Cancer Mortality Rate Drops for the 25th Consecutive Year, but Socioeconomic Gap Widens

For the 25th consecutive year, the cancer mortality rate in the United States has declined, according to The American Cancer Society’s annual report on cancer rates and trends. The overall 27% drop in mortality rate translates into 2.6 million fewer deaths from cancer between the years 1991 and 2016.

The report, published this week in CA: A Cancer Journal for Clinicians, draws on mortality data from the National Center for Health Statistics and population-based cancer incidence data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results program. According to the report, the cancer death rate rose for most of the 20th century, driven in large part by lung cancer deaths associated with tobacco use. Since the peak of 215.1 deaths per 100,000 individuals in 1991, the cancer death rate has dropped steadily by approximately 1.5% per year.

The declining cancer rate is due, in large part to reductions in smoking and to advancements in the early detection and treatment and cancers, according to the report; the rate of death attributable to lung cancer dropped by 48% from 1990 to 2016 among men and by 23% from 2002 to 2016 among women. Prostate cancer mortality saw 4% reductions per year for 2 decades due to diagnosis at an earlier stage and advancements in treatment. Similarly, the death rates for breast cancer dropped by 40% from 1989 to 2016, prostate cancer dropped by 51% from 1993 to 2016, and colorectal cancer dropped by 53% from 1970 to 2016.

Despite these positive trends, cancer remains a pressing health issue in the United States. In 2016, 22% of all deaths were from cancer, making it the second-leading cause of death after heart disease. There has also been an uptick in death rates from 2012 to 2016 for cancers of the liver, pancreas, uterine corpus, brain, nervous system, soft tissue, and sites within the oral cavity and pharynx associated with human papilloma virus.

The report also indicated that the racial gap in US cancer mortality is narrowing—with the disparity in cancer deaths between black and white individuals declining from a peak of 33% in 1993 to 14% in 2016—but socioeconomic disparities are widening.

Socioeconomic deprivation was, prior to the mid-1980s, linked with lower cancer mortality; rates of colorectal cancer in men in the poorest US counties were approximately 20% lower than those in affluent counties in early 1970s, but are 35% higher today. This fact is due in large part to changes in smoking patterns and diet that influence colorectal cancer risk, as well as less access to screening and advanced treatments among disadvantaged populations in these poorer counties.

“These [poor] counties are low-hanging fruit for locally focused cancer control efforts, including increased access to basic health care and interventions for smoking cessation, healthy living, and cancer screening programs,” wrote the authors. “A broader application of existing cancer control knowledge with an emphasis on disadvantaged groups would undoubtedly accelerate progress against cancer,” they wrote, noting that approximately 34% of cancer deaths among Americans aged 25 to 74 years could be avoided if socioeconomic disparities were eliminated.

Looking ahead, in 2019, the report estimates, 1,762,450 new cases of invasive cancer will be diagnosed in the United States, which is equivalent to more than 4800 cases per day. Furthermore, an estimated 606,880 Americans will die from cancer, a number that corresponds to 1700 deaths per day. The greatest number of deaths are expected to be from cancers of the lung, prostate, and colorectum in men, and cancers of the lung, breast, and colorectum in women.

Monica M. Bertagnolli, MD, FACS, FASCO, the president of the American Society of Clinical Oncology, said in a statement that the report provides both "encouraging and concerning news." While she celebrated the progress made, she also noted that the report showed that where a patient lives can dictate their chances of surviving cancer and that many patients cannot access high-quality care or be involved in research.

"This report also highlights our long-standing concerns about the underrepresentation of individuals from lower socioeconomic populations in cancer clinical trials and the access to treatment advances these trials may provide," Bertagnolli said. "We must work to ensure every patient has access to cancer care that reflects their individual needs as well as the opportunity to participate in research and contribute to progress."

Reference

Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. CA Cancer J CLin. 2019;0:1-28. doi: 10.3322/caac.21551.