Moving in the right direction
In the latest look at cancer numbers in the United States, collected in the Annual Report to the Nation on the Status of Cancer, 1975-2014, there are some encouraging trends, with survival rates up and death rates attributed to cancer decreasing. The annual report is released collaboratively by the American Cancer Society, the Centers for Disease Control and Prevention, the National Cancer Institute (NCI) and the North American Association of Central Cancer Registries (NAACCR), and it also appeared online in the Journal of the National Cancer Institute.
Death rates are down for 11 of 16 top cancers in men, and for 13 of 18 top cancers in women. In terms of overall cancer deaths between 2000 and 2014, those numbers dropped an average of 1.8 percent per year for men, an average of 1.4 percent per year for women and an average of 1.7 percent per year for children and adolescents (ages 0 to 19). The decline in cancer mortality is attributed primarily to a decrease in tobacco use, since a full third of cancer deaths are related to tobacco. Early detection and better treatments are also highlighted as causes for these more promising numbers.
“The continued drops in overall cancer death rates in the United States are welcome news, reflecting improvements in prevention, early detection, and treatment,” said Betsy A. Kohler, executive director of NAACCR. “But this report also shows us that progress has been limited for several cancers, which should compel us to renew our commitment to efforts to discover new strategies for prevention, early detection and treatment, and to apply proven interventions broadly and equitably.”
The NCI notes on its website that “Cancer survival rates for all cancers combined have been improving since 1975. Improvements in survival are likely related to advances in treatment and declines in surgical mortality. Better anesthesia, supportive care and quality improvement programs may have reduced the rate of surgical deaths among cancer patients. Research has led to major breakthroughs in therapies for some cancer types, such as non-Hodgkin lymphoma and chronic myelogenous leukemia. These treatments have contributed to the increase in five-year survival.”
In fact, five-year survival for the most common cancer types—breast, lung, prostate, colon and bladder—has improved from 50 percent in 1975 to 66 percent in 2017, according to the report. Breast cancer survival rates rose from 75 percent to 91 percent from 1975 to 2012; lung from 12 to 19 percent; prostate from 68 to 99 percent; colon from 50 to 66 percent; and bladder from 72 to 79 percent.
When compared to cancer cases diagnosed in 1975-1977, the five-year survival rates for cancers diagnosed in 2006-2012 increased markedly for all cancer types except cervical and uterine cancers. The most improvement in survival was seen in prostate and kidney cancers, with increases of 25 percent or more, as well as non-Hodgkin lymphoma, myeloma and leukemia.
Those cancers with the lowest five-year relative survival for cases diagnosed between 2006 and 2012 include pancreatic (8.5 percent), liver (18.1 percent), lung (18.7 percent), esophageal (20.5 percent), stomach (31.1 percent) and brain cancer (35 percent). The cancer types with the highest survival were prostate (99.3 percent), thyroid (98.3 percent), melanoma (93.2 percent) and female breast cancer (90.8 percent). Given that prostate cancer and breast cancer are the second most common cancer types for men and women respectively (lung cancer being number one for both sexes), this is particularly encouraging.
“While trends in death rates are the most commonly used measure to assess progress against cancer, survival trends are also an important measure to evaluate progress in improvement of cancer outcomes,” said Dr. Ahmedin Jemal of the American Cancer Society, lead author of the study. “We last included a special section on cancer survival in 2004, and as we found then, survival improved over time for almost all cancers at every stage of diagnosis. But survival remains very low for some types of cancer and for most types of cancers diagnosed at an advanced stage.”
As for incidence rates between 1999 and 2013, they have continued to decrease for men and remain stable for women. NCI noted on its website that “Over the last five years, the Average Annual Percent Change (AAPC) for all major sites combined was -2.3 percent per year for men and 0 percent per year for women. Because prostate cancer is the most common cancer among men, its decreasing rate of new cases between 1999 and 2013 brought down the overall incidence rate for men.” Between 2009 and 2013, nine of the 17 most common cancers for men had lower incidence rates, and eight of the 18 most common cancer types for women also saw decreased incidence.
“This report found that tobacco-related cancers have low survival rates, which underscores the importance of continuing to do what we know works to significantly reduce tobacco use,” Dr. Lisa C. Richardson, director of CDC’s Division of Cancer Prevention and Control, remarked in a press release. “In addition, every state in the nation has an adult obesity prevalence of 20 percent or more. With obesity as a risk factor for cancer, we need to continue to support communities and families in prevention approaches that can help reverse the nation’s obesity epidemic. We need to come together to create interventions aimed at increasing the uptake of recommended, effective cancer screening tests and access to timely cancer care.”