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The association between individual-level poverty and relapse in children receiving maintenance treatment for acute lymphoblastic leukemia (ALL) remains unclear. In a secondary analysis of COG-AALL03N1, we used data from US Census Bureau to categorize patients living below year-specific federal poverty thresholds, calculated using self-reported annual household income and size of household. Participants living 120% below federal poverty thresholds were categorized as living in extreme poverty. Hazard of relapse was estimated using multivariable proportional subdistributional hazards regression for patients living in extreme poverty while receiving ALL maintenance therapy after adjusting for relevant predictors. Among 592 patients in this analysis, 12.3% of the patients were living in extreme poverty. After a median follow-up of 7.9y, the cumulative incidence of relapse at 3y from study enrollment among those living in extreme poverty was significantly higher (14.3%, 95% confidence interval [CI]= 7.3-23.6) compared to those not living in extreme poverty (7.6%, 95%CI=5.5-10.1, P=0.04). Multivariable analysis demonstrated that children living in extreme poverty had a 1.95-fold greater hazard of relapse (95%CI=1.03-3.72, P=0.04) compared to those not living in extreme poverty; this association was mitigated after inclusion of race/ethnicity in the model (hazard ratio=1.68, 95%CI=0.86-3.28, P=0.1), likely due to collinearity between race/ethnicity and poverty. A greater proportion of children living in extreme poverty were non-adherent to mercaptopurine (57.1% vs 40.9%, P=0.04); however, poor adherence did not completely explain the association between poverty and relapse risk. Future studies need to understand the mechanisms underlying the association between extreme poverty and relapse risk. Clinical Trial number: NCT00268528.

Introduction: Higher BMI at ALL diagnosis is associated with an increased risk of post-induction residual leukemia (Orgel, Blood 2014) and relapse (Butturini, JCO 2007). However, children may experience significant changes in BMI during the pre-maintenance phases of ALL treatment (Withycombe, Pediatr Blood Cancer 2009), necessitating an examination of the association between BMI during maintenance and relapse risk. We hypothesized that higher BMI during maintenance would be associated with a greater risk of relapse. We also explored the association between BMI and red cell thioguanine (TGN) levels to understand whether BMI-associated variations in TGN biodistribution explained the BMI-relapse association. Methods: We used data from COG-AALL03N1 (primary aim was 6MP adherence) to examine the association between BMI during maintenance and relapse risk. Eligibility for enrollment on AALL03N1 included age ≤21y at ALL diagnosis and receiving maintenance therapy in first remission. The current analysis was limited to patients with wild-type thiopurine methyltransferase genotype. BMI (exposure variable) was calculated as sex- and age-based percentile per CDC normative data, and operationalized as normal/underweight [ Results: The sociodemographic and disease characteristics of the 676 study participants are summarized in the Table. Median BMI%ile was 88.5 (range, 0-100); normal/underweight: 43%, overweight/obese: 45%, and morbidly obese: 12%. As shown in the Figure, cumulative incidence of relapse at 2y from start of maintenance therapy was significantly greater among patients with morbid obesity (11.9±4.3%) when compared to those who were overweight/obese (5.4±1.6%) and underweight/normal weight (4.1±1.4%). After adjusting for the variables listed above, we found that patients with morbid obesity had a 3.2-fold greater hazard of relapse (95%CI=1.4-7.5, P=0.008) when compared to patients who were normal/underweight. After adjusting for age at enrollment, sex, race/ethnicity, 6MPDI, and time from initiation of maintenance, patients with morbid obesity had lower mean red cell TGN levels compared to