Association between cigarette smoking and colorectal cancer in the Women's Health Initiative

Colorectal Cancer: Is it Still a Disease of the Elderly?

<b><br>Introduction:</b> Colorectal cancer is becoming an increasingly significant health issue, being one of the more commonly diagnosed malignancies. Colorectal tumors account for 10% of all malignant cancers in women and 12% in men. Incidence is higher in the male population, especially among younger individuals. It is commonly believed that colorectal cancer is predominantly associated with advanced age. However, colorectal surgeons, who specialize in the treatment of this type of cancer, are observing a growing number of cases among middle-aged and younger individuals.</br> <b><br>Aim:</b> The aim of our study was to investigate whether colorectal cancer still predominantly affects elderly individuals, how frequently it is diagnosed in younger patients, and whether the location of tumors in the intestines of younger patients aligns with data from elderly individuals.</br> <b><br>Materials and methods:</b> The study was conducted retrospectively and included a cohort of 1771 patients who underwent surgical procedures due to colorectal cancer between 2012 and 2015 at the Department of General and Colorectal Surgery at the Medical University of Łódź and between 2014 and 2017 at the Department of General Surgery with a Division of Surgical Oncology at the District Health Center in Brzeziny. Data were analyzed regarding the frequency of colorectal cancer occurrence by age, tumor location in different age groups, and disease stage according to age. Age groups included <40 years, 41-50 years, 51-70 years, and >70 years.</br> <b><br>Results:</b> The study encompassed a total of 1771 patients, with 988 (55.79%) being males and 783 (44.21%) females. The mean age of the patients was 65.27 11.12 years. The highest number of cases was observed in the age range of 60-70 years and 70-80 years. It was found that colorectal tumors in males more frequently occurred on the left side of the colon and rectum, while in females, they were more commonly located on the right side of the colon, which was statistically significant (P = 0.007). Younger age groups of patients (<40 years, 40-50 years) had a similar male-to-female ratio, whereas in age groups above 50 years, males significantly outnumbered females (P = 0.049). The study revealed that in the group of patients below 40 years of age, an advanced stage of colorectal cancer was significantly more common; stage D occurred over twice as often as in the 51-70 age group and over three times as often as in the >70 age group.</br> <b><br>Conclusions:</b> The incidence of colorectal cancer in Poland is steadily increasing, with a growing number of diagnoses in younger individuals. Research findings demonstrate that males, especially those in younger age groups, are at a higher risk of developing colorectal cancer. A higher disease stage is more frequently observed in younger patients, possibly due to delayed diagnosis and symptomatic treatment. Screening programs should be adjusted to the changing age groups at higher risk. Our study underlines the need to raise public awareness regarding colorectal cancer, particularly among the younger population.</br>.

Prevalence of incidental colorectal cancer and polyps in autopsies of different populations: a systematic review with meta-regression analysis

The colorectal cancer (CRC) and polyps incidentally found in autopsies represent the lesions that have not actually caused problems throughout the lifetime and thus may not need to be removed during screening. This study aimed to investigate the prevalence of incidental CRC (iCRC) and polyps in autopsies of different populations. A systematic search was performed on 19 August 2022 to identify autopsy studies that provided data on prevalence of iCRC, adenomatous polyps, hyperplastic polyps, and/or all polyps combined. The prevalence was pooled with the random-effects model. Subgroup and multivariable meta-regression analyses were conducted to investigate the heterogeneity. Forty-three eligible studies including 59,656 autopsies were identified, with 94% conducted before 1990 when CRC screening was uncommon or not available. The pooled prevalence was 0.7% (95% confidence interval [CI], 0.3-1.2%) for iCRC, 18.4% (95% CI, 13.3-24.1%) for adenomatous polyps, 16.4% (95% CI, 8.7-25.9%) for hyperplastic polyps, 26.3% (95% CI, 15.4-38.8%) for all polyps combined, and 29.9% (95% CI, 14.8-47.6%) for iCRC plus polyps. The prevalence of iCRC was higher (1.2%) in white-predominant populations but lower (0.4%) after excluding low-quality studies. Multivariable analyses showed that the prevalence of polyps was higher in white-predominant populations and higher-quality studies, increased with age, and showed a downward trend from "before 1975" through "after 1985". In conclusion, the prevalence of iCRC in autopsies was not low, considering the average lifetime risk of CRC, while incidental polyps were common. Both varied greatly in different populations. These findings may have implications when weighing the benefits and harms of screening.

