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Exploring potential risk factors associated with interval colorectal cancer

Lin, Jonathan (2019) Exploring potential risk factors associated with interval colorectal cancer. Master's Thesis, University of Pittsburgh. (Unpublished)

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Background: Colonoscopy has become the most commonly used screening test for colorectal cancer (CRC) with a 10-year interval recommended for those who are 50 years and older in the United States. There is new evidence that interval CRC occurs less than 5 years after a prior negative colonoscopy. The objective of this study was to assess potential risk factors associated with interval CRC.
Method: To conduct this study, we reviewed approximately 64,000 colonoscopy records of patients who were 40 years and older and seen in the UPMC health system during 2013-2015. Demographic data, hospital locations, colonoscopy and pathology reports were abstracted from medical records. Patients diagnosed with CRC after 6 months but less than 5 years following the index negative colonoscopy procedure were defined as having interval CRC. Both bivariate analysis and logistic regression model were used to examine potential risk factors associated with interval CRC. Statistical significance level was set at 0.05. Statistical analysis was performed using SAS Version 9.4.
Result: We identified 323 patients diagnosed with invasive CRC. Among them, 88 patients had a prior colonoscopy. Among those with prior colonoscopy, 45 patients (51%) were diagnosed with interval CRC who were older at prior colonoscopy compared with those with non-interval CRC (67 years vs. 62.6 years; p=0.035). Also, their sex, race, age and family history of CRC were not different from those with non-interval CRC. The results of logistic regression models showed that, compared to those with non-interval CRC, those with interval CRC were more likely to be older at prior colonoscopy and females (p<0.05).
Conclusion:To reduce the risk of developing interval CRC, our findings suggest that the screening interval for CRC be shorter for female and older patients. Yet, this result should be interpreted with caution given the small sample in one health system. Further studies with larger study population in various geographical areas are necessary to fully explore risk factors associated with interval CRC and reduce the public health burden of interval CRC.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Lin, Jonathanjyl20@pitt.eduJYL20
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairGlynn,
Committee MemberSchoen,
Committee MemberBrenda,
Date: 30 January 2019
Date Type: Publication
Defense Date: 29 November 2018
Approval Date: 30 January 2019
Submission Date: 24 July 2018
Access Restriction: 5 year -- Restrict access to University of Pittsburgh for a period of 5 years.
Number of Pages: 56
Institution: University of Pittsburgh
Schools and Programs: School of Public Health > Epidemiology
Degree: MS - Master of Science
Thesis Type: Master's Thesis
Refereed: Yes
Uncontrolled Keywords: colorectal cancer, interval cancer
Date Deposited: 30 Jan 2019 17:31
Last Modified: 01 Jan 2024 06:15


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