normal/underweight patients (mean difference: -27.2±7.4 pmol/8 x 10 8 erythrocytes, P=0.0002). However, inclusion of TGN in the model did not alter the association between BMI and hazard of relapse (HR=3.8, 95%CI, 1.6-9.0, P=0.003). These findings did not change after adjusting for 6MP adherence in the sub-cohort with available adherence data (n=435). Conclusion: Morbid obesity during maintenance for childhood ALL is associated with relapse as well as lower systemic exposure to 6MP. However, lower TGN levels do not explain the relation between BMI and relapse risk. Therefore, there is a need to understand the mechanism of the relation between morbid obesity during maintenance and relapse risk in children with ALL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Previous investigations of cancer survivors report that the cumulative incidence of subsequent leukemia plateaus between 10 and 15 years after primary therapy. Risk beyond 15 years has not been comprehensively assessed, primarily because of lack of long-term follow-up. Among 5-year survivors from the Childhood Cancer Survivor Study cohort, 13 pathologically confirmed cases of subsequent leukemia occurred ≥ 15 years after primary malignancy, with a mean latency of 21.6 years (range, 15-32 years). Seven were acute myeloid leukemia (2 acute promyelocytic leukemia with t(15;17), 2 with confirmed preceding myelodysplastic syndrome), 4 acute lymphoblastic leukemia (2 pre-B lineage, 1 T cell, 1 unknown), and 2 other. Two acute myeloid leukemia cases had the 7q− deletion. The standardized incidence ratio was 3.5 (95% confidence interval, 1.9-6.0). Median survival from diagnosis of subsequent leukemia was 2 years. This is the first description of a statistically significant increased risk of subsequent leukemia ≥ 15 years from primary diagnosis of childhood cancer.

Survivors of childhood acute lymphoblastic leukemia (ALL) are at risk for late effects of cancer therapy. Five-year ALL survivors (< 21 years at diagnosis; n = 5760 eligible, 4151 participants), diagnosed from 1970 to 1986 were compared with the general population and a sibling cohort (n = 3899). Cumulative mortality of 5760 5-year survivors was 13% at 25 years from diagnosis. Recurrent ALL (n = 483) and second neoplasms (SNs; n = 89) were the major causes of death. Among 185 survivors, 199 SNs occurred, 53% in the CNS. Survivors reported more multiple chronic medical conditions (CMCs; odds ratio [OR], 2.8; 95% CI, 2.4-3.2) and severe or life-threatening CMCs (OR, 3.6; 95% CI, 3.0-4.5) than siblings. Cumulative incidence of severe CMCs, including death, 25 years from diagnosis was 21.3% (95% CI, 18.2-24.4; 23.3% [95% CI, 19.4-27.2] and 13.4% [95% CI, 8.4-18.4] for irradiated and nonirradiated survivors, respectively). Survivors reported more adverse general and mental health, functional impairment, and activity limitations compared with siblings (P < .001). Rates of marriage, college graduation, employment, and health insurance were all lower compared with sibling controls (P < .001). Long-term survivors of childhood ALL exhibit excess mortality and morbidity. Survivors who received radiation therapy as part of their treatment or had a leukemia relapse are at greatest risk for adverse outcomes.

Donor cell leukemia is a rare complication after allogeneic hematopoietic stem cell transplantation. A 12-month-old boy underwent unrelated donor umbilical cord blood transplant (UCBT) for refractory Langerhan's cell histiocytosis. Forty months after transplantation, he developed acute myeloid leukemia. Cytogenetic and molecular analysis confirmed donor cell origin. The Cord Blood Bank (CBB) contacted the donor's family and established that the child, now 7 years old, was healthy. This represents the first reported case of donor cell leukemia following UCBT. This case illustrates that donor cell leukemia is a rare but real event after UCBT as with other stem cell sources and highlights the need for CBBs to maintain linkage data between donors and recipients.