Smoking-induced microbial dysbiosis in health and disease

Smoking is associated with an increased risk of cancer, pulmonary and cardiovascular diseases, but the precise mechanisms by which such risk is mediated remain poorly understood. Additionally, smoking can impact the oral, nasal, oropharyngeal, lung and gut microbiome composition, function, and secreted molecule repertoire. Microbiome changes induced by smoking can bear direct consequences on smoking-related illnesses. Moreover, smoking-associated dysbiosis may modulate weight gain development following smoking cessation. Here, we review the implications of cigarette smoking on microbiome community structure and function. In addition, we highlight the potential impacts of microbial dysbiosis on smoking-related diseases. We discuss challenges in studying host–microbiome interactions in the context of smoking, such as the correlations with smoking-related disease severity versus causation and mechanism. In all, understanding the microbiome’s role in the pathophysiology of smoking-related diseases may promote the development of rational therapies for smoking- and smoking cessation-related disorders, as well as assist in smoking abstinence.

Cigarette Smoking Associated with Colorectal Cancer Survival: A Nationwide, Population-Based Cohort Study

We investigate whether cigarette smoking is associated with survival in patients with colorectal cancer (CRC) through a nationwide population-based cohort study in Taiwan. The Taiwan Cancer Registry and National Health Insurance Research Database were used to identify data from patients with CRC from 2011 to 2017. Tobacco use was evaluated based on the smoking status, intensity, and duration before cancer diagnosis. A total of 18,816 patients was included. A Kaplan–Meier survival analysis indicated smoking to be significantly associated with the CRC mortality risk (log-rank p = 0.0001). A multivariable Cox model indicated that smoking patients had a 1.11-fold higher mortality risk (HR = 1.11, 95% CI = 1.05–1.19) than nonsmoking patients did. This increased risk was also present in patients with CRC who smoked 11–20 cigarettes per day (HR = 1.16; 95% CI = 1.07–1.26) or smoked for >30 years (HR = 1.14; 95% CI = 1.04–1.25). Stratified analyses of sex and cancer subsites indicated that the effects of smoking were higher in male patients and in those with colon cancer. Our results indicate that cigarette smoking is significantly associated with poor survival in patients with CRC. An integrated smoking cessation campaign is warranted to prevent CRC mortality.

Causal Effects of Lifetime Smoking on Breast and Colorectal Cancer Risk: Mendelian Randomization Study

BACKGROUND

Observational evidence has shown that smoking is a risk factor for breast and colorectal cancer. We used Mendelian randomization (MR) to examine causal associations between smoking and risks of breast and colorectal cancer.

METHODS

Genome-Wide Association Study summary data were used to identify genetic variants associated with lifetime amount of smoking (n = 126 variants) and ever having smoked regularly (n = 112 variants). Using two-sample MR, we examined these variants in relation to incident breast (122,977 cases/105,974 controls) and colorectal cancer (52,775 cases/45,940 controls).

RESULTS

In inverse-variance weighted models, a genetic predisposition to higher lifetime amount of smoking was positively associated with breast cancer risk [OR per 1-SD increment: 1.13; 95% confidence interval (CI): 1.00-1.26; P = 0.04]; although heterogeneity was observed. Similar associations were found for estrogen receptor-positive and estrogen receptor-negative tumors. Higher lifetime amount of smoking was positively associated with colorectal cancer (OR per 1-SD increment, 1.21; 95% CI, 1.04-1.40; P = 0.01), colon cancer (OR, 1.31; 95% CI, 1.11-1.55; P < 0.01), and rectal cancer (OR, 1.36; 95% CI, 1.07-1.73; P = 0.01). Ever having smoked regularly was not associated with risks of breast (OR, 1.01; 95% CI, 0.90-1.14; P = 0.85) or colorectal cancer (OR, 0.97; 95% CI, 0.86-1.10; P = 0.68).

