The number of deaths due to cancer in the United States is continuing to decline in men, women, and children across all major racial and ethnic groups, according to the authors of the 2018 Annual Report to the Nation on the Status of Cancer.
The "most notable exceptions" to the decline are uterine cancer and liver cancer in both men and women, say Kathleen A. Cronin, PhD, MPH, of the Division of Cancer Control and Population Sciences at the National Cancer Institute (NCI) in Bethesda, Maryland, and colleagues.
In addition, the incidence of late-stage prostate cancer has increased since 2015, and mortality rates have plateaued following decades of significant decline, as highlighted by Serban Negoita, MD, DrPH, of the NCI Surveillance Research Program, and colleagues.
The report, issued by the American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the NCI, and the North American Association of Central Cancer Registries (NAACCR), was published online May 22 in Cancer.
In a press release issued by the NCI, Director Ned Sharpless, MD, called the report "an encouraging indicator of progress we're making in cancer research. It's clear that interventions are having an impact."
However, he also noted that the report "highlights areas where more work is needed."
The report notes that from 1999 to 2015, overall cancer mortality decreased by an average of 1.8% each year in men and by 1.4% in women.
In men, 2010-2014 incidence rates decreased for seven of the 17 most common types of cancer. However, in men, there was an increase in the incidence of leukemia, melanoma, myeloma, and cancers of the kidney, liver, oral cavity, pancreas, and thyroid cancers. The greatest increase was in liver cancer. From 2011 to 2015, mortality rates decreased for 11 of the 18 most common types of cancer in men.
Similarly, cancer incidence rates in women declined for seven of the 18 most common cancers, and mortality rates declined for 14 of the 20 most common cancers. The greatest decrease in incidence was for colorectal cancer. For women, between 2010 and 2014, the incidence of leukemia, melanoma, myeloma, and cancers of the breast, uterus, kidney, liver, oral cavity and pharynx, pancreas, and thyroid increased.
In children up to 14 years of age, overall cancer mortality from 2011 to 2015 decreased by an average of 1.5% annually, but overall cancer incidence rates increased by 0.8% per year from 2010 to 2014.
Mortality rates for lung and colorectal cancer decreased in both men and women. It also decreased for breast cancer in women and prostate cancer in men. However, in both men and women, death rates increased for cancer of the liver, pancreas, and brain. Mortality rates also increased in men for cancers of the oral cavity and pharynx, soft tissue (including the heart), and nonmelanoma skin cancer. In women, mortality increased for uterine cancer.
The increases in liver cancer mortality may be related to the high prevalence of hepatitis C virus infection among baby boomers, Cronin and colleagues point out. It may also be related to the high prevalence of obesity in the United States, which is believed to be a contributing factor to increases in uterine and pancreatic cancer mortality. The increase in mortality due to cancers of the oral cavity and pharynx cancer among white men is thought to be associated with human papillomavirus infection, they note.
Significant differences remain in cancer incidence and mortality based on sex, race, and ethnicity, pointed out Otis W. Brawley, MD, chief medical officer for the ACS, in the press release. "We need to continue working to understand the reasons for the disparities and how to most efficiently continue supporting and, if possible, accelerate these declines," he said.
Cancer incidence rates decreased in men by 2.2% per year for all cancer sites combined but did not change in women between 2010 and 2014.
For all cancers combined, the highest incidence rates were in black men and white women; cancer death rates were higher in black men and women than in any other racial group. Rates of cancer incidence and mortality were higher in non-Hispanic white men and women compared to men and women of Hispanic origin.
From 2007 to 2013, for the four most common cancers, the rates of 5-year survival by cancer stage at diagnosis were highest for early-stage breast and colorectal cancer and for melanoma. However, in lung cancer, survival remained low for all stages of disease, ranging from a 5-year survival rate of 55% for stage I disease to 4% for stage IV.
For stage I breast cancer, the 5-year survival was 100%; it decreased to 26.5% for stage IV disease. In colorectal cancer, the 5-year survival was 88.1% for stage I disease and 12.6% for stage IV disease. In melanoma, for stage I disease, survival after 5 years was 99.5%, but it was only 16% for stage IV disease.
Upswing in Late-Stage Prostate Cancer
Overall prostate cancer incidence rates declined an average of 6.5% each year between 2007 and 2014, from a rate of 163 new cases per 100,000 men in 2007 to 104 new cases per 100,000 in 2014.
However, the incidence of metastatic disease increased from a rate of 7.8 per 100,000 men in 2010 to 9.2 per 100,000 in 2014, Negoita and colleagues say. In addition, prostate cancer mortality, which has been in decline since 1993, began to level off between 2013 and 2015.
"The increase in late-stage disease and the flattening of the mortality trend occurred contemporaneously with the observed decrease in PSA [prostate-specific antigen] screening in the population," said Negoita in the press release.
"Although suggestive, this observation does not demonstrate that one caused the other, as there are many factors that contribute to incidence and mortality, such as improvements in staging and treating cancer. Additional research is needed to get a more comprehensive understanding of the recent trends and the possible relationship with PSA screening, as well as the relationship with other factors that may be associated with these trends," he commented
The trend for more late-stage prostate cancer occurring in the United States was described recently in a presentation at the annual meeting of the European Association of Urology, as reported by Medscape Medical News. A retrospective analysis of almost 20,000 US men with prostate cancer showed a consistent increase in the number of patients presenting with cancer of Gleason score 8 or higher. This increase followed recommendations in 2012 from the US Preventive Services Task Force against routine PSA testing in asymptomatic men.
"If our data are correct, the most important thing to do is to start screening more intensely again," lead author Thomas Ahlering, MD, University of California, Irvine, told Medscape Medical News at the time.
Materials provided by Medscape.