Pediatric Cancers among Alaska Native People

Abstract

Objective: To evaluate the descriptive epidemiology of pediatric cancers among Alaska Native people.

Study design: We used data from the Alaska Native Tumor Registry, a population-based registry capturing cancer information among Alaska Native people 1969-present. Specifically, we examined all cases of cancer diagnosed among individuals ages 0-19 years. Cases were classified according to the International Classification of Childhood Cancers, 3rd edition (ICCC-3). We estimated incidence and distribution of cases by ICCC-3 cancer site, comparing between the time periods 1969-1996 and 1997-2016. We assessed 12-month and 5-year cause-specific survival, and examined differences over the time period, adjusted for age, sex, and ICCC-3 site.

Results: Incidence rates of pediatric cancers increased between 1969 and 1996 (n = 134) and 1997 and 2016 (n = 186) among Alaska Native people, from 139.8 in 1 000 000 (95% CI, 116.99-165.7) to 197.54 in 1 000 000 (95% CI, 170.1-228.1). Distribution of ICCC-3 sites differed between time periods (P < .0001). Finally, cancer survival was high; the 12-month survival probability from all ICCC-3 sites combined was 0.88 (95% CI, 0.84-0.92) and the 5-year survival probability was 0.76 (95% CI, 0.70-0.81) for 1969-2016. After adjusting for age, sex, and ICCC-3 site, we observed a 57% decrease in the risk of death when comparing Alaska Native pediatric cancer cases diagnosed in 1997-2016 with those diagnosed in 1969-1996.

Conclusions: This information will be of value for our understanding of pediatric cancers among Indigenous peoples of the US, and will also be informative for clinicians providing care to this population.

Keywords: Native American; cancer surveillance; childhood cancers.

Figure 1.

Distribution of pediatric cancer cases among ICCC-3 sites, by time period, stratified by age at diagnosis, among Alaska Native children, 1969-2016.

Figure 2.

Change in incidence rate for childhood cancers, by age and ICCC-3 site, between time period (1969-1996 and 1997-2016). ^a Data are not given where cell case counts <10. ^b Differences were calculated as percent change between earlier time-period and recent time-period i.e., positive change indicates rate was higher in the recent time-period.

Figure 3.

Survival probabilities among Alaska Native pediatric cancer cases (all sites, age <20 years); by period of diagnoses: 1969-1996 (solid line), 1997-2016 (dashed line) (shadings show 95% confidence intervals)