CONCLUSIONS

These findings are consistent with prior observational evidence and support a causal role of higher lifetime smoking amount in the development of breast and colorectal cancer.

IMPACT

The results from this comprehensive MR analysis indicate that lifetime smoking is a causal risk factor for these common malignancies.

Environmental tobacco smoke and cancer risk, a prospective cohort study in a Chinese population

Few prospective cohort studies have investigated associations between environmental tobacco smoke (ETS) and other cancer sites, in addition to lung cancer. We assessed these associations in a population-based prospective cohort study started from 2008 to 2011 with average of 9.1 years of follow-up, in Minhang district, Shanghai, China. The study included a total of 23,415 participants (8388 men, 15,027 women) and 205,515 person-years. Epidemiological data were collected by a standardized questionnaire including ETS exposure. Newly diagnosed patients with primary cancers and deaths were identified by record linkage system with the Shanghai Cancer Registry and Shanghai Vital Statistics. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression models, adjusting for potential confounders. During the study period, a total of 1462 patients with diagnoses of primary cancers were identified. Among all participants and non-smokers, ETS was associated with an increased risk of all smoking-related cancers (all: adjusted HR: 1.23, 95% CI: 1.05-1.43 and non-smokers: 1.24, 1.02-1.49), lung cancer (1.29, 0.98-1.71 and 1.27, 0.91-1.77), and stomach cancer (1.86, 1.21-2.85 and 1.75, 1.05-2.91), respectively. Furthermore, associations for lung and stomach cancers were the strongest among non-smoking females. The joint effects of both ETS and active smoking were strongest for all cancers, all smoking-related cancers, lung cancer, and stomach cancer. No clear interactions were observed. These results suggest that ETS exposure may increase the risk of smoking-related cancers in a Chinese population. Further studies on the relationship between ETS exposure and specific cancer sites are warranted to replicate our findings.

Smoking and colorectal cancer: A pooled analysis of 10 population-based cohort studies in Japan

Smoking has been consistently associated with the risk of colorectal cancer (CRC) in Western populations; however, evidence is limited and inconsistent in Asian people. To assess the association of smoking status, smoking intensity and smoking cessation with colorectal risk in the Japanese population, we performed a pooled analysis of 10 population-based cohort studies. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox's proportional hazards model and then pooled using a random-effects model. Among 363 409 participants followed up for 2 666 004 person-years, 9232 incident CRCs were identified. In men, compared with never smokers, ever smokers showed higher risk of CRC. The HRs (95% CI) were 1.19 (1.10-1.29) for CRC, 1.19 (1.09-1.30) for colon cancer, 1.28 (1.13-1.46) for distal colon cancer and 1.21 (1.07-1.36) for rectal cancer. Smoking was associated with risk of CRC in a dose-response manner. In women, compared with never smokers, ever smokers showed increased risk of distal colon cancer (1.47 [1.19-1.82]). There was no evidence of a significant gender difference in the association of smoking and CRC risk. Our results confirm that smoking is associated with an increased risk of CRC, both overall and subsites, in Japanese men and distal colon cancer in Japanese women.

