Plasma Metabolomics Analysis of Aspirin Treatment and Risk of Colorectal Adenomas

Despite substantial observational and experimental evidence that aspirin use can provide protection against the development of colorectal neoplasia, our understanding of the molecular mechanisms involved is inadequate and limits our ability to use this drug effectively and safely for chemoprevention. We employed an untargeted plasma metabolomics approach using liquid chromatography with high-resolution mass spectroscopy to explore novel metabolites that may contribute to the chemopreventive effects of aspirin. Associations between levels of metabolic features in plasma and aspirin treatment were investigated among 523 participants in a randomized placebo-controlled clinical trial of two doses of aspirin (81 or 325 mg/day) and were linked to risk of colorectal adenoma occurrence over 3 years of follow-up. Metabolic pathways that were altered with aspirin treatment included linoleate and glycerophospholipid metabolism for the 81-mg dose and carnitine shuttle for both doses. Metabolites whose levels increased with 81 mg/day aspirin treatment and were also associated with decreased risk of adenomas during follow-up included certain forms of lysophosphatidylcholine and lysophosphatidylethanolamine as well as trihydroxyoctadecenoic acid, which is a derivative of linoleic acid and is upstream of cyclooxygenase inhibition by aspirin in the linoleate and arachidonic acid metabolism pathways. In conclusion, our findings regarding lysophospholipids and metabolites in the linoleate metabolism pathway may provide novel insights into the chemopreventive effects of aspirin in the colorectum, although they should be considered hypothesis-generating at this time.

PREVENTION RELEVANCE

This research used metabolomics, an innovative discovery-based approach, to identify molecular changes in human blood that may help to explain how aspirin use reduces the risk of colorectal neoplasia in some individuals. Ultimately, this work could have important implications for optimizing aspirin use in the prevention of colorectal cancer.

Predictors of Incident Serrated Polyps: Results from a Large Multicenter Clinical Trial

BACKGROUND

Serrated polyps (SP) are important colorectal cancer precursors, yet their epidemiology is incompletely understood. We measured risk factors for incident sessile-serrated lesions (SSL) and microvesicular (MVHP) and goblet-cell rich (GCHP) hyperplastic polyp subtypes.

METHODS

We conducted a cohort study of patients undergoing colonoscopic surveillance nested within a chemoprevention trial. Outcomes of interest were ≥1 SPs, including SSLs, MVHPs, and GCHPs specifically. Multivariable generalized estimating equation models were used to estimate adjusted risk ratios (RR) and 95% confidence intervals (CI) for different polyp types.

RESULTS

Among 2,102 participants, a total of 1,615 SPs (including 212 SSLs) were found among 758 participants during follow-up. Prior history of SPs was strongly associated with subsequent occurrence of SPs. There was no apparent association between age, sex, or education and risk of SPs. Black participants were at lower risk of SSLs and MVHPs, but higher risk of GCHPs compared with white participants [RR, 0.40; 95% CI, 0.16-0.99); RR, 0.63 (95% CI, 0.42-0.96); and RR, 1.83 (95% CI, 1.23-2.72) respectively]. Alcohol and smoking exposure were also associated with SPs, including hyperplastic polyp subtypes in particular.

CONCLUSIONS

In this prospective study, the risk of SP subtypes differed by race, alcohol, and smoking status, and prior history of SPs. Risk factor associations for SPs differ from risk factors for conventional adenomas, supporting the concept of etiologic heterogeneity of colorectal cancer.

IMPACT

These findings allow for better risk stratification of patients undergoing colorectal cancer screening and could inform screening test selection.

Circulating Sex Hormones and Risk of Colorectal Adenomas and Serrated Lesions in Men

BACKGROUND

Sex hormones have been implicated in the etiology of colorectal neoplasia in women for over 40 years, but there has been very little investigation of the role of these hormones in men.

METHODS

Using data from an adenoma chemoprevention trial, we conducted a secondary analysis to examine serum hormone levels [testosterone, androstenedione, DHEA sulfate (DHEAS), and sex hormone binding globulin (SHBG)] and risk of colorectal precursors in 925 men. Multivariable logistic regression models were fit to evaluate adjusted associations between hormone levels and risk of "low-risk" (single tubular adenoma < 1 cm) and "high-risk" lesions (advanced adenoma or sessile serrated adenoma or right-sided serrated polyp or >2 adenomas of any size).

RESULTS

Overall, levels of free testosterone, total testosterone, androstenedione, DHEAS, or SHBG were not associated with either "low-risk" or "high-risk" early precursor lesions in the colorectum.

CONCLUSIONS

These findings do not support the role of sex hormones in early colorectal neoplasia among men.

IMPACT

This large prospective study address a missing gap in knowledge by providing information on the role of sex hormones in colorectal neoplasia in males.

Oral Antibiotics and Risk of New Colorectal Adenomas During Surveillance Follow-up

BACKGROUND

Antibiotics may increase colorectal neoplasia risk by modifying the gut microbiome. It is unknown whether use is associated with the risk of new colorectal adenomas among individuals with prior adenomas.

METHODS

We performed a secondary analysis of four randomized clinical trials for the chemoprevention of colorectal adenomas. Participants self-reported all currently used prescription drugs shortly after an initial colorectal adenoma diagnosis and two or three times a year thereafter over 3 to 5 years of follow-up. We estimated adjusted risk ratios (RR) with 95% confidence intervals (CI) for incident adenomas, analyzing the four trials together.

RESULTS

Cumulatively, the four trials enrolled 5,174 participants (3,491 men and 1,683 women), of whom 4,769 (92%) completed ≥1 follow-up colonoscopy. A total of 763 (15%) participants reported using oral antibiotics on ≥2 occasions. Overall, 39% of those using oral antibiotics at least twice developed new colorectal adenomas compared with 40% of those with no use or a single report of use (RR, 0.99; 95% CI, 0.90-1.10). No statistically significant associations were found in study-specific analyses, and results were similar for high- and low-risk adenoma findings, antibiotic class, anatomic location of adenomas, and analyses excluding those with interim colorectal exams.

CONCLUSIONS

Oral antibiotic use during colonoscopic surveillance after an initial adenoma diagnosis was not associated with risk of these polyps.

IMPACT

Any changes to the gut microbiome as a consequence of oral antibiotic use during surveillance may not affect the development of metachronous colorectal adenomas.

Risk of keratinocyte carcinomas with vitamin D and calcium supplementation: a secondary analysis of a randomized clinical trial

BACKGROUND

It is unknown whether dietary supplementation with vitamin D or calcium prevents keratinocyte carcinomas, also known as nonmelanoma skin cancers.

OBJECTIVES

This study aimed to determine whether daily vitamin D or calcium supplementation alters the risk of basal cell carcinoma (BCC) or invasive cutaneous squamous cell carcinoma (SCC).

METHODS

The Vitamin D/Calcium Polyp Prevention Study is a completed multicenter, double-blind, placebo-controlled, partial 2 × 2 factorial, randomized clinical trial of vitamin D, calcium, or both for the prevention of colorectal adenomas. During 2004-2008, a total of 2259 men and women, 45-75 y of age, recently diagnosed with a colorectal adenoma, were randomly assigned to 1000 IU/d of vitamin D3 or placebo and 1200 mg/d of calcium carbonate or placebo for 3 or 5 y, and followed after treatment ended. Reports of incident BCC or SCC were confirmed from pathology records.

RESULTS

During a median follow-up of 8 y, 200 (9%) participants were diagnosed with BCC and 68 (3%) participants were diagnosed with SCC. BCC incidence was unrelated to treatment with vitamin D compared with no vitamin D (HR: 0.96; 95% CI: 0.73, 1.26), calcium compared with no calcium (HR: 1.01; 95% CI: 0.74, 1.39), and both agents compared with neither (HR: 0.99; 95% CI: 0.65, 1.51). SCC incidence was unrelated to treatment with vitamin D compared with no vitamin D (HR: 0.79; 95% CI: 0.49, 1.27), but there was suggestive evidence of beneficial treatment effects for calcium compared with no calcium (HR: 0.60; 95% CI: 0.36, 1.01) and both agents compared with neither (HR: 0.42; 95% CI: 0.19, 0.91).

CONCLUSIONS

Calcium alone or in combination with vitamin D may reduce the risk of SCC, but not BCC. This trial was registered at clinicaltrials.gov as NCT00153816.

Metabolomics Analysis of Aspirin's Effects in Human Colon Tissue and Associations with Adenoma Risk

Although substantial evidence supports aspirin's efficacy in colorectal cancer chemoprevention, key molecular mechanisms are uncertain. An untargeted metabolomics approach with high-resolution mass spectrometry was used to elucidate metabolic effects of aspirin treatment in human colon tissue. We measured 10,269 metabolic features in normal mucosal biopsies collected at colonoscopy after approximately 3 years of randomized treatment with placebo, 81 or 325 mg/day aspirin from 325 participants in the Aspirin/Folate Polyp Prevention Study. Linear regression was used to identify aspirin-associated metabolic features and network analysis was used to identify pathways and predict metabolite identities. Poisson regression was used to examine metabolic features associations with colorectal adenoma risk. We detected 471 aspirin-associated metabolic features. Aside from the carnitine shuttle, aspirin-associated metabolic pathways were largely distinct for 81 mg aspirin (e.g., pyrimidine metabolism) and 325 mg (e.g., arachidonic acid metabolism). Among aspirin-associated metabolic features, we discovered three that were associated with adenoma risk and could contribute to the chemopreventive effect of aspirin treatment, and which have also previously been associated with colorectal cancer: creatinine, glycerol 3-phosphate, and linoleate. The last two of these are in the glycerophospholipid metabolism pathway, which was associated with 81 mg aspirin treatment and provides precursors for the synthesis of eicosanoids from arachidonic acid upstream of cyclooxygenase inhibition by aspirin. Conversely, carnitine shuttle metabolites were increased with aspirin treatment and associated with increased adenoma risk. Thus, our untargeted metabolomics approach has identified novel metabolites and pathways that may underlie the effects of aspirin during early colorectal carcinogenesis.

Folic acid supplementation and risk of colorectal neoplasia during long-term follow-up of a randomized clinical trial

BACKGROUND

The Aspirin/Folate Polyp Prevention Study previously found folic acid increased risk of advanced and multiple colorectal adenomas during a surveillance colonoscopy interval starting about 3 y after randomization.

OBJECTIVE

We conducted secondary analyses to evaluate folic acid effects with additional follow-up after treatment was stopped.

