Cancer Deaths in 2017 Result in More than 4 Million Potential Years of Life Lost

A study published in Cancer Epidemiology, Biomarkers & Prevention found that deaths from cancer accounted for more than 4 million potential years of life lost (PYLL) in 2017.¹

Even further, though the cancer types with the highest death rates per capita accounted for the greatest number of years lost, cancers that typically occur at younger ages carried a disproportionate share of the burden.

“Potential years of life lost (PYLL) is an estimate of the average years a person would have lived if he or she had not died prematurely,” first author Minkyo Song, MD, PhD, a research fellow at the National Cancer Institute, said in a press release.² “Given that cancer is the leading cause of death in those younger than 80 years old, it is important to study the effect of cancer death rates among younger people.”

In this study, investigators used US national death certificate data to measure PYLL and estimate the impact of cancer-related deaths. Of note, PYLL was defined as the sum of the total years of life lost prior to age 75 years.

A total of 45 categories of common cancers were grouped for cancer-specific calculations of PYLL and PYLL per death. According to death certificate data, there were 599,099 cancer deaths in the US in 2017. Based on this data, the researchers determined that 4,280,128 years of life were prematurely lost due to cancer in 2017.

The total number of PYLL was found to have increased slightly from the 4,262,397 PYLL recorded in 1990, despite an overall decrease in cancer deaths. During this time, overall cancer mortality dropped from 214.9 per 100,000 in 1990 to 152.7 per 100,000 in 2017.

“The change in PYLL due to cancer between 1990 and 2017 is driven by a combination of changes in cancer-related death rates and increases in the size and changes in the demographics of the US population,” the authors wrote. “Therefore, there was an increase in the total PYLL due to cancer-related deaths, despite declining mortality rates, which is driven by the growth and aging of the US population.”

In 2017, the largest number of PYLL was revealed to be due to deaths from cancers of the lung/bronchus (n = 891,313; 20.8%), colon/rectum (n = 409,538; 9.6%), and breast (n = 400,643; 9.4%). Moreover, cancers with the highest PYLLs typically also caused the largest number of deaths and had the highest mortality rates, with the exception being prostate cancer (5.1% of deaths, 2.0% of PYLL).

When looking at PYLL per death, PYLLs per death were greatest for deaths due to cancers of testis (mean, 34.0 years), bones/joints (mean, 26.4 years), and other endocrine sites including the thymus (mean, 25.2 years). This is important, as these rare cancers typically affect younger individuals.

In addition, the study also demonstrated that ethnic and racial minority groups account for a disproportionate share of the burden of premature cancer death. In 2017, 78% of all cancer deaths occurred in non-Hispanic white individuals, though only 70% of PYLL occurred in this group. By contrast, Hispanic individuals accounted for 7% of cancer deaths and 10% of PYLL, while Black individuals accounted for 12% of cancer deaths and 15% of PYLL.

“PYLL is a useful ‘complementary measure’ to cancer mortality rates. Together, they provide a more detailed picture of the social and economic toll of cancer,” explained Song. “PYLL can be used to estimate the impact of cancer death in younger populations. This metric highlights the enormous loss of life due to certain cancers that occur at younger ages, even if they occur infrequently.”

Importantly, the investigators noted that the study relied on the cause of death reported on death certificates, which are possibly subject to error. In addition, other studies have used different definitions of PYLL, thus contributing to some differences in reporting across the body of research on this topic.

“Mortality rates, PYLL, and PYLL per death are complimentary measures of cancer-related death that should be considered in tandem,” the study authors concluded. “PYLL and PYLL per death provide quantification of premature mortality that can be utilized to prioritize public health interventions focused on preventing premature deaths.”

References:

1. Song M, Hildesheim A, Shiels MS. Premature Years of Life Lost Due to Cancer in the United States in 2017. Cancer Epidemiology, Biomarkers & Prevention. doi: 10.1158/1055-9965.EPI-20-0782

2. Cancer Deaths Resulted in More Than 4 Million Potential Years of Life Lost in 2017 [news release]. Published November 13, 2020. Accessed November 13, 2020.