Smoking-Related Risks of Colorectal Cancer by Anatomical Subsite and Sex

The purpose of this study was to examine whether the increased risk of colorectal cancer due to cigarette smoking differed by anatomical subsite or sex. We analyzed data from 188,052 participants aged 45-75 years (45% men) who were enrolled in the Multiethnic Cohort Study in 1993-1996. During a mean follow-up period of 16.7 years, we identified 4,879 incident cases of invasive colorectal adenocarcinoma. In multivariate Cox regression models, as compared with never smokers of the same sex, male ever smokers had a 39% higher risk (hazard ratio (HR) = 1.39, 95% confidence interval (CI): 1.16, 1.67) of cancer of the left (distal or descending) colon but not of the right (proximal or ascending) colon (HR = 1.03, 95% CI: 0.89, 1.18), while female ever smokers had a 20% higher risk (HR = 1.20, 95% CI: 1.06, 1.36) of cancer of the right colon but not of the left colon (HR = 0.96, 95% CI: 0.80, 1.15). Compared with male smokers, female smokers had a greater increase in risk of rectal cancer with number of pack-years of smoking (P for heterogeneity = 0.03). Our results suggest that male smokers are at increased risk of left colon cancer and female smokers are at increased risk of right colon cancer. Our study also suggests that females who smoke may have a higher risk of rectal cancer due to smoking than their male counterparts.

The hazards of smoking and the benefits of cessation: a critical summation of the epidemiological evidence in high-income countries

In high-income countries, the biggest cause of premature death, defined as death before 70 years, is smoking of manufactured cigarettes. Smoking-related disease was responsible for about 41 million deaths in the United States, United Kingdom and Canada, cumulatively, from 1960 to 2020. Every million cigarettes smoked leads to one death in the US and Canada, but slightly more than one death in the UK. The 21^st century hazards reveal that smokers who start smoking early in adult life and do not quit lose a decade of life expectancy versus non-smokers. Cessation, particularly before age 40 years, yields large reductions in mortality risk. Up to two-thirds of deaths among smokers are avoidable at non-smoking death rates, and former smokers have about only a quarter of the excess risk of death compared to current smokers. The gap between scientific and popular understanding of smoking hazards is surprisingly large.

Characteristics of the Salivary Microbiota in Patients With Various Digestive Tract Cancers

The salivary microbiota is constantly swallowed and delivered to the digestive tract. These bacteria may be associated with gastrointestinal diseases. This case-control study examined the salivary microbiota in patients with digestive tract cancer (DTC) and evaluated their differential distribution based on the cancer sites. We collected saliva samples from 59 patients with cancer in any part of the digestive tract (tongue/pharynx, esophagus, stomach, and large intestine) and from 118 age- and sex-matched control subjects. There was no significant difference in periodontal status between DTC patients and control subjects (P = 0.72). We examined the bacterial diversity and composition in saliva by 16S ribosomal RNA gene sequencing. Salivary bacterial diversity in DTC patients was significantly higher than that in control subjects [number of operational taxonomic units (OTUs), P = 0.02; Shannon index, P < 0.01; Chao1, P = 0.04]. Eleven differentially abundant OTUs in DTC patients were identified using the linear discriminant analysis effect size (LEfSe) method. Based on the cancer sites, the diversity of salivary bacteria was especially higher in tongue/pharyngeal or esophageal cancer patients than in control subjects. Among the 11 differentially abundant OTUs in DTC patients, an OTU corresponding to Porphyromonas gingivalis was more abundant in the saliva of all groups of DTC patients compared to that in control subjects, and an OTU corresponding to Corynebacterium species was more abundant in all groups other than gastric cancer patients (P < 0.01). In addition, the relative abundances of OTUs corresponding to Fusobacterium nucleatum, Streptococcus parasanguinis II, and Neisseria species were significantly higher in tongue/pharyngeal cancer patients compared to their abundances in control subjects (P < 0.01). The relative abundance of an OTU corresponding to the Neisseria species was also significantly higher in gastric cancer patients and that of an OTU corresponding to Actinomyces odontolyticus was significantly higher in colorectal cancer patients (P < 0.01). These results suggest that the salivary microbiota might be associated with various digestive tract cancers.

