Bottom Line: Patients who are diagnosed with adenomas, a possible precursor of colorectal cancer, often do not receive subsequent colonoscopies within the recommended time frame.

Journal in Which the Study was Published: Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Author: Jessica Chubak, PhD, senior scientific investigator at Kaiser Permanente Washington Health Research Institute.

Background: Adenomas are a type of polyp that can potentially become cancer. A person’s risk of cancer is higher if they have been diagnosed with certain types of adenomas, or if they have large or numerous adenomas, Chubak explained. 

“When a patient is found to have some of these higher-risk findings, guidelines recommend that they come back for another colonoscopy in three years. This is called surveillance colonoscopy, and it improves our chances of preventing colorectal cancer or detecting it at an early stage,” Chubak said. 

How the Study Was Conducted: In this study, Chubak and colleagues analyzed patterns and factors associated with the receipt of colonoscopy within approximately three years of a diagnosis of high-risk adenoma or adenomas. The study was part of the National Cancer Institute (NCI)-funded Population-based Research Optimizing Screening through Personalized Regimens (PROSPR) consortium, a multi-site program aimed at evaluating cancer screening processes. 

Researchers studied 6,909 patients ages 50 to 89 who had received a colonoscopy at which one or more high-risk adenomas were discovered. The patients had been treated at one of three Kaiser Permanente systems, or Parkland Health & Hospital System, a safety-net system that treats patients regardless of their insurance status or ability to pay. The researchers used electronic health records data to identify patients who had been diagnosed with high-risk findings during initial (index) colonoscopies, and to ascertain whether they had received subsequent colonoscopies within the next three years. 

Results: The study found that in the three Kaiser Permanente systems, between 47 percent and 59.5 percent of study participants received a subsequent colonoscopy within six months to three and a half years after the colonoscopy with high-risk findings. At the Parkland safety-net system, 18.3 percent received the subsequent colonoscopy during the recommended time frame. 

Author’s Comments: Chubak said the significantly lower rate at Parkland was most likely due to differences in resources and patient populations. She said differences among the Kaiser Permanente systems may reflect organizational differences, such as patient outreach procedures, medical center capacity, or ease of scheduling. She added that the challenge of delivering timely surveillance colonoscopies is widespread; studies in other systems and settings have also found that many patients do not receive colonoscopies during the recommended time frame.

Chubak noted that, at the time of the study, Kaiser Permanente did not have a centralized surveillance program, but has since implemented a comprehensive system for improving surveillance. Also, the Parkland system has since implemented a system to ensure that patients with these types of adenomas receive recommendations to come for surveillance colonoscopy within three years. Chubak and her fellow researchers expect to study these changes in the future. 

The researchers identified several patient-related factors associated with timely receipt of a subsequent colonoscopy. Patients who had been diagnosed with more adenomas or whose adenomas had certain high-risk histologies were more likely to get the subsequent colonoscopy in the recommended time frame. Age was another factor; study participants aged 60-74 were more likely than the reference age group of 50- to 54-year-olds to get timely colonoscopies, and those aged 80-89 were less likely. 

Chubak said this study supports the need for health care professionals to make sure patients are aware of all recommended screening guidelines, and to provide support when possible. 

“We encourage patients and health care providers to talk about how and when to test for colorectal cancer, and we encourage health care systems to find ways to support patients and providers in following the guidelines,” she said. “In the future, it will be important to understand what types of reminders work best for different patient populations and in different health care settings.” 

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