We undertook an analysis of 2,150 recipients of bone marrow transplant (BMT) at the University of Minnesota to determine the incidence of post- BMT malignant neoplasms (MNs). Fifty-one patients developed 53 MNs, compared with 4.3 expected from general population rates (standardized incidence ratio [SIR], 11.6, 95% confidence interval [CI], 8.2–14.5). These included 22 occurrences of B-cell lymphoproliferative disorder (BLPD), 17 solid nonhematopoietic tumors, 10 myelodysplastic syndromes (MDS), 1 acute myelogenous leukemia (AML), 2 non-Hodgkin's lymphoma (NHL), and 1 Hodgkin's disease (HD). The estimated actuarial incidence of any post-BMT malignancy was 9.9% +/- 2.3% at 13 years posttransplant. The cumulative probability of BLPD plateaued at 1.6% +/- 0.3% by 4 years from transplant and factors independently associated with increased risk included in vitro T-cell depletion of marrow (relative risk (RR) = 11.9, P < .001), HLA mismatch (RR = 8.9, P < .001), use of antithymocyte globulin (ATG) for graft versus host disease (GVHD) prophylaxis (RR = 5.9, P < .001) or in the preparative regimen (RR = 3.1, P = .03) and primary immunodeficiency (RR = 2.5, P = .06). The cumulative probability of developing solid malignancy was 5.6% +/- 2.2% at 13 years from BMT. Malignant melanomas were the most common (SIR, 10.3, 95% CI 1.9 to 25.4). The actuarial incidence of MDS/AML plateaued at 2.1% +/- 0.8% at 9 years and was seen most often in older patients receiving autologous peripheral blood stem cells for HD or NHL. These data document that BMT recipients are at an increased risk of later malignancy, which may add significant morbidity and mortality to the transplant process. Methods for screening and identification of individuals at increased risk need to be addressed in future studies.

Myelodysplastic syndrome (MDS) is a complication of conventional antineoplastic therapy but has rarely been reported after autologous bone marrow transplantation (ABMT). We reviewed records of 206 patients who underwent ABMT for lymphoma at the University of Minnesota (Minneapolis, MN) between 1974 and 1993. Of 206 patients who underwent ABMT for non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD), 9 patients developed an MDS or secondary acute leukemia between 5 and 60 months (median 34 months) post-BMT. Two patients had relapsed after transplant and received additional therapy before the diagnosis of MDS. They were censored from the statistical analysis, resulting in a cumulative incidence of 14.5% +/- 11.6% (95% confidence interval) at 5 years. Three patients (15.2% +/- 18.0%) had HD, and four (14.0% +/- 14.7%) had NHL. In vitro BM purging had no affect on the incidence of MDS, although patients receiving peripheral blood stem cells had a projected MDS incidence of 31% +/- 33% versus 10.5% +/- 12% if BM cells were used (p = .0035). The patients had received a median of 14 cycles (range, 6 to 40) of chemotherapy before autologous transplantation; Five of nine patients received radiation therapy before BMT conditioning, and all patients received radiation before the diagnosis of MDS. No BM cytogenetic abnormalities were evident pretransplant in three of three patients studied, and all nine had normal pretransplant BM morphology. All patients had morphologic BM findings typical of MDS, and six of six studied had clonal cytogenetic abnormalities. At the diagnosis of MDS, all nine patients were without clinical, radiographic, or autopsy evidence of recurrent lymphoma; Three of the nine patients have died from complications of cytopenias at 23, 36, and 45 months after transplant (3 to 10 months after the diagnosis of MDS), whereas 6 survive 8 to 63 months after transplantation (1 to 34 months post-MDS). These data emphasize the cumulative leukemogenic potential of standard and salvage radiation and chemotherapy regimens and highlight treatment-induced MDS as an important and frequent late complication of potentially curative BM transplant therapy.

