Parental cigarette smoking and the risk of acute leukemia in children

BACKGROUND

Studies of the relation between parental smoking and childhood leukemia have produced inconsistent results. In the largest case-control studies of childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) conducted to date, the authors evaluated leukemia risk relative to parental self-report of cigarette smoking.

METHODS

In telephone interviews in which a structured questionnaire was used, parents of 1842 ALL patients, 517 AML patients, and their matched controls were asked about their cigarette smoking habits before, during, and after the pregnancy with the index child. Risk of leukemia was examined by histologic type, age of the child at diagnosis, immunophenotype (for ALL), and French-American-British morphology group (for AML).

RESULTS

The risk of ALL was not associated with the father's ever having smoked (odds ratio [OR] = 1.04, 95% confidence interval [CI] 0.90-1.20) or the mother's ever having smoked (OR = 1.04, 95% CI 0.91-1.19). Similarly, no significant risk of AML was observed for paternal (OR = 0.88, 95% CI 0.67-1.16) or maternal smoking (OR = 0.95, 95% CI 0.74-1.22). The relative risk of leukemia was not significantly different from the null for parental smoking in any time period during or around the index pregnancy, nor was it related to the number of cigarettes, the number of years of smoking, or the number of pack-years. A small number of sporadic, statistically significant associations were found, but overall there appeared to be no association between parental cigarette smoking and ALL or AML, or any subgroup of leukemia.

CONCLUSIONS

Parental smoking while pregnant or exposure to cigarette smoke shortly after birth is unlikely to contribute substantially to the risk of childhood leukemia in North America.

Urinary excretion of isoflavonoids and the risk of breast cancer

Isoflavonoids are a group of biologically active phytochemicals that humans are exposed to mainly through soy food intake. Because of the similar chemical structure of these compounds and estradiol, it has been hypothesized that isoflavonoids may be related to the risk of breast cancer. Overnight urine samples from 60 incident breast cancer cases and their individually matched controls were assayed for urinary excretion rates of five major isoflavonoids (daidzein, genistein, glycitein, equol, and O-desmethylangolensin) and total phenols. These subjects were from a large population-based case-control study conducted in Shanghai, and urine samples from breast cancer cases were collected before any cancer therapy to minimize the potential influence of the disease and its sequelae on study results. Urinary excretion of total phenols and all individual isoflavonoids, particularly glycitein, was substantially lower in breast cancer cases than controls. For total isoflavonoids, the mean excretion was 13.95 nmol/mg creatinine (SD, 20.76 nmol/mg creatinine) for cases and 19.52 nmol/mg creatinine (SD, 25.36 nmol/mg creatinine) for controls (P for difference = 0.04). The case-control difference was more evident when median levels of these compounds were compared, with the median excretion of all major isoflavonoids being 50-65% lower in cases than in controls. Individuals in the highest tertile of daidzein, glycitein, and total isoflavonoids had about half the cancer risk of those in the lowest tertile. The adjusted odds ratio for breast cancer was 0.14 (95% confidence interval, 0.02-0.88) for women whose urinary excretion of both phenol and total isoflavonoids was in the upper 50% compared with those in the lower 50%. The results from this study support the hypothesis that a high intake of soy foods may reduce the risk of breast cancer.

Risk factors for severe hemorrhagic cystitis following BMT

Hemorrhagic cystitis (HC) is a common toxicity of preparative regimens for bone marrow transplantation (BMT). Severe HC often requires prolonged and expensive hospitalization, and occasionally can result in death. To investigate the risk factors for severe HC, we conducted a retrospective study among 1908 patients who received BMTs at the University of Minnesota during 1974 to 1993. A previous report from our institution reported on 977 of these patients. We identified all patients with genitourinary complication within 100 days post-BMT from the BMT database. Medical charts for these patients were reviewed to determine whether the patient had HC and also the grade of HC. A total of 208 HC cases were identified during the study period. Of them, 92 patients had severe HC, an incidence of 5% (95% CI = 4-6%). We found that grade II-IV graft-versus-host disease (RR = 2.56; 95% CI = 1.43-4.56), use of busulfan (RR = 2.69; 95% CI = 1.35-5.35), and age at transplant (RR = 2.20; 95% CI = 1.27-3.81, for age of 10-30 compared to age of 0-9) were related to an increased risk of HC. In contrast, transplant year was inversely associated with the risk of HC (trend test, P < 0.01). We did not find any significant difference in HC with the use of prophylactic Mesna.

