The relations of alcoholic beverage use to colon and rectal cancer

The authors prospectively studied the incidence of cancers of the colon and rectum in 106,203 men and women, both white and black, who supplied data at northern California Kaiser Permanente facilities about use of alcoholic beverages in 1978-1984. Analysis controlling for age, sex, race, body mass index, coffee use, total serum cholesterol, and education showed a positive association of alcohol use to both types of cancer, which was stronger for rectal cancer (trend test, p = 0.03) than for colon cancer (trend test, p = 0.11). When persons with a daily intake of three or more drinks were compared with abstainers, relative risk for rectal cancer was 3.17 (95% confidence interval (CI): 1.05-9.57) and relative risk for colon cancer was 1.71 (95% CI: 0.92-3.19). Women with a daily intake of three or more drinks had a relative risk for colon cancer of 2.56 (95% CI: 1.03-6.40) compared with 1.16 (95% CI: 0.46-2.90) for men. Among drinkers, preference for wine, beer, or hard liquor had no significant independent relation to either type of cancer; those who preferred beer were at slightly greater risk of rectal cancer, but those who preferred wine were more likely to develop colon cancer. These data suggest that total alcohol use, but no one specific beverage type, is associated with increased risk of rectal cancer.     

#68 Is there a true “shift” to the right in the incidence of colorectal cancer?

PURPOSE: A recent “shift” in the incidence of colorectal cancer (CRC) to right-sided colon cancers has been reported. Whether this “shift” resulted from a true increase in the incidence of right colon cancers or decline in left colon cancers is unknown. To disentangle these potential explanations, we examined temporal trends in proportion of right colon, left colon, and rectal cancers as well as incidence rates.METHODS: Using data from the NCI SEER program, proportions and age-adjusted incidence rates were calculated for right colon, left colon, and rectal cancers by race over three-year time periods from 1978–1998. Proportion of cases by age at diagnosis was also calculated.RESULTS: Although the proportion of individuals diagnosed with right colon cancer increased for whites (1978–1980 = 34%;1996–1998 = 40%) and blacks (1978–1980 = 37%;1996–1998 = 44%), the proportions with left colon and rectal cancers decreased. Between 1978–1998, age-adjusted incidence rates of left colon cancer declined in whites (1978–1980 = 16/100,000; 1996–1998 = 13/100,000) and blacks (1978–1980 = 18/100,000;1996–1998 = 12/100,000, while the incidence rates of right colon cancer (1978–1980 = 14/100,000;1996–1998 = 15/100,000) did not change significantly. Age-adjusted incidence rates of rectal cancer remained stable for blacks (10/100,000) and declined for whites (1978–1980 = 15/100,000; 1996–1998 = 12/100,000). Overall, 43% of individuals >60 years diagnosed with CRC had right colon cancer. Smaller proportions were diagnosed with left colon (31%) or rectal cancer (26%). Conversely, among individuals <60 years, 28% had right colon, 34% left colon, and 38% rectal.CONCLUSION: 1) The “shift” to right colon cancer is due to a decline in the incidence of left colon and rectal cancers, while the incidence of right colon cancers remains unchanged. 2) In the elderly, the majority of colon cancers are found in the right colon. This has important implications for choice of screening method used in the elderly.     

Moderate beer consumption and the risk of colorectal cancer

The relationship between beer consumption and the risk of colon and rectal cancer was considered in a case‐control study conducted in northern Italy. The study was based on 828 histologically confirmed incident cases of colon cancer, 498 of rectal cancer, and 2,024 controls in hospital for a wide spectrum of acute, nonneoplastic, nonalcohol‐related diseases. Beer drinking was reported by 6% of colon cancer cases, 7% of rectal cancer cases, and 10% of controls; regular beer drinkers (≥1 drinks/day) made up 2.6% of colon cancer cases, 3.2% of rectal cancer cases, and 4.1% of controls. Thus the multivariate relative risks (RR) for irregular drinkers were 0.6 [95% confidence interval (CI) 0.4–1.0] for colon and 0.7 (95% CI 0.4–1.2) for rectum. Corresponding values for regular drinkers were 0.7 (95% CI 0.4–1.2) for colon and 0.9 (95% CI 0.5–1.5) for rectal cancer. Despite the low frequency of beer drinking in this study, and hence its limited statistical power, the originality of the population in terms of colorectal cancer incidence, patterns of risk factor exposure, and the large dataset provide interesting and useful confirmation that moderate beer drinking is not associated with elevated colon or rectal cancer risk.     