Background We describe the pattern and incidence of SMNs with 10 additional years of follow-up of an international cohort (Bhatia, N Engl J Med, 1996; Bhatia, J Clin Oncol, 2003) of children with HL diagnosed between 1955 and 1986 at age 16 y or younger. Methods Medical record review was used to identify SMNs, define vital status and describe therapeutic exposures. Pathology reports served to validate SMNs. Cumulative incidence (CI) utilized competing risk methods. Standardized incidence ratio (SIR) and absolute excess risk (AER/10,000 p-y) utilized age-, gender- and year-matched rates in the general population. Cox regression techniques (using calendar time as time scale) identified predictors of SMN risk. Results The cohort included 1023 patients diagnosed with HL at a median age of 11 y, and followed for a median of 26.8 y (IQR, 16.4-33.7). Eighty-nine percent had received radiation, either alone (22%), or in combination with chemotherapy (67%). Alkylating agent (AA) score was defined as follows: 1 AA for 6 m = AA score of 1; 2 AA for 6 m or 1 AA for 12 m = AA score of 2, etc. The AA score was 1-2 for 54% and 3+ for 16%; 30% did not receive AA. A total of 188 solid SMNs developed in 139 patients (breast [54], thyroid [24], lung [11], colorectal [11], bone [8], other malignancies [80]. Table summarizes SIR (95%CI), CI, and AER by attained age. The cohort was at an 11.1-fold increased risk of developing solid SMNs (excluding non-melanoma skin cancers) compared with the general population (95% CI, 9.4-13.0). CI of solid SMNs was 25.2% at 40 y from HL diagnosis (Fig 1). Among patients aged ≥40 y, 79% of total AER was attributable to breast, thyroid, colorectal and lung SMNs (Table). Thirty-seven patients developed >1 solid SMN; the cumulative incidence of the 2nd SMN was 19.6% at 10 years from diagnosis of the 1st SMN. Breast Cancer: Females (n=41) had a 20.9-fold increased risk, and males (n=3) a 45.8-fold increased risk c/w general population. Age at HL of 10-16 y vs. Conclusion In this cohort of HL survivors with 20,344 p-y of follow-up, the greatest excess risk of SMNs among those > 40 y was attributable to breast, thyroid, colorectal and lung SMNs. Observed risks for the most common SMNs were comparable to or greater than known high-risk groups within the general population. Disclosures: No relevant conflicts of interest to declare.

Abstract 4633 Background Chronic health conditions are commonly reported by survivors of childhood leukemia and lymphoma. To further understand the socio-economic impact of these reported conditions, we sought to determine overall and cause-specific rates of hospitalization among survivors of childhood leukemia/lymphoma and to compare these rates with those of the U.S. population. Methods From the CCSS, 5,637 5 year survivors of childhood leukemia/lymphoma, who participated in the 2000 follow-up questionnaire, were identified. Data related to hospitalizations occurring during the years 1992-2005 were collected and hospitalization rates among survivors were determined. For comparison, hospitalization rates in the general U.S. population were obtained from the National Hospital Discharge Survey (NHDS). Indirect standardization was used to calculate age- and sex- standardized incidence ratios (SIR) and absolute excess risks (AER). The reasons for hospitalization were described and cause specific hospitalization rates were also compared with those of the general U.S. population. Results At follow up, the mean age was 29.2 years (SD: 7.6; range: 14.0-51.0) and the mean time since diagnosis was 20.8 years (SD: 4.6; range 13.3-31.7). Overall, the hospitalization rates of survivors of childhood leukemia, non-Hodgkin lymphoma (NHL) and Hodgkin disease (HD) were 1.3 (95% CI: 1.2-1.3), 1.2 (95% CI: 1.1, 1.3) and 1.9 times (95% CI: 1.8, 2.0) that of the general U.S. population, respectively. Survivors, regardless of diagnosis, were more likely than the general population to be hospitalized for infection, endocrine, cardiovascular, gastrointestinal and genitourinary reasons, as well as external causes (Figure 1). The greatest AER was associated with hospitalization for neoplasm. Survivors of leukemia and NHL were approximately 5 times [SIRleukemia: 5.4 (95% CI: 4.8; 6.2) and SIRNHL: 4.8; (95% CI: 3.6, 6.1)] and HD survivors 10.2 times (95% CI: 8.9, 11.7) more likely than the general population to be hospitalized for this reason. Survivors of HD had 6.5 times (95%CI: 5.6, 7.5) the rate of hospitalization for cardiovascular causes and 4.4 times (95% CI: 3.6, 5.2) the rate of hospitalization for pulmonary causes when compared with the general U.S. population. These findings are consistent with reports indicating an increased risk for second cancers, particularly breast cancer after chest irradiation, and conditions such as pneumonitis, lung fibrosis, cardiomyopathy and coronary artery disease among Hodgkin patients. Survivors of leukemia had 5.2 times (95% CI: 4.4, 6.2) the rate of hospitalization for neurological reasons compared with the general population, likely reflecting late effects of treatment with cranial and spinal radiation. Interestingly, survivors have a significantly lower rate of hospitalization for psychological reasons when compared with the U.S. population (Figure 1). Conclusions Long-term survivors of childhood leukemia/lymphoma experience a significantly increased rate of hospitalization. Additional research is needed to further quantify the overall healthcare utilization and economic impact of treatment-related complications as this population ages. These findings also emphasize the importance of ongoing medical surveillance that includes screening and prevention strategies, which may impact the occurrence of serious medical conditions resulting in hospitalization. Disclosures: No relevant conflicts of interest to declare.