The value of four imaging modalities in diagnosing lymph node involvement in rectal cancer: an overview and adjusted indirect comparison

Several systematic reviews have investigated the accuracy of imaging modalities for lymph node involvement of rectal cancer, but there are considerable differences in conclusions. This overview aimed to assess the methodological and reporting quality of systematic reviews that evaluated the diagnostic value of imaging modalities for lymph node involvement in patients with rectal cancer and to compare the diagnostic value of different modalities for lymph node involvement. The PubMed, EMBASE, Cochrane Library and Chinese Biomedicine Literature were searched to identify relevant systematic reviews. The methodological quality was assessed using the AMSTAR checklist, and the reporting quality was assessed using PRISMA-DTA checklist. The indirect comparison was conducted to compare the accuracy of different imaging modalities. Seven systematic reviews involving 353 primary studies were included. The median (Range) AMSTAR scores were 6.0 (4.0-9.0); the median (Range) PRISMA-DTA scores were 18.0 (11.0-23.0). Sensitivity of MRI [0.69 (95% CI 0.63, 0.77)] was significantly higher than that of ERUS [0.57 (95% CI 0.53, 0.62)]. Specificity of ERUS [0.80 (95% CI 0.77, 0.83)] was significantly higher than that of CT [0.72 (95% CI 0.67, 0.78)]. Positive likelihood ratio of EUS [3.04 (95% CI 2.75, 3.36)] was significantly higher than that of CT [2.21 (95% CI 1.69, 2.90)]. EUS had better diagnostic value than CT and ERUS in the diagnosis of lymph node involvement. Compared with CT and ERUS, MRI was more sensitive. EUS and MRI had comparable diagnostic accuracy, but no modality was proved to be particularly accurate.

Association between Race and Cancer-Related Mortality among Patients with Colorectal Cancer in the United States: A Retrospective Cohort Study

Colorectal cancer (CRC) is the third most common cause of mortality in the United States (US). Differences in CRC mortality according to race have been extensively studied; however, much more understanding with regard to tumor characteristics’ effect on mortality is needed. The objective was to investigate the association between race and mortality among CRC patients in the US during 2007–2014. A retrospective cohort study using data from the Surveillance, Epidemiology, and End Results (SEER) Program, which collects cancer statistics through selected population-based cancer registries during in the US, was conducted. The outcome variable was CRC-related mortality in adult patients (≥18 years old) during 2007–2014. The independent variable was race of white, black, Asian/Pacific Islander (API), and American Indian/Alaska Native (others). The covariates were, age, sex, marital status, health insurance, tumor stage at diagnosis, and tumor size and grade. Bivariate analysis was performed to identify possible confounders (chi-square tests). Unadjusted and adjusted logistic regression models were used to study the association between race and CRC-specific mortality. The final number of participants consisted of 70,392 patients. Blacks had a 32% higher risk of death compared to whites (adjusted odds ratio (OR) 1.32; 95% confidence interval (CI) 1.22–1.43). Corresponding OR for others were 1.41 (95% CI 1.10–1.84). API had nonsignificant adjusted odds of mortality compared to whites (0.95; 95% CI 0.87–1.03). In conclusion, we observed a significant increased risk of mortality in black and American Indian/Alaska Native patients with CRC compared to white patients.

Comparative study between amputation of the rectum in the classic Lloyd-Davies position and in ventral decubitus

OBJECTIVE

to evaluate the benefits and disadvantages of the ventral decubitus position compared with that of Lloyd-Davies in patients submitted to abdominoperineal amputation of the rectum.

METHODS

we conducted a retrospective study of 56 patients submitted to abdominoperineal amputation of the rectum due to distal rectal and anal canal neoplasms, treated at the Central Hospital of the Santa Casa de Misericórdia in São Paulo between 2008 and 2017.