Usual dietary consumption of soy foods and its correlation with the excretion rate of isoflavonoids in overnight urine samples among Chinese women in Shanghai

Soy foods and certain soy constituents, particularly isoflavones, have been suggested to have potential cancer-inhibitory effects in laboratory and epidemiological studies. Chinese women in Shanghai consume high levels of soy foods and have low incidence rates of breast and other hormone-related cancers. To assess the usual dietary consumption of soy foods and evaluate the correlation of soy food consumption with the urinary excretion of isoflavonoids in overnight urine samples in this population, we analyzed data from 60 healthy women included in an ongoing population-based case-control study of breast cancer in Shanghai. Usual consumption of soy foods in the previous five-year period was assessed using a food-frequency questionnaire, and urinary excretion of daidzein, genistein, glycitein, equol, and O-desmethylangolensin was measured from overnight urine samples collected at the time of dietary assessment. Virtually all women (96.7%) in Shanghai consumed soy foods at least once a week. The median intake of soy food was 100.6 g/day, with 25th and 75th percentiles of 36.8 and 238.2 g, respectively. The median intake of isoflavones was 39.26 mg/day, and there was a nearly fourfold difference between the 25th and 75th percentiles of this measurement. With the increasing intake of soy foods, urinary excretion rates of total isoflavonoids and all individual major isoflavonoids were increased in a dose-response manner (trend test p < or = 0.05). At individual levels the urinary excretion rate of total isoflavonoids was correlated closely with dietary soy food intake, with a correlation coefficient of around 0.5 (p < 0.001). These results indicate that the urinary excretion rate of total isoflavonoids measured from overnight urine samples may reflect reasonably well the usual intake of soy foods in a population with a high level of soy food consumption.

Pathologic features of initial adenomas as predictors for metachronous adenomas of the rectum

BACKGROUND

Colorectal cancer is the third most common cancer in the world, arising mostly from pre-existing adenomatous polyps (adenomas) of the large bowel. Patients with colorectal adenomas are at increased risk of colorectal cancer because of a high recurrence rate for adenomas. We followed a cohort of 1490 patients with rectal adenomas to determine whether recurrence might be related to pathologic characteristics of the initial adenomas.

METHODS

The patients were identified in Haining County, China, from 1977 through 1978 by means of examination with a 15-cm rigid sigmoidoscope. They were followed by endoscopic examination at years 2, 4, 6, 11, and 16 after their initial polypectomy. New adenomas in the rectum were identified in 280 patients in these follow-up examinations.

RESULTS

Statistically significant twofold to threefold elevated risks of metachronous (recurrent) adenomas were observed for patients who had more than two initial adenomas or whose most advanced initial adenoma was more than 1.0 cm in size, was of villous/tubulovillous type, or showed moderate to severe dysplasia. Much stronger associations were observed for advanced metachronous neoplasms, which are defined as cancers or adenomas with severe dysplasia, with multivariate adjusted relative risks (95% confidence interval) of 4.2 (1.8-9.9) for a large initial adenoma (>1.0 cm), 8.1 (4.2-15.6) for villous/tubulovillous architecture, and 14.4 (5.0-41.3) for severe dysplasia. In particular, patients who had a large (>1.0 cm) adenoma with severe dysplasia at baseline had a relative risk of 37 (7.8-174.7) of developing advanced metachronous neoplasms compared with patients who had small adenoma(s) with mild dysplasia.

CONCLUSIONS

The risk of metachronous adenomas is closely related to the pathology of initial adenomas, thus allowing identification of a high-risk group of adenoma patients for close surveillance after their initial polypectomy.

Analysis of failure times for multiple infections following bone marrow transplantation: an application of the multiple failure time proportional hazards model

We report an application of the proportional hazards model for multiple failure times in a study arising from the Bone Marrow Transplant Database at the University of Minnesota. The study compared the risk of infections after transplantation for patients who received allogeneic bone marrow transplants from unrelated donors (URD) versus related donors (RD). In 249 patients there was a total of 365 infections in 2.5 years of follow-up. The multiple failure time model uses all the data and provides empirical estimates of standard errors that incorporate the within-person dependencies in the data. The estimate of relative risk associated with URD was 1.4 (naive 95 per cent confidence interval 1.14 to 1.73, empirical 1.08 to 1.79), compared to the estimate 1.6 (naive or empirical, 1.1 to 2.1) from the proportional hazards model on 165 first infections only. The multivariate model gives great flexibility in modelling, for example, in accommodating a separate base hazard function for each type of failure and in allowing analysis of intervals between infections as an alternative to analysis of time from a marker event, here transplantation.