Background: Second primary malignancies and premature death are a concern for patients surviving treatment for childhood lymphomas. Despite in-depth reports on second cancer risk after Hodgkin lymphoma, there is limited published information on clinical, demographic, and treatment risk factors for second malignant neoplasms (SMNs) or deaths after non-Hodgkin lymphoma (NHL). Methods: We assessed mortality and SMNs among 1,082 five-year survivors of NHL in the Childhood Cancer Survivor Study, a multi-institutional North American retrospective cohort study of pediatric cancer survivors diagnosed between 1970 and 1986 before age 21. We searched the National Death Index for dates and causes of death and inquired about SMNs in periodic questionnaires, with confirmation of all reported SMNs by a study pathologist. We calculated standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) based on United States population rates. We calculated relative risks (RRs) for death and SMNs by demographic, clinical, and treatment characteristics using proportional hazards modeling. Medical physicists determined organ exposure to radiation therapy (RT) based on clinical RT records. Results: There were 87 deaths among 5-year survivors (SMR=4.2, 95% confidence interval (CI): 1.8, 4.1). Leading causes of death were NHL (n=21), solid tumors (n=17), circulatory diseases (n=12), and leukemia (n=10). There were elevated rates of mortality due to NHL, solid tumor SMNs, leukemia, cardiac disease, and pneumonia. The mortality rate remained elevated beyond 20 years after NHL. Risk factors for death included NHL relapse (RR=8.5), doxorubicin (RR=1.8), bleomycin (RR=4.1), platinum agents (RR=4.0), and cardiac RT exposure (RR=1.8). There were 31 SMNs, including 27 solid tumor SMNs (SIR=3.9, 95%.CI: 2.6, 5.7), specifically SMNs of the breast (n=6, SIR=9.1), thyroid (n=6, SIR=9.4), oral cavity and pharynx (n=3), brain and nervous system (n=3), bone (n=2) and urinary bladder (n=2). Risk factors for solid tumor SMNs were female sex (RR=3.1), mediastinal NHL disease (RR=5.2), and breast RT exposure (RR=4.3). Overall cumulative incidence of solid tumor SMNs from 5 to 20 years after NHL diagnosis was 0.03 (95% CI: 0.02, 0.05). Conclusions: We identified a four-fold risk of mortality and three-fold risk of SMNs in a large cohort of pediatric NHL survivors relative to the general U.S. population. Survivors of childhood NHL, particularly those treated with chest RT, may be at continued increased risk of early mortality and solid tumor SMNs. Health care providers responsible for this population should remain alert to second cancers and other severe late health outcomes.