METHODS

In total, 1021 participants recently diagnosed with colorectal adenomas were randomly assigned to 1 mg/d of folic acid (n = 516) or placebo (n = 505), with or without aspirin, beginning 6 July 1994. The original 3-y treatment period was extended into a subsequent colonoscopy interval, but eventually stopped prematurely on 1 October 2004. With additional post-treatment follow-up, a total of 663 participants who extended treatment completed a second colonoscopic surveillance interval after the initial 3-y follow-up. In addition, 490 participants provided information regarding a subsequent surveillance colonoscopy occurring before completion of follow-up on 31 May 2012, including 325 who had agreed to extended treatment. Study endpoints included conventional adenomas, sessile serrated adenomas/polyps (SSA/Ps), or colorectal cancer, and RRs with 95% CIs were adjusted for baseline characteristics associated with availability of follow-up.

RESULTS

Among those who extended treatment, any colorectal neoplasia was found in 118 (36%) participants assigned to placebo and 146 (43%) assigned to folic acid during the second surveillance interval (RR: 1.21; 95% CI: 0.99, 1.47; P = 0.06). Increased risk of SSA/P with extended folic acid supplementation was statistically significant during the second surveillance interval (RR: 1.94; 95% CI: 1.02, 3.68; P = 0.04). There was no evidence of post-treatment effects for any colorectal neoplasia (RR: 1.01; 95% CI: 0.80, 1.28; P = 0.94), and the post-treatment effect for SSA/P was no longer statistically significant (RR: 1.38; 95% CI: 0.59, 3.19; P = 0.46).

CONCLUSIONS

Delayed treatment effects were not observed, but folic acid may increase SSA/P risk. This trial was registered at clinicaltrials.gov as NCT00272324.

Body Composition and Aspirin Dose for Colorectal Adenoma Prevention in a Randomized Clinical Trial

BACKGROUND

Visceral adiposity is a risk factor for colorectal adenomas, and aspirin is an established chemopreventive agent. Evidence from clinical trials suggests the effectiveness of aspirin at preventing cardiovascular disease and cancer may require higher doses for higher body weight.

METHODS

Body mass index, body surface area, fat-free mass, and fat mass were calculated from baseline height and weight in 1,121 participants of the Aspirin/Folate Polyp Prevention Study, a double-blind, placebo-controlled, 3 × 2 factorial randomized clinical trial of low-dose (81 mg/day) or high-dose (325 mg/day) aspirin and/or 1 mg/day folic acid to prevent metachronous colorectal adenomas. Participants were treated during a surveillance colonoscopy interval of approximately 3 years. Risk ratios (RR) with 95% confidence intervals (CI) for any colorectal neoplasia and high-risk adenoma (HRA, advanced or ≥3 adenomas) were estimated from log-linear regression.

RESULTS

We did not find evidence to suggest aspirin dose-response differed by body composition measurements, including weight alone. Among those weighing ≥ 80 kg, treatment effects for low-dose aspirin (RR for colorectal neoplasia, 0.75; 95% CI, 0.60-0.94; RR for HRA, 0.52; 95% CI, 0.31-0.86) and high-dose aspirin (RR for colorectal neoplasia, 0.88; 95% CI, 0.72-1.08; RR for HRA, 0.68; 95% CI, 0.43-1.09) were not meaningfully different than for those weighing 70-79 kg or <70 kg.

CONCLUSIONS

Measurements of body composition calculated from height and weight did not modify aspirin treatment effects for colorectal adenoma prevention.

IMPACT

Aspirin dosing strategies accounting for body weight suggested in previous trials of colorectal cancer may not apply to adenomas.

No Evidence for Posttreatment Effects of Vitamin D and Calcium Supplementation on Risk of Colorectal Adenomas in a Randomized Trial

Vitamin D and calcium supplementation are postulated to have chemopreventive effects against colorectal neoplasia, yet in our previously reported randomized trial, there was no overall efficacy of calcium and/or vitamin D₃ against colorectal adenoma recurrence. It is possible vitamin D₃ and calcium chemopreventive effects are not detectable until beyond the 3- to 5-year follow-up captured in that trial. Accordingly, we explored possible vitamin D and calcium effects on posttreatment (observational) adenoma occurrence. In this secondary analysis of the observational follow-up phase of the Vitamin D/Calcium Polyp Prevention Study, participants who completed the treatment phase were invited to be followed for one additional surveillance colonoscopy cycle. We evaluated adenoma occurrence risk at surveillance colonoscopy, with a mean of 55 ± 15 months after treatment follow-up, according to randomized treatment with vitamin D versus no vitamin D, calcium versus no calcium, and calcium plus vitamin D versus calcium alone. Secondary outcomes included advanced and multiple adenomas. Among the 1,121 participants with observational follow-up, the relative risk (95% confidence interval, CI) of any adenoma was 1.04 (0.93-1.17) for vitamin D versus no vitamin D; 0.95 (0.84-1.08) for calcium versus no calcium; 1.07 (0.91-1.25) for calcium plus vitamin D versus calcium; and 0.96 (0.81-1.15) for calcium plus vitamin D versus neither. Risks of advanced or multiple adenomas also did not differ by treatment. Our results do not support an association between supplemental calcium and/or vitamin D₃ for 3 to 5 years and risk of recurrent colorectal adenoma at an average of 4.6 years after treatment.

Calcium and vitamin D supplementation and increased risk of serrated polyps: results from a randomised clinical trial

OBJECTIVE

Serrated lesions such as sessile serrated adenomas or polyps (SSA/Ps) are important colorectal cancer precursors, but aetiological factors for these lesions are largely unknown. We aimed to determine the effects of calcium and vitamin D supplementation on the incidence of serrated polyps (SPs) in general and hyperplastic polyps and SSA/Ps specifically.

DESIGN

Participants with one or more adenoma at baseline were randomised to receive 1200 mg/day of elemental calcium, 1000 IU/day of vitamin D₃, both or neither agent. Treatment continued for 3 or 5 years, when risk of polyps was determined from surveillance colonoscopy (treatment phase). Outcomes after treatment ceased were also assessed (observational phase). Adjusted risk ratios (aRRs) of SPs were determined via multivariable generalised linear models.

RESULTS

SPs were diagnosed in 565 of 2058 (27.5%) participants during the treatment phase and 329/1108 (29.7%) during the observational phase. In total, 211 SSA/Ps were identified during follow-up. In the treatment phase, there was no effect of either calcium or vitamin D on incidence of SSA/Ps. However, during the later observational phase, we observed elevated risks of SSA/Ps associated with calcium alone and calcium+vitamin D treatment (aRR (95% CI): 2.65 (1.43 to 4.91) and 3.81 (1.25 to 11.64), respectively).

CONCLUSION

In a large multicentre chemoprevention study, we found evidence that calcium and vitamin D supplementation increased the risk of SSA/Ps. This appeared to be a late effect: 6-10 years after supplementation began. These possible risks must be weighed against the benefits of calcium and vitamin D supplementation. : Trial registration NUMBER: NCT00153816; Results.

Body mass index, calcium supplementation and risk of colorectal adenomas

Calcium supplementation (1,200 mg/day) did not significantly reduce colorectal adenomas in our recent randomized, controlled trial (Vitamin D/Calcium Polyp Prevention Study, VCPPS, 2004-2013) in contrast to our previous trial (Calcium Polyp Prevention Study, CPPS, 1988-1996). To reconcile these findings, we identified participant characteristics that differed between the study populations and modified the effect of calcium supplementation on adenomas or high-risk findings (advanced or multiple adenomas). Compared to the CPPS, more participants in the VCPPS were obese (body mass index (BMI) ≥30 kg/m² ; 37.5% vs. 24.4%) and fewer had normal BMI (BMI <25 kg/m² ; 18.5% vs. 31%). BMI appeared to modify the effect of calcium supplementation on adenomas and especially on high risk-findings: in the VCPPS, there was a 44% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.56, 95% CI = 0.26-1.23), but not among overweight (RR = 1.09, 95% CI = 0.62-1.91) or obese (RR = 1.54, 95% CI = 0.92-2.57) individuals (p_interaction = 0.03). Similarly, in the CPPS, there was a 56% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.44, 95% CI = 0.26-0.74), but not among overweight (RR = 0.87, 95% CI = 0.55-1.39) or obese (RR = 1.02, 95% CI = 0.57-1.82) individuals (p_interaction = 0.02). Standardization of each trial's findings to the BMI distribution in the other attenuated calcium's protective effect on adenomas in the CPPS but enhanced it in the VCPPS. In conclusion, 1,200 mg/day calcium supplementation may reduce risk of colorectal adenomas among those with normal BMI but not in overweight or obese individuals; and differences in BMI distribution partially account for the apparent difference in calcium efficacy between the two trials.

Factors Associated With Shorter Colonoscopy Surveillance Intervals for Patients With Low-Risk Colorectal Adenomas and Effects on Outcome

BACKGROUND & AIMS

Endoscopists do not routinely follow guidelines to survey individuals with low-risk adenomas (LRAs; 1-2 small tubular adenomas, < 1 cm) every 5-10 years for colorectal cancer; many recommend shorter surveillance intervals for these individuals. We aimed to identify the reasons that endoscopists recommend shorter surveillance intervals for some individuals with LRAs and determine whether timing affects outcomes at follow-up examinations.

METHODS

We collected data from 1560 individuals (45-75 years old) who participated in a prospective chemoprevention trial (of vitamin D and calcium) from 2004 through 2008. Participants in the trial had at least 1 adenoma, detected at their index colonoscopy, and were recommended to receive follow-up colonoscopy examinations at 3 or 5 years after adenoma identification, as recommended by the endoscopist. For this analysis we collected data from only participants with LRAs. These data included characteristics of participants and endoscopists and findings from index and follow-up colonoscopies. Primary endpoints were frequency of recommending shorter (3-year) vs longer (5-year) surveillance intervals, factors associated with these recommendations, and effect on outcome, determined at the follow-up colonoscopy.

RESULTS

A 3-year surveillance interval was recommended for 594 of the subjects (38.1%). Factors most significantly associated with recommendation of 3-year vs a 5-year surveillance interval included African American race (relative risk [RR] to white, 1.41; 95% confidence interval [CI], 1.14-1.75), Asian/Pacific Islander ethnicity (RR to white, 1.7; 95% CI, 1.22-2.43), detection of 2 adenomas at the index examination (RR vs 1 adenoma, 1.47; 95% CI, 1.27-1.71), more than 3 serrated polyps at the index examination (RR=2.16, 95% CI, 1.59-2.93), or index examination with fair or poor quality bowel preparation (RR vs excellent quality, 2.16; 95% CI, 1.66-2.83). Other factors that had a significant association with recommendation for a 3-year surveillance interval included family history of colorectal cancer and detection of 1-2 serrated polyps at the index examination. In comparisons of outcomes, we found no significant differences between the 3-year vs 5-year recommendation groups in proportions of subjects found to have 1 or more adenomas (38.8% vs 41.7% respectively; P = .27), advanced adenomas (7.7% vs 8.2%; P = .73) or clinically significant serrated polyps (10.0% vs 10.3%; P = .82) at the follow-up colonoscopy.

