Dietary factors and truncating APC mutations in sporadic colorectal adenomas

Inactivating mutations in APC are thought to be early, initiating events in colorectal carcinogenesis. To gain insight into the relationship between diet and inactivating APC mutations, we evaluated associations between dietary factors and the occurrence of these mutations in a Dutch case-control study of sporadic colorectal adenomas (278 cases; 414 polyp-free controls). Direct-sequencing was used to screen adenomas for mutations in the mutation cluster region of APC; truncating mutations were detected in 161 (58%) of the adenomas. Red meat consumption was significantly differently related to polyps with truncating APC mutation (APC(+) polyps) compared to polyps without truncating APC mutation (APC(-) polyps) (highest vs. lowest tertile, odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.3-1.0). High intake of red meat and fat seemed to increase the risk of APC(-) polyps only (APC(+) vs. controls: red meat, OR = 1.0, 95% CI = 0.6-1.6; fat, OR = 1.1, 95% CI = 0.6-1.9; APC(-) vs. controls: red meat, OR = 1.8, 95% CI = 1.0-3.1; fat, OR = 1.9, 95% CI = 1.0-3.7). Intake of carbohydrates was inversely associated with both polyp groups, most noticeably with APC(-) polyps. Most other evaluated dietary factors were not distinctively associated with a specific APC status. None of the dietary factors was specifically associated with a particular type of truncating APC mutation. Our data suggest that red meat and fat may increase the risk of APC(-) polyps in particular, whereas carbohydrates may especially decrease the risk of APC(-) polyps. However, most examined dietary factors do not appear to be specifically associated with the occurrence of truncating APC mutations in colorectal adenomas but seem to affect both pathways equally.     

Concomitant DFMO and sulindac chemoprevention of colorectal adenomas: a major clinical advance

In a randomized, placebo-controlled, double-blind clinical trial by Meyskens et al. the combination of difluoromethylornithine and sulindac has been shown to be strikingly effective for prevention of sporadic colorectal adenomas. This concomitant use of two drugs to suppress the progression of preneoplastic lesions represents the first major clinical success of the application of the principle of 'combination chemoprevention'. Neither drug alone has previously had clinical utility at the low doses used in this trial. The combination of the two agents has provided synergistic efficacy in suppression of carcinogenesis, while minimizing any undesirable adverse effects. This study should be the impetus for further clinical investigation of the use of multiple drugs for chemoprevention of cancer.     

Difluoromethylornithine plus sulindac for the prevention of sporadic colorectal adenomas: a randomized placebo-controlled, double-blind trial

Preclinical studies of chemoprevention drugs given in combination at low doses show remarkable efficacy in preventing adenomas with little additional toxicities, suggesting a strategy to improve risk to benefit ratios for preventing recurrent adenomas. Three hundred seventy-five patients with history of resected (> or =3 mm) adenomas were randomly assigned to receive oral difluoromethylornithine (DFMO) 500 mg and sulindac 150 mg once daily or matched placebos for 36 months, stratified by use of low-dose aspirin (81 mg) at baseline and clinical site. Follow-up colonoscopy was done 3 years after randomization or off-study. Colorectal adenoma recurrence was compared among the groups with log-binomial regression. Comparing the outcome in patients receiving placebos to those receiving active intervention, (a) the recurrence of one or more adenomas was 41.1% and 12.3% (risk ratio, 0.30; 95% confidence interval, 0.18-0.49; P < 0.001); (b) 8.5% had one or more advanced adenomas, compared with 0.7% of patients (risk ratio, 0.085; 95% confidence interval, 0.011-0.65; P < 0.001); and (c) 17 (13.2%) patients had multiple adenomas (>1) at the final colonoscopy, compared with 1 (0.7%; risk ratio, 0.055; 0.0074-0.41; P < 0.001). Serious adverse events (grade > or =3) occurred in 8.2% of patients in the placebo group, compared with 11% in the active intervention group (P = 0.35). There was no significant difference in the proportion of patients reporting hearing changes from baseline. Recurrent adenomatous polyps can be markedly reduced by a combination of low oral doses of DFMO and sulindac and with few side effects.     

