Forward progress seen in pediatric cancer survival rates

Strides have been made in recent decades to improve childhood cancer survival rates, and for many today’s prognosis following a diagnosis is far different than it would have been 40 years ago. However, 2 recent studies show that in spite of overall improvement in survival rates, there are some cancer types and demographic groups who haven’t seen an improvement.

One study published in JAMA Pediatrics¹ looked at 67,061 US children and adolescents who had been diagnosed with a first primary malignant cancer when they were aged 0 to 19 years. The average age at diagnosis was 9.66 years. Cancer amenability was defined using 5-year relative survival rates for 103 cancer types. Roughly 54% of the sample were male.

The race/ethnicity demographics for the sample were:

·      Non-Hispanic white: 35,186 (52.5% of the sample)

·      Hispanic of any race: 19,220 (28.7% of the sample)

·      Non-Hispanic black: 7100 (10.6% of the sample)

·      Non-Hispanic Asian or Pacific Islander: 4981 (7.4% of the sample)

·      Non-Hispanic American Indian/Alaskan Native: 574 (0.9% of the sample)

When compared with non-Hispanic white children and adolescents, the investigators found a higher adjusted hazard ratio (aHR) of death for high-amenability than low-amenability cancers among non-Hispanic black patients (high: aHR, 1.59; 95% CI, 1.41-1.80 vs low: aHR, 1.35; 95% CI, 1.24-1.47; P=0.002 for interaction) and Hispanic patients of any race (high: aHR, 1.63; 95% CI, 1.50-1.78 vs low: aHR, 1.16; 95% CI, 1.08-1.25; P <0.001 for interaction). Similar patterns were seen in the other races/ethnicities but they were not statistically significant.

Survival rates for some cancer types have room to improve

The other study, published in the Journal of the National Cancer Institute,² looked at the trends in cancer survival for adolescents and young adults (AYAs). Researchers used the Surveillance, Epidemiology, and End Results database to find AYAs who had been diagnosed with cancer between 1975 and 2011 and had survived 5 years or more following the diagnosis. The diagnosis era was used to estimate cumulative mortality from all causes: the primary cancer, other cancer, and noncancer/nonexternal causes (ie, excluding accidents, suicide, homicide).

The sample included 282,969 5-year AYA cancer survivors. Researchers found that the 5-year mortality from all causes had decreased from 8.3% (95% CI, 8.0%-8.6%) among survivors diagnosed between 1975 and 1984 to 5.4% (95% CI, 5.3%-5.6%) among those diagnosed in the period 2005 to 2011. Decreases in mortality from the primary cancer (6.8% to 4.2% between these time periods) were considered the main explanation for the shift.

Investigators discovered that little improvement in primary cancer mortality was seen for some cancer types such as cervical/uterine, bladder, and colorectal. Late mortality from noncancer/nonexternal causes had some reduction in cases of leukemia; kidney cancer; trachea, lung, and bronchus cancers; Hodgkin lymphoma; and head and neck cancers.

References:

1. Delavar A, Barnes JM, Wang X, Johnson KJ. Associations between race/ethnicity and US childhood and adolescent cancer survival by treatment amenability. JAMA Pediatr. February 24, 2020. Epub ahead of print. doi: 10.1001/jamapediatrics.2019.6074

2. Anderson C, Nichols HB. Trends in late mortality among adolescent and young adult (AYA) cancer survivors. J Natl Cancer Inst. March 3, 2020. Epub ahead of print. doi: 10.1093/jnci/djaa014