Background: Survival for ALL has improved substantially: current five-year survival rates are approximately 80% yet survivors continue to experience late medical and social effects. Objective: To report rates of mortality and second neoplasm (SN) and selected social outcomes from a large cohort of childhood ALL survivors. Methods: Five year survivors of ALL (n=4151) diagnosed < age 21, from 1970–1986 were compared to population rates or a sibling control group (n=3899) for mortality, SN, education, marriage, health insurance and employment. Results: Survivors and siblings were 53% and 48% male; median ages were 26 and 31yrs respectively. Survivors had a mean age of 6 yrs (range 0–20) at diagnosis and had a mean follow-up of 22 yrs (range 16–34). Sixty two percent received chemotherapy (CT) + radiation therapy (RT), 5.2% underwent marrow transplant with CT +/− RT, while 27% received CT only. Among 5yr survivors, 417 deaths occurred; cumulative mortality was 12% at 25 yrs. Recurrent ALL accounted for 67% of deaths, while 13% (n=55) died of SN. Standardized mortality rate (95% confidence intervals) for malignant SNs was 14.0 (10.7–17.9). Survival at 25 yrs was 94% for patients who never reported relapse and 59% for patients who reported a relapse (p Conclusion: In the largest long-term follow-up study of its kind, the CCSS cohort demonstrated a significant improvement in survival over time among 5-yr survivors of ALL with and without history of relapse. Death after cohort entry was due most commonly to ALL, although SNs contributed substantially. HS graduation rates for survivors were comparable to the sibling cohort, but the rates were significantly lower for college graduation and for marraige. Although lower than siblings, majority of survivors reported being employed and having health insurance. There was no significant difference between the survivors of relapsed and non-relapsed ALL, with respect to their socioeconomic outcomes. Rates (percentage), Age Standardized to Siblings Sibling Non-relapse Relapse p-value Relapse vs. Non * p for rows 1 & 2 HS grad 97 93 97 College grad 52 41 41 .78* Never married 21 34 46 .10 Ever employed 100 98 97 .07 Health Insurance 90 86 88 .86

Survival rates for childhood AML continue to improve. Limited data exist on the comprehensive assessment of late medical and social effects experienced by these aggressively treated individuals. This analysis includes 272 5-yr survivors of AML participating in the CCSS diagnosed ≤ age 21, between 1970–1986. AML survivors who received a blood or marrow transplant are excluded from the current analysis. Comparisons among treatment groups and to a sibling control group are age and gender adjusted. Survivors (55% female) were on average 7 yrs old at dx and 28 yrs at follow-up, 56% received chemotherapy only, 34% chemotherapy/RT. Average follow-up was 22.6 yrs (16.1–33.5). Among these 5-yr survivors, overall survival was 97% (95% CI, 94–98%) at 10 yrs and 94% (95% CI, 92–97%) at 20 yrs. Six individuals reported 8 recurrences a mean of 11.1 yrs (5.6–16.6) from diagnosis, 2 died from relapse, 1 from congestive heart failure (CHF), and 1 from a myocardial infarction (MI). All cause standardized mortality ratio was 4.7 (95% CI 2.8–7.5). Cumulative incidence of recurrent AML at 10 and 20 years was 1.8% (95% CI 0.2–3.4%) and 3.7% (95% CI 1.4–5.9%), respectively. Eight survivors reported 10 subsequent malignant neoplasms (SMN) (5 breast cancers, 3 CNS tumors, 1 ovarian tumor, 1 salivary gland tumor) a mean of 18.7 yrs (9.2–26.4) from diagnosis, 3 with a history of RT exposure. SMN cumulative incidence at 20 yrs was 1.6% (95% CI 0.02–3.3%) with a standardized incidence ratio of 3.2 (95% CI 1.4–6.0). Six cardiac events (5 CHF and 1 MI) occurred a mean of 16.4 yrs (12.8–18.4) from diagnosis, 20-yr cumulative incidence 2.4% (95% CI 0.5–4.4%). Among those aged 25 yrs or more, marriage rates were similar among AML survivors and the general U.S. population (59%), but lower compared to siblings (69%) (p

