Monitoring colorectal cancer survivors: What’s done currently and what’s next?

This article reviewed the current views on how best to monitor colorectal cancer survivors in order to detect return of cancer locally or at new sites as early as possible.

Over 1 million individuals develop colorectal cancer each year and 66% of these patients will be treated surgically with curative intent. Unfortunately around 33% will experience relapse of the original cancer or will develop a second colorectal cancer (metachronous cancer). Almost 100% of patients with cancer recurrence will relapse during the first 5 years after initial treatment.

In theory surveillance (monitoring) should benefit patients, however, uncertainty still exists around this topic. There is some evidence of a modest increase in survival time but improvements in cancer-specific survival time have not be shown. Therefore, improved understanding of how best to monitor colorectal cancer survivors is important.

The authors examined published reports relating to surveillance strategies in colorectal cancer survivors

Surveillance guidelines

Based on evidence from clinical trials a number of organizations have published surveillance recommendations. These recommendations include combinations of laboratory assays as well as imaging of the chest, abdomen and pelvis. The intensity of surveillance ranges greatly across countries, with patients in the United States receiving more intensive surveillance than European patients.

Innovations in surveillance

Some recent research investigated more patient-centered, cost-effective survivorship care. An Australian and a Norwegian study compared follow-up care lead by surgeons to general practitioner lead care. Rates of recurrence, mortality and quality-of-life between the two types of care were similar. However, surgeons initiated more imaging tests than general practitioners and the cost of surgeon lead care was significantly more.

The idea of patient tailored surveillance is also being considered. This approach would determine individual patients’ risk of cancer recurrence and adapt the level of surveillance based on the risk. Future studies are needed to determine what the most useful risk factors are.

Future research

A number of questions still remain regarding how best to approach surveillance in colorectal cancer survivors. Does surveillance impact on survivors’ quality of life? Anxiety surrounding multiple medical tests and waiting for the results can take its toll on patients. Therefore, the psychological impact of repeated testing needs to be considered.

For how long should surveillance continue? Although, it is generally accepted that it should continue for 5 years, there is no concrete evidence that this timeframe is the most appropriate. There is continued debate regarding whether shorter or longer timeframes would be better.

How important are colonoscopies (a thin, flexible tube with a camera is inserted through the anus which allows the doctor to look inside the large intestine)? Colonoscopies are excellent for detecting high risk growths or tumors in the intestine. However, there is a small risk of the intestine getting punctured and bleeding. For this reason future work should determine which patients are at highest risk of the cancer returning and spare other patients regular colonoscopies.

The authors concluded that optimizing colorectal cancer surveillance represents a very complex medical task. To date no trials have provided strong evidence of what surveillance strategy works best. As a result, the guidelines and recommendations differ across different countries and organizations.