How does a tumor develop?
The vast majority of rectal tumors are adenocarcinomas growing from glandular cells of the mucous membrane. The process begins with an adenomatous polyp, in which genetic changes gradually accumulate. The tumor first remains within the mucous membrane, then grows into the intestinal wall, spreads to the surrounding fatty tissue and lymph nodes, and later spreads to the liver and lungs. Both treatment and prognosis depend on how deep the tumor has grown and whether the lymph nodes are affected.
- Adenocarcinoma - the main histological type
- Development from an adenomatous polyp over several years
- The stage is determined by the depth of germination and lymph nodes
- Distant screenings are more often in the liver and lungs
- Hereditary forms of Lynch syndrome and polyposis
Causes and risk factors
The main factor is age: after 45 years, the frequency increases noticeably. Heredity plays a significant role: cancer or intestinal polyps in parents or siblings increases the risk, and hereditary syndromes make it very high. In terms of lifestyle, the top priorities are overweight, physical inactivity, smoking, regular alcohol consumption, and a diet high in red and processed meat with a lack of vegetables and whole grains. A separate group consists of people with long-term ulcerative colitis and Crohn's disease.
- Age over 45 years
- Adenomatous intestinal polyps
- Bowel cancer in close relatives
- Lynch syndrome, familial adenomatous polyposis
- Obesity and sedentary lifestyle
- Smoking and alcohol
- Long-term ulcerative colitis and Crohn's disease
Symptoms
Early tumors usually do not hurt. The first sign is often blood in the stool, often dark and mixed with feces, as well as mucus. The rhythm of the intestines changes: constipation or diarrhea appears, alternation of both, the stool becomes thin. Characterized by false urges and the feeling that the intestines have not emptied completely. As the tumor grows, pain in the pelvis and sacrum, weakness due to anemia, and weight loss are added. Complete obstruction requires immediate assistance.
- Blood and mucus in the stool
- Changes in stool shape and frequency
- False urges, feeling of incomplete emptying
- Pain in the rectum, perineum, sacrum
- Weakness, pallor, anemia
- Loss of weight and appetite
Diagnostics and screening
The doctor can feel about a third of rectal tumors with a regular digital examination, so it should not be neglected. The main method is colonoscopy with biopsy: it examines the entire large intestine and confirms the diagnosis histologically. To plan treatment, an MRI of the pelvis is performed, assessing the spread of the tumor in the wall and tissue, as well as MSCT of the chest and abdomen to exclude distant foci. CEA is determined before treatment and then for control. Screening from age 45 includes a stool test for occult blood and a colonoscopy.
- Digital rectal examination
- Colonoscopy with biopsy and histology
- MRI of the pelvic organs
- MSCT of the chest and abdomen
- REA as a marker of control
- Fecal occult blood as a screening test
Treatment and prevention
The tactics are determined by a council of oncologist, surgeon and radiotherapist based on MRI results. Early tumors are removed through the anus or endoscopically. In more common forms, the main method remains surgery to remove a section of the intestine and surrounding tissue along with the lymph nodes; Radiation or chemoradiotherapy is often given before surgery to shrink the tumor and preserve the sphincter. After surgery, chemotherapy is prescribed as indicated. Prevention is real: screening, polyp removal, normal weight, quitting smoking, more vegetables and whole grains.
- Endoscopic or local removal of early tumors
- Rectal resection with lymph node dissection
- Preoperative radiation and chemoradiotherapy
- Chemotherapy after surgery according to indications
- Formation of a stoma if necessary, often temporary
- Screening from 45 years of age and removal of polyps
- Weight control, smoking cessation, more fiber