RESULTS

patients' mean age was 63.08 years, 48.2% of them women and 51.8%, men. Adenocarcinoma was the histological type, in 94.6% of cases, and squamous cell carcinoma, in 5.4%. The position of Lloyd-Davies was adopted in 66.1% of the procedures, and the ventral position, in 33.9%. At the time of surgery, four patients had synchronous metastases: hepatic (one case), pulmonary (one case) and simultaneous liver and lung (two cases). Neoadjuvant treatment was performed in 85.7% of the patients. Late postoperative complications occurred in 13 patients operated in the classic position and in one patient operated on in the ventral decubitus position. The overall survival time for the group operated in the classic position was on average 45.7 months, while in the group operated on in the ventral decubitus position it was 15.5 months.

CONCLUSION

the ventral position group presented less need for intraoperative intravenous volume infusion and fewer postoperative complications, whereas the Lloyd-Davies group had better surgical and anesthetic times. Relapse, disease-free time, and overall survival should be evaluated at a longer follow-up time.

Diagnostic accuracy of endoscopic ultrasound, computed tomography, magnetic resonance imaging, and endorectal ultrasonography for detecting lymph node involvement in patients with rectal cancer: A protocol for an overview of systematic reviews

BACKGROUND

Rectal cancer is one of the most common tumors and is the leading cause of cancer-related deaths in developed countries. Lymph node involvement remains the strongest prognostic factor associated with a worse prognosis in patients with rectal cancer. Several systematic reviews have investigated the accuracy of endoscopic ultrasound, computed tomography, magnetic resonance imaging, and endorectal ultrasonography for lymph node involvement of rectal cancer and compared the diagnostic accuracy of different imaging techniques, but there are considerable differences in conclusions. This study aims to assess the methodological quality and reporting quality of systematic reviews and to determine which diagnostic imaging techniques is the optimal modality for the diagnosis of lymph node involvement in patients with rectal cancer.

METHODS

We will search PubMed, EMBASE, Cochrane Library, and Chinese Biomedicine Literature to identify relevant studies from inception to June 2018. We will include systematic reviews that evaluated the accuracy of diagnostic imaging techniques for lymph node involvement. The methodological quality will be assessed using AMASAR checklist, and the reporting quality will be assessed using PRISMA-DTA checklist. The pairwise meta-analysis and indirect comparisons will be performed using STATA V.12.0.

RESULTS

The results of this overview will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This overview will provide comprehensive evidence of different diagnostic imaging techniques for detecting lymph node involvement in patients with rectal cancer.

ETHICS AND DISSEMINATION

Ethics approval and patient consent are not required as this study is an overview based on published systematic reviews.

PROSPERO REGISTRATION NUMBER

CRD42018104906.

Controversy on the correlation of red and processed meat consumption with colorectal cancer risk: an Asian perspective

This study aimed to investigate the relationship between meat intake and colorectal cancer risk from an Asian, particularly Korean, perspective. A report by the International Agency for Research on Cancer (IARC) published in 2015 concluded that intake of processed and red meat increases the risk of developing colorectal cancer. We conducted an in-depth analysis of prospective, retrospective, case-control and cohort studies, systematic review articles, and IARC monograph reports, which revealed that the IARC/WHO report weighted the results of studies based in Western countries more and that the correlation between intake of processed meat products and colorectal cancer incidence in Asians is not clearly supported. Among 73 epidemiological studies, approximately 76% were conducted in Western countries, whereas only 15% of studies were conducted in Asia. Furthermore, most studies conducted in Asia showed that processed meat consumption is not related to the onset of cancer. Moreover, there have been no reports showing significant correlation between various factors that directly or indirectly affect colorectal cancer incidence, including processed meat products types, raw meat types, or cooking methods. Further epidemiological studies taking each country's food culture into consideration are required to reliably elucidate the effects of processed meat product intake, especially on cancer incidence.

The impact of passive smoking on the risk of colorectal neoplasia in never, former, and current smokers

BACKGROUND AND AIM

Active smoking is well known to be a risk factor for colorectal neoplasia (CRN). However, it remains unclear whether passive smoking is also related to the risk of CRN. This study investigated the effect of passive smoking on the risk of CRN in never, former, and current smokers.

METHODS

A cross-sectional study was performed on asymptomatic examinees who underwent colonoscopy as part of a health check-up.