A subset analysis of a phase II trial evaluating the use of DFMO as maintenance therapy for high-risk neuroblastoma

Neuroblastoma is a sympathetic nervous system tumor, primarily presenting in children under 6 years of age. The long-term prognosis for patients with high-risk neuroblastoma (HRNB) remains poor despite aggressive multimodal therapy. This report provides an update to a phase II trial evaluating DFMO as maintenance therapy in HRNB. Event-free survival (EFS) and overall survival (OS) of 81 subjects with HRNB treated with standard COG induction, consolidation and immunotherapy followed by 2 years of DFMO on the NMTRC003/003b Phase II trial were compared to a historical cohort of 76 HRNB patients treated at Beat Childhood Cancer Research Consortium (BCC) hospitals who were disease-free after completion of standard upfront therapy and did not receive DFMO. The 2- and 5-year EFS were 86.4% [95% confidence interval (CI) 79.3%-94.2%] and 85.2% [77.8%-93.3%] for the NMTRC003/003b subset vs 78.3% [69.5%-88.3%] and 65.6% [55.5%-77.5%] for the historical control group. The 2- and 5-year OS were 98.8% [96.4-100%] and 95.1% [90.5%-99.9%] vs 94.4% [89.3%-99.9%] and 81.6% [73.0%-91.2%], respectively. DFMO maintenance for HRNB after completion of standard of care therapy was associated with improved EFS and OS relative to historical controls treated at the same institutions. These results support additional investigations into the potential role of DFMO in preventing relapse in HRNB.     

Selenium supplementation and colorectal adenomas: an analysis of the nutritional prevention of cancer trial

Selenium status has been inversely associated with colorectal cancers (CRC) and adenomas. This investigation evaluates the association between selenium supplementation and prevalent and incident colorectal adenomas and CRC detected during the Nutritional Prevention of Cancer trial follow-up. Of the 1,312 randomized to 200 mcg of selenized yeast of matching placebo, 598 participants underwent endoscopic screening (flexible sigmoidoscopy or colonoscopy) for CRC sometime during the follow-up period, which ended in February 1, 1996. There was no colorectal screening performed at baseline. Of those screened, 77% were male (with a mean age of 62.8 years), 42% were former and 25% were current smokers. Adenomas were classified as prevalent (identified at the first endoscopic examination post-randomization during the follow-up period) or incident (identified at the second or subsequent examination). Ninety-nine prevalent and 61 incident adenomas were ascertained. Logistic regression odds ratios (OR) and 95% confidence intervals (CI) were calculated, adjusting for age, gender and smoking status. For prevalent adenomas, there was a suggestive but nonsignificant decrease in risk associated with selenium treatment (OR = 0.67, 95% CI = 0.43-1.05). Subjects in the lowest tertile of baseline selenium (OR = 0.27, 95% CI = 0.09-0.77) and current smokers (OR = 0.27, 95% CI = 0.11-0.66) had significant reductions in risk. The OR for incident adenomas was 0.98 (95% CI = 0.57-1.68). In addition to being associated with a reduced risk of incident CRC, selenium supplementation was associated with a significantly reduced risk of prevalent adenomas, but only among subjects with either a low baseline selenium level or among current smokers.     

构建血清蛋白质质谱模型判别家族性腺瘤性息肉病与散发性肠腺瘤

目的 筛选家族性腺瘤性息肉病(FAP)的特异表达蛋白,构建判别FAP与散发性肠腺瘤的血清蛋白指纹图谱诊断模型.方法 采集19例FAP和16例散发性肠腺瘤患者的血清,以表面增强激光解吸电离飞行时间质谱仪(SELDI-MS-TOF)和阴离子CM01蛋白质芯片检测并筛选两组对象间的血清差异表达蛋白质峰,以支持向量机方法构建判别模型.结果 FAP与散发性肠腺瘤相比,P<0.01的蛋白质峰有6个,其中质荷比为5640、3160、4180和4290的蛋白质峰在FAP中高表达,质荷比为3940和3400的蛋白质峰在散发性肠腺瘤患者中高表达.以质倚比分别为5640、3160和4290的蛋白质峰为基础,联合质荷比为3940、13 750和4300的蛋白质峰所建立的模型判别效果最佳,对FAP与散发性肠腺瘤的判别准确率分别为94.7%和93.7%.结论 SELDI-TOF-MS能有效筛选FAP与散发性肠腺瘤的差异表达蛋白,支持向量机方法所建立的质谱模型判别效果较好,为进一步研究FAP的分子发病机制提供了切入点.     

