Overall cancer rates decreasing, but with ‘striking’ burden among young women
For all cancer types, U.S. mortality rates continued to decline among adults and children from 1999 to 2016, with decreasing incidence rates for men and stable incidence rates for women, according to the Annual Report to the Nation on the Status of Cancer.
The report — the product of a joint effort of American Cancer Society, CDC, NCI and North American Association of Central Cancer Registries (NAACCR) — also showed both favorable and unfavorable trends among adults aged 20 to 49 years. For that group, incidence and death rates appeared to be higher among women than men, a reverse trend from that of the general population.
“We are encouraged by the fact that this year’s report continues to show declining cancer mortality for men, women and children, as well as other indicators of progress,” Betsy A. Kohler, executive director of NAACCR, said in a press release. “There are also several findings that highlight the importance of continued research and cancer prevention efforts.”
From 2011 to 2015, overall cancer incidence rates were 494.3 per 100,000 among men and 420.5 per 100,000 among women, showing men had about 1.2 times greater incidence of all cancers compared with women. These rates reflected a 2.1% (95% CI, –2.6 to –1.6) yearly decrease among men, with stable rates among women.
Researchers noted the important stabilization among women in thyroid cancer rates, which had been increasing in prior years.
From 2012 to 2016, cancer mortality rates decreased 1.8% per year among men and 1.4% among women. The death rate for all cancers combined was 1.4 times higher among men vs. women (193.1 vs. 137.7 per 100,000). Researchers reported “rapid declines” in melanoma-related mortality rates among men and women (5-year average annual percent change [AAPC], –5% and –4.9%; P < .001 for both) contributed to the overall decrease.
Cancer incidence rates increased by about 0.9% per year among both children and adolescents, but cancer mortality rates decreased by 1.3% to 1.6% in children and adolescents across ethnicities.
The report highlighted several changes among adults aged 20 to 49 years. For this group, overall cancer incidence rates from 2011 to 2015 were lower among men than women (115.3 vs. 203.3 per 100,000).
During that period, cancer incidence decreased among men aged 20 to 49 years (5-year AAPC, –0.7%; 95% CI, –1 to –0.4), but increased among women (5-year AAPC, 1.3%; 95% CI, 0.7-1.9).
Overall cancer death rates also were higher among women than men in this age group (27.1 vs. 22.8 per 100,000), with a 2.3% (95% CI, –2.4 to –2.2) yearly decrease among men and a 1.7% (95% CI, –1.8 to –1.6) yearly decrease among women.
The most common cancers per 100,000 individuals aged 20 to 49 years included colorectal (13.1), testicular (10.7) and melanoma (9.8) among men, and breast (73.2), thyroid (28.4) and melanoma (14.1) among women.
Researchers noted that this incidence of breast cancer “far exceeded the incidence of any other cancer among younger adults during 2011-2015.” Further, breast cancer death rates “were more than double the rates for any other cause of cancer death among males or females,” they added, with figures representing the leading cause of cancer death among women aged 30 to 49 years and the third leading cause of cancer death among those aged 20 to 29 years.
“The greater cancer burden among women than men ages 20 to 49 was a striking finding of this study,” Elizabeth Ward, PhD, lead author of the study and a consultant at NAACCR, said in the release. “The high burden of breast cancer relative to other cancers in this age group reinforces the importance of research on prevention, early detection and treatment of breast cancer in younger women.”
Researchers also noted important trends among young adults in malignant brain and other nervous system cancers, which collectively were the 11th most invasive cancer among men and the 12th most common among women in this age group.
During 2011 to 2015, the incidence of malignant brain and other nervous system cancers decreased 0.5% (95% CI, –0.7 to –0.2) per year in men and 0.3% (95% CI –0.5 to 0) per year in women, whereas nonmalignant central nervous system tumors increased an average of 3.7% (95% CI, 3.1-4.4) per year in men and 3.2% (95% CI, 2.5-3.9) in women.
Data broken down by ethnicity continue to show the highest cancer mortality rates among black men and black women for all cancer sites combined and for nearly half of the most common cancers. Black men and white women had the highest overall cancer incidence rates, whereas Asian/Pacific Islander men and women had the lowest overall rates.
“Major declines overall in cancer mortality point in the right direction, yet significant differences remain in cancer cases and deaths based on gender, ethnicity, and race,” Robert R. Redfield, MD, director of the CDC, said in the release. “A better understanding of these discrepancies improves cancer diagnosis and recovery for all patients and is vital to our public health mission.” – by Alexandra Todak
Disclosures: Please see the study for a full list of all authors’ relevant financial disclosures.