Maternal leisure-time exercise and timely delivery

OBJECTIVES

This study investigated whether, in a general obstetric population, exercise in pregnancy affects the timeliness of delivery. The hypothesis was that maternal exercise would not raise the risk of preterm birth.

METHODS

A community cohort of 557 prenatal patients was followed up until the time of delivery. Data were collected on exercise in each trimester: none, low-moderate (< 1000 kcal [4184 kJ]/wk in energy expenditure), or heavy (> or = 1000 kcal/wk). Timely delivery was adopted as an outcome criterion. Thus, in the analysis, a term birth was treated as optimal and survival techniques were used to estimate risks for both preterm and postdates delivery.

RESULTS

No association was found between low-moderate exercise and gestational length. Heavier exercise appeared to reduce, rather than raise, the risk of preterm birth. The adjusted relative risk among conditioned heavy exercisers was 0.11 (95% confidence interval = 0.02, 0.81). After term, conditioned heavy exercisers delivered faster than nonexercisers.

CONCLUSIONS

The most important finding was the lack of evidence that vigorous maternal exercise is a risk factor for preterm delivery. A promising finding was that conditioned heavy exercisers have timely deliveries.

Outcomes following mechanical ventilation in children undergoing bone marrow transplantation

Between 1976 and 1992, 869 patients <19 years of age underwent BMT at the University of Minnesota for a variety of malignant and non-malignant disorders. One hundred and ninety-six required mechanical ventilation (MV) at some time from the start of pre-BMT cyto reduction through the first year following BMT. Reasons for MV included respiratory compromise, upper airway management and non-pulmonary indications for respiratory support. In multivariate models, underlying diagnosis, receipt of HLA-mismatched marrow and the presence of acute graft-versus-host disease (aGVHD) were independent predictors of the need for MV. Indication for MV, underlying diagnosis, and presence of aGVHD were independent predictors of successful extubation. Overall survival at 2 years was 14% among MV patients and 52% among non-MV patients. While the need for MV during BMT reduces the overall likelihood of survival, 40% of children who required MV were successfully extubated; 35% of these extubated patients were long-term survivors. This outcome is better than that reported for adult BMT patients requiring respiratory support, who show survival of <5% at 6 months following BMT. Our data suggest extrapolation of outcome data from adult to pediatric patients is not appropriate and aggressive care of pediatric patients requiring respiratory support is not futile.

Effect of low-dose oral glutamine on painful stomatitis during bone marrow transplantation

Painful oral mucositis is a common complication after bone marrow transplantation (BMT). Glutamine is a nutrient for rapidly dividing cells and the major energy source for intestinal epithelium. This study tested whether an oral glutamine preparation could decrease the severity of oral mucositis in patients undergoing BMT. Glutamine or a placebo (glycine) were administered from admission until day +28 in 193 BMT patients in a randomized, double-blind, placebo-controlled study at a dose of 1.0 g amino acid/m2/dose swish and swallow four times a day. In autologous BMT patients (n = 87) glutamine was associated with significantly less mouth pain by self report and by opiate use (5.0+/-6.2 days of morphine for glutamine vs 10.3+/-9.8 days for placebo; P= 0.005). Matched sibling BMT patients had no effect by self report and an increased duration of opiate use (23.2+/-5.7 days for glutamine vs 16.3+/-8.3 days for placebo) (P = 0.002). However, day 28 survival of allogeneic patients was improved by glutamine. No significant differences in TPN use, rate of relapse or progression of malignancy, parenteral antibiotic use, acute or chronic GVHD, or days of hospitalization were observed in either autologous or allogeneic recipients. No toxicity of glutamine was observed. We conclude that oral glutamine can decrease the severity and duration of oropharyngeal mucositis in autologous BMT patients but not in allogeneic BMT patients, possibly due to interaction with methotrexate.