CYP1A1, cigarette smoking, and colon and rectal cancer

Cytochrome P-450 (CYP) is involved in the activation and metabolism of polycyclic aromatic hydrocarbons in tobacco products. The authors evaluated the association of two polymorphisms in the CYP1A1 gene--the noncoding Msp I polymorphism in the 3'-untranslated region and the Ile462Val polymorphism in exon 7--with colon and rectal cancer. The authors used data from two incident case-control studies of colon cancer (1,026 cases and 1,185 controls) and rectal cancer (820 cases and 1,036 controls) conducted in California and Utah (1991-2002). CYP1A1 genotype was not associated with colon or rectal cancer. Having GSTM1 present, a CYP1A1 variant allele, and the rapid-acetylator NAT2 imputed phenotype was associated with increased risk of colon cancer (odds ratio = 1.7, 95% confidence interval: 1.2, 2.3). Among men, the greatest colon cancer risk was observed for having any CYP1A1 variant allele and currently smoking (odds ratio = 2.5, 95% confidence interval: 1.3, 4.8; Wald chi(2)test: p < 0.01). Assessment of GSTM1 and CYP1A1 and rectal cancer in men showed a twofold elevation in risk for more than 20 pack-years of smoking, except among those with GSTM1 present who had a variant CYP1A1 allele. These data support the association between smoking and colon and rectal cancer. Smoking may have a greater impact on colorectal cancer risk based on CYP1A1 genotype; this might further be modified by GSTM1 for rectal cancer risk.     

Importance of district of residence and known primary site for bowel cancer survival: analysis of data from Wessex Cancer Registry.

STUDY OBJECTIVE--The aim was to compare survival with colon and rectal cancer across the 10 districts of Wessex taking into account the age and sex of the individual. DESIGN--The study was based on registrations on the Wessex Cancer Registry between 1979 and 1984 with colon and rectal cancer. Survival up to 31 December 1986 was examined using a Cox regression model; individuals surviving to the end of the follow up period were treated as censored in the analysis. Survival was examined in the first fortnight, the first month, and the first six months after registration separately. PARTICIPANTS--The data comprised 6239 residents of the Wessex Region who had been diagnosed with colon cancer and 3203 residents diagnosed with rectal cancer. For 140 cases survival data or age were missing and these cases were excluded. MEASUREMENTS AND MAIN RESULTS--Results are presented in the format of a league table giving the order of districts from lowest to highest survival rates. No significant differences in survival are found between districts in relation to rectal cancer. We find that one or two districts have consistently high or low survival rates with colon cancer in various periods of follow up, but cannot differentiate between the districts in the centre of the list. Site unspecified is considered as an explanatory variable; it is more predictive than district, and it approaches the importance of age in explaining survival with colon cancer. CONCLUSIONS--There are significant differences in survival with colon cancer between districts; however data on stage at registration are not available and we are unable to say whether the differences in survival are due to differences in stage at diagnosis or differences in survival with similar stage at diagnosis. We found that cases where the site of the cancer within the colon was not recorded on the register have significantly lower survival, and we suggest that site unspecified may be related to stage at diagnosis.     

Prognostic value of the presence of the mutation of the codons 12, 13 and 61 in K-ras oncogene in colorectal cancer]

