Intestinal Cancer: An Overview
Intestinal cancer refers to malignancies that develop in the intestines, which form the major part of the digestive tract. The intestines are divided into the small intestine (duodenum, jejunum, and ileum) and the large intestine (colon and rectum). While cancer in the large intestine (colorectal cancer) is far more common, primary cancer of the small intestine is relatively rare.
The small intestine is responsible for most nutrient absorption after food leaves the stomach, while the large intestine absorbs water and forms stool. Most intestinal cancers are adenocarcinomas, which arise from glandular cells lining the intestinal wall. Other types include carcinoid tumors (neuroendocrine), lymphomas, gastrointestinal stromal tumors (GISTs), and sarcomas.
Here are anatomical illustrations showing the position of the small and large intestines in the human body:
Risk Factors, Symptoms, and Detection Challenges
Risk factors for small intestine cancer include certain genetic syndromes (such as familial adenomatous polyposis, Lynch syndrome, and Peutz-Jeghers syndrome), chronic inflammatory conditions (like Crohn’s disease), celiac disease, and previous radiation therapy to the abdomen. Lifestyle factors such as smoking and a diet high in processed foods may also contribute, though evidence is less strong compared to colorectal cancer.
Symptoms are often vague and appear late because the small intestine has a large capacity and tumors can grow without immediate obstruction. Common signs include abdominal pain or cramping, unexplained weight loss, nausea, vomiting, fatigue, blood in the stool (which may be dark or tarry), anemia from chronic bleeding, and changes in bowel habits.
Detection is challenging due to the small intestine’s length and location. Standard colonoscopy reaches only the beginning of the small intestine, so specialized tests like capsule endoscopy, double-balloon enteroscopy, CT/MR enterography, or small bowel follow-through imaging are often needed.
Here is a visual representation comparing a healthy intestinal lining to one affected by tumors or abnormal growths:
Diagnosis and Treatment Approaches
Diagnosis usually starts with blood tests (to check for anemia or tumor markers), followed by imaging studies. Endoscopic procedures or surgical exploration may be required for biopsy and confirmation.
Treatment depends on the cancer type, location, size, and stage. Surgery is the primary approach for most cases, involving removal of the affected segment of the intestine along with nearby lymph nodes. In the small intestine, procedures aim to preserve as much healthy bowel as possible to maintain nutrient absorption.
For advanced disease or certain tumor types (like GISTs or neuroendocrine tumors), targeted therapies, chemotherapy, or hormone therapies may be used. Radiation is less common due to the mobility of the small bowel but can be considered in specific situations.
Here is an endoscopic view illustrating how tumors or polyps may appear inside the small intestine:
Prevention strategies overlap with general digestive health recommendations: maintaining a balanced diet rich in fruits, vegetables, and fiber, avoiding smoking, and managing chronic inflammatory conditions. For individuals with known genetic risks, regular surveillance through specialized endoscopy or imaging is recommended.
Early detection improves outcomes significantly. If you experience persistent abdominal symptoms, unexplained weight loss, or other warning signs, consult a gastroenterologist or specialist for thorough evaluation. Multidisciplinary care involving surgeons, oncologists, and nutritionists supports the best possible management of intestinal cancer.