Role of polyamines in arginine-dependent colon carcinogenesis in Apc(Min) (/+) mice

We evaluated the role of polyamines in arginine-dependent intestinal tumorigenesis in Apc(Min) (/+) mice. Arginine is a substrate for ornithine synthesis and thus can influence polyamine production. Supplementing the diet with arginine increased intestinal and colonic polyamine levels and colonic carcinogenesis. Inhibiting polyamine synthesis with D,L-alpha-diflouromethylornithine (DFMO) decreased small intestinal and colonic polyamine pools. In mice provided basal diet, but not when supplemented with arginine, DFMO decreased small intestinal tumor number and burden, and increased intestinal apoptosis. In mice provided supplemental arginine in the diet, DFMO induced late apoptosis and decreased tumorigenesis in the colon. DFMO slightly reduced tumor incidence, number, and size while significantly decreasing tumor burden and grade. These changes in colon tumorigenesis did not occur in mice not provided supplemental arginine. Our study indicates that polyamines play unique roles in intestinal and colonic carcinogenesis in Apc(Min) (/+) mice. Inhibition of polyamine synthesis suppresses the arginine-dependent risk of colon tumorigenesis, resulting in apoptosis induction and decreased tumorigenesis, in this murine model.     

Randomized phase II trial of sulindac, atorvastatin, and prebiotic dietary fiber for colorectal cancer chemoprevention

Sulindac, atorvastatin, or prebiotic dietary fiber may reduce colorectal cancer (CRC) risk. However, clinical trial data are currently limited. We conducted a randomized, phase II chemoprevention trial involving subjects 40 years or older, with previously resected colon cancer or multiple/advanced colorectal adenomas. Magnification chromoendoscopy (MCE) was performed to identify and characterize rectal aberrant crypt foci (ACF); eligibility criteria required five or more rectal ACFs at baseline. Intervention assignments were as follows: (a) atorvastatin 20 mg qd; (b) sulindac 150 mg bid; (c) oligofructose-enriched inulin (as ORAFTI?Synergy1) 6 gm bid; or (d) control (maltodextrin) 6 gm bid, for 6 months. Percent change in rectal ACF number (%ΔACF) within arm was the primary endpoint. Secondary endpoints included changes in proliferation (Ki67) and apoptosis (caspase-3), as measured from normal mucosa biopsy samples. Among 85 eligible randomized subjects, 76 (86%) completed the trial per protocol. The median (range) of rectal ACF was 9 (5-34) and 8 (0-37) at baseline and postintervention, respectively. The median (SD) for %ΔACF was 5.6 (-69% to 143%), -18.6 (-83% to 160%), -3.6 (-88% to 83%), and -10.0 (-100% to 117%) in the atorvastatin, sulindac, ORAFTI?Synergy1 and control arms, respectively. Neither within-arm (P = 0.12-0.59) nor between-arm (P = 0.30-0.92) comparisons of %ΔACF were statistically significant. The active and control interventions also seemed to have similar effects on mucosal proliferation and apoptosis (P > 0.05 for each comparison). Data from this multicenter, phase II trial do not provide convincing evidence of CRC risk reduction from 6-month interventions with atorvastatin, sulindac, or ORAFTI?Synergy1, although statistical power was limited by the relatively small sample size.     

Non-steroidal anti-inflammatory drug use is associated with reduction in recurrence of advanced and non-advanced colorectal adenomas (United States)

Objective: To prospectively examine the association between non-steroidal anti-inflammatory drugs (NSAIDs) use (including dose and dosage schedule) and the recurrence of colorectal adenomas among individuals who were diagnosed with an adenoma at entry into a clinical trial. Methods: For this analysis, participants who completed the full follow-up (n = 1905) for the Polyp Prevention Trial (PPT) were evaluated. Information on current use and dose of NSAIDs and other drugs was obtained at baseline and at each subsequent study visit over the duration of the trial. The study endpoint was the recurrence of colorectal adenomas in the 3 years between the 1-year trial colonoscopy (T1) and the end of the trial colonoscopy (T4). Results: There was a significant reduction in overall adenoma recurrence among NSAIDs users (odds ratio [OR] = 0.77; 95% confidence interval [CI]: 0.63–0.95), with the greatest effect seen in advanced polyps (OR = 0.51; CI: 0.33–0.79). Among aspirin users, we observed a significant dose response for overall adenoma recurrence, with a 40% reduction in the OR association (OR = 0.56; 95% CI: 0.31–0.99) among those taking more than 325 mg per day. Conclusion: This prospective study provides further evidence that NSAIDs may play an important role in the chemoprevention of recurrent colorectal adenomas, even those with advanced features.     