Despite of extensive and intensive investigations, the predictive and prognostic value of c-K-ras mutation is not unequivocal. There has been reported about investigation the occurrence of mutations in the 88 colorectal cancer patient's specimen using polymerase chain reaction. Age: 61.9 years (27-80), gender 8 male, 42 female. Dukes' stages: 43 at the B, 35 at C, 10 at D. Primary of tumour: 52 colon, 36 rectal adenocarcinoma. Mutation out of one of the three ras-codons was detectable in the 54 cases, more frequently at the stage Dukes' C (p < 0.05). The ras-mutation concerned to more elevated death-rate in the stages Dukes' B and C (p < 0.01). Mean survival time to progression was significantly longer at the stage Dukes' B if mutation had not been detected (p < 0.01). The occurrence of the rate of genetic alteration was significantly more frequent at tumours of right-side colon, than left side (p < 0.02) or rectum (p < 0.05) one's. However, at the age of 41-50 years it was significantly more presented at the cases of rectal cancer (p < 0.01). At the age of 51-60 years mutations were detected among men at higher rate (p < 0.05). The cases of local recurrences concerned by mutation at the codon of 13 (p < 0.05). Occurrence of ras-oncogene is the sign of extremely malignant potential of tumour. This fact manifested itself in the time to progression and mean survival time of patients at same clinical or pathological stage. The higher frequency of genetic alterations at the proximal colon may be the reason of more unfavourable prognosis of the disease localised to this site. Reconstructing the molecular events, the presence of ras mutation can serve as a basis for prognosis of the disease and permit of potentially individualised therapeutic intervention.     

Tea consumption and the risk of colorectal cancer in Sweden.

The association between tea drinking and colorectal cancer risk remains unclear. The evidence for black tea is sparse but may indicate an increased risk with regular use. Because black tea is a common beverage in many populations, the significant twofold increased risk of colon cancer recently reported from a large prospective cohort of male Finnish smokers is disconcerting. Using Cox proportional hazards models to estimate relative risks, we examined this association in a large, population-based prospective cohort study in Sweden. During an average 9.6 years of follow-up of our cohort of 61,463 women (588,270 person-yr), we observed 460 incident cases of colorectal cancer (291 colon, 159 rectal, and 10 with both colon and rectal cancer). We observed no association between tea consumption and combined colorectal cancers in age- or multivariate-adjusted models. With the use of collapsed exposure categories, the multivariate-adjusted relative risk for the highest exposure (> or = cups/day) compared with the lowest (never or seldom) was 0.97 (95% confidence interval = 0.63-1.48, p for trend = 0.34). Examining the association by cancer subsite, we observed no association between tea consumption and proximal, distal, or combined colon cancers. We did, however, observe a nonsignificant positive association with rectal cancers, which became stronger and statistically significant among women > or = 65 years of age at baseline. Our data do not support the strong, dose-dependent positive association with colon cancer found in the Finnish study.     

Childhood body mass index and height in relation to site-specific risks of colorectal cancers in adult life

As colorectal cancers have a long latency period, their origins may lie early in life. Therefore childhood body mass index (BMI; kg/m²) and height may be associated with adult colorectal cancer. Using a cohort design, 257,623 children from The Copenhagen School Health Records Register born from 1930 to 1972 with measured heights and weights at ages 7 to 13 years were followed for adult colon and rectal adenocarcinomas by linkage to the Danish Cancer Registry. Hazard ratios (HRs) with 95% confidence intervals (CI) were estimated by Cox proportional hazard regressions. During follow-up, 2676 colon and 1681 rectal adenocarcinomas were diagnosed. No sex differences were observed in the associations between child BMI or height and adult colon or rectal cancers. Childhood BMI and height were positively associated with colon cancer; at age 13 years the HRs were 1.09 (95% CI 1.04–1.14) and 1.14 (95% CI 1.09–1.19) per z-score, respectively. Children who were persistently taller or heavier than average, had increased risk of colon cancer. Similarly, growing taller or gaining more weight than average was positively associated with colon cancer. No associations were observed between BMI or height and rectal cancer. Childhood BMI and height, along with above average change during childhood are significantly and positively associated with adult colon cancers, but not with rectal cancer, suggesting different etiologies.     

Health risk behaviors: examining social inequalities in bladder and colorectal cancers

PURPOSE: The objective of this study is to estimate the proportion of the relationship between low socioeconomic status (SES) and the incidence of these cancer types accounted for by health risk behaviors. METHODS: A study population of 569 bladder, 592 colon, and 558 rectal cancer cases and 1549 controls was used to investigate health risk behaviors and SES effects. Odds ratios and 95 % confidence intervals (CIs) estimated by multivariate logistic regression approximated relative risks. The explanatory role of health risk behaviors was assessed by the change in the risk estimate on SES following their omission from the model. RESULTS: For each cancer site, individual education remained a predictor of risk after controlling for health risk behaviors. Adjustments for health risk behaviors (smoking) shifted the age- and sex-adjusted relative risk (RR) associated with bladder cancer from 2.24 to 1.74 (29.5%). No health risk behaviors (smoking, diet, obesity) resulted in substantial change in the low education risk estimates for colon cancer (RR = 2.88) or rectal cancer (RR = 2.42). CONCLUSIONS: Given the strength of SES relationships persisting after adjustment for health risk behaviors, this study suggests that our knowledge of SES pathways and risk factors for bladder, colon, and rectal cancers is incomplete.     