Dietary habits and stomach cancer in Shanghai, China

Stomach cancer remains the second leading cancer in incidence in Shanghai, China, despite its decline over the past 2 decades. To clarify risk factors for this common malignancy, we conducted a population-based case-control study in Shanghai, China. Included in the study were 1,124 stomach cancer patients (age 20-69) newly diagnosed in 1988-1989 and 1,451 controls randomly selected among Shanghai residents. Usual adult dietary intake was assessed using a comprehensive food frequency questionnaire. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models. Risks of stomach cancer were inversely associated with high consumption of several food groups, including fresh vegetables and fruits, poultry, eggs, plant oil, and some nutrients, such as protein, fat, fiber and antioxidant vitamins. By contrast, risks increased with increasing consumption of dietary carbohydrates, with odds ratios (ORs) of 1.5 (95% confidence interval [CI] 1.1-2.1) and 1.9 (95% CI 1.3-2.9) in the highest quartile of intake among men (p for trend=0.02) and women (p=0.0007), respectively. Similar increases in risk were associated with frequent intake of noodles and bread in both men (p=0.07) and women (p=0.05) after further adjustment for fiber consumption. In addition, elevated risks were associated with frequent consumption of preserved, salty or fried foods, and hot soup/porridge, and with irregular meals, speed eating and binge eating. No major differences in risk were seen according to subsite (cardia vs. non-cardia). Our findings add to the evidence that diet plays a major role in stomach cancer risk and suggest the need for further evaluation of risks associated with carbohydrates and starchy foods as well as the mechanisms involved.

Dietary habits and stomach cancer in Shanghai, China

Stomach cancer remains the second leading cancer in incidence in Shanghai, China, despite its decline over the past 2 decades. To clarify risk factors for this common malignancy, we conducted a population-based case-control study in Shanghai, China. Included in the study were 1,124 stomach cancer patients (age 20-69) newly diagnosed in 1988-1989 and 1,451 controls randomly selected among Shanghai residents. Usual adult dietary intake was assessed using a comprehensive food frequency questionnaire. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models. Risks of stomach cancer were inversely associated with high consumption of several food groups, including fresh vegetables and fruits, poultry, eggs, plant oil, and some nutrients, such as protein, fat, fiber and antioxidant vitamins. By contrast, risks increased with increasing consumption of dietary carbohydrates, with odds ratios (ORs) of 1.5 (95% confidence interval [CI] 1.1-2.1) and 1.9 (95% CI 1.3-2.9) in the highest quartile of intake among men (p for trend=0.02) and women (p=0.0007), respectively. Similar increases in risk were associated with frequent intake of noodles and bread in both men (p=0.07) and women (p=0.05) after further adjustment for fiber consumption. In addition, elevated risks were associated with frequent consumption of preserved, salty or fried foods, and hot soup/porridge, and with irregular meals, speed eating and binge eating. No major differences in risk were seen according to subsite (cardia vs. non-cardia). Our findings add to the evidence that diet plays a major role in stomach cancer risk and suggest the need for further evaluation of risks associated with carbohydrates and starchy foods as well as the mechanisms involved.

Dietary habits and stomach cancer in Shanghai, China

Stomach cancer remains the second leading cancer in incidence in Shanghai, China, despite its decline over the past 2 decades. To clarify risk factors for this common malignancy, we conducted a population-based case-control study in Shanghai, China. Included in the study were 1,124 stomach cancer patients (age 20-69) newly diagnosed in 1988-1989 and 1,451 controls randomly selected among Shanghai residents. Usual adult dietary intake was assessed using a comprehensive food frequency questionnaire. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models. Risks of stomach cancer were inversely associated with high consumption of several food groups, including fresh vegetables and fruits, poultry, eggs, plant oil, and some nutrients, such as protein, fat, fiber and antioxidant vitamins. By contrast, risks increased with increasing consumption of dietary carbohydrates, with odds ratios (ORs) of 1.5 (95% confidence interval [CI] 1.1-2.1) and 1.9 (95% CI 1.3-2.9) in the highest quartile of intake among men (p for trend=0.02) and women (p=0.0007), respectively. Similar increases in risk were associated with frequent intake of noodles and bread in both men (p=0.07) and women (p=0.05) after further adjustment for fiber consumption. In addition, elevated risks were associated with frequent consumption of preserved, salty or fried foods, and hot soup/porridge, and with irregular meals, speed eating and binge eating. No major differences in risk were seen according to subsite (cardia vs. non-cardia). Our findings add to the evidence that diet plays a major role in stomach cancer risk and suggest the need for further evaluation of risks associated with carbohydrates and starchy foods as well as the mechanisms involved.

Family history of cancer and autoimmune disease and risk of leukemia in infancy: a report from the Children's Cancer Group (United States and Canada)

OBJECTIVES

As there are some suggestions that a family history of cancer or autoimmune disease might be associated with an increased risk of leukemia in children, we explored this possibility using data from a matched case-control study conducted by the Children's Cancer Group.

METHODS

We compared the family history of cancer and autoimmune diseases of 302 infant leukemia cases (diagnosed within the first 18 months of life) with that of 668 individually matched controls in the United States and Canada.