Calcium, dietary, and lifestyle factors in the prevention of colorectal adenomas

BACKGROUND: Many studies have suggested a role for calcium in reducing the risk of colorectal adenomas and cancer but its effectiveness may be dependent on interactions with other dietary and/or lifestyle factors. We examined the association between calcium and prevalence of adenomas and assessed whether the association was stronger in biologically plausible subgroups. METHODS: Cross-sectional data from 222 cases and 479 adenoma-free controls who underwent colonoscopies and completed food frequency and lifestyle questionnaires were used in the analyses. Multivariable logistic regression was used to estimate the association between calcium and prevalence of adenomas. Stratified analyses and the likelihood ratio test were used to examine effect modification by various demographic, lifestyle, and behavioral factors. RESULTS: Overall, little association was observed comparing total calcium intake of > or = 900 mg/day to < 500 mg/day (adjusted odds ratio [OR] = 0.85, 95% confidence interval [CI]: 0.53-1.37). However, stronger associations were observed in patients with lower fat intake and in those who regularly (> or = 15 times/month) took nonsteroidal antiinflammatory drugs (NSAIDs). Specifically, total calcium intake of > or = 900 mg/day was associated with a lower prevalence of adenomas among patients with lower fat intake (OR = 0.47, 95% CI: 0.25-0.91) but not among those with higher fat intake (OR = 1.20, 95% CI: 0.61-2.35; P-value for interaction = .01). For NSAIDs, the associations were OR = 0.37 (95% CI: 0.16-0.86) for regular NSAID users and OR = 1.27 (95% CI: 0.73-2.22) with infrequent or nonuse of NSAIDs, respectively (P = .06). CONCLUSIONS: The data suggest that a lower-fat diet and regular NSAID use may enhance calcium's effectiveness as a colorectal cancer preventive agent.     

Tissue levels of fish fatty acids and risk of colorectal adenomas: a case-control study (Netherlands)

Epidemiological and animal studies have suggested that a high ratio of n–3 fish fatty acids to arachidonic acid (AA), might protect against colorectal carcinogenesis. Competition of n–3 and n–6 fatty acids, especially AA, for the enzyme cyclooxygenase-2 may be responsible for this effect. To examine the relation between fish intake and colorectal adenomas, data from a Dutch case–control study were analysed. All 52 cases and 57 controls filled out a food questionnaire, underwent a full colonic examination and have had a fat biopsy from the buttock. Intake of fish and fish fatty acids was inversely associated with colorectal adenomas although not statistically significant. For the ratio of fish fatty acids to AA, the ORs in the second and third tertile were 1.2 and 0.8 (p-trend = 0.78). Tissue levels of fish fatty acids were inversely associated and tissue levels of AA were positively associated with adenomas, although not statistically significant. However, the OR for the ratio of fish fatty acids to AA was 0.2 in the second and third tertile (p-trend = 0.002). In line with the hypothesis, a high ratio of fish fatty acids to AA in adipose tissue was associated with a lower risk of colorectal adenomas.     

