Comparing Risk Factors in Individuals With Conventional High-Risk Adenomas and Clinically Significant Serrated Polyps

Abstract

Introduction: Serrated polyps (SP) and conventional adenomas derive from two distinct biological pathways with presumably different risk factors. However SPs and conventional adenomas can occur together and published data suggest that adults with both may have a different risk profile than adults with high risk adenomas (HRA) alone. For example, adults with conventional HRA and clinically significant SPs (CSSP; defined below) have a higher risk for metachronous HRA than adults with HRA alone (Schreiner Gastro 2010). We used the population based New Hampshire Colonoscopy Registry (NHCR) to examine the risk profile of individuals with conventional HRAs, CSSPs, and those adults with both HRA and CSSP. Our hypothesis was that current smoking would be strongly associated with having both HRA and CSSP. Methods: We defined HRA as: adenomas >/= 1 cm, villous, high grade dysplasia, multiple adenomas (> 2) and colorectal cancer (CRC). CSSPs included any SPs >/= 1 cm, sessile serrated polyps, traditional serrated adenomas and proximal SPs were >5 mm. Risk factors examined included age, sex, BMI, smoking, alcohol intake, exercise, education level and family history of CRC. We categorized smoking as never, former and current. A multivariable analysis was performed for adults with HRA only, CSSP only and those with both HRA and CSSP. The comparison group were those adults with normal exams. Finally, we did a multivariable analysis comparing adults with both HRA and CSSP to those with HRA only. Results: In the NHCR between 2009-14, we had 20,587 adults with normal exams, 1406 with HRA only, 943 with CSSP only and 154 with HRA and CSSP. Results of the multivariable analyses are shown in Table 1. Higher BMI was associated with a higher risk for HRA as well as CSSP. Older age was a risk factor for HRA only. Current smoking was associated with an approximately 2 fold increased risk for HRA or CSSP and an even greater risk for both HRA and CSSP (aOR=6.43 95% CI: 4.02-10.28) compared to those with no polyps Furthermore, adults with HRA and CSSP were more likely to be current smokers than those with HRA alone (aOR=2.75 95% CI:1.67-4.54; P=0.0003).Table: Table. Risk factors for adults with HRA only ( n =1406), CSSP only ( n =943) and both HRA and CSSP ( n =154)Conclusion: While current smoking is a significant risk for HRA and CSSP individually, current smokers may be at particularly high risk for having both HRA and CSSP. These data suggest that current smokers may benefit from more intense screening given their higher risk for synchronous HRA and CSSP. These findings highlight an area in need of further research.