-host disease (GVHD). There was no difference in the rate of leukaemic relapse at 24-36 months after BMT in patients with acute lymphocytic, acute nonlymphocytic, or monocytic leukaemia. The results of this trial show that human M-CSF improves the outcome of BMT without any influence on the occurrence of leukaemic relapse or GVHD.

A cohort mortality study and a case-control study of workers potentially exposed to styrene in the reinforced plastics and composites industry

The cohort consisted of 15,908 men and women who worked for at least six months between 1948 and 1977 in 30 participating manufacturing plants in the reinforced plastics and composites industry. These workers were occupationally exposed to the working environment in the industry, which included exposure to styrene. Cause specific mortality analyses were performed based on the standardised mortality ratio (SMR) with the United States population as a comparison. No significant excess of cause specific mortality was found for the total cohort. Mortality from cancer was slightly less than expected (SMR = 88.1). For cancer of the respiratory system, a small non-significant excess was detected (SMR = 116.1). For lymphatic and haematopoietic cancer, a non-significant deficit was found (SMR = 73.3). The observed mortality from leukaemia was similar to that expected (five observed v 4.76 expected deaths). The plants with hot processes (injection moulding, centrifugal casting, compression moulding, continuous lamination, and pultrusion) experienced a significantly increased SMR (177.9) for respiratory cancer, which was more than twice that (78.3) for those with cold processes (resin mixing, lay up and spray up, bag moulding, and filament winding). As potential exposure to styrene from hot processes is considerably less than that from the cold processes, this finding could not be attributed to occupational exposures. A subsequent nested case-control study consisting of 40 cases of deaths from respiratory cancer was conducted. Further information on detailed work history, occupational exposures, and smoking history was collected. The case-control study did not show any significant association between respiratory cancer and direct exposure to styrene (contained in polyester resins), duration of exposure to styrene, the type of process (hot or cold), or whether a resin was used. A statistically significant association (relative risk = 7.33) was found between cigarette smoking and respiratory cancer among the study subjects.