钙镁输液预防奥沙利铂神经毒性的作用:一个Ⅲ期试验(英文)

Objective:This study is a prospective randomized, double-blind, placebo-controlled study to evaluate the effect of calcium and magnesium (Ca/Mg) infusion on amelioration of oxaliplatin neuropathy, the dose-limiting toxicity. Methods:Sixty patients with resected colorectal carcinoma (CRC) planned to receive adjuvant oxaliplatin-containing regimen were randomly assigned to two arms; Arm A:patients received Ca/Mg were given as 1 gm Ca gluconate and 1 gm MgSO 4 in 250 mL of intravenous (IV) solution over 30 min pre and post oxaliplatin infusion, and Arm B:patients received 250 mL of IV solution without Ca/Mg over 30 min pre and post oxaliplatin infusion. Primary outcome was to assess percentage of patients with oxaliplatin-induced neurotoxicity. Neurotoxicity was assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 3.0. Results:Sixty patients in both arms were assessed, 30 with Ca/Mg infusion and 30 without. Patients developed neurotoxicity in arm A were significantly lower than that in arm B after the end of treatment; 7 (23.3%) and 14 (46.6%) respectively (P < 0.05), and significantly lower duration of neuropathy in months (8 ± 2.5 vs 18 ± 3) respectively (P < 0.001). Conclusion:Use of IV Ca/Mg showed a statistically significant reduction of peripheral neuropathy (PN) in patients with CRC receiving oxaliplatin in the adjuvant settings.     

The effect of difluoromethylornithine on decreasing prostate size and polyamines in men: results of a year-long phase IIb randomized placebo-controlled chemoprevention trial.

BACKGROUND: Prostate cancer is a major health issue, and prevention of prostate cancer and/or its progression will yield benefits for men. Difluoromethylornithine (DFMO) is an antiproliferative agent, inhibiting ornithine decarboxylase, the first enzyme in the polyamine pathway, and has been studied as a therapeutic and chemopreventive agent. The prostate has high levels of tissue polyamines and has shown sensitivity to DFMO both in vitro and in vivo. METHODS: Eighty-one men participated in a 1-year randomized trial of placebo or DFMO. Prostate volume determination and biopsy of the prostate for histology and polyamine content were done at baseline and after 12 months. Other biomarker variables were assessed, including total and free prostate-specific antigen and prostate-specific antigen doubling time. RESULTS: Compared with baseline, men receiving DFMO had a smaller increase in prostate volume (0.14 cm(3)) than those on placebo (2.95 cm(3); P = 0.0301) at 1 year. In addition, DFMO caused a 60.8% reduction of prostate putrescine levels compared with a 139.5% increase in the placebo arm (P = 0.0014). Stratification by ornithine decarboxylase genotype showed that DFMO reduced prostate volume (P = 0.029) and putrescine levels (P = 0.0053) in the AA + GA group but not in the GG group. There were no grade 3 or 4 toxicities. There was no clinical ototoxicity, with one subclinical grade 2 hearing decline on audiogram. CONCLUSION: In this randomized placebo-controlled trial, DFMO induced a decrease of prostate putrescine levels and rate of prostate growth. The potential of this compound for prostate cancer or hyperplasia should be further studied.     

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.     

Randomized trial of dietary fiber and Lactobacillus casei administration for prevention of colorectal tumors

The epidemiologic evidence that dietary fiber protects against colorectal cancer is equivocal. No large-scale clinical study of the administration of Lactobacillus casei has been reported. We examined whether dietary fiber and L. casei prevented the occurrence of colorectal tumors. Subjects were 398 men and women presently free from tumor who had had at least 2 colorectal tumors removed. Subjects were randomly assigned to 4 groups administered wheat bran, L. casei, both or neither. The primary end point was the presence or absence of new colorectal tumor(s) diagnosed by colonoscopy after 2 and 4 years. Among 380 subjects who completed the study, 95, 96, 96 and 93 were assigned to the wheat bran, L. casei, both and no treatment groups, respectively. Multivariate adjusted ORs for occurrence of tumors were 1.31 (95% CI 0.87-1.98) in the wheat bran group and 0.76 (0.50-1.15) in the L. casei group compared to the control group. There was a significantly higher number of large tumors after 4 years in the wheat bran group. The occurrence rate of tumors with a grade of moderate atypia or higher was significantly lower in the group administered L. casei. No significant difference in the development of new colorectal tumors was observed with administration of either wheat bran or L. casei. However, our results suggest that L. casei prevented atypia of colorectal tumors.     

Ethnic disparities in the risk of colorectal adenomas associated with aspirin and statin use: a retrospective multiethnic study

Background

Although data on the inverse association between colorectal adenomas (CRA) and daily aspirin or statin therapy exists in white and black patients, scarce data exists on these associations in the Hispanic population. With a rapidly increasing Hispanic population in the United States, defining the association in Hispanics is crucial.