CONCLUSIONS

Possibly influenced by patients' family history, race, quality of bowel preparation, or number or size of polyps, endoscopists frequently recommend 3-year surveillance intervals instead of guideline-recommended intervals of 5 years or longer for individuals with LRAs. However, at the follow-up colonoscopy, similar proportions of participants have 1 or more adenomas, advanced adenomas, or serrated polyps. These findings support the current guideline recommendations of performing follow-up examinations of individuals with LRAs at least 5 years after the index colonoscopy.

Lifestyle and Other Factors Explain One-Half of the Variability in the Serum 25-Hydroxyvitamin D Response to Cholecalciferol Supplementation in Healthy Adults

BACKGROUND

Many factors have been associated with serum 25-hydroxyvitamin D [25(OH)D] concentrations in observational studies, with variable consistency. However, less information is available on factors affecting the magnitude of changes in serum 25(OH)D resulting from vitamin D supplementation.

OBJECTIVE

This study aimed to identify factors associated with the serum 25(OH)D response to supplementation with 1000 IU cholecalciferol/d during the first year of a large, multicenter, randomized, placebo-controlled colorectal adenoma chemoprevention trial.

METHODS

Eligible older adults who were not vitamin D-deficient [serum 25(OH)D ≥12 ng/mL] were randomly assigned in a modified 2 × 2 factorial design to 1 of 4 groups: daily 1000 IU cholecalciferol, 1200 mg Ca as carbonate, both, or placebo. Women could elect 2-group (calcium ± cholecalciferol) random assignment. In secondary analyses, we used multivariable models to assess factors associated with serum 25(OH)D concentrations in all enrollees (n = 2753) and with relative changes in serum 25(OH)D after 1 y cholecalciferol supplementation among those randomly assigned (n = 2187).

RESULTS

In multivariable models, 8 factors accounted for 50% of the variability of proportional change in serum 25(OH)D after cholecalciferol supplementation. Larger increases were associated with being female (34.5% compared with 20.5%; P < 0.001) and with lower baseline serum 25(OH)D (P < 0.0001), optimal adherence to study pill intake (P = 0.0002), wearing long pants and sleeves during sun exposure (P = 0.0002), moderate activity level (P = 0.01), use of extra vitamin D-containing supplements during the trial (P = 0.03), and seasons of blood draw (P ≤ 0.002). Several genetic polymorphisms were associated with baseline serum 25(OH)D and/or serum response, but these did not substantially increase the models' R² values. Other factors, including body mass index, were associated with serum 25(OH)D at baseline but not with its response to supplemental cholecalciferol.

CONCLUSIONS

The factors that most affected changes in serum 25(OH)D concentrations in response to cholecalciferol supplementation included sex, baseline serum 25(OH)D, supplement intake adherence, skin-covering clothes, physical activity, and season. Genetic factors did not play a major role. This trial was registered at www.clinicaltrials.gov as NCT00153816.

Association between adenoma location and risk of recurrence

BACKGROUND AND AIMS

The biological environment varies across the colorectum and may therefore affect neoplastic growth differently in the proximal and distal colon. The aim of the study was to evaluate the risk for recurrent adenomas and their anatomic location based on adenoma location at baseline colonoscopy.

METHODS

Data were extracted from 3 adenoma prevention trials (n = 2430). Participants had at least 1 adenoma at baseline colonoscopy and underwent subsequent surveillance colonoscopy, at which time metachronous adenomas could be detected. We calculated the risk ratio (RR) and the 95% confidence interval (CI) for metachronous adenomas by location of the baseline lesion and considered the impact of advanced neoplasia and multiplicity.

RESULTS

At baseline, 522 patients (21.5%) had adenomas only in the proximal colon, 1266 patients (52.1%) had adenomas only in the distal colorectum, and 642 (26.4%) had adenomas in both regions. Overall, 877 patients (36.5%) had metachronous adenomas during the follow-up period. Those with only proximal adenomas at baseline had a higher risk of metachronous adenomas compared with patients with only distal adenomas (RR, 1.17; 95% CI, 1.01-1.35). A greater proximal risk was found after restricting the analysis to patients with multiple proximal adenomas versus multiple distal adenomas (RR, 1.35; 95% CI, 1.10-1.67). The risk of recurrent adenomas on the same side was 48% higher for patients with only proximal adenomas at baseline compared with those with only distal adenomas at baseline (RR, 1.48; 95% CI, 1.22-1.80).

CONCLUSIONS

Patients with proximal adenomas only have a modestly greater risk of adenoma recurrence than patients with adenomas limited to the distal colon, and have a greater likelihood of adenoma recurrence on the same side compared with patients with distal adenomas. This observation suggests that biological factors may differentially affect neoplasia growth across the colon.

A Trial of Calcium and Vitamin D for the Prevention of Colorectal Adenomas

BACKGROUND

Epidemiologic and preclinical data suggest that higher intake and serum levels of vitamin D and higher intake of calcium reduce the risk of colorectal neoplasia. To further study the chemopreventive potential of these nutrients, we conducted a randomized, double-blind, placebo-controlled trial of supplementation with vitamin D, calcium, or both for the prevention of colorectal adenomas.

METHODS

We recruited patients with recently diagnosed adenomas and no known colorectal polyps remaining after complete colonoscopy. We randomly assigned 2259 participants to receive daily vitamin D3 (1000 IU), calcium as carbonate (1200 mg), both, or neither in a partial 2×2 factorial design. Women could elect to receive calcium plus random assignment to vitamin D or placebo. Follow-up colonoscopy was anticipated to be performed 3 or 5 years after the baseline examinations, according to the endoscopist's recommendation. The primary end point was adenomas diagnosed in the interval from randomization through the anticipated surveillance colonoscopy.

RESULTS

Participants who were randomly assigned to receive vitamin D had a mean net increase in serum 25-hydroxyvitamin D levels of 7.83 ng per milliliter, relative to participants given placebo. Overall, 43% of participants had one or more adenomas diagnosed during follow-up. The adjusted risk ratios for recurrent adenomas were 0.99 (95% confidence interval [CI], 0.89 to 1.09) with vitamin D versus no vitamin D, 0.95 (95% CI, 0.85 to 1.06) with calcium versus no calcium, and 0.93 (95% CI, 0.80 to 1.08) with both agents versus neither agent. The findings for advanced adenomas were similar. There were few serious adverse events.

CONCLUSIONS

Daily supplementation with vitamin D3 (1000 IU), calcium (1200 mg), or both after removal of colorectal adenomas did not significantly reduce the risk of recurrent colorectal adenomas over a period of 3 to 5 years. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00153816.).

Abstract 4584: VDR genotype modifies vitamin D efficacy for colorectal adenoma prevention in a randomized controlled trial

Objective: Although epidemiological and pre-clinical research suggests that vitamin D and calcium supplementation reduce colorectal carcinogenesis, we found that they had no effect on risk of colorectal adenoma recurrence in a recently completed randomized controlled trial (Vitamin D/Calcium Polyp Prevention Study, NCT00153816). We now examine whether the effect of supplementation may be modified by common genetic variants in vitamin D and calcium pathway genes previously associated with 25-hydroxyvitamin D levels or other health outcomes.

Methods: 41 candidate single nucleotide polymorphisms (SNPs) in 7 genes (GC, DHCR7, CYP2R1, CYP27B1, CYP24A1, VDR and CASR) were genotyped in non-Hispanic white trial participants (N = 1,676). All had at least one adenoma at a baseline colonoscopy and were randomized to treatment with vitamin D3 (1000 IU/day), calcium (1200 mg/day), both or placebo in a modified 2×2 factorial design. Participants were followed until a subsequent colonoscopy 3 or 5 years later and assessed for the presence of at least one adenoma or advanced adenoma (adenoma ≥1 cm, or with &gt;25% villous histology and/or high-grade dysplasia, or cancer). Adjusted risk ratios (RRs) and 95% confidence intervals (CIs) were used to estimate genotype effects, treatment effects and interactions. To account for multiple testing, based on the effective number of independent SNPs, statistical significance was defined as p&lt;0.002.

Results: VDR SNP rs731236 (Taq1, minor allele frequency 0.39) statistically significantly modified the effect of vitamin D3 treatment on advanced adenomas (interaction RR = 0.49, 95% CI = 0.31-0.76, P = 0.001) but not on any adenoma (interaction RR = 0.94, 95% CI = 0.80-1.11, P = 0.48). Among participants (N = 249, 15%) with the homozygous variant genotype, the risk of an advanced adenoma was 15.2% among those randomized to placebo, and 3.2% among those randomized to vitamin D; a risk reduction of 78% for vitamin D supplementation (RR = 0.22, 95% CI = 0.08-0.63, P = 0.005). In contrast, among participants with one or more wild type allele (N = 1400, 85%), the risk of an advanced adenoma was 8.8% among those randomized to placebo, and 10.5% among those randomized to vitamin D; an apparent risk increase of 19% for vitamin D supplementation (RR = 1.19, 95% CI = 0.86-1.64, P = 0.3). Several other VDR SNPs in linkage disequilibrium with rs731236 had borderline statistically significant interactions. However, there were only nominally statistically significant (P&lt;0.05) interactions of SNP genotypes with calcium treatment on adenoma outcomes.

Conclusions: Our results suggest that the effect of vitamin D3 supplementation on colorectal carcinogenesis depends on common genetic variants in VDR, with a 78% reduction in risk of advanced adenomas in individuals with the rs731236 homozygous variant genotype, and no benefit in individuals with one or more wild type alleles.

Note: This abstract was not presented at the meeting.

Citation Format: Elizabeth L. Barry, Leila A. Mott, Judith R. Rees, Dennis J. Ahnen, Roberd M. Bostick, Robert S. Bresalier, Douglas J. Robertson, Robert W. Summers, John A. Baron. VDR genotype modifies vitamin D efficacy for colorectal adenoma prevention in a randomized controlled trial. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4584. doi:10.1158/1538-7445.AM2015-4584

Calcium supplementation increases blood creatinine concentration in a randomized controlled trial

Background

Calcium supplements are widely used among older adults for osteoporosis prevention and treatment. However, their effect on creatinine levels and kidney function has not been well studied.

Methods

We investigated the effect of calcium supplementation on blood creatinine concentration in a randomized controlled trial of colorectal adenoma chemoprevention conducted between 2004–2013 at 11 clinical centers in the United States. Healthy participants (N = 1,675) aged 45–75 with a history of colorectal adenoma were assigned to daily supplementation with calcium (1200 mg, as carbonate), vitamin D₃ (1000 IU), both, or placebo for three or five years. Changes in blood creatinine and total calcium concentration were measured after one year of treatment and multiple linear regression was used to estimate effects on creatinine concentrations.

