Colorectal cancer has been a topic of increasing attention in recent weeks and months. One reason is that research findings have led to a new hypothesis how patients can be grouped, selected and treated. This will be the topic of a following blog posts in this series.
The other interesting finding is the change in colorectal cancer (CRC) incidence in different age groups. According to the American Cancer Society (ACS) when all ages are combined, new diagnoses of CRC went down in the US since the mid-1980s. This has been proposed to be mostly due to improved screening and testing practice so that the disease is caught early when still curable. In some cases, screening reveals the growth of pre-cancerous benign polyps that can be surgically removed before they become malignant.
The decrease in CRC patient numbers has been driven by older adults. At the same time CRC incidence in younger and middle-aged patients is increasing drastically (1,2). Rebecca L. Siegel from the ACS recently published that the risk to be diagnosed with CRC for Americans younger than age 50 years has escalated back to the level of those born ca. 1890. (3)
Briefly, the research team conducted a retrospective study of patients age 20 and older that were diagnosed with invasive CRC between 1974 and 2013. The findings were quite alarming. While in the late 1970s and early 1980s, CRC incidence in people below the age of 50 decreased and above the age of 50 increased, the findings flipped afterwards. Starting in the mid-1980s, CRC increased in the younger and decreased in the older population. The reasons described in the discussion part of the research article included changes in dietary patterns and less active life style that can lead to obesity.
In her discussion, Rebecca Siegel proposed to put more effort in CRC awareness campaigns among clinicians and the general public. Also screening should begin before the age of 50.
Considering all of the above, we have a scary high number of CRC patients in the US. The US Cancer Statistic Center published on the ACS website that in 2017, there will be an estimated >135,000 new CRC cases and >50,000 deaths. CRC is more frequent and leads more often to death in men than in women. Incidence and death rates are different between states. While incidence rates are highest in North Dakota, Kentucky, Louisiana and Mississippi, they are lowest in Utah, Colorado, Arizona and New Mexico. Death rates are highest in Arkansas, West Virginia, Lousiana and Mississippi and lowest in Utah and Colorado. CRC is more frequent in African American followed by American Indians and Alaska Natives, Caucasians and Hispanics and least frequent in Asian and Pacific Islanders. (4)
The findings from the ACS emphasize how important constant awareness and up-to-date medical literacy is among healthcare providers and healthcare users all over the US but possibly in some states in particular. This is a great example how education can solve problems in an individual’s life and our society.
- Rebecca L. Siegel et al. (2017) Colorectal Cancer Incidence Patterns in the US, 1974-2013. JNCI 109 (8).