Patient must be regularly controlled by the physician for years after the completion of the treatment. It is crucial to attend all follow-up appointments on time. Patient is evaluated with regards to cancer relapse and treatment side effects through necessary laboratory and imaging tests during these follow-up examinations.
Some side effects may persist for years after the completion of the treatment, and some of them may arise a long time later.
Actually, frequency of follow-up examinations is determined by the cancer stage and relapse chance of the patient.
Patients are advised to see their doctors in every 3-6 months for a few years after the treatment, then in every 6 months for the subsequent years. Frequency of these examinations may be reduced for patients who are treated for early diagnosed cancer.
It is advised to have colonoscopy within a year of the surgical operation. If the results are normal, next test is generally performed 3 years later for majority of the patients. If found normal again, tests are advised to be repeated in every 5 years.
These tests are requested based on the stage of the cancer and other factors. For patients who are under relapse risk, CT may be performed annually after the treatment. If the patient had metastasis in liver or lungs and had these removed, such tests may be requested more frequently.
Blood tests for tumor markers
Carcinoembryonic antigen (CEA) and CA 19-9 are tumor marker substances that can be detected in the blood of some colorectal cancer patients. It is especially important to check their blood levels before starting the treatment.
If the levels are high before the treatment and return to normal levels after the surgery, it is beneficial to test their blood levels regularly in follow-ups. They are generally tested in every few months for the first years after the completion of the treatment and in every 6 months thereafter.
If the tumor marker levels increase again during the controls, this condition may be a warning sign for cancer relapse and patient must be evaluated with colonoscopy and radiological tests. If the tumor marker level is not high at the time of first cancer diagnosis, then these tests will not be very helpful for the follow-up.