Results

After one year of treatment, blood creatinine was 0.013±0.006 mg/dL higher on average among participants randomized to calcium compared to placebo after adjustment for other determinants of creatinine (P = 0.03). However, the effect of calcium treatment appeared to be larger among participants who consumed the most alcohol (2–6 drinks/day) or whose estimated glomerular filtration rate (eGFR) was less than 60 ml/min/1.73 m² at baseline. The effect of calcium treatment on creatinine was only partially mediated by a concomitant increase in blood total calcium concentration and was independent of randomized vitamin D treatment. There did not appear to be further increases in creatinine after the first year of calcium treatment.

Conclusions

Among healthy adults participating in a randomized clinical trial, daily supplementation with 1200 mg of elemental calcium caused a small increase in blood creatinine. If confirmed, this finding may have implications for clinical and public health recommendations for calcium supplementation.

Trial Registration

ClinicalTrials.gov NCT00153816

Genetic variants in CYP2R1, CYP24A1, and VDR modify the efficacy of vitamin D3 supplementation for increasing serum 25-hydroxyvitamin D levels in a randomized controlled trial

CONTEXT

Adequate serum 25-hydroxyvitamin D concentrations, [25(OH)D], are required for optimal bone health, and low levels are associated with chronic diseases.

OBJECTIVE

We investigated whether 41 candidate single nucleotide polymorphisms (SNPs) in vitamin D and calcium pathway genes (GC, DHCR7, CYP2R1, CYP27B1, CYP24A1, VDR, and CASR) are associated with [25(OH)D] or modify the increase in [25(OH)D] from vitamin D3 supplementation.

DESIGN AND SETTING

Baseline and year 1 [25(OH)D] measurements from a randomized controlled trial conducted at 11 clinical centers in the United States.

PARTICIPANTS

A total of 1787 healthy non-Hispanic white participants aged 45-75 years.

INTERVENTIONS

Vitamin D3 (1000 IU/d), calcium carbonate (1200 mg/d elemental), both, or placebo.

MAIN OUTCOME MEASURES

Genotype main effects and interactions with vitamin D3 treatment estimated using multiple linear regression.

RESULTS

The baseline serum [25(OH)D] was 25.4 ± 8.7 ng/mL (mean ± SD). Associations with baseline levels were discovered for SNPs in CYP24A1 (rs2209314, rs2762939) and confirmed for SNPs in GC and CYP2R1. After 1 year, [25(OH)D] increased on average by 6.1 ± 8.9 ng/mL on vitamin D3 treatment and decreased by 1.1 ± 8.4 ng/mL on placebo. The increase in [25(OH)D] due to vitamin D3 supplementation was modified by genotypes at rs10766197 near CYP2R1, rs6013897 near CYP24A1, and rs7968585 near VDR.

CONCLUSIONS

The increase in [25(OH)D] attributable to vitamin D3 supplementation may vary according to common genetic differences in vitamin D 25-hydroxylase (CYP2R1), 24-hydroxylase (CYP24A1), and the vitamin D receptor (VDR) genes. These findings have implications for achieving optimal vitamin D status and potentially for vitamin D-related health outcomes.

C-reactive protein and risk of colorectal adenomas or serrated polyps: a prospective study

Serum C-reactive protein (CRP) is a sensitive marker of systemic inflammation. Because there is a well-recognized relationship between local inflammation and colorectal cancer, we aimed to evaluate whether serum CRP levels were associated with the occurrence of colorectal adenomas and serrated polyps using data from a large adenoma prevention trial. A total of 930 participants with a history of colorectal adenomas were enrolled in a randomized trial of calcium supplementation (1,200 mg/day) for the prevention of colorectal adenomas. Outcomes in this analysis are metachronous adenomas (and advanced neoplasms specifically), and serrated polyps at follow-up colonoscopy. High-sensitivity CRP levels were measured 1 year following baseline colonoscopy. Multivariate analysis was performed to estimate risk ratios (RR) using Poisson regression, controlling for potential confounders. We measured serum CRP levels in 689 participants (mean CRP, 3.62 ± 5.72 mg/L). There was no difference in CRP levels with respect to calcium versus placebo treatment assignment (P = 0.99). After adjustment for potential confounders, we found no association between CRP level and risk of recurrent adenoma or advanced lesion [quartile 4 vs. quartile 1: RR, 95% confidence interval (CI) = 0.99 (0.73-1.34) and 0.92 (0.49-1.75), respectively]. Similarly, no association was seen between CRP levels and risk of serrated polyps or proximal serrated polyps [quartile 4 vs. quartile 1: RR (95% CI) = 1.32 (0.85-2.03) and 1.19 (0.54-2.58), respectively]. In conclusion, this large prospective colorectal adenoma chemoprevention study found no significant relationship between CRP levels and occurrence of adenomas, advanced neoplasms, or serrated polyps.

Vitamin D3 supplementation and upper respiratory tract infections in a randomized, controlled trial

BACKGROUND

Randomized controlled trials testing the association between vitamin D status and upper respiratory tract infection (URTI) have given mixed results. During a multicenter, randomized controlled trial of colorectal adenoma chemoprevention, we tested whether 1000 IU/day vitamin D(3) supplementation reduced winter episodes and duration of URTI and its composite syndromes, influenza-like illness (ILI; fever and ≥2 of sore throat, cough, muscle ache, or headache) and colds (no fever, and ≥2 of runny nose, nasal congestion, sneezing, sore throat, cough, swollen or tender neck glands).

METHODS

The 2259 trial participants were aged 45-75, in good health, had a history of colorectal adenoma, and had a serum 25-hydroxyvitamin D level ≥12 ng/mL. They were randomized to vitamin D(3) (1000 IU/day), calcium (1200 mg/day), both, or placebo. Of these, 759 participants completed daily symptom diaries. Secondary data included semiannual surveys of all participants.

RESULTS

Among those who completed symptom diaries, supplementation did not significantly reduce winter episodes of URTI (rate ratio [RR], 0.93; 95% confidence interval [CI], .79-1.09) including colds (RR, 0.93; 95% CI, .78-1.10) or ILI (RR, 0.95; 95% CI, .62-1.46), nor did it reduce winter days of illness (RR, 1.13; 95% CI, .90-1.43). There was no significant benefit according to adherence, influenza vaccination, body mass index, or baseline vitamin D status. Semiannual surveys of all participants (N = 2228) identified no benefit of supplementation on ILI (odds ratio [OR], 1.14; 95% CI, .84-1.54) or colds (OR, 1.03; 95% CI, .87-1.23).

CONCLUSIONS

Supplementation with 1000 IU/day vitamin D(3) did not significantly reduce the incidence or duration of URTI in adults with a baseline serum 25-hydroxyvitamin D level ≥12 ng/mL.

Abstract 2196: Genetic correlates of serum 25-hydroxyvitamin D levels and response to vitamin D supplementation

Epidemiological studies indicate that vitamin D has antineoplastic effects in the colorectum and suggest that vitamin D supplementation may be a promising chemopreventative approach to reduce risk of colorectal cancer. Thus, it is important to consider how genetic factors may modify vitamin D status and response to vitamin D supplementation. We investigated this question among 2,259 participants randomized in the Vitamin D/Calcium Polyp Prevention Study, an on-going, double-blind, placebo-controlled clinical trial of supplementation with vitamin D3 (1000 IU/day) and/or calcium carbonate (1200 mg elemental calcium/day) for the prevention of colorectal adenomas. Candidate single nucleotide polymorphisms (SNPs) were genotyped in or near seven genes involved in vitamin D or calcium metabolism, transport or signaling. Excluding SNPs with MAF&lt;5% and r2&gt;0.8, 23 SNPs were analyzed in vitamin D binding protein (GC), 25-hydroxylase (CYP2R1), 24-hydroxylase (CYP24A1), 1-hydroxylase (CYP27B1), 7-dehydrocholesterol reductase (DHCR7), vitamin D receptor (VDR), and calcium-sensing receptor (CaSR). These included 5 SNPs previously associated with circulating 25-hydroxyvitamin D levels in genome-wide association studies (GWAS): rs2282679, rs12785878, rs3829251, rs10741657 and rs6013897. Linear regression was used to estimate associations with baseline serum 25-hydroxyvitamin D levels and with levels of 25-hydroxyvitamin D achieved after approximately one year of vitamin D supplementation in the trial after adjusting for baseline levels. Analyses were restricted to non-Hispanic white participants (82%) to avoid population stratification and additive genetic models were used. Baseline 25-hydroxyvitamin D was statistically significantly associated with genotype at 3 GWAS hits in GC, DHCR7 and CYP2R1 and at 5 other SNPs in GC, CYP2R1 and CYP24A1. When response to supplementation was investigated, compliance with pill taking was taken into account by restricting analyses to optimally compliant subjects. Genotype at 3 SNPs in VDR, CYP2R1, and CYP24A1 statistically significantly modified the 25-hydroxyvitamin D level achieved with vitamin D supplementation. In conclusion, we have identified variation in or near key vitamin D and calcium pathway genes that modify serum 25-hydroxyvitamin D status and the response to supplementation with vitamin D. This research may identify individuals at risk for poor response to vitamin D supplementation. The public health significance of this work is substantial due to the prevalence of vitamin D insufficiency and the high incidence of colorectal cancer, osteoporosis, and other common diseases associated with poor vitamin D status.

Citation Format: Elizabeth L. Barry, Leila A. Mott, Janet L. Peacock, Judith R. Rees, John A. Baron. Genetic correlates of serum 25-hydroxyvitamin D levels and response to vitamin D supplementation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2196. doi:10.1158/1538-7445.AM2013-2196

CYP2C9 variants increase risk of colorectal adenoma recurrence and modify associations with smoking but not aspirin treatment

PURPOSE

The cytochrome P450 2C9 enzyme (CYP2C9) is involved in metabolism of endogenous compounds, drugs, and procarcinogens. Two common nonsynonymous polymorphisms in CYP2C9 are associated with reduced enzyme activity: CYP2C9*2 (rs1799853, R144C) and CYP2C9*3 (rs1057910, I359L).

METHODS

We investigated whether CYP2C9 genotype was associated with risk of colorectal adenoma and/or modified associations with aspirin treatment or cigarette smoking in a cohort of 928 participants in a randomized trial of aspirin chemoprevention. Generalized linear regression was used to compute relative risks (RRs) and 95 % confidence intervals (95 % CIs). Multiplicative interactions terms were used to assess effect modification.

