The main function of the rectum is the formation and excretion of fecal material. Therefore, defecation disorders are the first symptoms of the disease. It may be constipation or diarrhea, at first the symptoms are transient, but with the growth of the neoplasm, the feces of normal consistency become very rare.
Often there are false urges, when with a small amount of feces there is an overwhelming desire to evacuate one’s bowels, which is called «rectal spittle». Very often, after defecation there is no feeling of complete emptying of the intestine, if the cancer is located near the anus, then during the bowel movement there is a disturbing pain.
The second sign is appearance of blood in the feces, at first only by streaks, then clots are released, sometimes with an admixture of mucus. The presence of mucus without blood is not considered a sign of rectal cancer. With chronic blood loss, blood test is made for anemia, a lack of red blood cells and hemoglobin.
Intense chronic pain occurs during invasion of the entire intestine wall and involvement of the pelvic nerve plexus. If the cancer spreads to the urinary bladder, then symptoms of a cystitis resistant to standard treatment appear. When cancer invades vaginal tissues, there is pain during intercourse.
Rectal cancer progresses aggressively even with a favorable histological structure, a well differentiated adenocarcinoma. The process is prone to relapse and rapid metastasic spreading, most often to the liver and lungs. The high degree of malignancy coincides with the sensitivity to irradiation and chemotherapy, but cancer cells quickly develop resistance, that is, a self-defense strategy. The leading treatment method is surgery, which is preceded by radiation therapy (RT), sometimes together with several cycles of chemotherapy (CT), and prophylactic medication is excluded only at stage I.
It is assumed that radical treatment should by itself provide unconditional recovery, but for rectal adenocarcinoma, surgery alone cannot cure the condition. Cancer of this part of the large intestine is treated comprehensively, that is, using all the methods: surgery, irradiation and anticancer drugs.
The main set of therapeutic measures can be supplemented by innovative local methods of destruction by various physical factors and targeted drugs. But with an advanced process, even the most advanced approach does not promise a complete cure, that’s why it is so important to identify the malignant process at the very beginning, preferably at the stage of a villous polyp.
The neoplasm is detected by digital examination, and an endoscopic examination called sigmoidoscopy is always performed, during which a piece of the tumor is taken for microscopy. A colonoscopy is always performed, because occurrence in the large intestine of several cancer nodules at once is rare but possible.
Before starting treatment, MRI of the lesser pelvis is performed to establish the size of the formation and involvement of the neighboring organs and tissue of the lesser pelvis.
Radical treatment of rectal cancer necessarily includes surgery. At stage 1, endoscopic surgery or the most sparing and organ-preserving resection is performed.
The scope of intervention at stage 2 depends on the localization of the tumor in the organ and its true size, a poorly differentiated adenocarcinoma requires chemotherapy. At stage 3, preventive chemotherapy is required after surgery, supplemented with irradiation.
In inoperable rectal cancer, photodynamic therapy is used that improves penetration of chemotherapy drugs into the tumor and increases efficiency.