Associations between regional socioeconomic deprivation and cancer risk: Analysis of population-based Cancer Registry data from Bavaria, Germany

ObjectivePrevious research from other countries shows a positive association between cancer risk and regional deprivation. This study explores this association for lung and colorectal cancers in Germany.MethodRegional deprivation was assessed by the ‘Bavarian Index of Multiple Deprivation’. Cancer data were provided by the Cancer Registry of Bavaria (2003–2006). The association between cancer risk and regional deprivation was evaluated by multilevel Poisson regression analysis.ResultsCrude incidence and mortality rates (per 1000 people) in the least deprived areas were 1.46 and 0.92 for lung cancer, 2.82 and 0.69 for colorectal cancer. For lung cancer, the age-adjusted relative risk (RR) for incidence in the most deprived districts (compared with the least deprived) in men was 1.41 (95% CI: 1.28–1.54), for mortality 1.59 (95% CI: 1.40–1.80); in women, an elevated RR was seen for mortality (1.24, 95% CI: 1.06–1.46). For colorectal cancer, the RR for incidence (men: 1.31, 95% CI: 1.17–1.46; women: 1.25, 95% CI: 1.12–1.40) and mortality (men: 1.51, 95% CI: 1.28–1.80; women: 1.49, 95% CI: 1.26–1.77) was always highest in the most deprived districts.ConclusionAt the district level in Bavaria, the risk for lung and colorectal cancers mostly increases with increasing regional deprivation.     

城市区级医院大肠癌因症就诊早发现初探

[目的 ]　探索城市区级医院开展大肠癌因症就诊早发现工作的成效。 [方法 ]　对 10 2 0例肛肠症状病人采用四项检查 (直肠指检、大便隐血试验、X线气钡双重造影和纤维结肠镜检查 )。 [结果 ]　共检出大肠癌 49例 ,检出率 4.8%。 49例中直肠癌 17例 (34 .7% ) ,结肠癌 32例 (6 5 .3% ) ,其中近侧结肠癌占全部结肠癌的 43.3%。大肠癌分期早期 (A期 )癌 13例 ,占 2 6 .5 %。早期癌位于远侧大肠 (直肠、乙结肠 ) 11例 (84.6 % ) ,位于近侧大肠 (升结肠和盲肠 ) 2例 (15 .4% )。 [结论 ]　随着上海市大肠癌发病趋向近侧大肠的变化 ,采用纤维结肠镜检查可提高近侧大肠癌的检出率。     

Dietary patterns associated with colon and rectal cancer: results from the Dietary Patterns and Cancer (DIETSCAN) Project

BACKGROUND: An analysis of dietary patterns or combinations of foods may provide insight regarding the influence of diet on the risk of colon and rectal cancer. OBJECTIVE: A primary aim of the Dietary Patterns and Cancer (DIETSCAN) Project was to develop and apply a common methodologic approach to study dietary patterns and cancer in 4 European cohorts: the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (Finland-ATBC), the Netherlands Cohort Study (NLCS) on Diet and Cancer, the Swedish Mammography Cohort (SMC), and the Ormoni e Dieta nella Eziologia dei Tumori (Italy-ORDET). Three cohorts (ATBC, NLCS, and SMC) provided data on colon and rectal cancer for the present study. DESIGN: The cohorts were established between 1985 and 1992; follow-up data were obtained from national cancer registries. The participants completed validated semiquantitative food-frequency questionnaires at baseline. RESULTS: Exploratory factor analysis, conducted within each cohort, identified 3-5 stable dietary patterns. Two dietary patterns-Vegetables and Pork, Processed Meats, Potatoes (PPP)-were common across all cohorts. After adjustment for potential confounders, PPP was associated with an increased risk of colon cancer in the SMC women (quintile 4(multivariate) relative risk: 1.62; 95% CI: 1.12, 2.34; P for trend = 0.01). PPP was also associated with an increased risk of rectal cancer in the ATBC men (quintile 4(multivariate) relative risk: 2.21; 95% CI: 1.07, 4.57; P for trend = 0.05). Neither pattern was associated with the risk of colon or rectal cancer in the NLCS women and men. CONCLUSION: Although certain dietary patterns may be consistent across European countries, associations between these dietary patterns and the risk of colon and rectal cancer are not conclusive.     