CCG-2961 tested an intensively timed induction therapy consisting of cytarabine (AC), etoposide, thioguanine, dexamethasone, idarubicin and daunorubicin. Patients in remission after induction were randomized to a second induction course (Arm A) or a 3-drug combination of fludarabine, AC, and idarubicin (Arm B). Course 3 for patients with related donors was bone marrow transplantation (BMT); for those without donors, high dose AC/l-asparaginase. After Course 3 patients without donors were randomized to 14 infusions of Interleukin 2 (IL2) over 18 days or follow-up. CNS prophylaxis was intrathecal AC. Eligibility included all subtypes of de novo AML except acute promyelocytic leukemia and AML in patients with Down syndrome. CCG-2961 opened in Oct.1996 and closed in Dec. 2002. The DSMC suspended the study between Oct. 1999 and May 2000 while the 2961 Committee developed supportive care policies to reduce treatment-related mortality (TRM). CCG-2961 enrolled 900 de novo patients aged 3 days to 21 years, with 495 and 405 patients accruing pre-and post suspension respectively. Remission induction rate is 88.5%. With median follow-up of 3.6 years (range: 0 – 8.1 years), event-free survival (EFS) at 3 years is 44±3% and survival (OS) 57±3%. Disease-free survival (DFS) following Course 2 Arms A and B are not different, although relapse is significantly higher in Arm A (7.3% .vs. 3.1% P=0.018) and TRM more common in Arm B (7.9% vs.4.2% P=0.059), despite 7 less days of neutropenia in Arm B (P17 years, Afro-American and Hispanic ethnicity, body mass index 95th percentile for age, absence of related marrow donor, WBC > 50,000/mm3, karyotype with −7/7q, −5/5q- or > cytogenetic 5 abnormalities, FLT3/ITD, >15 % morphologic blasts on day 14 or >0.5% immunologically detectable blasts at the end of induction. CCG-2961 confirms the efficacy and high TRM of intensively timed therapy. Neither fludarabine nor IL2 increases DFS or OS, and availability of a donor does not improve outcomes in those with favorable cytogenetics.

Little is known about the etiology of childhood leukemia. Elevated birth weight (> 4000 g) is gaining acceptance as a risk factor, particularly for children diagnosed < 2 years of age, but the underlying biological or physiological explanation for this association has yet to be defined. At least three recent studies have demonstrated a positive association with childhood leukemia and maternal anemia during pregnancy. Physiologic anemia of pregnancy, which results from normal plasma volume expansion, is thought to produce optimal blood viscosity for the low flow area of the placenta and is associated with the highest average birth weights in the offspring. We therefore hypothesized that maternal physiologic anemia of pregnancy would have a positive association with infant leukemia. To test this hypothesis, we utilized data from a case-control study conducted by the Children’s Oncology Group (COG) that consisted of 240 incident cases of acute infant leukemia (< 12 months of age) diagnosed between 1996 and 2002 and 255 controls obtained by random digit dialing. Maternal blood counts were obtained by medical record abstraction. Information regarding the patients’ diagnoses and cytogenetic/molecular abnormalities were obtained from COG institutions. Physiologic anemia of pregnancy was defined as a hemoglobin concentration of < 11 g/dL in the second or third trimester of pregnancy (WHO classification). Anemia earlier in pregnancy is more frequently due to nutritional deficiencies and can be associated with poor fetal outcomes and thus was excluded. Maternal hemoglobin values from the second or third trimester were available for 178 case and 180 control mothers. Data were analyzed using unconditional logistic regression. We found no evidence that physiologic anemia of pregnancy was associated with birth weight of > 4000 g (odds ratio (OR) 1.05, 95% confidence interval (CI)=0.55–1.99) Overall, the OR for physiologic anemia of pregnancy and risk of infant leukemia was 0.85 (95%CI=0.53–1.37). The association remained non-significant when cases were divided into acute myeloid leukemia (AML) (n=63) and acute lymphocytic leukemia (ALL) (n=115) with ORs of 0.64 (95%CI=0.32–1.30) and 0.98 (95%CI=0.58–1.66), respectively. The association was also not significant when cases were stratified by MLL gene abnormality status (OR=0.77; 95%CI=0.42–1.40 and OR=0.88; 95%CI=0.45–1.73, for cases with (n=92) and without (n=62) an MLL gene abnormality, respectively). These associations remained non-significant when the data were adjusted for birth weight, maternal race, and birth order. More stringent criteria for anemia also did not modify the results. We found no evidence for an increased risk of infant leukemia in the offspring of mothers with physiologic anemia of pregnancy. This work was supported by NIH R01 CA79940 and the Children’s Cancer Research Fund.