The association between socioeconomic status and survival among children with Hodgkin and non-Hodgkin lymphomas in a universal health care system

Background: The association between socioeconomic status (SES) and cancer survival has been studied extensively in adults. However, little is known about this relationship in the pediatric population, specifically in jurisdictions with universal health care insurance programs. Our aim was to determine whether lower SES is associated with poorer survival in pediatric Hodgkin (HL) and non-Hodgkin lymphoma (NHL) patients in Ontario.Procedure: All incident cases of HL and NHL in children between 0 and 14 years old diagnosed in Ontario between January 1st, 1985 and December 31st, 2006 were identified through the Pediatric Oncology Group of Ontario Networked Information System. Neighborhood income quintile and material deprivation quintile at diagnosis were used as proxies for SES. Cox proportional hazards regressions were used to assess the association between SES and the risk of event-free or overall survival.Results: A total of 692 patients were included in the analysis: 302 HL and 390 NHL. SES was not associated with survival (overall or event-free) among HL and NHL patients (P > 0.05 for all four comparisons, i.e., HL/NHL, EFS/OS) after adjustment for age, sex, period of diagnosis, and disease stage. There were no differences in the distribution of disease stage across SES strata at the time of diagnosis. Similarly, the distribution of deaths among long-term survivors (survived ≥5 years from diagnosis) did not differ across SES strata (P > 0.05).Conclusions: SES was not associated with risk of death among pediatric HL and NHL patients in Ontario. This was consistent through the cancer trajectory, including diagnosis, treatment, and survivorship

The Association Between Total Duration of Breastfeeding and Serum 25-Hydroxyvitamin D

BACKGROUND: Breastfed infants are at increased risk for developing vitamin D deficiency and rickets due to minimal vitamin D in breast milk. While previous research supports the association between exclusive breast-feeding and vitamin D deficiency, little is known about the effect of total duration of breastfeeding, which includes both the periods of exclusive breastfeeding and after the introduction of complementary foods, on vitamin D status. OBJECTIVES: To determine whether total duration of breastfeeding is associated with serum 25-hydroxyvitamin D (25-OHD) level in early childhood and to explore the effect of vitamin D supplementation on the relationship between total duration of breastfeeding and vitamin D status. DESIGN/METHODS: A cross-sectional study of healthy children seen for primary health care between September 2011 and August 2013 was conducted through the TARGet Kids! practice-based research network. Adjusted linear regression was used to determine the association between total duration of breastfeeding and serum 25-OHD and to explore the effect of vitamin D supplementation. Adjusted logistic regression was used to assess the probability of 25-OHD <20 ng/mL in supplemented vs. non-supplemented children. RESULTS: An association that was modified by vitamin D supplementation was identified between total duration of breastfeeding and serum 25-OHD (P=0.0251). Every one month increase in total duration of breastfeeding was associated with a 0.11 ng/mL lower median serum 25-OHD level (95% CI −0.20, −0.02 ng/mL) among children who were not supplemented. The odds of serum 25-OHD <20 ng/mL increased by 6% with every one month increase in total duration of breastfeeding among children who were not supplemented (OR=1.06, 95% CI 1.03, 1.10). There was no statistically significant association between total duration of breastfeeding and 25-OHD among children who did receive vitamin D supplementation (P=0.43). CONCLUSION: Breastfed children who do not receive vitamin D supplementation beyond the first year of life may be at an increased risk of inadequate vitamin D status. Vitamin D supplementation appears to mitigate this risk. These findings support the use of vitamin D supplementation during breastfeeding of any type and duration

Differential survival improvement for patients 20-29 years of age with acute lymphoblastic leukemia

Objective: To compare improvement in survival from 1986 to 2009 for acute lymphoblastic leukemia (ALL) patients 1-14, 15-19 and 20-29 years in Ontario and United States.Methods: This population-based analysis used data from Ontario Cancer Registry (OCR) and Surveillance Epidemiology and End Results (SEER).Results: In OCR, there was steady improvement in survival by period of diagnosis in all three age groups. In SEER, there was no improvement in survival for patients aged 20-29 years.Conclusions: Survival in Ontario and the United States has improved for patients with ALL aged 1-19 years. However, survival has improved among patients aged 20-29 years only in Ontario

Subsequent malignant neoplasms in pediatric cancer patients treated with and without hematopoietic SCT

Pediatric cancer patients are at increased risk of subsequent malignant neoplasms (SMNs). However, little is known about the contribution of hematopoietic SCT (HSCT) to the development of SMNs. The objective of this study was to compare the incidence of SMNs in a population cohort of childhood cancer survivors treated with and without HSCT. A cohort of 7986 children (age 0-14 years) diagnosed with cancer in the province of Ontario, Canada between 1985 and 2009 was identified in POGONIS (Pediatric Oncology Group of Ontario Networked Information System), a population-based active cancer registry, and linked to a clinical HSCT database. Among this cohort, 796 patients had an HSCT as part of their primary treatment. Of the 375 allogeneic HSCT patients, 14 (3.7%) developed a SMN at a median follow-up of 12.3 years (range: 2.0-22.9 years). Of the 421 autologous HSCT patients, 8 (1.9%) developed a SMN at a median of 4.5 years (range: 1.3-14.3 years). Of the 7190 patients who did not receive an HSCT, 160 (2.2%) developed a SMN at a median follow-up of 6.8 years (range: 0.0-24.9 years). The 15-year cumulative incidence of SMN was 3.1% among the allogeneic HSCT group, 2.5% among the autologous group and 2.3% in the non-HSCT group. The cumulative incidence curves for the allogeneic HSCT and non-transplant groups only diverged after ~15 years from primary diagnosis. Our findings further corroborate the observation that children who undergo allogeneic HSCT are at a significantly increased risk of developing SMN compared with pediatric cancer survivors treated without HSCT

Late mortality after hematopoietic SCT for a childhood malignancy

Hematopoietic SCT (HSCT) has been used as a curative therapy for pediatric malignancies. Survivors of HSCT are at risk for disease recurrence, late morbidity and mortality. We assessed late mortality (≥2 years post-HSCT) in a population-based cohort of children who underwent HSCT for a malignancy. Mortality outcomes were determined by linking a clinical transplant database with the Canadian province of Ontario's pediatric cancer mortality files. Seven hundred and fifty-four children underwent HSCT (371 allogeneic, 383 autologous). Of the 479 (63.5%) who were alive ≥2 years post HSCT, 98 (20.5%) suffered a late death. Late mortality in the allogeneic HSCT group was 14.9% (median follow-up 10.0 years; range: 2.0-25.6 years), mainly due to relapse of the primary malignancy (64.7%). Chronic GVHD and second malignancies were not major causes of late mortality. A total of 25.5% suffered a late death following autologous HSCT (median follow-up 6.7 years; range: 2.0-22.2 years). Recurrence of the primary malignancy accounted for 87.5% of these deaths. Recurrence of the primary malignancy is the predominant cause of late mortality after HSCT. In contrast to studies of adult patients, non-relapse mortality is less common in children, and death due to chronic GVHD and secondary malignancies is uncommon