9 January 2019
The American Cancer Society has just published their updated “Cancer Facts and Figures”, documenting cancer incidence and mortality rates. When combined by disease site, cancer death rates have decreased by 27% from 1991-2016, resulting in approximately 2.6 million cancer deaths avoided. From 2007 – 2016, cancer death rates have declined approximately 1.8% per year for men, and 1.4% per year for women. From 2006 – 2015, rates of cancer development increased approximately 2% per year for men and were stable for women. It is anticipated that there will still be more than 1.7 million new cancers diagnosed and 600,000 cancer-related deaths in 2019.
The most common cancers in men are lung, prostate and colorectal, and the most common cancers in women are breast, lung and colorectal. Breast cancer accounts for 30% of all new cancer diagnoses in women.
Lung cancer is the most frequent cause of cancer-related deaths in both men and women. Much of the decline in incidence and mortality is attributed to a decline in smoking rates, but it important to note that many cases of lung cancer occur in non-smokers. Rates of new lung cancer cases have decreased by 3% per year in men and 1.5% per year in women, and these differences are not fully explained by smoking rates – especially in cases of lung cancer in younger women. In addition, while lung cancer related deaths in men decreased by 48%, women only experienced a 23% reduction in death rates.
Improvements in screening and treatment have resulted in a decreased number of deaths due to lung, breast colorectal and prostate cancer, and breast cancer death rates decreased approximately 40% from 1989 – 2016. However, there has been a modest increase in breast cancer incidence, in part due to the association of breast cancer development with post-menopausal obesity as well as alcohol intake.
While the prostate cancer death rate has decreased, there has been some flattening of the curve from 2013-2016. This may be related to more recent guidelines that do not recommend routine testing of the prostate-specific antigen (PSA) in patients without symptoms.
Colorectal cancer death rates declined 53% from 1970 – 2016, but in patients younger than age 55, new cases of colorectal cancer have increased almost 2% per year since the mid 1990s
Death rates in cancers related to obesity, including pancreatic and uterine cancer, have been increasing. Deaths due to liver cancer have also risen, with an increasing number of cases related to obesity rather than alcohol and chronic hepatitis.
There has been a decline in the racial gaps in mortality rates, but blacks are still 14% more likely to die of cancer compared to whites (33% 25 years ago). While this is encouraging, the economic gap is growing, especially related to cancers that have seen improvements due to early screening and treatment, improved nutrition and smoking cessation.
It was noted that cancer risk increases with age, and those over 85 account for approximately 8% of all new cancer diagnoses. Cancer is also noted to be the 2ndleading cause of death, after heart disease in this population. There may be many challenges to diagnosis and treatment in older adults due to the presence of co-existing medical conditions as well as other factors.
It is important to note some limitations of the report. Information is gathered from several sources and data may be incomplete. The current report notes incidence rates through 2014 and survival data through 2015.
The general downward trend in cancer incidence and improvement in survival is encouraging, but there is much work to be done.