Association of vegetable, fruit, and grain intakes with colorectal cancer: the Multiethnic Cohort Study

BACKGROUND: It is uncertain whether or not vegetables, fruit, or grains protect against colorectal cancer. OBJECTIVE: In a large prospective study, we investigated the association of vegetable, fruit, and grain intakes with colorectal cancer risk. DESIGN: Between 1993 and 1996, 85 903 men and 105 108 women completed a quantitative food-frequency questionnaire that included approximately 180 foods and beverages in the Multiethnic Cohort Study. A diagnosis of colorectal cancer was made in 1138 men and 972 women after an average follow-up of 7.3 y. Cox proportional hazards models were used to calculate multivariate-adjusted relative risks and 95% CIs for colorectal cancer. RESULTS: In men, multivariate adjustment for energy intake, dietary, and nondietary variables resulted in relative risks in the highest quintile group of 0.74 (95% CI: 0.59, 0.93; P for trend = 0.02) for vegetables and fruit combined, 0.80 (95% CI: 0.64, 0.99; P for trend = 0.09) for fruit alone, and 0.85 (95% CI: 0.69, 1.05; P for trend = 0.05) for vegetables alone. When colon and rectal cases were separated among men, the inverse associations were stronger for colon than for rectal cancer. In women, none of the associations with vegetables, fruit, or vegetables and fruit combined were significant. Grain intake was not associated with colorectal cancer for either men or women. CONCLUSION: The intake of vegetables and fruit was inversely related to colorectal cancer risk among men but not among women. The association appears stronger for colon than for rectal cancer.     

Prospective study on milk products, calcium and cancers of the colon and rectum

OBJECTIVE: To study the relationship between consumption of milk and milk products, calcium, lactose and vitamin D and occurrence of colorectal cancers. DESIGN: Prospective cohort study. SUBJECTS: A total of 9959 men and women aged 15 y or older without history of cancer at baseline. During a 24 y follow-up, 72 new cancers of the large bowel (38 in the colon and 34 in the rectum) were detected. RESULTS: Consumption of milk and total milk products was suggested to be inversely related to colon cancer incidence, whereas no similar association was seen for rectal cancer. The relative risk between the highest and lowest quartiles of intake adjusted for potential confounding factors was 0.46 (95% confidence interval 0.14-1.46, P for trend 0.09) for milk and 0.37 (95% CI=0.12-1.39, P for trend 0.06) for total milk products. Lactose intake showed a similar inverse relationship with colon cancer: the relative risk was 0.31 (95% CI=0.08-1.15, P for trend 0.03). Intake of vitamin D or total dietary calcium was not significantly related to colorectal cancer risk, whereas calcium provided by fermented milk products was associated with increased colorectal cancer incidence; in the highest quartile the multivariate adjusted relative risk for colorectal cancer was 2.07 (95% CI=1.00-4.28). CONCLUSIONS: Our results indicate that individuals showing high consumption of milk have a potentially reduced risk of colon cancer; however, the association does not appear to be due to intake of calcium, vitamin D, or to specific effects of fermented milk. SPONSORSHIP: This study was supported by a grant from the Swedish Cancer Foundation.     