RESULTS

CYP2C9 genotype was associated with increased risks for adenoma recurrence of 29 % (RR = 1.29, 95 % CI 1.09-1.51) for ≥1 variant allele (CYP2C9*2 or *3) and 47 % (RR = 1.47, 95 % CI 1.19-1.83) for ≥1 CYP2C9*3 allele. The risk for advanced lesions or multiple (≥3) adenomas was increased by 64 % (RR = 1.64, 95 % CI 1.18-2.28) for ≥1 variant allele (CYP2C9*2 or *3) and 79 % (RR = 1.79, 95 % CI 1.16-2.75) for ≥1 CYP2C9*3 allele. Genotype modified associations with smoking, but not aspirin treatment. The adenoma risk was increased by 26 % (RR = 1.26, 95 % CI 0.99-1.58) for former smokers and 60 % (RR = 1.60, 95 % CI 1.19-2.15) for current smokers among wild-type individuals, but there was no increased risk among individuals with ≥1 variant allele (CYP2C9*2 or *3) (p (interaction) = 0.04).

CONCLUSIONS

Carriers of CYP2C9 variants with lower enzyme activity have increased overall risk of colorectal adenoma but reduced adenoma risk associated with cigarette smoking. These results may be due to effects on the synthesis of endogenous eicosanoids and/or reduced activation of procarcinogens in smoke by CYP2C9 variants.

Variants downstream of the ornithine decarboxylase gene influence risk of colorectal adenoma and aspirin chemoprevention

Increased mucosal polyamine levels and ornithine decarboxylase (ODC) activity are associated with an increased risk of colorectal neoplasia and aspirin treatment reduces risk. Previous studies suggest that a single-nucleotide polymorphism (SNP) in the promoter of the ODC gene (rs2302615) may be associated with adenoma risk and/or response to aspirin chemoprevention. However, a comprehensive investigation of common genetic variation in the region of ODC gene is lacking. Using a tag SNP approach, we investigated associations between genotype or haplotype and adenoma risk among a cohort of 792 non-Hispanic white participants in a randomized trial of aspirin. Generalized linear regression was used to compute relative risks (RR) and 95% confidence intervals (95% CI) adjusted for age and sex. The false discovery rate was used to account for multiple testing. Interactions terms were used to assess whether genotype modified the effect of aspirin treatment. Of 15 SNPs analyzed, seven were statistically significantly associated with adenoma risk. However, in multiple SNP regression models, only two of these, located downstream of the gene, were independently associated with risk: rs11694911 (RR = 1.29; 95% CI, 1.08-1.53; P = 0.005) and rs2430420 (RR = 1.20; 95% CI, 1.03-1.40; P = 0.022). In addition, there was evidence that rs2430420 and rs28362380 modified the effect of aspirin treatment, whereas the previously investigated SNP, rs2302615, had no statistically significant main effect or interaction with aspirin treatment. Our findings suggest that common genetic variants located downstream (3') of the ODC gene influence risk of colorectal adenoma and may also impact the efficacy of aspirin chemoprevention.

Folic acid and prevention of colorectal adenomas: a combined analysis of randomized clinical trials

Observational data suggest that lower folate status is associated with an increased risk of colorectal neoplasia, implying that folate may be useful as a chemopreventive agent. We conducted a combined analysis of three large randomized trials of folic acid supplementation for the prevention of metachronous adenomas in patients with an adenoma history. Participants included 2,632 men and women who had a history of adenomas randomized to either 0.5 or 1.0 mg/day of folic acid or placebo and who had a follow-up endoscopy 6 to 42 months after randomization [mean = 30.6 (standard deviation = 8.1) months]. We used random-effects meta-analysis to estimate risk ratios (RRs) and 95% confidence intervals (CIs). The RR comparing folic acid versus placebo was 0.98 (95% CI = 0.82-1.17) for all adenomas and 1.06 (95% CI = 0.81-1.39) for advanced lesions. Folic acid was associated with a nonsignificant decreased risk of any adenoma among subjects in the lowest quartile of baseline plasma folate (≤ 11 nmol/L) and no effect among individuals in the highest quartile (> 29 nmol/L, p for trend = 0.17). There was a nonsignificant trend of decreasing risk of any adenoma associated with folic acid supplements with increasing alcohol intake. During the early follow-up reported here, more deaths occurred in the placebo group than in the folic acid group (1.7% vs. 0.5%, p = 0.002). In conclusion, after up to 3.5 years of folic acid use, there is no clear decrease or increase in the occurrence of new adenomas in patients with a history of adenoma.

Baseline plasma total homocysteine and adenoma recurrence: results from a double blind randomized clinical trial of aspirin and folate supplementation

BACKGROUND

Elevated plasma total homocysteine (tHcy) is an accepted marker of functional folate deficiency but may have independent effects on colorectal neoplasia risk. It is uncertain whether plasma tHcy is associated with risk at the low levels common in a folate-fortified population.

METHODS

Study subjects, about half of whom were recruited after fortification of grain products with folic acid in the United States and Canada, consisted of 871 individuals with a recent history of one or more colorectal adenomas who were randomized to receive either a 1 mg/day folic acid supplement or a placebo within one of three randomly assigned aspirin treatment groups (placebo, 81, or 325 mg/day). Nonfasting plasma tHcy was determined by a gas chromatograph mass chromatography method. We estimated adjusted risk ratios and 95% confidence intervals (95% CI) for one or more adenoma recurrences for each quartile of baseline plasma tHcy using generalized linear regression with an overdispersed Poisson approximation to the binomial.

RESULTS

The Q4/Q1 adjusted risk ratio for any adenoma was 0.98 (95% CI, 0.70-1.38; P trend = 0.17) in the placebo group, and 0.81 (95% CI, 0.58-1.12; P-trend = 0.17) in the folic acid group. Results were similar for adenomas with advanced features. There was no modification by sex, aspirin treatment group or MTHFR 677C>T genotype.

CONCLUSIONS

Plasma tHcy is not an independent marker for an increase in colorectal adenoma recurrence risk in postfortification populations in which plasma tHcy levels are in the lower range of values.

IMPACT

Controlling plasma tHcy levels is unlikely to favorably modify adenoma recurrence risk in folate-fortified populations.

Abstract 2889: Folic acid for the prevention of colorectal adenomas: Combined analysis of randomized clinical trials

Studies have suggested that poor folate status is associated with a higher risk of colorectal adenomas and cancer. However, some epidemiological and animal studies have provided contradictory evidence. Data from a few randomized clinical trials of folic acid supplementation for the prevention of colorectal adenomas have been reported. Two small trials reported at least suggestions of benefit, but this was not observed in two much larger trials, the Aspirin/Folate Polyp Prevention Study (AFPPS) and the United Kingdom Colorectal Adenoma Prevention (ukCAP). Findings from Nurses’ Health Study/Health Professional Follow-Up Study (NHS/HPFS) showed no overall risk reduction, but some indications of decreased risks in selected subgroups of individuals. To obtain more precise clinical evidence on the effects of folic acid on incident adenoma occurrence, we conducted a collaborative pooled analysis of the largest trials: AFPPS, NHS/HPFS and the ukCAP trials, focusing on the treatment periods of the studies. To address the possibility that there may be subgroups of individuals who may be more susceptible to the effects of folic acid in the large bowel, we conducted a stratified analysis by selected patient characteristics and dietary exposures. Participants included 2,007 men and women with a recent history of adenomas randomized to 0.5 or 1.0 mg/day of folic acid (n=1,008) or placebo (n=999) who had a follow-up colonoscopy 6 to 42 months after randomization (mean=30.6 (SD=8.1) months). We used random-effects meta-analysis to estimate risk ratios (RR's) and 95% confidence intervals (CI). The RR comparing folic acid vs. placebo for the occurrence of at least one adenoma was 0.99 (95% CI=0.84−1.16). For advanced lesions, the RR was 1.05 (95% CI=0.80-1.39). There was a non-significant increased risk among individuals with two or more baseline adenomas (RR, 1.14; 95% CI=0.98 -1.33) and no association among those with only one adenoma at baseline (RR, 0.88; 95% CI=0.73-1.06, P-interaction=0.03). Folic acid supplementation was also associated with a non-significantly increased risk of adenomas for individuals in the highest tertile of baseline plasma folate (&gt;25 nmol/L) (RR, 1.19; 95% CI=0.92-1.53), and a non-significantly lower risk in those in the lowest tertile (&lt;13.5 nmol/L) (RR, 0.79; 95% CI=0.43-1.43, P-interaction=0.39). Among non-drinkers, there was a non-significant increase in risk of adenoma recurrence in the folic acid groups (RR=1.33, 95% CI=0.63-2.81), in contrast to a null effect among subjects who consumed one or more drinks per day (RR= 0.95, 95% CI=0.54-1.69, p-interaction=0.74). Similar results were observed for advanced lesions. Results from this pooled analysis suggest that during the first few years of folic acid use, there is no clear decrease or increase in the occurrence of new adenomas in patients with a recent adenoma history.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2889.

Using the results of a baseline and a surveillance colonoscopy to predict recurrent adenomas with high-risk characteristics

BACKGROUND

Suggested intervals for postpolypectomy surveillance colonoscopy are currently based on the adenoma findings from the most recent examination.

OBJECTIVE

To determine the risk for clinically significant adenoma recurrence on the basis of the results of 2 previous colonoscopies.

DESIGN

Prospective cohort study.

SETTING

Academic and private centers in North America.

PATIENTS

Participants in an adenoma chemoprevention trial in which all participants had 1 or more adenoma found on complete colonoscopy at entry. For this analysis, only participants whose qualifying adenoma was their first were included. All participants then underwent second and third study colonoscopies at roughly 3-year intervals.

MEASUREMENTS

Proportion of patients with high-risk findings at the third study colonoscopy--either at least 1 advanced (> or = 1 cm or advanced histology) adenoma or multiple (> or = 3) adenomas.

RESULTS

Fifty-eight of 564 participants (10.3%) had high-risk findings at the third study examination. If the second examination showed high-risk findings, then results from the first examination added no significant information about the probability of high-risk findings on the third examination (18.2% for high-risk findings on the first examination vs. 20.0% for low-risk findings on the first examination; P = 0.78). If the second examination showed no adenomas, then the results from the first examination added significant information about the probability of high-risk findings on the third examination (12.3% if the first examination had high-risk findings vs. 4.9% if the first examination had low-risk findings; P = 0.015).

LIMITATION

This observational study cannot specifically examine adenoma recurrence risk at intervals suggested for patients with low-risk adenomas (for example, 5 years vs. 10 years).

CONCLUSION

Information from 2 previous examinations may help identify low-risk populations that benefit little from intense surveillance. Surveillance guidelines might be tailored in selected patients to use information from 2 previous examinations, not just the most recent one.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Gastrin, Helicobacter pylori, and colorectal adenomas

BACKGROUND & AIMS

Hypergastrinemia and Helicobacter pylori (Hp) infection have been associated with an increased risk for colorectal neoplasia in some studies. However, data from large prospective studies of both associations are lacking. The aim of this study was to evaluate whether serum gastrin levels and/or infection with Hp are associated with the subsequent development of colorectal adenomas.