RESULTS

Although not significant, cancer history in parents was found to be associated with an elevated risk of infant leukemia (odds ratio [OR] = 1.4, 95 percent confidence interval [CI] = 0.6-3.6), predominantly acute myeloid leukemia (AML) (OR = 2.2, CI = 0.6-9.0). Cancer history among second-degree relatives was also related to a nonsignificantly elevated risk of AML. Family history of autoimmune diseases, on the other hand, was generally not found to be related to the risk of infant leukemia.

CONCLUSION

This study provided no strong evidence that family history of cancer or autoimmune disease is a major risk factor for infant leukemia.

Early gram-positive bacteremia in BMT recipients: impact of three different approaches to antimicrobial prophylaxis

Antimicrobial prophylaxis against gram-positive bacteremia (GPB) following BMT may prevent infections but promote antimicrobial resistance. In a sequential cohort study involving 289 consecutive BMT recipients we compared three protocols for prevention of GPB (vancomycin prophylaxis, penicillin/cefazolin prophylaxis, and no specific GPB prophylaxis) with respect to incidence of GPB, mortality, and vancomycin use. GPB was associated with increased mortality (27% vs 15%; P = 0.02), but contributed to only five of 52 deaths in the study population, and only one of 15 subjects with viridans streptococcal bacteremia developed fatal septic shock. Vancomycin prophylaxis reduced the incidence of GPB (11%) compared to penicillin/cefazolin (27%) or no prophylaxis (40%) (all P < 0.03), but did not significantly reduce mortality. The incidence of fungemia, gram-negative bacteremia, and infection-associated mortality was unaffected by GPB prophylaxis. Vancomycin use was substantially greater in the vancomycin prophylaxis group. We conclude that in comparison with vancomycin prophylaxis, BMT support regimens that do not include vancomycin prophylaxis allow reduced overall vancomycin use without an apparent increase in early post-BMT mortality, despite the greater associated frequency of GPB.

Relationship of plasma pharmacokinetics of high-dose oral busulfan to the outcome of allogeneic bone marrow transplantation in children with thalassemia

We analyzed plasma pharmacokinetics of busulfan in 64 children and young adults (age 2.8-26; median 11 years) with homozygous beta-thalassemia transplanted with bone marrow from HLA-identical sibling donors. A uniform conditioning regimen was employed, using busulfan 14 or 16 mg/kg in 12 divided doses, and cyclophosphamide 120 or 200 mg/kg. Three sets of parameters were examined in this homogenous patient population: (1) factors that affect the plasma kinetics of busulfan, such as age and pre-transplant liver status defined by liver function tests, ferritin levels and liver biopsy; (2) busulfan-related toxicity: occurrence of veno-occlusive disease, seizures and idiopathic interstitial pneumonitis; and (3) the relationship between busulfan exposure and transplant outcome: engraftment delay or rejection, aplasia, occurrence of mixed chimeras and mortality. Kinetic analysis of first and 10th dose (using area under the curve (AUC), maximum and minimum concentration) as comparable, showing no sign of accumulation or decline in busulfan plasma levels over time. Age and liver status did not influence busulfan metabolism. No relationship was found between busulfan exposure and toxicities or transplant outcome. We conclude that busulfan monitoring is not predictive in children and young adults with homozygous beta-thalassemia receiving busulfan and high-dose cyclophosphamide along with histocompatable sibling donor marrow.

Do standing, lifting, climbing, or long hours of work during pregnancy have an effect on fetal growth?

We assessed prospectively the impact of length of the work week and job activity on fetal growth. Among 575 women who worked during pregnancy, neither prolonged standing, frequent lifting, or climbing at work, nor a high composite activity score showed an association with fetal growth, as measured by birthweight for gestational age. Long hours of work, however, did reduce fetal growth. Infants of women working long hours late in pregnancy showed decreases in gestation-adjusted birthweight of about 80 gm (95% confidence limits = -238, +74 gm), compared with women working 20 hours or less. When long hours (> 40 hours per week) were combined with job activity, the estimated reductions ranged up to 350 gm. At lower weights (< or = 3,000 gm), categorical analyses showed elevated odds ratios (1.1-1.8) for climbing, lifting, and long hours and for the combination of prolonged standing with a lengthy work week. These results indicate that long weeks of physically demanding work could lead to fetal growth reductions that may be clinically significant. Consistent with this suggestion, infants of women who worked part-time had the highest mean birthweights. Hours of work, not only job tasks, may be important for pregnant workers.

