Colorectal cancer (CRC) is one of the main causes of cancer related deaths. Patients diagnosed with CRC are treated with surgery to remove the tumor and affected tissue. If the tumor affects the entire thickness of the colon or rectal wall it is referred to as being stage II; if the local lymph nodes are also affected the cancer is referred to as being a stage III cancer. Even following surgery residual cancer cells can remain in the body. As a result, patients with stage III CRC (and some stage II patients) are at a high risk of the cancer returning in the same location or a different location (metastasis). To minimize this risk, patients with stage III cancer are routinely treated with chemotherapy following surgery, with the aim of destroying cancer cells that remain in the body. This is referred to as adjuvant chemotherapy.
Chemotherapy is given to a patient in rounds. This means the patient receives treatment for a set number of days and then has a set number of days off to recover from the adverse effects of the treatment (treatment and recovery period = one round). The number of days for each part of this varies depending on the type of cancer and the drugs used for chemotherapy treatment. The number of rounds and time that the treatment is over also varies. The period of time that chemotherapy treatment for stage III CRC is given for is currently prescribed based on clinical studies that were carried out in the 1990s. However, over the past ten years studies have been carried out to look at the best length of time to give chemotherapy.
This paper looks at 5 clinical studies including patients with both stage II and III CRC. These studies compared 6 months of chemotherapy with 9 to 12 months of chemotherapy. This review is limited as it only compares studies which used the chemotherapy drug Fluorouracil (5FU). It does however show that patients did not have a longer time without the cancer reoccurring if they were given chemotherapy for 9 to 12 months nor did they have a better survival rate. This therefore indicates that patients should not receive 5FU-based chemotherapy for longer than 6 months. If they do, the side effects and risks of the treatment may outweigh its benefit.
Published By :
Cochrane database of systematic reviews
Date :
Jan 20, 2010
