CRC is one of the most prevalent cancer types worldwide, with an estimated 1.36 million people diagnosed in 2012. The mortality rate of CRC is approximately half of its global incidence. A total of 694,000 people died from CRC in 2012, making it the fourth most common cause of cancer death in the world. The incidence is noticeably higher in men than in women (ratio 1.4), however there is up to a ten-fold difference in incidence in different parts of the world.
Colorectal cancer (CRC) occurs when malignant (cancer) cells form in the tissues of the bowel (colon or rectum). The majority of cancers occurring in the colon or rectum are adenocarcinomas, cancers that originate in glandular tissue, and account for 95 percent of all large bowel tumors. For most people, CRC begins as a polyp on the inner lining of the colon or rectum and grows into a tumor over the period of several years. Metastatic colorectal cancer (mCRC) occurs when the cancer has spread to another part of the body.
Most colorectal cancers do not cause any symptoms in the early stages, so they can grow 'silently' for years while the patient feels perfectly healthy. When clinical symptoms occur, the tumor is often at an advanced stage.
Some patients notice changes in their pattern of bowel movements (unexplained diarrhea or constipation). Patients may also have pain, and if the cancer is situated near the anus there may be red blood when moving the bowels. As a person loses blood over time, they will develop anemia, or lowered red blood cell count, causing them to feel tired and weak. Unexplained weight loss is another sign that a cancer may be present, but this is by no means exclusive to CRC.
The five-year survival rate of people diagnosed with stage I colorectal cancer, where the tumor is confined to the organ in which it started, is 74 percent. However, by stage IV, when the cancer has spread to distant sites, the five-year survival rate decreases to only six percent.
Treating Colorectal Cancer
Treatment options depend on the stage of the cancer.
Many people with early CRC can have surgery to remove the cancer. Following surgery, some doctors will give radiotherapy and/or chemotherapy to prevent the cancer from coming back. Doctors will also give chemotherapy to kill any remaining cancer cells left behind after the operation.
Once colorectal cancer has metastasized to another part of the body, the chances of being cured dramatically decline. Chemotherapy, radiotherapy and surgery are all options for mCRC, however chemotherapy is often supplemented with the use of biologic therapies.
Biologic therapies are drugs that help the body to control the growth of cancer cells. They are targeted therapies that use drugs or antibodies to identify and attack specific cancer cells without harming normal cells.
If definite metastases are present, chemotherapy and targeted therapies are used to prolong the patient's life even if it is no longer possible to cure the cancer.
Recently, additional treatment options have become available for patients whose metastatic colorectal cancer progresses following the use of standard approved therapies. Many patients maintain good performance status and could be candidates for additional treatment options.
Advice for patients
Each body reacts differently to medicines. Therefore it is impossible to tell which medicine works best for you. Please consult your physician.