Epidemiology of childhood leukemia

Leukemia is the most common malignancy among children under the age of 15. It has recently been shown that the incidence rate of acute lymphoblastic leukemia, the predominant type of childhood leukemia in the United States and many European countries, is increasing among young children. Several recent etiologic studies focusing on the investigation of leukemia risk among young children have suggested that maternal exposures during pregnancy, such as low-dose radiation from the Chernobyl accident, parental alcohol consumption, and dietary habits, may be related to the risk of leukemia in infants. Paternal preconception smoking has also been reported to be associated with an increased risk of childhood leukemia, particularly among young children. Other etiologic hypotheses investigated recently include the association of childhood leukemia with infection and with birth weight. This paper briefly surveys the progress of epidemiologic research on childhood leukemia in 1996.

Body mass index and the risk of cancers of the gastric cardia and distal stomach in Shanghai, China

The divergent incidence patterns of gastric cardia and distal stomach cancers suggest different etiologies. Although obesity has recently been linked to cardia cancer in Western populations, its association with distal stomach cancer remains unclear. This study examined the relation of anthropometric measurements to risk by subsites of stomach cancer in a Chinese population. We identified 1124 population-based cases of stomach cancer, ages 20-69 years, newly diagnosed between December 1988 and November 1989 in Shanghai, China. Controls (n = 1451) were randomly selected from permanent Shanghai residents and frequency-matched to cases by age and sex. Information on demographic characteristics, height and weight, diet, smoking, and other exposures was obtained by trained interviewers in person. The body mass index (BMI) was calculated as weight in kilograms divided by height in square meters and categorized into quartiles based on the distribution among controls. Odds ratios and 95% confidence intervals were estimated using logistic regression models, simultaneously adjusting for age, education, income, cigarette smoking (men only), alcohol drinking (men only), intake of total calories, and chronic gastric diseases. For gastric cardia cancer, the odds ratios among men were 1.4, 1.5, and 3.0 in the second, third, and fourth quartiles of usual BMI (P for trend, < 0.01). Among women, elevated risks also were associated with excess weight, but the gradient in risk was not smooth. Risk patterns for usual body weight, maximum BMI, and minimum BMI were similar to those found for usual BMI. For distal stomach cancer, no association with usual BMI was observed among men, but a slightly elevated risk was seen among women. Our observations in China support recent findings in Western populations that obesity contributes to the risk of gastric cardia cancer, especially among men.

Prior immunity-related medical conditions and oesophageal cancer risk: a population-based case-control study in Shanghai

To investigate the role of immunity-related medical conditions in the aetiology of oesophageal cancer, data were analysed from a population-based case-control study, conducted in Shanghai during 1992-93. Information on histories of selected autoimmune diseases and allergic conditions was obtained from 163 incident cases of oesophageal cancer and 275 age- and sex-matched controls through personal interviews using a structured questionnaire. A significant 2.4-fold excess risk (95% CI, 1.3-4.4) of oesophageal cancer was associated with a history of autoimmune diseases after adjustment for age and sex. In contrast, a history of allergy was associated with a reduced risk (adjusted OR = 0.6, 95% CI = 0.4-0.9). The risk was also reduced 30-40% among individuals who reported having a moderate or strong skin reaction to mosquito bites. This study suggests that host immune function may be involved in the aetiology of oesophageal cancer. Further investigations into the mechanism of these observed associations are warranted.

Evaluating the relationships among maternal reproductive history, birth characteristics, and infant leukemia: a report from the Children's Cancer Group

PURPOSE

Specific events in the mother's reproductive history and certain birth characteristics have been associated with childhood leukemia. Few studies have explored these associations specifically in infants.

METHODS

The Children's Cancer Group (CCG) conducted three separate case-control studies of childhood leukemia that involved similar methodologies and data collection. Data from interviews of the mothers of a total of 303 children diagnosed with leukemia at 1 year of age or younger and their matched controls (n = 468) were available from the three studies. These data included maternal reproductive history (stillbirths, abortions, and miscarriages) and certain birth characteristics of the index child.

RESULTS

Compared with controls, cases were significantly more likely to be female (P < 0.01) and were more often heavier at birth (particularly cases diagnosed after 6 months of age (odds ratio, 4.18; 95% confidence interval, 1.75-10.02)). Overall, there were no statistically significant differences between cases and controls in regard to maternal report of any type of previous fetal loss. Finally, being a later-born child was associated with an increased risk of acute myeloid leukemia but not of acute lymphoblastic leukemia.

