Ziad Gellad

BACKGROUND: Colorectal cancer (CRC) screening guidelines generally recommend healthy lifestyle choices for cancer prevention. However, studies have shown inconsistent associations between various risk factors and advanced neoplasia (AN) development. AIM: To identify potentially modifiable baseline dietary and lifestyle risk factors associated with AN among an asymptomatic Veteran population, while accounting for prior colonoscopic findings and varying surveillance intensity.

METHODS: We used data from a prospective colonoscopy screening study collected by the VA Cooperative Studies Program. From 1994 to 1997, 3,121 asymptomatic Veterans aged 50-75 received a baseline colonoscopy screening, at which time they selfreported dietary and lifestyle information. Veterans were subsequently assigned to colonoscopy surveillance regimens and followed for 10 years. AN was defined as invasive CRC or any adenoma ≥1 cm, or with villous histology, or high-grade dysplasia. To detect associations with AN diagnosis, we utilized a longitudinal joint model with two sub-models. A multivariate logistic regression modeled the longitudinal probability of AN, while a time-to-event process adjusted for survival. Here we focus on the multivariate logistic regression, representing associations of dietary and lifestyle risk factors with the odds of being diagnosed with AN.

RESULTS: Of the 3,121 Veterans, 1,915 received at least one colonoscopy following baseline screening. Among the 1,915, we detected a significant positive association with AN for current daily smokers (odds ratio (OR) 1.43, 95% CI: 1.02-2.01) compared to those with prior or no history. We found a protective effect for each 100 IU of dietary vitamin D consumed (OR 0.95, 95% CI: 0.95-0.99). We did not detect any significant associations with BMI, red meat consumption, or physical activity. We found that African American race had a lower odds of AN compared to Caucasian race (OR 0.57, 95% CI: 0.32-0.97).

CONCLUSIONS: We identified smoking status and vitamin D consumption as potentially modifiable baseline risk factors associated with AN development. While these results suggest possible points of intervention and targeted screening, more evidence is required across more diverse populations. Future efforts should focus on understanding changes in such risk factors on associations with AN for patients over time. Finally, racial differences in AN incidence merit further investigation.

BACKGROUND: Colorectal cancer (CRC) screening guidelines generally recommend healthy lifestyle choices for cancer prevention. However, studies have shown inconsistent associations between various risk factors and advanced neoplasia (AN) development. AIM: To identify potentially modifiable baseline dietary and lifestyle risk factors associated with AN among an asymptomatic Veteran population, while accounting for prior colonoscopic findings and varying surveillance intensity.

METHODS: We used data from a prospective colonoscopy screening study collected by the VA Cooperative Studies Program. From 1994 to 1997, 3,121 asymptomatic Veterans aged 50-75 received a baseline colonoscopy screening, at which time they selfreported dietary and lifestyle information. Veterans were subsequently assigned to colonoscopy surveillance regimens and followed for 10 years. AN was defined as invasive CRC or any adenoma ≥1 cm, or with villous histology, or high-grade dysplasia. To detect associations with AN diagnosis, we utilized a longitudinal joint model with two sub-models. A multivariate logistic regression modeled the longitudinal probability of AN, while a time-to-event process adjusted for survival. Here we focus on the multivariate logistic regression, representing associations of dietary and lifestyle risk factors with the odds of being diagnosed with AN.

RESULTS: Of the 3,121 Veterans, 1,915 received at least one colonoscopy following baseline screening. Among the 1,915, we detected a significant positive association with AN for current daily smokers (odds ratio (OR) 1.43, 95% CI: 1.02-2.01) compared to those with prior or no history. We found a protective effect for each 100 IU of dietary vitamin D consumed (OR 0.95, 95% CI: 0.95-0.99). We did not detect any significant associations with BMI, red meat consumption, or physical activity. We found that African American race had a lower odds of AN compared to Caucasian race (OR 0.57, 95% CI: 0.32-0.97).

CONCLUSIONS: We identified smoking status and vitamin D consumption as potentially modifiable baseline risk factors associated with AN development. While these results suggest possible points of intervention and targeted screening, more evidence is required across more diverse populations. Future efforts should focus on understanding changes in such risk factors on associations with AN for patients over time. Finally, racial differences in AN incidence merit further investigation.

BACKGROUND: Colorectal cancer (CRC) screening guidelines generally recommend healthy lifestyle choices for cancer prevention. However, studies have shown inconsistent associations between various risk factors and advanced neoplasia (AN) development. AIM: To identify potentially modifiable baseline dietary and lifestyle risk factors associated with AN among an asymptomatic Veteran population, while accounting for prior colonoscopic findings and varying surveillance intensity.