Case-control study of lung cancer among sugar cane farmers in India

OBJECTIVES: To investigate the risk of lung cancer among sugar cane farmers and sugar mill workers. METHODS: A case-control study was conducted based in six hospitals in the predominantly sugar cane farming districts of the province of Maharashtra in India. Newly diagnosed, histologically confirmed cases were identified from these hospitals between May 1996 and April 1998. Other cancers were chosen as controls and matched to cases by age, sex, district of residence, and timing of diagnosis. RESULTS: Adjusting for confounders, an increased risk of lung cancer was found for workers ever employed on a sugar cane farm (odds ratio (OR) 1.92, 95% confidence interval (95% CI) 1.08 to 3.40). Increased risks were found for work involving preparation of the farm (OR 1.81, 95% CI 0.99 to 3.27) and burning of the farm after harvesting (OR 1.82, 95% CI 0.99 to 3.34). Non-significant increases in risks were found for harvesting the crop (OR 1.41, 95% CI 0.70 to 2.90) and processing the cane in the mills (OR 1.70, 95% CI 0.20 to 12.60). CONCLUSIONS: Exposure to fibres of biogenic amorphous silica (BAS) formed from silica absorbed from the soil and deposited in the leaves of the sugar cane crop or crystalline silica formed as a result of conversion of BAS to cristobalite at high temperatures may account for the increased risks of lung cancer among sugar cane farmers.     

Prospective study of major dietary patterns and colorectal cancer risk in women.

A number of prospective cohort studies have examined the relations of individual dietary variables to risk of colorectal cancer. Few studies have addressed the broader eating patterns that reflect many dietary exposures working together. Using data from a prospective study of 61,463 women, with an average follow-up period of 9.6 years (between 1987 and 1998) and 460 incident cases of colorectal cancer, the authors conducted a factor analysis to identify and examine major dietary patterns in relation to colorectal cancer risk. Using proportional hazards regression to estimate relative risks, the authors found no clear association between a "Western," "healthy," or "drinker" dietary pattern and colorectal cancer risk. However, the data suggested that consuming low amounts of foods that constitute a "healthy" dietary pattern may be associated with increased risks of colon and rectal cancers. An inverse association with the "healthy" dietary pattern was found among women under age 50 years, although the number of cancers in this age group was limited and interpretation of this finding should be cautious. In this age group, relative risks for women in increasing quintiles of the "healthy" dietary pattern, compared with the lowest quintile, were 0.74 (95% confidence interval (CI): 0.41, 1.31), 0.69 (95% CI: 0.39, 1.24), 0.59 (95% CI: 0.32, 1.07), and 0.45 (95% CI: 0.23, 0.88) (p for trend = 0.03). The role of overall eating patterns in predicting colorectal cancer risk requires further investigation.     

Serum insulin-like growth factor I and subsequent risk of colorectal cancer among Japanese-American men

Recent reports suggest that colorectal cancer is positively related to insulin-like growth factor I (IGF-I) and inversely related to insulin-like growth factor binding protein 3 (IGFBP-3). To evaluate these associations further and separately for colon and rectal cancer, the authors conducted a nested case-control study in a cohort of 9,345 Japanese-American men examined in Hawaii in 1971-1977. A total of 177 incident colon cancer cases and 105 incident rectal cancer cases were identified from 1972 to 1996. These patients' stored sera and those of 282 age-matched controls were measured for IGF-I and IGFBP-3. The adjusted mean level of IGF-I was higher in colon cancer cases than in controls (154.7 ng/ml vs. 144.4 ng/ml; p = 0.01). However, the multivariate odds ratio for the highest quartile compared with the lowest was just 1.8 (95% confidence interval: 0.8, 4.3). Adjusted mean IGF-I levels were similar between rectal cancer cases and their controls. For IGFBP-3, adjusted mean levels were lower for both colon and rectal cancer cases than for their matched controls, but the differences were not significant. The IGF-I results weakly support findings from other studies and suggest that there are differences in IGF-I findings between colon and rectal cancer cases. It is possible that IGF-related risk is confounded by other factors that may vary among different cohorts. Further research is needed to clarify these relations.     