METHODS

Subjects (all with a history of adenoma formation) were drawn from 2 previously completed adenoma chemoprevention trials. Participants underwent clearing colonoscopy at baseline with follow-up colonoscopy 1 and 4 years after enrollment. We used commercially available assays on fasting blood specimens to measure serum gastrin levels and Hp serologies 1 year after randomization. Risk ratios for adenoma and advanced adenoma development during the subsequent 3 years were computed by generalized linear regression.

RESULTS

Of the 1794 subjects randomized in the 2 trials, 685 had available serum and were included in the analyses. Gastrin levels were significantly higher in the 239 subjects with Hp titers indicating infection (mean, 88.3 pg/mL) than in those not infected (mean, 73.9 pg/mL; P < .001). In fully adjusted models, gastrin levels were not associated with incident adenoma development (risk ratio [RR], 1.10; 95% confidence interval [CI], 0.78-1.54) or advanced adenoma formation (RR, 0.82; 95% CI, 0.33-2.03). A positive Hp serology was associated with a decreased risk for adenoma formation (RR, 0.76; 95% CI, 0.60-0.96).

CONCLUSIONS

Neither hypergastrinemia nor serologic evidence of Hp infection were associated with an increased risk for recurrent adenoma development. These results do not support the notion that gastrin promotes colorectal carcinogenesis, at least at the stage of adenoma development.

Cognitive-behavioral management of chemotherapy-related cognitive change

Adjuvant chemotherapy can produce mild cognitive decline among breast cancer survivors which adversely effects function and quality of life. However, no treatment to date has been proposed or developed for this problem despite large numbers of cancer patients who report post-treatment memory dysfunction. This paper presents data from a single arm pilot study of a brief cognitive-behavioral treatment aimed at helping breast cancer survivors manage cognitive dysfunction associated with adjuvant chemotherapy (Memory and Attention Adaptation Training; MAAT). Participants were twenty-nine women who were an average of 8 years post-chemotherapy for stage I and II breast cancer. All had reported complaints regarding memory and attention. Improvements in self-report of cognitive function, quality of life and standard neuropsychological test performance were observed at post-treatment, 2-month and 6-month follow-up. Participants also reported high treatment satisfaction and rated MAAT as helpful in improving ability to compensate for memory problems. Given these results, the treatment appears to be a feasible and practical cognitive-behavioral program that warrants continued evaluation among cancer survivors who experience persistent cognitive dysfunction.

Folic acid for the prevention of colorectal adenomas: a randomized clinical trial

CONTEXT

Laboratory and epidemiological data suggest that folic acid may have an antineoplastic effect in the large intestine.

OBJECTIVE

To assess the safety and efficacy of folic acid supplementation for preventing colorectal adenomas.

DESIGN, SETTING, AND PARTICIPANTS

A double-blind, placebo-controlled, 2-factor, phase 3, randomized clinical trial conducted at 9 clinical centers between July 6, 1994, and October 1, 2004. Participants included 1021 men and women with a recent history of colorectal adenomas and no previous invasive large intestine carcinoma.

INTERVENTION

Participants were randomly assigned in a 1:1 ratio to receive 1 mg/d of folic acid (n = 516) or placebo (n = 505), and were separately randomized to receive aspirin (81 or 325 mg/d) or placebo. Follow-up consisted of 2 colonoscopic surveillance cycles (the first interval was at 3 years and the second at 3 or 5 years later).

MAIN OUTCOME MEASURES

The primary outcome measure was occurrence of at least 1 colorectal adenoma. Secondary outcomes were the occurrence of advanced lesions (> or =25% villous features, high-grade dysplasia, size > or =1 cm, or invasive cancer) and adenoma multiplicity (0, 1-2, or > or =3 adenomas).

RESULTS

During the first 3 years, 987 participants (96.7%) underwent colonoscopic follow-up, and the incidence of at least 1 colorectal adenoma was 44.1% for folic acid (n = 221) and 42.4% for placebo (n = 206) (unadjusted risk ratio [RR], 1.04; 95% confidence interval [CI], 0.90-1.20; P = .58). Incidence of at least 1 advanced lesion was 11.4% for folic acid (n = 57) and 8.6% for placebo (n = 42) (unadjusted RR, 1.32; 95% CI, 0.90-1.92; P = .15). A total of 607 participants (59.5%) underwent a second follow-up, and the incidence of at least 1 colorectal adenoma was 41.9% for folic acid (n = 127) and 37.2% for placebo (n = 113) (unadjusted RR, 1.13; 95% CI, 0.93-1.37; P = .23); and incidence of at least 1 advanced lesion was 11.6% for folic acid (n = 35) and 6.9% for placebo (n = 21) (unadjusted RR, 1.67; 95% CI, 1.00-2.80; P = .05). Folic acid was associated with higher risks of having 3 or more adenomas and of noncolorectal cancers. There was no significant effect modification by sex, age, smoking, alcohol use, body mass index, baseline plasma folate, or aspirin allocation.

CONCLUSIONS

Folic acid at 1 mg/d does not reduce colorectal adenoma risk. Further research is needed to investigate the possibility that folic acid supplementation might increase the risk of colorectal neoplasia.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00272324.

Measures of cumulative exposure from a standardized sun exposure history questionnaire: a comparison with histologic assessment of solar skin damage

Ultraviolet radiation exposure is the dominant environmental determinant of all major forms of skin cancer; however, the nature of the association is incompletely understood. Existing instruments to capture sun exposure history tend to yield reproducible results, but the validity of these responses is unknown. To address this question, the authors examined the relation between responses to a standardized sun exposure instrument and histologic evidence of actinic damage in a population-based study of keratinocyte cancers from New Hampshire diagnosed from July 1, 1997, through March 31, 2000. A single study dermatopathologist histologically reviewed the adjacent skin of 925 skin cancer biopsies for the presence of solar keratoses and the extent of solar elastosis. The authors compared these measures with responses to a personal interview on history of sunburns, sunbathing, and time spent outdoors. Focusing on site-specific exposure, they found variables that estimated cumulative exposure related to histologic evidence of actinic damage. In contrast, measures of acute/intermittent exposure were generally unrelated to solar damage histologically. Findings suggest that cumulative, but not intermittent, measures of sun exposure derived from a personal interview appear to reflect a person's exposure history based on histologic evidence.

Aspirin may be more effective in preventing colorectal adenomas in patients with higher BMI (United States)

Obesity is a risk factor for colon cancer, possibly due to elevated levels of circulating cytokines derived from adipose tissue. Aspirin, which may affect the levels of these cytokines, has been shown in randomized controlled trials to decrease the risk of colorectal adenomas. We hypothesized that the chemopreventive effect of aspirin might be greater in individuals with higher body mass index (BMI). Data were available from the Aspirin/Folate Polyp Prevention Study, a randomized controlled trial of aspirin and folic acid to prevent recurrent colorectal adenomas. Obesity was defined as BMI > or = 30 (kg/m2), overweight as BMI of 25-29 (kg/m2) and normal weight as BMI <25 (kg/m2). For the analysis of the effect of aspirin on the recurrence of colorectal adenoma by BMI, we computed risk ratios for aspirin versus placebo within the three BMI strata using a modified Poisson model. Overall the risk reduction of adenomas with a daily dose of 325 mg aspirin was greater among subjects with higher BMI. Among obese subjects the risk ratio (RR) for advanced adenomas compared with placebo was 0.44 (95% CI 0.17-1.10), versus RR = 1.23 (95% CI 0.55-2.77) among those with normal weight. However, 81 mg aspirin daily did not interact with BMI to modify the risk of adenomas in such a fashion. The more pronounced effect of 325 mg aspirin in individuals with higher BMI suggests a possible protective role of anti-inflammatory aspirin against increased adipose-driven cytokines among obese subjects.

Human Papillomavirus Infection and Incidence of Squamous Cell and Basal Cell Carcinomas of the Skin

BACKGROUND

Although infection with human papillomaviruses (HPVs) is a major risk factor for several epithelial cancers, an etiologic relationship between HPV and keratinocyte cancers, such as squamous cell carcinomas (SCCs) and basal cell carcinomas (BCCs), remains unclear.

METHODS

In a population-based case-control study of 252 SCC case patients, 525 BCC case patients, and 461 control subjects, we used multiplex serology to detect antibodies in plasma samples against 16 HPV types from phylogenetic genera alpha, beta, and mu. Multiplex serology is a new method that is based on fluorescent bead technology and allows simultaneous detection of antibodies against up to 100 different in situ affinity-purified recombinant HPV proteins. Data on sun sensitivity, outdoor exposure, and other risk factors for keratinocyte cancers were collected through personal interviews. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated via unconditional logistic regression models.

RESULTS

Overall, we detected HPV antibodies more frequently in SCC patients than in control subjects (OR = 1.6, 95% CI = 1.2 to 2.3), but we found no difference in HPV seropositivity between BCC case patients and control subjects (OR = 0.8, 95% CI = 0.6 to 1.1). Among HPV types, seropositivity to HPV types in genus beta (OR = 1.5, 95% CI = 1.0 to 2.1), particularly HPV 5 (OR = 1.8, 95% CI = 1.0 to 3.1), was associated with SCC risk. Individuals with tumors on chronically sun exposed sites were more likely to be seropositive for beta HPV types than individuals with SCC at other anatomic sites. The highest SCC risk was associated with positivity for multiple HPV types and, among individuals seropositive for HPV beta, a tendency to sunburn; however, the associations had limited statistical precision.

CONCLUSIONS

Our findings support a role for HPV types from the genus beta in the pathogenesis of SCC.

Quality of life of long-term survivors of breast cancer and lymphoma treated with standard-dose chemotherapy or local therapy

PURPOSE

This study compared the quality of life (QOL) of long-term survivors of breast cancer and lymphoma who had been treated with standard-dose systemic chemotherapy or local therapy only.

PATIENTS AND METHODS

Long-term survivors (mean, 10.0 +/- 5.3 years after treatment) of breast cancer or lymphoma who had been treated with systemic chemotherapy (breast, n = 141, age = 57.0 +/- 10.1 years; lymphoma, n = 66, age = 55.8 +/- 13.5 years) or local therapy only (breast, n = 294, age = 65.8 +/- 9.1 years; lymphoma, n = 37, age = 50.4 +/- 12.8 years) were interviewed by phone using the Quality of Life-Cancer Survivors Tool.

