Over the past quarter of a century, the cancer death rate in the United States has been steadily declining due to lower smoking rates, earlier detection, and better treatment, according to a report released Tuesday by the American Cancer Society (ACS). The cancer death rate dropped by 27 percent between 1991 and 2016, during which more than 2.6 million lives were saved.
The bad news is, not everyone benefited equally. Despite progress, researchers found that mortality rates among the nation’s poorest residents were significantly higher for cancers that are both preventable and treatable if detected early, and that gap continues to widen.
Lung and liver cancer death rates are 40 percent higher for men in poor counties, and cervical cancer deaths are twice as high for women in poor counties, according to the report. In addition, the rate of obesity-related cancers is on the rise.
Liver cancer death rates increased by 1.2 percent per year among men and 2.6 percent per year among women, from 2012 to 2016. Other obesity-related cancers include endometrial cancer (cancer of the lining of the uterus), which increased 2.1 percent per year from 2012 to 2016, and pancreatic cancer, which increased 0.3 percent per year among men during this same time period
Dr. Ruben Mesa, director of the UT Health San Antonio MD Anderson Cancer Center, said the findings in the report “are important but not surprising.”
Issues of diet, physical activity, access to health care, and health literacy and education all contribute to the cancer mortality rate for this population, Mesa said. “Obesity rates are very much on the radar of the local cancer community. Obesity will likely pass tobacco as the most preventable cause of cancer in the future.”
The prevalence of obesity continues to rise in San Antonio. In 2014, the San Antonio Metropolitan Health District reported that 71 percent of adults in Bexar County were overweight or obese. Of children ages 10-17 in Bexar County in 2013, 27 percent of black and Hispanic children were obese, as were 12 percent of white children, according to a report by the Centers for Disease Control and Prevention.
Excess body fat increases risk for certain cancers such as kidney, pancreas, and liver, largely due to the inflammation caused by visceral fat – the fat that surrounds vital organs.
Of obesity-related cancers, liver cancer is of particular concern as rates of diagnosis continue to rise in San Antonio and South Texas, Mesa said. A 2014 study out of UT Health found that the incidence of liver cancer rates among Latinos in South Texas is higher than elsewhere in the country.
According to the ACS report, liver cancer deaths have been increasing nationwide since the 1970s, and initially most of the increase was tied to hepatitis C infections spread among drug users. But now obesity accounts for a third of liver cancer deaths and is more of a factor than hepatitis.
“Obesity was first identified as a risk factor for cancer in the 1990s, but over time we have seen it impact even less common cancers, contributing to higher rates than expected,” Mesa said. In Texas, 3,329 liver cancer cases were reported to the Centers for Disease Control and Prevention, more than triple the rate in 1999.
In Bexar County from 2011 to 2015, 1,390 new cases of liver cancer were reported, and 10 people died of liver cancer.
Cancer is the second-leading cause of death in the nation, taking the lives of more than 160,000 Americans in 2016, behind only heart disease. It is also the second-leading cause of death in both Texas and Bexar County.
The ACS report predicts more than 1.7 million new cancer cases and 600,000 cancer deaths will occur in 2019, amounting to more than 4800 new cancer cases to be diagnosed per day.
Despite progress, we still lose way too many people to cancer,” Mesa said. “Our community, like many, continues to struggle with adequate cancer screening and education,” which is key to reducing rates.
While advances in early detection and treatment are having a positive impact, the ACS report has some mixed news about the impact of routine prostate-specific antigen (PSA) testing to screen for prostate cancer, the second-leading cause of cancer death in men.
Although some health care experts credit PSA testing for the prostate cancer death rate falling by half over two decades, there has been long-standing debate surrounding its use in routine testing due to concerns it was leading to overdiagnosis and overtreatment.
Dr. Michael Liss, assistant professor of urology at UT Health San Antonio, said that while screening played a role in reducing prostate cancer deaths, it “is only one component to the larger care of a man being diagnosed with prostate cancer.”
“We must not forget about [clinical cancer trials] providing data to reduce metastasis and potentially prolong life,” Liss said. “The multidisciplinary team care approach to aggressive cancer, supporting translational research efforts, and the willingness and opportunity for patients to enroll in clinical trials is the only way to continue to reduce cancer death.”