By Tom Ulrich
Earlier this month, the American Cancer Society (ACS) released "Cancer Statistics, 2014," their annual estimate of new cancers diagnoses and deaths for the year ahead. The report was heavily focused on adult malignancies – not surprisingly, given that the number of adult cancer patients in the nation is orders of magnitudes greater than that of childhood patients – but did hold a few insights into childhood cancers.
It showed, for instance, that cancer is still the leading cause of disease-related death among children in the U.S. Leukemias, brain and other nervous system tumors, and sarcomas – tumors of the bones, joints and soft tissues – topped the list of the most lethal cancers for both boys and girls.
But that’s pretty much where "Cancer Statistics, 2014" left off when it came to childhood cancers. However, the ACS also released a separate report in December – "Annual Report to the Nation on the status of cancer, 1975-2010" – that held a bit more news when it came to the recent pediatric cancer trends in the U.S.
And that news was…mixed.
The bad, then the good
"Annual Report to the Nation" employed the same mix of National Cancer Institute and CDC data used in "Cancer Statistics, 2014" to detail the current state and short- and long-term trends in cancer incidence rates and cancer mortality rates
From a pediatric perspective, the report’s first finding was sobering: Between 2006 and 2010 (the most recent time period they analyzed), the incidence rate (the number of new cases in a specified time interval) for pediatric cancers wentup by 0.8 percent per year – meaning that more children were being diagnosed with cancer.
That’s not a large percentage change, but it continues a trend dating back to 1992, and it runs counter to the overall trend in cancer incidence rates nationally (which over the last few years have been going down by 0.4 percent per year).
"The increase in the incidence of pediatric cancer is driven largely by increases in leukemia and brain tumors," notes Lisa Diller, MD, chief medical officer of Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, going on to underscore that the reasons for these increases aren’t clear. "Just as we must support research to further reduce the deaths from childhood cancer, we also must support research to understand the troubling increase in incidence."
"The continuing decline in mortality is testament to the research and clinical trials that have advanced our understanding of pediatric cancer."
But while more children are developing cancer, fewer are dying from it. Childhood cancer mortality rates over the same time period fell by 2.4 percent per year, a steeper decline than the 1.5 percent reduction seen for all cancers nationally.
"The continuing decline in mortality is testament to the research and clinical trials that have advanced our understanding of pediatric cancer," says Diller. "We must continue to support research to give children with difficult-to-treat cancers more options that will lead to cure."
A. Lindsay Frazier, MD, a solid tumor specialist and epidemiologist at Dana-Farber/Boston Children’s, also sees lessons in the two reports’ data about how a child’s health can impact her risk of cancer years or decades down the line. "Although the overall incidence of cancer is declining in adults, adult melanoma continues to climb, due in part to excess sun exposure during early childhood."
Frazier also thinks that the adult data in "Cancer Statistics, 2014" highlight the need to better understand socioeconomic factors that impact children’s health. "The regional and racial differences in both incidence and mortality in adult cancers suggest we should take a closer look at the societal factors that affect a child’s chance for cure, and how we can overcome them."