Original Study
Interval Colorectal Cancer After Colonoscopy

https://doi.org/10.1016/j.clcc.2014.11.001Get rights and content

Abstract

Background

As more patients are screened for colorectal cancer a small but significant number of interval cancers develop after colonoscopy for colorectal cancer screening.

Materials and Methods

We reviewed records of 75,314 adult patients who underwent colonoscopy for screening or diagnostic purposes between 1998 and 2006 inclusively, and identified 77 who developed interval cancers within the next 5 years. We reviewed their original endoscopic findings to determine the clinical and endoscopic factors that might predict a greater risk for future cancers.

Results

Patients aged ≥ 60 years had a higher risk of an interval neoplasm (P < .0001). Interval cancers were more common on the right side of the colon and in the hepatic flexure (both P < .0001). We did not observe an increased rate of interval cancers in patients with poor preparation (P = .799); however, examination completion rates did affect the rate of interval cancers (P = .016).

Conclusion

Better identification of higher risk patients and assurance of follow-up examinations might increase the percentage of colon cancers discovered at an early stage. Special attention to careful examination of the right colon is key.

Introduction

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of death from cancer in the United States.1, 2 The 5-year survival rate is 90% if the disease is localized at the time of diagnosis, but this rate decreases to 68% if it is spread regionally, and further decreases to 10% if distant metastases have developed.1 The relatively slow progression from a benign but detectable adenoma to invasive cancer provides the opportunity to devise a screening and treatment strategy that detects and removes neoplastic tissues while they are still treatable. Most deaths from CRCs can be prevented with regular colonoscopy coupled with the removal of polyps.2, 3, 4

Currently, the preferred strategy dictates that individuals older than the age of 50 should have a colonoscopy every 10 years, with high-risk patients screened more frequently.5 Adenomas can be reduced by 76% to 90%, with a significant reduction in CRC mortality, in patients who undergo a clearing colonoscopy.5, 6 However, this strategy is not perfect, because cancers are observed during the time interval between the initial colonoscopy and the recommended follow-up examination, which are called ‘interval cancers.’ These can be the result of a rapidly growing tumor which becomes established after the initial examination or there could be a cancerous or precancerous lesion that was not appreciated or removed during the initial examination. Studies have found miss rates of 5% to 16.8% for polyps, with smaller polyps being missed more often, and advanced adenomas being missed in 5.4% of colonoscopies.7, 8, 9 Population- or clinical registry-based studies suggest that interval colon cancers account for 3% to 9% of cancer patients but will increase as screening programs extend to more people.10, 11, 12 We began monitoring our patient population for interval cancers as part of an institutional quality management program and to improve our understanding of the characteristics of the patients, and the procedures. As a provider center we had access to clinical data not available in registry programs, allowing us to identify factors that could potentially affect the interval cancer rate. Thus, we report a single-institution experience which has the advantage of having more specific clinical data and a heterogeneous patient population including post-neoplasia surveillance patients, which is representative of practice in the United States.

Section snippets

Materials and Methods

We used our endoscopy unit's electronic endoscopic report writer, ProVation MD (ProVation Medical, Minneapolis, MN) to identify all individuals who had a colonoscopy between January 1, 1998 and December 31, 2006 at Massachusetts General Hospital. Individuals younger than the age of 18, those with a history of inflammatory bowel disease, or whose endoscopic examination was a flexible sigmoidoscopy were excluded from this population. A total of 86,005 colonoscopies were performed on 75,314

Results

Of the 86,005 colonoscopies performed during our study period, 77 of these examinations resulted in an instance of interval cancer (0.090%). If the interval window was shortened to 3 years, there were 37 cases (0.043%). In a review of examinations that were indicated for cancer screening and/or family history of colon cancer or polyps, we found 27 interval cancer cases out of a total of 36,992 examinations (0.073%). In a review of only screening examinations, we found only 17 interval cancers,

Discussion

As screening with colonoscopy becomes more widely used, interval cancers will become proportionally more prevalent and might have differing clinical characteristics. Our analysis of a heterogeneous and realistic clinical population, with access to their primary medical records, identified features that could help predict which patients are at higher risk and might benefit from more frequent screening or an altered approach to screening. The current screening strategy is highly effective, but

Conclusion

Results of our study suggest that identification and screening of high-risk patients such as older patients with a history of neoplasia, and thorough examination, including an examination of the cecum, are important for cancer detection. Patient risk factors should be considered in devising cancer screening strategies, which might be different from high-risk surveillance recommendations. Interval cancers should be considered a practical quality indicator and can be measured in cancer centers

Acknowledgments

This study was funded, in part, by a grant from the Oliver S. and Jennie R. Donaldson Charitable Trust. Wendy Ho, MD, and William Puricelli, BSN, contributed to the data collection and analysis of earlier portions of this study.

References (32)

  • J. Vicari

    Performing a quality colonoscopy: just slow down!

    Gastrointest Endosc

    (2010)
  • R. Nishihara et al.

    Long-term colorectal cancer incidence and mortality after lower endoscopy

    N Engl J Med

    (2013)
  • T.F. Imperiale et al.

    Five-year risk of colorectal neoplasia after negative screening colonoscopy

    N Engl J Med

    (2011)
  • A.G. Zauber et al.

    Colonoscopic polypectomy and long-term prevention of colorectal-cancer deaths

    N Engl J Med

    (2012)
  • S.B. Ahn et al.

    The miss rate for colorectal adenoma determined by quality-adjusted, back-to-back colonoscopies

    Gut Liver

    (2012)
  • P.J. Pickhardt et al.

    Location of adenomas missed by optical colonoscopy

    Ann Intern Med

    (2004)
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