CONCLUSIONS

The relationships among birthweight, prior fetal loss, and risk of infant leukemia appear to be complex. Further studies of infant leukemia that incorporate molecular as well as epidemiologic data may help to elucidate these differences.

Autologous bone marrow versus non-mobilized peripheral blood stem cell transplantation for lymphoid malignancies: a prospective, comparative trial

Autologous transplantation using bone marrow stem cells (BMSC) or peripheral blood stem cells (PBSC) is widely used for non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). We report a randomized, comparative trial comparing BMSC vs. non-mobilized PBSC for responsive NHL or HD. Patients randomized to BMSC (n = 13) vs. PBSC (n = 15) had more rapid neutrophil recovery (median 23 vs. 30 days), RBC independence (25 vs. 62 days), platelet independence (24 vs. 54 days), and shorter hospital stay. However, neither relapse, overall survival, nor relapse-free survival were different receiving BMSC vs. PBSC (all P > .7). Concurrently, 54 others (34 BMSC, 20 PBSC) were assigned non-randomly because of resistant disease or marrow unsuitable for harvest and similar patterns of engraftment favoring BMSC over PBSC were observed. In the entire group, BMSC transplantation (n = 47) led to quicker neutrophil recovery (P = .02), RBC (P = .06), and platelet independence (P =.04) and earlier hospital discharge (P = .02) vs. PBSC (n = 35). No difference in relapse, overall, or relapse-free survival were observed using BMSC vs. PBSC. These data suggest that non-mobilized PBSC are a satisfactory alternative to BMSC in patients with unsuitable marrow; however, transplantation with non-mobilized PBSC was associated with slower hematologic recovery, and longer hospital stay. No difference in tumor recurrence rates was observed between the PBSC or BMSC recipients. Unprimed PBSC transplantation offered no clinical advantage to BMSC.

Paternal cigarette smoking and the risk of childhood cancer among offspring of nonsmoking mothers

BACKGROUND

Cigarette smoking has been shown to increase oxidative DNA damage in human sperm cells. Assessment of the role of cigarette smoking in the etiology of childhood cancer has focused primarily on the effect of maternal smoking. Similar studies in relation to paternal smoking, however, have been inconclusive. Few studies have evaluated the effect of paternal smoking in the preconception period, and most of these could not disentangle the effects of paternal from maternal smoking.

PURPOSE

We investigated the relationship of paternal smoking, particularly in the preconception period, with childhood cancer among offspring of the nonsmoking mothers.

METHODS

We conducted a population-based, case-control study in Shanghai, People's Republic of China, where the prevalence of smoking is high among men but extremely low among women. The study included 642 childhood cancer case patients (<15 years of age) and their individually matched control subjects. Information concerning parental smoking, alcohol drinking, and other exposures of the index child was obtained by direct interview of both parents of the study subjects. Odds ratios (ORs), derived from conditional logistic regression models, were used to measure the association between paternal smoking and risk of childhood cancers.

RESULTS AND CONCLUSIONS

Paternal preconception smoking was related to a significantly elevated risk of childhood cancers, particularly acute leukemia and lymphoma. The risks rose with increasing pack-years of paternal preconception smoking for acute lymphocytic leukemia (ALL) (P for trend = .01), lymphoma (P for trend = .07), and total cancer (P for trend = .006). Compared with children whose fathers had never smoked cigarettes, children whose fathers smoked more than five pack-years prior to their conception had adjusted ORs of 3.8 (95% confidence interval [CI] = 1.3-12.3) for ALL, 4.5 (95% CI = 1.2-16.8) for lymphoma, 2.7 (95% CI = 0.8-9.9) for brain tumors, and 1.7 (95% CI = 1.2-2.5) for all cancers combined. Statistically significant increased risks of cancer were restricted to children under the age of 5 years at diagnosis or those whose fathers had smoked during all of the 5 years prior to conception.

IMPLICATIONS

Further studies are needed to confirm the association of paternal smoking with increased risk of cancer in offspring, to clarify the pattern of risks in relation to the timing of cigarette smoking, and to elucidate the biologic mechanism involved in predisposing the offspring to cancer. For example, it may be that paternal smoking induces prezygotic genetic damage that, in turn, acts as the predisposing factor.

Unrelated donor bone marrow transplantation for children with acute leukemia

PURPOSE

To test the use of unrelated donor bone marrow transplantation (URD BMT) to cure children with high-risk acute leukemias.

