What was the research about?
Regular follow-up tests can help patients who have had surgery for colorectal cancer find out if the cancer has come back. These tests may include CT scans or other imaging scans and blood tests. But researchers don’t know if having more tests works better for patients than having fewer tests.
In this study, the research team compared health data for patients who received care at two types of clinics:
- Clinics that gave patients more tests. At these clinics, patients received an average of 2.9 imaging scans and 4.3 blood tests over three years.
- Clinics that gave patients fewer tests. At these clinics, patients received an average of 1.6 imaging scans and 1.6 blood tests over three years.
What were the results?
Being in a clinic that gave more or fewer tests made no difference in
- How often tests found that patients’ cancer came back
- How often patients had a second surgery to treat colorectal cancer
- How likely patients were to live five years after their first surgery
Overall, after five years, 19 percent of patients had colorectal cancer that came back. Patients who had more advanced cancer were more likely to have cancer that came back.
Who was in the study?
The research team looked at data from a national cancer registry and health records for patients who had had surgery for stage I–III colorectal cancer between 2006 and 2007. Of these, 4,341 patients went to clinics that gave more tests, and 4,188 went to clinics that gave fewer tests. Among patients, 86 percent were white, 10 percent were African American, and 4 percent were of another race. The average patient age was 68, and 52 percent were women.
What did the research team do?
The research team looked at patient records to see how often patients got follow-up tests at 1,175 clinics. Then the team compared patients who had follow-up tests at clinics that gave more tests and clinics that gave fewer tests. The team looked at patients’ health for up to five years after their original surgery.
A group of patients, doctors, and health professionals helped design the study and analyze the data.
What were the limits of the study?
Results may have been different if researchers had used other ways to categorize clinics into groups that give more versus fewer tests. The team compared patients based on the type of clinic they went to for follow-up tests. But some patients at the clinics that gave more tests might have had fewer tests.
Future research could use a different study design to compare follow-up methods, such as following patients who have more versus fewer tests going forward.
How can people use the results?
Patients who have had colorectal cancer and their doctors can use the results to discuss how often to have follow-up tests.
To compare the effectiveness of high versus low levels of surveillance intensity in detecting cancer recurrence and in improving overall survival following surgical resection for patients with colorectal cancer (CRC)
|Design||Observational: cohort study|
|Population||8,529 patients diagnosed with stage I–III adenocarcinoma of the colon or rectum and treated with definitive surgical resection within 1 year of diagnosis|
|Outcomes||5-year rates of recurrence detection, surgical resection, and overall survival|
|Timeframe||Up to 5-year follow-up for study outcomes after surgical resection|
This retrospective observational cohort study compared the effectiveness of high- versus low- intensity surveillance facilities on improving five-year rates of CRC recurrence detection, surgical resection, and overall survival among patients with CRC who underwent surgical resection for CRC between 2006 and 2007.
Researchers reviewed data from a national cancer registry merged with medical records of patients for the purpose of classifying 1,175 accredited treatment facilities as performing either high- or low-intensity surveillance. They based their classification on the use of two tests to detect cancer recurrence: CT or other imaging, and carcinoembryonic antigen (CEA) levels. In the three years following surgery, high-intensity surveillance facilities performed an average of 2.9 imaging and 4.3 CEA tests per patient, and low-intensity surveillance facilities performed an average 1.6 imaging and 1.6 CEA tests per patient.
Researchers then compared outcomes for 4,341 patients who received care at high-intensity surveillance facilities and 4,188 patients who received care at low-intensity surveillance facilities. Of these patients, 86% were white, 10% were African American, and 4% were other races. The average age was 68, and 52% were female.
Controlling for patient demographics, tumor characteristics, and environmental factors, researchers used Cox proportional hazards regression to assess the risk of cancer recurrence and measure the association of surveillance intensity with five-year rates of recurrence detection, surgical resection, and overall survival.
Clinicians, patients, and patient advocates helped design the study and interpret the results.
Across facilities, the five-year recurrence rate was 19%, with 82% of recurrent disease detected within three years of initial resection. The risk of recurrence was higher among patients with higher-stage cancer at diagnosis.
Five-year rates of recurrence detection, surgical resection, and overall survival did not differ significantly between patients receiving care at high- and low-intensity surveillance facilities.
Researchers assigned patients to analysis groups based on the surveillance intensity of the treatment facilities where the patients were receiving care. Results may have been different if researchers had defined surveillance intensity in another way. Some patients in high-intensity facilities may have received low-intensity surveillance.
Conclusions and Relevance
In this study, surveillance intensity at facilities was not associated with five-year rates of recurrence detection, surgical resection, or overall survival among patients who underwent CRC resection.
Future Research Needs
Future research could prospectively validate the effect of different levels of surveillance intensity on detection of CRC recurrence and overall survival.
Final Research Report
View this project's final research report.
More to Explore...
Studying the Frequency of Testing for Colorectal Cancer Survivors (right)
Principal Investigator George Chang discusses this project, which examined whether the frequency of follow-up testing of colorectal cancer survivors had an effect on the detection of recurrence or survival.
Benefits and Drawbacks of Cancer Surveillance
Principal Investigator George Chang shares some of the most common benefits and drawbacks of cancer surveillance, including patient anxiety.
How Frequently Should Cancer Survivors be Screened for Disease Recurrence? Is More Always Better?
In August 2019, the National Alliance of Healthcare Purchaser Coalitions hosted a webinar discussion about the frequency of testing and screening practices following surgery for colorectal cancer. The webinar featured George J. Chang, MD, MS, who discussed his findings’ possible impact for employers and influence on medical guidelines, and compared current US practices in relation to other countries.
Article Highlight: For patients who have surgery to remove colorectal tumors, reoccurrence of tumors is a major concern. Researchers in this study reported in JAMA that healthcare facilities that do more-frequent surveillance failed to detect recurring cancers any sooner than facilities that do less-frequent surveillance. The study, which analyzed data from more than 8,000 patients, also found no link between the intensity of surveillance and overall survival, suggesting more-frequent surveillance provided no health benefit.
Results of This Project
Related Journal Citations
Stories and Videos
Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.
The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments.
Peer reviewers commented, and the researchers made changes or provided responses. The comments and responses included the following:
- The reviewers asked why the analyses did not connect the intensity of cancer surveillance at the individual patient level directly, rather than at the facility level. The researchers indicated that individual patients’ surveillance intensity typically was related to their risk of recurrence, thus leading to potential bias at the individual patient level.
- Since the study observed no difference in survival based on surveillance intensity, the reviewers said it would have been interesting to include patients who did not have any surveillance. The researchers said their study excluded patients who received no surveillance because that is not in line with recommended practice and is often associated with patient factors that could bias findings.
- The reviewers said it would be helpful to see an economic analysis of the difference between high-intensity and low-intensity surveillance facilities since the study implies that the low-intensity facilities provided similar quality of care more efficiently. The researchers said an economic analysis was beyond the scope of this study and would have been difficult to conduct given the lack of identifying information collected about patients. An analysis of costs to operate high- versus low-intensity surveillance facilities would also fall outside of PCORI’s restrictions on funding cost effectiveness research.
- The reviewers asked the researchers to justify combining colon and rectal cancer outcomes, since these are distinct diseases with different treatments and prognoses. The researchers said that despite the differences between them, the follow-up strategies for the two diseases are the same, and the two surveillance intensity groups had a balanced number of colon and rectal cancer patients.
Conflict of Interest Disclosures
Study Registration Information
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