Sigmoid Colon Cancer Symptoms

Sigmoid colon cancer is a malignancy of the sigmoid colon, the S-shaped portion of the large intestine that connects the descending colon to the rectum. Colorectal cancers, including sigmoid colon cancer, are the second most deadly type of cancer, according to the National Cancer Institute. The institute estimates that roughly 147,000 new cases are diagnosed each year, while the annual death rate from colorectal cancers hovers close to 50,000.

Function

• As with all segments of the gastrointestinal system, the sigmoid colon plays its own unique role in the body's overall digestive and excretory processes. Stool is stored in this portion of the large intestine "until a 'mass movement' [muscular contraction] empties it into the rectum once or twice a day," according to the Cleveland Clinic Health System.

Symptoms

• Cancer of the sigmoid colon, as with other types of colorectal cancer, often has few, if any, symptoms in its early stages. So an absence of symptoms is no indication that cancer is not present. However, possible symptoms of this form of cancer include blood in the stool, diarrhea, a bowel obstruction, narrow stools and unexplained anemia and/or weight loss.

Significance

• Because sigmoid cancer is often asymptomatic, particularly during its early stages, it is important to schedule regular examinations to ensure that no problems have developed. This type of examination is called a sigmoidoscopy, and it is done with a scope that provides the doctor with a close-up look at the linings of the sigmoid colon and rectum.

Considerations

• If the sigmoidoscopic examination reveals a polyp or other unusual growth in the lower portion of the colon, a tissue sample will be taken and sent to the laboratory for microscopic evaluation. The results will be returned to your doctor, who will pass them along to you. If the biopsy results are negative for the presence of malignant tissue, then you're in the clear, at least until your next exam. If the test indicates the presence of cancer, your doctor will recommend a course of treatment.

Types

• Sigmoid colon cancer is classified by stages, each of which is determined by the size of the tumor involved and the degree to which it has penetrated the affected tissue. Stage 1 cancer is characterized by one or more small tumors that have not yet penetrated the mucosal layer of the colon's lining. In stage 2 cancer, the tumors are slightly larger and have penetrated the muscle wall of the sigmoid colon. Stage 3 cancer indicates the presence of even larger malignant growths and the spread of cancerous cells to nearby lymph nodes.

Treatment

• Surgery is the normal method of treatment for all stages of sigmoid colon cancer. For those who have stage 1 or 2 cancer, surgery is likely to be the only mode of treatment. If the disease has progressed to stage 3, surgery will need to be followed by radiation and/or chemotherapy to kill or retard the growth of cancer cells that have spread beyond the colon.