From the Guidelines
Colorectal cancer consistently declined in both incidence and mortality between 1975 and 2015. This decline is attributed to several factors, including improved screening methods, earlier diagnosis, and better treatment modalities 1. The incidence of colorectal cancer decreased from 54.5 to 38.6 per 100,000 people from 2000 to 2015, and the 5-year mortality rate decreased from 45% between 2011 and 2015 to 13.2% between 2016 and 2020 1.
Key Factors Contributing to the Decline
- Improved screening methods, such as colonoscopy and fecal occult blood tests, have led to earlier detection and removal of precancerous polyps 1.
- Increased screening rates among adults aged 50 to 75 years, from approximately 42% in 2000 to 72.2% in 2021, have contributed to the decline in incidence and mortality 1.
- Better treatment modalities, including surgery, chemotherapy, and targeted therapies, have improved survival rates for patients with colorectal cancer 1.
Epidemiology and Risk Factors
- Colorectal cancer is the third most commonly diagnosed cancer and the second most common cause of cancer death in the United States 1.
- The risk of developing colorectal cancer depends on factors such as age, family history, and lifestyle factors, including smoking, high red meat consumption, obesity, and physical inactivity 1.
- Individuals with a personal history of adenoma, colon cancer, or inflammatory bowel disease, as well as those with a significant family history of colorectal cancer or inherited syndromes, are considered at high risk and should be actively screened 1.
From the Research
Cancer Trends Between 1975 and 2015
- The question of which cancer consistently declined in both incidents and mortality between 1975 and 2015 is addressed by examining trends in various types of cancer.
- According to the provided studies, there is no direct information on the specific cancer type that declined in both incidents and mortality between 1975 and 2015 2, 3, 4, 5.
- However, a study on progress in cancer mortality, incidence, and survival provides some insights into global trends in cancer 6.
- The study found that cancer mortality has declined over the last three decades in most high-income countries, reflecting improvements in cancer prevention, diagnosis, and management 6.
- Mortality from all cancers and most common cancer sites has declined over the last 25 years, except for the pancreas and lung (in women) 6.
- The patterns for incidence are less consistent between countries, except for a steady decrease in stomach cancer in both sexes and lung cancer in men 6.
- Survival for all cancers and the selected cancer sites increased in all countries, even if there is still a substantial variability 6.
- Although the study does not provide specific information on the decline of a particular cancer type between 1975 and 2015, it suggests that overall cancer trends have improved in recent decades 6.