METHODS: We used data from a prospective colonoscopy screening study collected by the VA Cooperative Studies Program. From 1994 to 1997, 3,121 asymptomatic Veterans aged 50-75 received a baseline colonoscopy screening, at which time they selfreported dietary and lifestyle information. Veterans were subsequently assigned to colonoscopy surveillance regimens and followed for 10 years. AN was defined as invasive CRC or any adenoma ≥1 cm, or with villous histology, or high-grade dysplasia. To detect associations with AN diagnosis, we utilized a longitudinal joint model with two sub-models. A multivariate logistic regression modeled the longitudinal probability of AN, while a time-to-event process adjusted for survival. Here we focus on the multivariate logistic regression, representing associations of dietary and lifestyle risk factors with the odds of being diagnosed with AN.

RESULTS: Of the 3,121 Veterans, 1,915 received at least one colonoscopy following baseline screening. Among the 1,915, we detected a significant positive association with AN for current daily smokers (odds ratio (OR) 1.43, 95% CI: 1.02-2.01) compared to those with prior or no history. We found a protective effect for each 100 IU of dietary vitamin D consumed (OR 0.95, 95% CI: 0.95-0.99). We did not detect any significant associations with BMI, red meat consumption, or physical activity. We found that African American race had a lower odds of AN compared to Caucasian race (OR 0.57, 95% CI: 0.32-0.97).

CONCLUSIONS: We identified smoking status and vitamin D consumption as potentially modifiable baseline risk factors associated with AN development. While these results suggest possible points of intervention and targeted screening, more evidence is required across more diverse populations. Future efforts should focus on understanding changes in such risk factors on associations with AN for patients over time. Finally, racial differences in AN incidence merit further investigation.

PURPOSE: Examine whether baseline colonoscopy findings are associated with non-Colorectal Cancer (CRC) mortality in a Veteran screening population.

BACKGROUND: Although screening colonoscopy findings are associated with future risk of CRC mortality, whether these findings are also associated with non- CRC mortality remains unknown.

METHODS: The Cooperative Studies Program (CSP) #380 cohort is comprised of 3,121 Veterans age 50-75 who underwent screening colonoscopy from 1994-97. Veterans were followed for 10 years or death, as verified in electronic medical records. Those who died from CRC-specific causes were excluded from this analysis (n=18, 0.6%). Hazard ratios (HR) for risk factors on non-CRC mortality were calculated by Cox Proportional Hazard model, adjusting for demographics, baseline comorbidities, and lifestyle factors. Information on comorbidities, family history, diet, physical activity, and medications were obtained from self-reported questionnaires at baseline.

RESULTS: Of the included 3,103 Veterans, most were male (n=3,021, 96.8%), white (n=2,609, 83.6%), with a mean age of 62.9. During the 10-year follow-up period, 837 (27.0%) Veterans died from non-CRC causes. The risk of non-CRC mortality was higher in Veterans with ≥3 small adenomas (HR 1.45, p=0.02), advanced adenomas (HR 1.34, p=0.04), or CRC (HR 3.00, =0.05) on baseline colonoscopy when compared to Veterans without neoplasia. Additionally, increasing age (HR 1.07, <0.001), modified Charlson score (HR 1.57 for 3-4 points, <0.001, compared to 0-2 points) and current smoking (HR 2.09, <0.001, compared to former and non-smokers) were associated with higher non-CRC mortality. On the other hand, increasing physical activity (HR 0.88, <0.001), family history of CRC (HR 0.75, =0.02), and increased BMI (HR 0.73-0.75, <0.01) were associated with reduced non-CRC mortality. Neither race, NSAID use (including aspirin), or dietary factors impacted non-CRC mortality.

CONCLUSIONS: In a Veteran CRC screening population, we found that high-risk adenomas or CRC on baseline colonoscopy were independently associated with increased non-CRC mortality within 10 years. Future work will examine the cause-specific factors associated with non-CRC mortality in these groups to 1) identify potential high-yield strategies for tailored non-CRC mortality risk reduction during CRC screening, and 2) better determine when competing risks of non-CRC mortality outweigh the benefit of follow up colonoscopy.

PURPOSE: Examine whether baseline colonoscopy findings are associated with non-Colorectal Cancer (CRC) mortality in a Veteran screening population.

BACKGROUND: Although screening colonoscopy findings are associated with future risk of CRC mortality, whether these findings are also associated with non- CRC mortality remains unknown.

