A new study in seven high-income countries shows that while the incidence of colorectal cancer, (otherwise known as colon or bowel cancer). is decreasing for adults over 50, it is substantially increasing among younger adults. In the UK younger people are now at higher risk of bowel cancer than older generations.
The study into colorectal cancer incidence by the International Agency for Research on Cancer, (IARC), was published this month in The Lancet. It does not pinpoint root causes for this alarming annual increase among younger people. The study researchers suggest, however, that lifestyle issues related to obesity, exercise and diet are the most likely cause.Should the increase in bowel cancer among younger adults continue, researchers suggest that screening guidelines must be reconsidered, and screening should be lowered to age 45.
Bowel cancer is the fourth most common cancer and the second biggest cancer killer in UK. In USA it is the third leading cause of cancer mortality. The key to reducing bowel cancer mortality is early detection through screening. Bowel screening acts to reduce the cancer incidence by detecting and removing precancerous lesions or detecting existing cancer lesions early. Survival is more than 90% for adults if the bowel lesions are detected at this early stage. While the decrease in bowel cancer incidence among older people is testament to the efficacy of the current screening programme, the IARC study highlights the need for action to counteract the rising incidence of the disease in adults aged under 50.
Counteraction can best be done by attacking the ongoing lifestyle problems of obesity, alcohol abuse, inadequate exercise and faulty diet, as well as reducing the screening age if that does not overstretch the public health system to a point where earlier screening has the unintended consequence of lengthening colonoscopy waiting times for those at high risk. Free screening is currently available in parts of UK for adults aged 55 or 60. In Scotland and Australia screening is available for adults aged 50. In New Zealand it is available for adults over 60 while it is recommended for adults aged 50 in USA and Canada.
The UK Government announced in August 2018 that it intends to lower the bowel cancer screening age to 50 and the NHS and PHE are presently looking into how this can be achieved satisfactorily. Bowel cancer is treated by surgery, chemotherapy and radiation. Over the past decade however, researchers have learned more about gene and protein changes in the cells causing bowel cancer. New drugs have been developed to specifically target these changes. These can be used with traditional chemotherapy, or alone if chemotherapy has ceased to work.
Immunotherapies are showing outstanding results as a cancer treatment, but bowel cancer fails to respond well to approved immunotherapies. This is largely because of highly immunosuppressive environments that curb the body’s immune defences. Research to rectify this is ongoing in a number of countries.
Changes in colorectal incidence in seven high-income countries.
Bowel Cancer screening
Benefits, Harms and Cost-Effectiveness of Potential Age Extensions to the National Bowel Cancer Screening Program in Australia.
Colorectal Cancer: Risk Factors and Prevention
What You Need to Know about Colorectal Cancer: Slideshow
Bowel Cancer Treatment