Methods

The study sample included 1,843 consecutive patients who underwent a colonoscopy (screening or diagnostic) from 2009 to 2011 at a community hospital in East Meadow, New York. Data was then extracted from patient charts regarding aspirin and/or statin use. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) were calculated to assess the association between colonoscopy findings and aspirin, statin, or aspirin/statin use.

Results

In our total population including all races, aspirin user had an increased risk for having two or more adenomas (OR =1.73, 95% CI: 1.00, 2.99, P=0.05) and presence of an adenoma in the proximal colon (OR =1.66, 95% CI: 1.07, 2.58, P=0.02). In the total study population, those who used both statin and aspirin had an increased risk for having two or more adenomas (OR =2.56, 95% CI: 1.21, 5.39, P=0.01). In the Hispanic population, users of both medications had an increased risk for having two or more adenomas (OR =19.04, 95% CI: 1.30, 280.09, P=0.03), adenoma present in the distal colon (OR =5.75, 95% CI: 1.64, 20.21, P=0.01) and largest adenoma in distal colon (OR =5.75, 95% CI: 1.64, 20.21, P=0.01).

Conclusions

Aspirin use and aspirin/statin use was associated with abnormal colonoscopy findings, particularly in the Hispanic population. These findings may be due to environmental factors such as dietary, colonic flora, or genetic susceptibility. The findings warrant further investigational research, particularly in Hispanics.     

Fruit and vegetable intakes and risk of colorectal cancer and incident and recurrent adenomas in the PLCO cancer screening trial

The roles of fruits and vegetables in colorectal cancer development are unclear. Few prospective studies have assessed the association with adenoma, a known precursor to colorectal cancer. Our aim was to evaluate the association between fruit and vegetable intake and colorectal cancer development by evaluating the risk of incident and recurrent colorectal adenoma and colorectal cancer. Study participants were identified from the intervention arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Fruit and vegetable intake was measured using a self‐reported dietary questionnaire. Total fruit and vegetable intake was not associated with reduced incident or recurrent adenoma risk overall, but a protective association was observed for multiple adenomas (Odds ratio _{3rd tertile vs. 1st tertile} = 0.61, 95% confidence interval (CI): 0.38, 1.00). Higher fruit and vegetable intakes were associated with a borderline reduced risk of colorectal cancer (Hazard ratio (HR) _{3rd tertile vs. 1st tertile} = 0.82, 95% CI: 0.67, 1.01), which reached significance amongst individuals with high processed meat intakes (HR = 0.74, 95% CI: 0.55, 0.99). Our results suggest that increased fruit and vegetable intake may protect against multiple adenoma development and may reduce the detrimental effects of high processed meat intakes on colorectal cancer risk.     

Glucose intolerance and adenomas of the sigmoid colon in Japanese men (Japan)

Objectives: The purpose was to investigate the relation between glucose tolerance and risk of sigmoid colon adenomas, a well-established precancerous lesion, in Japanese men.Methods: In the consecutive series of 7,637 men aged 48 to 59 years who received a preretirement health examination at four hospitals of the Self Defense Forces (SDF) in Japan from 1986 to 1994, we identified 821 cases of sigmoid colon adenomas and 4,372 controls with normal sigmoidoscopy or colonoscopy at 60 cm or more from the anus. Glucose tolerance status was classified as normal, impaired glucose tolerance (IGT), newly diagnosed non-insulin dependent diabetes mellitus (NIDDM), or diabetes mellitus under treatment, based ona75g oral glucose tolerance test and medical history. Statistical adjustment was made for body mass index (wt/ht2), cigarette smoking, alcohol use, rank of the SDF, and hospital.Results: Modest increases in adenoma risk were observed for newly diagnosed NIDDM and diabetes mellitus under treatment while there was no association between IGT and adenoma risk. When small (< 5 mm in diameter) and large (5+ mm) adenomas were analyzed separately, increased risk associated with newly diagnosed NIDDM was more pronounced for small adenomas, and diabetes mellitus under treatment showed a slightly stronger association with large adenomas.Conclusions: The findings suggest that NIDDM is associated with modestly increased risk of sigmoid colon adenomas, and add to evidence that hyperinsulinemia increases colon cancer risk.