Inflammatory Bowel Disease Has a Role in Early-Onset Colorectal Cancer
In this article
Early-onset colorectal cancers (before age 50) have become a major topic in oncology. According to new research, patients with early-onset metastatic colorectal cancer may have underlying, undiagnosed inflammatory bowel disease (IBD) in up to 10% of cases. This study was presented in October 2022 at the AACR Special Conference: Colorectal Cancer meeting.
What Is Inflammatory Bowel Disease?
Inflammatory bowel disease (IBD) is a term for two conditions characterized by chronic inflammation of the gastrointestinal tract: Crohn's disease and ulcerative colitis. Long-term inflammation damages the gastrointestinal tract. We also refer to these diseases simply as colitis.
What Are the Main Types of IBD?
| Crohn's disease | Ulcerative colitis | |
| Anatomical area affected | It can affect any part of the gastrointestinal tract (from the mouth to the anus). It most commonly affects the small intestine, the section before the large intestine. | It occurs in the large intestine (colon) and rectum. |
| Damaged areas | Damaged areas appear in patches next to areas of healthy tissue. | Damaged areas occur throughout the colon (rather than in patches), generally beginning in the rectum and spreading toward the large intestine. |
| Characteristics of inflammation | Inflammation can reach multiple layers of the gastrointestinal walls. | Inflammation is found only in the innermost layer of the colon lining. |
NOTE: No particular food, diet or lifestyle causes, prevents or treats inflammatory bowel disease. Your diet, or eating pattern, does not cause inflammatory bowel disease or a flare-up. However, changing your eating habits and the foods you choose can help reduce signs and symptoms during flare-ups. A person can identify foods that trigger their colitis and try to avoid them.
What Are the Symptoms of IBD?
- Persistent diarrhea
- Abdominal pain
- Rectal bleeding/bloody stools.
- Weight loss
- Fatigue
What Causes IBD?
- The immune system responds inappropriately to environmental triggers, such as a virus or bacterium, causing inflammation in the gastrointestinal tract.
- There also appears to be a genetic component. Someone with a family history of IBD is more likely to develop this inappropriate immune response.
How Is IBD Diagnosed?
- Endoscopy of the esophagus and stomach for Crohn's disease; colonoscopy and a combination of imaging studies for ulcerative colitis, for example:
- Contrast bowel X-rays.
- Magnetic resonance imaging (MRI).
- Computed tomography (CT).
- Stool samples.
- Blood tests.
How Is IBD Treated?
- The most common types of medicines used to treat IBD are:
- 5-aminosalicylic acids.
- Immunomodulators.
- Corticosteroids.
- Biologic agents.
- Surgery may be performed to remove damaged parts of the gastrointestinal tract.
Differences Between Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD)
Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) may sound the same, but they are very different conditions. An accurate diagnosis is essential for treating either condition.
Both affect the digestive system, including the esophagus, stomach and intestines. IBS is a chronic syndrome consisting of a group of symptoms and complaints. IBD, on the other hand, means chronic inflammation of the intestines; this type of inflammation does not occur in IBS.
IBS involves chronic abdominal pain and changes in bowel habits (diarrhea, constipation or alternating between the two). Symptoms can vary from person to person and often change over time, making management difficult.
IBS does not turn into IBD or cause permanent damage to your intestines, such as intestinal bleeding, other intestinal diseases or cancer. However, it can significantly affect your quality of life.
The Association Between Early-Onset Colorectal Cancer and Colitis
In recent years, increases in early-onset colorectal cancer cases (diagnosed before age 50) have been reported worldwide. The study discussed here showed that, in patients with early-onset metastatic colorectal cancer (mCRC), colitis-associated mCRC was also associated with shorter overall survival. According to the study presenter, Dr. Oscar E. Villarreal of the University of Texas MD Anderson Cancer Center in Houston, identifying these high-risk patients is important given the potential implications for disease course and treatment decisions.
Dr. Villarreal explained that people with inflammatory bowel disease (IBD) have a high risk of colorectal cancer (CRC). Some studies suggest that the disease course in colitis-associated colorectal cancer is worse than in sporadic colorectal cancers (not attributable to a particular cause), but few studies have focused specifically on patients whose cancer has metastasized and who also have colitis.
Because patients with colitis-associated colorectal cancer tend to be younger than other colorectal cancer patients, some researchers have suggested that part of the increasing incidence of early-onset colorectal cancer may result from unrecognized colitis in young individuals.
In the study, Dr. Villarreal and his team's aim was to determine what proportion of patients with early-onset mCRC might have previously undiagnosed IBD and whether survival differed between patients with colitis-associated mCRC and those with sporadic mCRC (not attributable to a particular cause).
Patients registered at MD Anderson Cancer Center were included in the study. Of these, 32 had colitis-associated mCRC and 397 had sporadic mCRC. The validation cohort included 269 patients with colitis-associated mCRC and 29596 with sporadic mCRC.
Dr. Villarreal said that, because the researchers wanted to minimize potentially confounding variables related to hereditary cancer and focus specifically on colitis-associated mCRC, they excluded patients with high microsatellite instability mCRC from the analysis.
Study Details
Among early-onset mCRC cases in the study cohort, colitis-associated mCRC occurred more than twice as often as sporadic mCRC. The ratio was similar in the validation cohort.
Colorectal cancers most commonly have adenocarcinoma histology. However, the researchers also found that signet ring cell and mucinous histologies were associated with colitis-associated mCRC and early-onset mCRC.
Because signet ring cell and mucinous histologies were associated with both colitis-associated mCRC and early-onset mCRC, the researchers suggested that these histologies could be used as a biomarker of colitis-associated mCRC to predict previously unrecognized IBD in patients with early-onset mCRC.
Survival Differences in Young Patients
Dr. Villarreal and colleagues also found that patients with colitis-associated mCRC had shorter survival than patients with sporadic mCRC.
- In the validation cohort, median overall survival was significantly shorter for patients with colitis-associated mCRC than for those with sporadic mCRC (31 months versus 39 months, respectively).
- Among patients with early-onset mCRC, median overall survival was significantly shorter for those with colitis-associated mCRC than for those with sporadic mCRC (26 months versus 40 months, respectively).
In early-onset mCRC cases, additional factors (whether the tumor was in the right or left colon, sex, etc.) had no effect on median overall survival. For patients with late-onset mCRC, the difference in median survival between colitis-associated and sporadic mCRC was not as large as in the early-onset group. Median overall survival was 35 months and 38 months, respectively.
Conclusion
The study data suggest that patients with colitis-associated mCRC may have significantly worse outcomes than patients with mCRC not associated with colitis. In addition, young patients with colitis-associated mCRC have shorter overall survival than young patients with sporadic mCRC or patients with IBD who develop mCRC later in life.
More research is needed for better and more definitive results. However, the current study supports the hypothesis that approximately 10% of patients with early-onset mCRC may have cancer arising from subclinical (asymptomatic), unrecognized colitis.
Because signet ring cell and mucinous histologies are associated with both colitis-associated mCRC and early-onset mCRC, these histological subtypes may be used as a biomarker to predict disease course and guide treatment decisions in this high-risk patient group.
Sources
Was this article helpful?
Your feedback helps us improve our content.
Reader comments
Share your comment
Your name and comment are published only after administrator approval. Your email address is never shown to visitors.
Be the first to comment.