Obesity and colon and rectal cancer risk: a meta-analysis of prospective studies

BACKGROUND: Whereas obesity has been associated with an increased risk of colon cancer in men, a weak or no association has been observed in women. Results for rectal cancer have also been inconsistent. OBJECTIVE: The objective was to perform a meta-analysis to summarize the available evidence from prospective studies on the associations of overall and abdominal obesity with the risk of colon and rectal cancer. DESIGN: We searched MEDLINE (1966-April 2007) and the references of the retrieved articles. Study-specific relative risks (RRs) were pooled by using a random-effects model. RESULTS: Thirty prospective studies were included in the meta-analysis of body mass index (BMI; in kg/m(2)). Overall, a 5-unit increase in BMI was related to an increased risk of colon cancer in both men (RR: 1.30; 95% CI: 1.25, 1.35) and women (RR: 1.12; 95% CI: 1.07, 1.18), but the association was stronger in men (P < 0.001). BMI was positively associated with rectal cancer in men (RR: 1.12; 95% CI: 1.09, 1.16) but not in women (RR: 1.03; 95% CI: 0.99, 1.08). The difference in RRs between cancer sites was statistically significant (P < 0.001 in men and P = 0.04 in women). Colon cancer risk increased with increasing waist circumference (per 10-cm increase) in both men (RR: 1.33; 95% CI: 1.19, 1.49) and women (RR: 1.16; 95% CI: 1.09, 1.23) and with increasing waist-hip ratio (per 0.1-unit increase) in both men (RR: 1.43; 95% CI: 1.19, 1.71) and women (RR: 1.20; 95% CI: 1.08, 1.33). CONCLUSIONS: The association between obesity and colon and rectal cancer risk varies by sex and cancer site.     

细胞色素P450 2E1基因PstⅠ多态、腌制品与大肠癌关系的病例对照研究

目的：研究代谢酶细胞色素P450 2E1基因(CYP2E1)Pst Ⅰ多态性和腌制品与大肠癌易感性的关系。方法：采用人群基础的病例对照分子流行病学研究和PCR—RFLP技术,对126例大肠癌和343名健康对照Pst Ⅰ识别的CYP2E1基因型进行检测。结果：健康对照组CYP2E1基因野生型(C1／C1)为61．8％,杂合子(C1／C2)为35．8％,突变纯合子(C2／C2)为2．4％。调整年龄性别后,结肠癌病例中突变基因型频率54．9％(52．9％ C1／C2和2．0％ C2／C2)高于对照(OR 1．979,95％ CI 1．090—3．595),但直肠癌病例与对照比较,无统计学意义。分层分析发现,突变基因型、每周1或2次和隔天或每天吃腌制品单因素作用的大肠癌OR值分别1．935、2．122和2．315,而每周1或2次 突变型、隔天或每天吃 突变型联合作用后大肠癌OR值分别为2．272和3．127。分别分析结、直肠癌,腌制品对直肠癌的危险性在食用频率为每周1或2次时,差异有统计学意义,野生型和突变型的OR值分别为2．646和2．297,两者差异无统计学意义;而结肠癌危险性只有在Pst Ⅰ突变者隔天或每天吃腌制品时才剧增,OR值4．262(1．395～13．017),为野生型的2．69倍,差异有统计学意义。结论：CYP2E1 PstⅠG→C点突变是大肠癌的遗传易感性因素,与腌制品有协同作用,该作用在结肠癌尤为明显。     

Differences in Late‐Stage Diagnosis,Treatment, and Colorectal Cancer‐Related Death Between Rural and Urban African Americans and Whites in Georgia

Purpose: Disparities in health outcomes due to a diagnosis of colorectal cancer (CRC) have been reported for a number of demographic groups. This study was conducted to examine the outcomes of late‐stage diagnosis, treatment, and cancer‐related death according to race and geographic residency status (rural vs urban). Methods: This study utilized cross‐sectional and follow‐up data from the Surveillance, Epidemiology, and End Results (SEER) Program for all incident colon and rectal tumors diagnosed for the Atlanta and Rural Georgia Cancer Registries for the years 1992‐2007. Findings: Compared to whites, African Americans had a 40% increased odds (OR, 1.40; 95% CI, 1.30‐1.51) of late‐stage diagnosis, a 50% decreased odds (OR, 0.50; 95% CI, 0.37‐0.68) of having surgery for colon cancer, and a 67% decreased odds (OR, 0.33; 95% CI, 0.25‐0.44) of receiving surgery for rectal cancer. Rural residence was not associated with late stage at diagnosis or receipt of treatment. African Americans had a slightly increased risk of death from colon cancer (HR, 1.11; 95% CI, 1.00‐1.24) and a larger increased risk of death due to rectal cancer (HR, 1.24; 95% CI, 1.14‐1.35). Rural residents experienced a 15% increased risk of death (HR, 1.15; 95% CI, 1.01‐1.32) due to colon cancer. Conclusions: Further investigations should target African Americans and rural residents to gain insight into the etiologic mechanisms responsible for the poorer CRC outcomes experienced by these 2 segments of the population.