Colorectal cancer (CRC) is a malignancy that develops in the colon or rectum. This disease begins most often as a noncancerous growth, called a polyp, on the inner lining of the colon. Since these polyps can progress into cancer over time, their detection and removal through screening is a primary goal of prevention. This information is especially important for women, as specific biological and lifestyle factors influence their risk and presentation of CRC.
Female-Specific Incidence and Mortality Rates
Colorectal cancer is a common malignancy for women, with a lifetime risk of approximately 1 in 26 for developing the disease. Current estimates suggest that over 71,000 new cases of colon and rectal cancers will be diagnosed in women in the US in 2024 alone. It ranks as the third-leading cause of cancer-related death in women. While the overall incidence has declined in older adults due to widespread screening, rates in younger adults are increasing.
Rates of CRC in adults under the age of 50 have been increasing by about one to two percent each year since the mid-1990s. Colorectal cancer has now become the second-leading cause of cancer death for women in this younger age group. By 2030, a significant proportion of all new rectal and colon cancer cases will be diagnosed in individuals under 55.
Unique and Shared Risk Factors in Women
Shared risk factors include a sedentary lifestyle and a diet low in fiber and high in red or processed meats. Obesity, smoking, and a personal or strong family history of CRC or certain types of polyps are also established contributors to increased risk. These elements often combine to increase inflammation and affect the gut microbiome, which can promote the growth of cancerous cells.
Unique factors related to a woman’s reproductive history and hormonal exposure also play a role in CRC risk. Postmenopausal women who have used hormone replacement therapy (HRT), which typically includes estrogen, have frequently shown a reduced risk of developing CRC. Studies indicate that this association may translate to a 20 to 40 percent lower risk for women who take HRT. Furthermore, a history of long-term use of oral contraceptives and a longer cumulative duration of breastfeeding have also been associated with a modest decrease in the incidence of CRC.
Recognizing Warning Signs and Symptoms
Colorectal cancer symptoms can be subtle. Common signs include a persistent change in bowel habits, such as new-onset diarrhea or constipation that lasts more than a few days. Rectal bleeding or the presence of blood in the stool, which may appear bright red or dark and tar-like, is another symptom that warrants immediate medical attention. A feeling of incomplete emptying after a bowel movement can also be a sign of a blockage or growth in the rectum.
For women, symptoms like unexplained abdominal pain, cramping, or persistent bloating can often be mistakenly attributed to menstrual issues, Irritable Bowel Syndrome (IBS), or even ovarian cysts. Unexplained fatigue or weakness, which is often linked to anemia from slow, chronic blood loss in the digestive tract, is another symptom that may be overlooked. Women should pay close attention to the persistence of these symptoms, especially if they are not cyclical in nature or do not resolve within a few weeks, and consult a physician promptly.
Screening Guidelines and Prevention Strategies
The most effective tool for managing colorectal cancer risk is regular screening, which allows for the detection and removal of precancerous polyps before they can become malignant. For women at average risk, the current guidelines from major health organizations recommend initiating regular screening at age 45. Earlier screening may be recommended if a woman has a strong family history of CRC or a personal history of inflammatory bowel disease.
Screening options include visual exams and stool-based tests, each with different intervals:
- A colonoscopy, which allows a doctor to view the entire colon and remove polyps, is typically performed every 10 years.
- Stool-based tests, such as the high-sensitivity fecal immunochemical test (FIT) which looks for hidden blood, are non-invasive and generally done annually.
- Other options include a multi-targeted stool DNA test every three years or a CT colonography, often called a virtual colonoscopy, every five years.
Women can actively reduce their risk through specific lifestyle modifications. Maintaining a healthy body weight and regularly engaging in physical activity are effective methods for prevention. Dietary changes focused on increasing fiber intake from fruits and vegetables while limiting the consumption of red and processed meats are also recommended.