PATIENTS AND METHODS

Between June 1985 and December 1994, 50 children with acute leukemia (15 acute myelogenous leukemia [AML], 35 acute lymphoblastic leukemia [ALL]; 22 greater than second complete remission [CR]) received BMT from a URD at the University of Minnesota. Ages ranged from 0.9 to 17.5 years (median, 8.8). Median follow-up is 2.1 years (range, 1 to 7.3). Thirty patients (60%) received bone marrow fully matched at HLA-A,B and DRB1; 20 (40%) received bone marrow with a major or minor mismatch at a single HLA-A or B locus.

RESULTS

The median time to neutrophil engraftment was day 24 (range, 14 to 42 days) in those receiving matched and day 25 (range, 15 to 32 days) in those receiving mismatched marrow (P = .35). The incidence of grades III to IV graft-versus-host disease (GVHD) was 23% (95% confidence interval [CI], 7% to 39%) in matched and 32% (95% CI, 8% to 52%) in HLA-mismatched patients (P = .57). The incidence of chronic GVHD was 50% (95% CI, 28% to 72%) in matched and 57% (95% CI, 23% to 91%) in mismatched patients (P = .80). Disease-free survival for patients with ALL is 37% (95% CI, 21% to 53%) at 1 year and 30% (95% CI, 15% to 46%) at 2 years; for patients with AML, 53% (95% CI, 28% to 78%) at 1 year and 33% (95% CI, 6% to 60%) at 2 years.

CONCLUSION

URD BMT is an effective treatment for children with poor-prognosis acute leukemia and should be considered for all high-risk patients. Early referral of patients is strongly recommended.

Medical record validation of maternally reported birth characteristics and pregnancy-related events: a report from the Children's Cancer Group

Epidemiologic studies frequently obtain exposure information through subjects' self-report (personal interview or mailed questionnaire). The authors used data from a case-control study of infant leukemia, to assess the validity and reliability of maternally reported information on birth characteristics such as birth weight, reproductive history, and medical procedures. Cases were gathered from the Children's Cancer Group, a United States and Canadian cooperative clinical trails group with approximately 100 member and affiliate institutions, during 1983-1988. Telephone interviews were completed for 302 cases and 558 matched controls. Medical records of the index pregnancy were obtained for 287 cases and 467 controls. Correlations between medical charts and maternal interview were high for birth weight (r = 0.98, kappa = 0.9) and gestational age (r = 0.86, kappa = 0.6). Mean differences between the two sources were small, -10.5 g for birth weight and -0.36 weeks for gestational age. Reproductive history and medical procedures had high to moderate reliability. Problems after delivery and pregnancy complications generally had low validity and reliability. Little evidence of differential misclassification was found. Time between delivery and interview ranged from zero to 8 years and did not greatly affect reliability. This study suggests that validity and reliability of maternally reported pregnancy and delivery information may differ with the nature of the factor of interest, but is affected little by time from birth or case-control status.

Unrelated donor bone marrow transplantation for hematological malignancies-current status

We have explored the efficacy and toxicity of hematopoietic stem cell transplantation from unrelated donors for hematologic malignancies and other disorders. While most marrow donors have been identified through the National Marrow Donor Program in cooperation with many international registries, the recent development of unrelated donor umbilical cord blood (UCB) banks has allowed us to also evaluate this stem cell source. Analysis of the first 211 URD BMT performed at the University of Minnesota shows an overall survival of 33%, with older recipient age and transplant from a donor with a major HLA-A or B mismatch independently associated with poorer survival. Analysis of engraftment of URD marrow shows increasing risk of delayed or incomplete engraftment with increasing HLA disparity between URD and recipient. GVHD is increased in recipients of URD marrow compared with recipients of related donor marrow. Malignant relapse, however, is less frequent in URD marrow recipients, perhaps due to an increased graft-versus-leukemia effect. Formal assessment shows quality of life in long term URD BMT survivors (beyond 2 years) is excellent, and not different from that seen in sibling marrow recipients. Data from patients receiving unrelated donor UCB transplantation at the University of Minnesota indicate that UCB is an acceptable alternate source of stem cells, at least for young recipients, and may be associated with a reduced incidence of GVHD. Ongoing studies at the University of Minnesota include examination of the applicability of unrelated UCB transplantation to adult recipients, and of the degree of HLA-incompatibility which can be tolerated in UCB transplantation. Studies to identify the optimal GVHD prophylaxis for URD BMT, and to examine the role of class II matching in transplant outcome are in progress.