Understanding Colorectal Cancer and the Importance of Screening

Colorectal cancer is one of the most common and preventable forms of cancer, yet it remains a leading cause of cancer-related deaths worldwide. The key to reducing its impact lies in early detection through regular screening. Despite its proven effectiveness, many individuals delay or avoid screening due to misconceptions or lack of awareness.

Here, Dr. Shishin Yamada, general surgeon with Silver Cross Hospital, shares important information about colorectal cancer, the importance of screening, and how proactive measures can save lives.

Colorectal Cancer on the Rise in Younger Individuals

Colorectal cancer rates are rising among individuals under 50, and while the exact cause remains unclear, several factors may contribute. These include obesity, high sugar intake, processed foods, excessive meat and alcohol consumption, and sedentary lifestyles. Although genetics play a role, lifestyle and environmental factors are significant concerns.

“I wish there was one thing we could point at and say, ‘Here's what you need to change,’” Dr. Yamada said. “But, in general, probably the best advice is to eat healthy and exercise. Avoid processed foods and abstain from smoking and keep drinking to a minimum.”

Colonoscopy: Gold Standard of Colon Cancer Screening

A colonoscopy is considered the gold standard for colorectal cancer screening and has been a trusted procedure for over 50 years. During a colonoscopy, a flexible camera, about the size of a small finger and equipped with fiber-optic technology, is used to examine the colon’s walls after a thorough cleansing. This allows doctors to identify and address issues like lesions or early signs of cancer. The procedure is highly effective, as it not only detects abnormalities but can also enable immediate treatment, such as removing early-stage cancers, often without requiring surgery.

The most common complaint about colonoscopies is the bowel prep, which involves cleaning out the colon. While the prep can be inconvenient, the procedure itself is safe and typically done under sedation for comfort.

The colon's primary function is to reclaim water from liquid waste, much like a sewage treatment plant. Since most gastrointestinal problems occur in the colon, it’s crucial to clear it thoroughly during prep. This ensures doctors can view the colon’s walls clearly during the procedure, rather than obscured by waste, allowing for accurate detection and treatment of any issues.

“The prep is not as bad as it was years and years ago,” assures Dr. Yamada. “We don't have you drink a gallon of cleanser. It's shrunk down now, much less, more like a two-liter bottle so a lot easier than it used to be.”

Screening Recommendations

Family history significantly impacts colorectal cancer risk, with one in three cases linked to familial factors. For those with a family history, screening should begin 10 years before the age at which their relative was diagnosed.

Screening guidelines have also recently changed. As of 2021, the U.S. Preventive Services Task Force recommends starting routine colorectal cancer screening at age 45, lowered from age 50, due to increasing cases in younger individuals. Screening is generally advised up to age 75, with decisions for individuals aged 75–85 based on their overall health and ability to tolerate the procedure.

Colorectal Cancer Signs and Symptoms

Colorectal cancer symptoms can be mild or go unnoticed, but certain signs warrant medical attention. Key symptoms include rectal bleeding lasting more than two weeks, which is often mistaken for hemorrhoids. Blood in the stool, whether red from lower in the colon or black due to partially digested food from higher in the colon, should be evaluated. Changes in stool appearance, such as pencil-thin or ribbon-like shapes, unusual colors, or persistent diarrhea or constipation, may indicate an issue like a growth in the colon.

Any new or concerning bowel habit changes should prompt a discussion with a doctor, often leading to a recommended colonoscopy for further investigation.

“If something changes, communicate. Talk with your doctor about it and get yourself checked out,” urges Dr. Yamada. “That's one of the things we see often with colon cancer is that people say ‘I wish I'd come sooner. I wish this hadn't got to this point.’ This cancer is very treatable when caught early.”

Colorectal Cancer Stages: Early Detection Is Crucial

Colorectal cancer is categorized into early and advanced stages. In the early stage, the cancer is localized to a specific area, making it ideal for surgery to remove the tumor without impacting nearby vital organs. In advanced stages, when the cancer has spread to nearby organs or lymph nodes, treatment decisions are more complex.

A multidisciplinary tumor board often evaluates whether surgery is safe or if chemotherapy should be used first to shrink the tumor. Once reduced to a manageable size, surgery can then be performed to remove the cancer effectively.

“We are diagnosing colon cancers earlier and earlier, including those who are younger, and they have a better survival and better outcomes when we can catch it at an earlier stage in the progression of this cancer, before it's spread,” notes Dr. Yamada.

For more on colorectal cancer, and other health-related topics, check out the Silver Cross iMatter Health Podcast.