Causes and risk factors
The exact cause of cancer is not known, but various risk factors or predisposing factors have been put forth. It is found that the cells undergo an uncontrolled and abnormal proliferation which gives rise to formation of tumors. Genetic predisposition is one of the major causes. Hereditary Heredity plays a major role. People with weak immune system (HIV) are more prone for to cancer. Taking corticosteroid medications or any history of organ transplantation which hampers the immune system are certain other contributing factors. Although it is not clear, exposure to industrial and environmental factors, (e.g.,: nitrosamines) have found to cause a role in development of cancer. Certain diseases of the rectum also pose a risk factor for towards development of cancer, e.g.:, polyps , fissures., IBD, etc. Secondary affection of the rectum, i.e., metastasis from cancer present elsewhere in the body is the most prominent cause.
Clinical presentation:
In majority of the cases, the patient remains asymptomatic in the initial phases. As the pathology advances, various symptoms can be seen. The patient usually comes up with an alteration in the bowel habits. Episodes of diarrhea or constipation occurs. There can be alternate alternating constipation and diarrhea too. Change in size and shape of stools along with a feeling of incomplete evacuation is complained by the patient. Pain in abdomen, especially the lower abdomen, or a sense of discomfort occurs. The patient can complain of pain while passing stools. There occurs passage of bright red or dark colored blood. Along with this, weight loss, fatigue, loss of appetite, etc., can also be seen.
Investigations:
Diagnosis is done on the basis of symptoms narrated by the patient and the examination carried out by the doctor. Digital rectal examination is carried out. Per rectal bleeding occurring in patients above 50 years of age or even young adults complaining for the same should be screened for colorectal cancers first. An Colonoscopy is done in such patients. Ultrasonography along with colonoscopy is done. Certain investigations like routine blood test, blood markers for cancer, and CT scans of abdomen are firstly advised. On detection of any abnormal growth, a biopsy is done. A complete scan of the body (PET) scan is also recommended for metastasis.
Treatment:
The treatment plan depends upon the type and stage of cancer. Medications for symptomatic relief are administered. Various surgical options can be doneadopted. It consists of polypectomy, cryosurgery, or local excision of the tumor is done. In cases where the cancerous condition has spread to the walls of the rectum, the entire part of the rectum along with certain surrounding healthy cells tissues are removed. Radiation therapy is used. Targeted chemotherapy and immunotherapy immunotherapeutic agents are administered.
Recent update:
According to the study conducted by the American Cancer Society, colorectal cancer survivors who smoke cigarettes were at more than twice the risk of death than non-smoking survivors.