METHODS: The Cooperative Studies Program (CSP) #380 cohort is comprised of 3,121 Veterans age 50-75 who underwent screening colonoscopy from 1994-97. Veterans were followed for 10 years or death, as verified in electronic medical records. Those who died from CRC-specific causes were excluded from this analysis (n=18, 0.6%). Hazard ratios (HR) for risk factors on non-CRC mortality were calculated by Cox Proportional Hazard model, adjusting for demographics, baseline comorbidities, and lifestyle factors. Information on comorbidities, family history, diet, physical activity, and medications were obtained from self-reported questionnaires at baseline.

RESULTS: Of the included 3,103 Veterans, most were male (n=3,021, 96.8%), white (n=2,609, 83.6%), with a mean age of 62.9. During the 10-year follow-up period, 837 (27.0%) Veterans died from non-CRC causes. The risk of non-CRC mortality was higher in Veterans with ≥3 small adenomas (HR 1.45, p=0.02), advanced adenomas (HR 1.34, p=0.04), or CRC (HR 3.00, =0.05) on baseline colonoscopy when compared to Veterans without neoplasia. Additionally, increasing age (HR 1.07, <0.001), modified Charlson score (HR 1.57 for 3-4 points, <0.001, compared to 0-2 points) and current smoking (HR 2.09, <0.001, compared to former and non-smokers) were associated with higher non-CRC mortality. On the other hand, increasing physical activity (HR 0.88, <0.001), family history of CRC (HR 0.75, =0.02), and increased BMI (HR 0.73-0.75, <0.01) were associated with reduced non-CRC mortality. Neither race, NSAID use (including aspirin), or dietary factors impacted non-CRC mortality.

CONCLUSIONS: In a Veteran CRC screening population, we found that high-risk adenomas or CRC on baseline colonoscopy were independently associated with increased non-CRC mortality within 10 years. Future work will examine the cause-specific factors associated with non-CRC mortality in these groups to 1) identify potential high-yield strategies for tailored non-CRC mortality risk reduction during CRC screening, and 2) better determine when competing risks of non-CRC mortality outweigh the benefit of follow up colonoscopy.

PURPOSE: Examine whether baseline colonoscopy findings are associated with non-Colorectal Cancer (CRC) mortality in a Veteran screening population.

BACKGROUND: Although screening colonoscopy findings are associated with future risk of CRC mortality, whether these findings are also associated with non- CRC mortality remains unknown.

METHODS: The Cooperative Studies Program (CSP) #380 cohort is comprised of 3,121 Veterans age 50-75 who underwent screening colonoscopy from 1994-97. Veterans were followed for 10 years or death, as verified in electronic medical records. Those who died from CRC-specific causes were excluded from this analysis (n=18, 0.6%). Hazard ratios (HR) for risk factors on non-CRC mortality were calculated by Cox Proportional Hazard model, adjusting for demographics, baseline comorbidities, and lifestyle factors. Information on comorbidities, family history, diet, physical activity, and medications were obtained from self-reported questionnaires at baseline.

RESULTS: Of the included 3,103 Veterans, most were male (n=3,021, 96.8%), white (n=2,609, 83.6%), with a mean age of 62.9. During the 10-year follow-up period, 837 (27.0%) Veterans died from non-CRC causes. The risk of non-CRC mortality was higher in Veterans with ≥3 small adenomas (HR 1.45, p=0.02), advanced adenomas (HR 1.34, p=0.04), or CRC (HR 3.00, =0.05) on baseline colonoscopy when compared to Veterans without neoplasia. Additionally, increasing age (HR 1.07, <0.001), modified Charlson score (HR 1.57 for 3-4 points, <0.001, compared to 0-2 points) and current smoking (HR 2.09, <0.001, compared to former and non-smokers) were associated with higher non-CRC mortality. On the other hand, increasing physical activity (HR 0.88, <0.001), family history of CRC (HR 0.75, =0.02), and increased BMI (HR 0.73-0.75, <0.01) were associated with reduced non-CRC mortality. Neither race, NSAID use (including aspirin), or dietary factors impacted non-CRC mortality.

CONCLUSIONS: In a Veteran CRC screening population, we found that high-risk adenomas or CRC on baseline colonoscopy were independently associated with increased non-CRC mortality within 10 years. Future work will examine the cause-specific factors associated with non-CRC mortality in these groups to 1) identify potential high-yield strategies for tailored non-CRC mortality risk reduction during CRC screening, and 2) better determine when competing risks of non-CRC mortality outweigh the benefit of follow up colonoscopy.