RESULTS

Multivariate analysis of covariance, controlling for sex, age, education, stage of disease, and time since last treatment, revealed that survivors who had been treated with systemic chemotherapy scored significantly lower on overall QOL compared with survivors treated with local therapy only (P = .04). Analysis of covariance on the subscale scores revealed that, compared with survivors who received local therapy, survivors treated with chemotherapy scored significantly lower on the Social subscale (P < .0001), but no differences emerged on the Psychological or Spiritual subscales. There was a statistically significant interaction between treatment and diagnosis (P = .01), as measured by the Physical subscale, indicating that lymphoma survivors treated with chemotherapy scored worse than all other groups.

CONCLUSION

Important QOL differences emerged between the chemotherapy and local therapy groups, suggesting that long-term QOL may vary depending on the type of treatment and diagnosis.

Histamine receptor antagonists and incident colorectal adenomas

BACKGROUND

Prior studies suggest that histamines may modulate the development of colorectal neoplasia.

AIM

To assess whether histamine receptor antagonist use was associated with adenoma formation.

METHODS

Patients (n = 2366) were drawn from three adenoma chemoprevention trials. All underwent baseline colonoscopy with removal of adenoma(s) and were deemed free of remaining lesions; they were followed with surveillance colonoscopy. Medication use was assessed by questionnaire. Adjusted risk ratios for adenoma formation related to histamine receptor antagonist use (histamine H1 and H2 receptor, H1RA and H2RA) were determined using log linear models.

RESULTS

In pooled analyses, H1RA exposure was not associated with subsequent adenoma risk (RR = 1.10; 95% CI 0.97-1.25) or multiple adenoma formation (RR = 0.85; 95% CI 0.67-1.07). H2RA use also was not associated with adenoma (RR = 0.90; 95% CI 0.77-1.06), or multiple adenoma (RR = 0.77; 95% CI 0.57-1.04) in the pooled analyses, but H2RA users in the first trial had a decreased risk of adenoma (RR = 0.70; 95% CI 0.48-1.03) and multiple adenoma (RR = 0.31; 95% CI 0.12-0.79).

CONCLUSION

H2RA use was associated with reduced risk for adenoma in one trial, but not in the pooled analyses. Further study would be warranted before undertaking randomized trials of H2RAs for adenoma chemoprevention.

Reported Use of 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibitors Was Not Associated with Reduced Recurrence of Colorectal Adenomas

We did a secondary analysis of data from three large colorectal adenoma chemoprevention trials to assess the association between 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor use and reduced risk of recurrent colorectal adenomas. Reported use of HMG-CoA reductase inhibitors was not associated with a reduced recurrence of colorectal adenomas, multiple adenomas, or advanced adenomas. Lack of statistical power from limited exposure to HMG-CoA reductase inhibitors might be responsible for the lack of association.

Gender, smoking, glutathione--transferase variants and bladder cancer incidence: a population-based study

OBJECTIVE

Male gender, tobacco smoking and occupational exposure to arylamines and polycyclic aromatic hydrocarbons are the primary risk factors for bladder cancer. Emerging, and consistent data indicate that risk may be modified by polymorphisms in carcinogen metabolism genes, including those involving the glutathione-S-transferases. Recent work further suggests that susceptibility to the carcinogenic effects of tobacco on the bladder may differ among men and women.

METHOD

We investigated the gender specific risk of bladder cancer associated with glutathione-S-transferase M1 (GSTM1) and T1 (GSTT1) polymorphisms in a population-based case-control study of 354 bladder cancer cases and 542 controls.

RESULTS

We found an increased risk of bladder cancer associated with GSTM1 null genotype among women (OR 1.7; 95% CI 1.0-3.0), but not men (OR 0.9; 95% CI 0.7-1.3). Among women, the GSTM1 null genotype was associated with an elevated bladder cancer risk only among smokers (OR 2.3; 95% CI 1.1-4.5 in ever smokers versus OR 0.9; 95% CI 0.3-2.5 in never smokers). There was no apparent association between bladder cancer and the GSTT1 null polymorphism in either men or women, and we did not detect evidence of any GSTT1-smoking or GSTT1-GSTM1 gene-gene interaction.

CONCLUSION

Our data suggest that a subset of women may be particularly susceptible to tobacco-induced bladder cancer.

Occupation and bladder cancer risk in a population-based case-control study in New Hampshire

OBJECTIVE

To identify occupations with excess bladder cancer risk in New Hampshire, where bladder cancer mortality rates have been elevated for decades.

METHODS

Lifetime occupational histories were obtained from interviews with 424 cases and 645 controls in a population-based case-control study. Unconditional logistic regression models were used to estimate odds ratios (Ors) and 95% confidence intervals (CI) for each occupation, adjusted for age and smoking. Analyses by duration of employment were carried out and interactions with smoking were examined.

RESULTS

Male tractor-trailer truck drivers had an elevated risk for bladder cancer (OR = 2.4, CI = 1.4-4.1), with a significant positive trend in risk with increasing duration of employment (P (trend) = 0.0003). Male metal/plastic processing machine operators also had a significant excess (OR = 4.9, CI = 1.6-15.1), attributable mainly to molding/casting machine operators (OR = 16.6, CI = 2.1-131). Elevated risk was also observed for male fabricators, assemblers, and hand workers (OR = 1.8, CI = 1.0-3.4). Women in certain sales occupations (sales clerks, counter clerks, and cashiers) had a significant excess risk (OR = 2.2, CI = 1.3-3.9) and a significant trend with duration of employment (P (trend) = 0.016), as did female health service workers (OR = 4.1, CI = 1.6-10.7; P (trend) = 0.014). There was a positive interaction between smoking and employment as a health service worker (p = 0.036).

CONCLUSIONS

These findings are generally consistent with previous studies. Elevated risks for male molding/casting machine operators, female salesworkers, and female health service workers, especially those with a history of smoking, require further investigation.

Detection of Breast Cancer on Screening Mammography Allows Patients to Be Treated with Less-Toxic Therapy

OBJECTIVE

Therapy for breast cancer is accompanied by acute and chronic toxicity. Little research has been conducted to determine the impact of the mode of breast cancer detection on the likelihood of receiving different types of treatment. The objective of this study was to determine whether detection of breast cancer on screening mammography is associated with less-toxic therapy.

MATERIALS AND METHODS

The study group for this retrospective cohort study consisted of 992 women with invasive breast cancer detected on screening mammography (n = 460) or at physical examination (n = 532) at a single institution between 1990 and 2001. To address the generalizability of study findings, we compared the characteristics of study participants with those diagnosed with breast cancer in a population-based mammography registry.

RESULTS

The patients whose breast cancer was detected on screening mammography more frequently had lymph nodes free of metastases (84% vs 58%, p < 0.0001), had smaller tumors (1.5 vs 2.9 cm, p < 0.0001), were more likely to be treated with breast conservation (56% vs 32%, p < 0.0001), and were less likely to be treated with chemotherapy (28% vs 56%, p < 0.0001). In a multivariate analysis with adjustments for age and functional status, patients whose cancer was detected at physical examination were more than twice as likely to undergo mastectomy (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.9-3.3) and nearly three times as likely to be treated with chemotherapy (OR, 2.9; 95% CI, 2.1-3.9). For younger women (40-49 years old), the likelihood of receiving chemotherapy was more than doubled if the cancer was detected at physical examination rather than on screening mammograms (OR, 2.3; 95% CI, 1.3-4.0). For older women (>/= 70 years old), patients whose cancer was detected at physical examination were five times more likely to undergo mastectomy (OR, 5.8; 95% CI, 3.2-10.5) and four times more likely to receive chemotherapy (OR, 4.6; 95% CI, 1.6-13) than the group whose tumors were detected on screening mammography.

CONCLUSION

Breast cancers detected on screening mammography are smaller, are less likely to metastasize to lymph nodes, and are more likely to be treated with breast conservation and without chemotherapy. These findings provide an additional rationale for performing screening mammography, especially for women at age extremes for whom the survival benefit of screening mammography is debated.

Incidence of transitional cell carcinoma of the bladder and arsenic exposure in New Hampshire

OBJECTIVE

Arsenic is a known bladder carcinogen and populations exposed to high arsenic levels in their water supply have reported elevated bladder cancer mortality and incidence rates. To examine the effects of lower levels of arsenic exposure on bladder cancer incidence, we conducted a case-control study in New Hampshire, USA where levels above 10 micro/l are commonly found in private wells.

METHODS

We studied 383 cases of transitional cell carcinoma of the bladder cancer, newly diagnosed between July 1, 1994 and June 30, 1998 and 641 general population controls. Individual exposure to arsenic was determined in toenail clippings using instrumental neutron activation analysis.

RESULTS

Among smokers, an elevated odds ratio (OR) for bladder cancer was observed for the uppermost category of arsenic (OR: 2.17, 95% CI: 0.92-5.11 for greater than 0.330 mcg/g compared to less than 0.06 micro/g). Among never smokers, there was no association between arsenic and bladder cancer risk.

CONCLUSIONS

These, and other data, suggest that ingestion of low to moderate arsenic levels may affect bladder cancer incidence, and that cigarette smoking may act as a co-carcinogen.

The relationship of APOE genotype to neuropsychological performance in long-term cancer survivors treated with standard dose chemotherapy

PURPOSE

The primary purpose of this study was to compare the neuropsychological performance of long-term survivors of breast cancer and lymphoma treated with standard dose chemotherapy who carried the epsilon 4 allele of the Apolipoprotein E (APOE) gene to those who carry other APOE alleles.

PATIENTS AND METHODS

Long-term survivors (mean=8.8+/-4.3 years post-treatment) of breast cancer (N=51, age=55.9+/-8.8) or lymphoma (N=29, age=55.8+/-11.6) who had been treated with standard-dose chemotherapy completed a standardized battery of neuropsychological and psychological tests. Survivors were also classified into two groups based on the presence (N=17) or absence (N=63) of at least one epsilon 4 allele of APOE.

RESULTS

Analysis of covariance, controlling for age, gender, education, diagnosis, and WRAT-3 reading subtest (a proxy measure of baseline IQ), indicated that survivors with at least one epsilon 4 allele scored significantly lower in the visual memory (p<0.03) and the spatial ability (p<0.05) domains and tended to score lower in the psychomotor functioning (p<0.08) domain as compared to survivors who did not carry an epsilon 4 allele. No group differences were found on depression, anxiety, or fatigue.

CONCLUSIONS

The results of this study provide preliminary support for the hypothesis that the epsilon 4 allele of APOE may be a potential genetic marker for increased vulnerability to chemotherapy-induced cognitive decline.

A randomized trial of aspirin to prevent colorectal adenomas

BACKGROUND

Laboratory and epidemiologic data suggest that aspirin has an antineoplastic effect in the large bowel.

METHODS

We performed a randomized, double-blind trial of aspirin as a chemopreventive agent against colorectal adenomas. We randomly assigned 1121 patients with a recent history of histologically documented adenomas to receive placebo (372 patients), 81 mg of aspirin (377 patients), or 325 mg of aspirin (372 patients) daily. According to the protocol, follow-up colonoscopy was to be performed approximately three years after the qualifying endoscopy. We compared the groups with respect to the risk of one or more neoplasms (adenomas or colorectal cancer) at least one year after randomization using generalized linear models to compute risk ratios and 95 percent confidence intervals.

RESULTS

Reported adherence to study medications and avoidance of nonsteroidal antiinflammatory drugs were excellent. Follow-up colonoscopy was performed at least one year after randomization in 1084 patients (97 percent). The incidence of one or more adenomas was 47 percent in the placebo group, 38 percent in the group given 81 mg of aspirin per day, and 45 percent in the group given 325 mg of aspirin per day (global P=0.04). Unadjusted relative risks of any adenoma (as compared with the placebo group) were 0.81 in the 81-mg group (95 percent confidence interval, 0.69 to 0.96) and 0.96 in the 325-mg group (95 percent confidence interval, 0.81 to 1.13). For advanced neoplasms (adenomas measuring at least 1 cm in diameter or with tubulovillous or villous features, severe dysplasia, or invasive cancer), the respective relative risks were 0.59 (95 percent confidence interval, 0.38 to 0.92) and 0.83 (95 percent confidence interval, 0.55 to 1.23).

CONCLUSIONS

Low-dose aspirin has a moderate chemopreventive effect on adenomas in the large bowel.

Viewing tobacco use in movies: does it shape attitudes that mediate adolescent smoking?

BACKGROUND

Social cognitive theory posits that children develop intentions and positive expectations (utilities) about smoking prior to initiation. These attitudes and values result, in part, from observing others modeling the behavior. This study examines, for the first time, the association between viewing tobacco use in movies and attitudes toward smoking among children who have never smoked a cigarette.

DESIGN/SETTING

Cross-sectional school-based survey was used among randomly selected Vermont and New Hampshire middle schools. The sample consisted of 3766 middle school students (grades 5-8). The sample was primarily white and equally distributed by gender. The primary exposure was number of movie tobacco-use occurrences viewed. We first counted occurrences of tobacco use in each of 601 recent popular motion pictures. Each student was asked to select movies they had seen from a random subset of 50 movies. Based on movies the adolescent had seen, movie tobacco-use occurrences were summed to determine exposure . The outcome was susceptibility to smoking, positive expectations, and perceptions of smoking as normative behavior for adolescents or adults.

RESULTS

The movies in this sample contained a median of five occurrences of tobacco use (interquartile range=1, 12). The typical adolescent never-smoker had viewed 15 of the 50 movies on his/her list. From movies adolescents reported seeing, exposure to movie tobacco-use occurrences varied widely: median=80, and interquartile range 44 to 136. The prevalence of susceptibility to smoking increased with higher categories of exposure: 16% among students who viewed 0 to 50 movie tobacco occurrences; 21% (51 to 100); 28% (101 to 150); and 36% (>150). The association remained statistically significant after controlling for gender, grade in school, school performance, school, friend, sibling and parent smoking, sensation-seeking, rebelliousness, and self-esteem. Compared with adolescents exposed to < or =50 occurrences of tobacco use, the adjusted odds ratio of susceptibility to smoking for each higher category was 1.2 (95% confidence interval 0.9, 1.5), 1.4 (1.1, 1.9), and 1.6 (1.3, 2.1), respectively. Similarly, higher exposure to tobacco use in movies significantly increased the number of positive expectations endorsed by the adolescent and the perception that most adults smoke, but not the perception that most peers smoke.

CONCLUSIONS

This study provides empirical evidence that viewing movie depictions of tobacco use is associated with higher receptivity to smoking prior to trying the behavior.

A pediatric, practice-based, randomized trial of drinking and smoking prevention and bicycle helmet, gun, and seatbelt safety promotion

OBJECTIVE

To prevent early adolescent health risk behaviors and to maintain or improve safety behaviors, we compared the effects of 2 interventions, delivered through pediatric primary care practices. The interventions, based on an office systems' approach, sought to prevent early drinking and smoking or to influence bicycle helmet use, gun storage, and seatbelt safety for children who were followed from fifth/sixth grades through eighth/ninth grades.

DESIGN

Settings and Participants. Twelve pediatric practices in New England were paired according to practice size and assigned randomly within pairs to deliver the multicomponent interventions, which built on pediatric primary care clinicians performing as counselors and role models during health supervision visits and other office encounters.

INTERVENTION

One intervention arm focused on alcohol and tobacco use. The other intervention arm focused on gun safety, bicycle helmet, and seatbelt use. Office systems provided infrastructure that supported the clinician's role. Clinician messages encouraged family communication and rule setting about the issues of the middle school years. The intervention was initiated during a health supervision visit and continued for 36 months. Both child and parent received quarterly newsletters to reinforce the clinician messages.

OUTCOME MEASURES

The primary outcomes were ever drinking alcohol, ever smoking, ever using smokeless tobacco, using a bicycle helmet in the previous year, using a seatbelt in the previous 30 days, and guns in the child's home in locked storage.

RESULTS

The pediatric practices recruited 85% (N = 3525) of the practices' fifth/sixth grade children and their responding parents. We obtained 36 months' follow-up data on 2183 child-parent pairs. Chart audit verified that the intervention was implemented. Additional data from interviews and surveys showed that parents, children, and pediatric clinicians found the intervention useful. Despite this, comparisons between the 2 study arms show no significant intervention effects in the prevention of alcohol and tobacco use or gun storage or seatbelt safety. There was a negative effect in the alcohol arm. Only bicycle helmet use showed a positive outcome.

CONCLUSION

With rigorous evaluation, 2 office interventions failed to produce desired outcomes. Coordinated multiple settings for prevention interventions are probably necessary.

Use of tanning devices and risk of basal cell and squamous cell skin cancers

Use of artificial tanning devices that emit UV radiation, such as tanning lamps and tanning beds, has become increasingly popular in the United States. Although an excess risk of nonmelanoma skin cancers might be predicted from this exposure, little epidemiologic data exist. We conducted a population-based, case-control study that included 603 basal cell carcinoma (BCC) case patients, 293 squamous cell carcinoma (SCC) case patients, and 540 control subjects. Study participants were interviewed in person to obtain information on tanning device use, sun exposure history, sun sensitivity, and other risk factors for skin cancer. Overall, any use of tanning devices was associated with odds ratios of 2.5 (95% confidence interval [CI] = 1.7 to 3.8) for SCC and 1.5 (95% CI = 1.1 to 2.1) for BCC. Adjustment for history of sunburns, sunbathing, and sun exposure did not affect our results. Our findings suggest that the use of tanning devices may contribute to the incidence of nonmelanoma skin cancers. They highlight the need to further evaluate the potential risks of BCC and SCC that are associated with tanning lamp exposure and the appropriate public health response.

Neuropsychologic impact of standard-dose systemic chemotherapy in long-term survivors of breast cancer and lymphoma

PURPOSE

The primary purpose of this study was to compare the neuropsychologic functioning of long-term survivors of breast cancer and lymphoma who had been treated with standard-dose systemic chemotherapy or local therapy only.

PATIENTS AND METHODS

Long-term survivors (5 years postdiagnosis, not presently receiving cancer treatment, and disease-free) of breast cancer or lymphoma who had been treated with systemic chemotherapy (breast cancer: n = 35, age, 59.1 +/- 10.7 years; lymphoma: n = 36, age, 55.9 +/- 12.1 years) or local therapy only (breast cancer: n = 35, age, 60.6 +/- 10.5 years; lymphoma: n = 22, age, 48.7 +/- 11.7 years) completed a battery of neuropsychologic and psychologic tests (Center for Epidemiological Study-Depression, Spielberger State-Trait Anxiety Inventory, and Fatigue Symptom Inventory).

RESULTS

Multivariate analysis of variance, controlling for age and education, revealed that survivors who had been treated with systemic chemotherapy scored significantly lower on the battery of neuropsychologic tests compared with those treated with local therapy only (P <.04), particularly in the domains of verbal memory (P <.01) and psychomotor functioning (P <.03). Survivors treated with systemic chemotherapy were also more likely to score in the lower quartile on the Neuropsychological Performance Index (39% v 14%, P <.01) and to self-report greater problems with working memory on the Squire Memory Self-Rating Questionnaire (P <.02).

CONCLUSION

Data from this study support the hypothesis that systemic chemotherapy can have a negative impact on cognitive functioning as measured by standardized neuropsychologic tests and self-report of memory changes. However, analysis of the Neuropsychological Performance Index suggests that only a subgroup of survivors may experience long-term cognitive deficits associated with systemic chemotherapy.

The XRCC1 Arg399Gln polymorphism, sunburn, and non-melanoma skin cancer: evidence of gene-environment interaction

XRCC1, a protein directly involved in the repair of DNA base damage, contains at least three common polymorphisms. One of these, the codon 399 arg-->gln variant, has been associated with several cancer-related biomarkers, suggesting it may have functional significance in exposure-induced cancers. However, results from case-control studies have yielded conflicting results. We investigated the XRCC1 arg399gln polymorphism and its interaction with carcinogen exposure in a large, population-based case-control study of non-melanoma skin cancer. Cases were derived from an incident survey of all newly diagnosed non-melanoma skin cancer in New Hampshire, and controls were population based and frequency matched to cases on age and sex (n = 1176). Exposure information was derived from a detailed interviewer-administered questionnaire, and XRCC1 genotype was determined from blood-derived DNA using a PCR-RFLP method. Overall, the XRCC1 homozygous variant gln399gln genotype was related to a significantly reduced risk of both basal cell [BCC; odds ratio (OR) 0.7, 95% confidence interval 0.4-1.0] and squamous cell carcinoma (SCC; OR 0.6, 95% confidence interval 0.3-0.9). There was no significant gene-environment interaction of the variant XRCC1 genotype and a history of therapeutic X-ray exposure. However, there was a statistically significant multiplicative interaction of XRCC1 genotype and lifetime number of sunburns in SCC [likelihood ratio test (2 d.f.), P < 0.02]. Although the absolute risk of SCC associated with sunburns was similar across genotypes, the relative risk of SCC associated with painful sunburn history was significantly higher for homozygous variants than wild types (OR 6.8 for gln399gln and 1.5 for arg399arg). In summary, our data show that the homozygous XRCC1 variant (gln399gln) is associated with a lower risk of non-melanoma skin cancer and suggest that the etiology of sunburn-related SCC may be significantly different by XRCC1 genotype. These data, using the classic skin carcinogenesis model, provide new insight on the role of the XRCC1 399 polymorphism in neoplasia and may help explain the conflicting results relating this polymorphism to cancer risk at various sites.