RESULTS

Of 136 707 participants, 33 052 (24.2%) were never passive smokers, and 103 655 (75.8%) were ever passive smokers. The mean age of the study population was 41.0 years. The proportion of never, former, and current smokers was 56.9%, 21.4%, and 24.8%, respectively, and the proportion of overall CRN and advanced CRN (ACRN) was 15.4% and 1.7%, respectively. Ever passive smoke exposure was associated with an increased risk of overall CRN in never smokers (adjusted odds ratio [AOR] 1.08; 95% confidence interval [CI] 1.02-1.13) and former smokers (AOR 1.08; 95% CI 1.00-1.17) but not in current smokers (AOR 1.02; 95% CI 0.94-1.11). Additionally, it significantly increased the risk of ACRN among never smokers (AOR 1.17; 95% CI 1.01-1.35) and tended to increase the risk of ACRN among former smokers (AOR 1.26; 95% CI 0.99-1.61). Moreover, the risk of CRN increased with increasing frequency and duration of passive smoking in never and former smokers.

CONCLUSIONS

Passive smoking was an independent risk factor for CRN in never and former smokers. Never and former smokers who are highly exposed to passive smoke as well as current smokers should be given priority for colonoscopy.

Evaluation of the Impact of Cancer Treatment on the Adoption and Consolidation of Pro-Health Attitudes in the Field of Cancer in Treated Patients with Colon Cancer

Colorectal cancer is the second most common cause of cancer deaths worldwide. Although progress in the development of new drugs over the last two decades has expanded treatment options for this disease, many significant problems relating to their optimization remain to be solved. Data on the cancer knowledge and the healthy behavior and lifestyle in patients with colorectal cancer in Poland is missing. We analyzed the course and results of treatment of first-line chemotherapy in 165 patients diagnosed with colorectal cancer treated between May 2010 and December 2013. The respondent's knowledge in the field of cancer and their lifestyle before and after the treatment were rated. The results were compared with a control group. Mean age was 60.89 ± 8.69 years, median 59 years. The general knowledge about cancer and the level of healthy lifestyle before treatment were low. After treatment, both the knowledge about cancer and the level of healthy lifestyle increased compared to the control group. There was a clear relationship between the level of knowledge about cancer and the willingness to adopt attitudes and healthy behavior by patients. In our analysis, the overall quality of life in patients treated with first-line palliative chemotherapy of colorectal cancer did not change during treatment. Our results indicate the need to implement an educational program on cancer prevention in treated patients, and the analysis of quality of life and other factors than treatment effect remains controversial.

Factors Associated with Colorectal Cancer Among Jordanians: a Case- Control Study

Objective:

In recent years, the incidence of colorectal cancer (CRC) in Jordan has been on the rise. We aimed to determine associations with lifestyle factors, demographic and clinical variables.

Methods:

This case-control study included 102 patients diagnosed with CRC and 198 age and gender matched healthy subjects as controls. Cases were purposefully sampled; however, the control group were selected by simple random sampling of a cross-section of the population in Northern Jordan. Participating cases and controls completed an anonymous questionnaire inquiring about their demographic characteristics, lifestyle factors, and clinical variables. Data about the medical history and diagnosis of participating cases were obtained from the cases themselves and confirmed by reviewing their medical records.

Results:

In the cross tabulation analysis, the Chi square test showed that diabetes and hypertension were significantly associated with CRC (P <0.05). Additionally, regression modeling revealed that age ≥ 45 years (OR=10.93), positive family history for CRC (OR=5.53), physical inactivity (OR=7.4), cigarette smoking (OR=3.71), and having other types of cancer (OR=13.61) were all associated with increased risk of CRC.

Conclusions:

Physical inactivity and cigarette smoking are among the top modifiable risk factors for CRC among Jordanians. Moreover, diabetes and hypertension were found to be statistically significant risk factors in univariate, but not multivariate analysis. More effective strategies for elevating awareness and prevention are required at both national and international levels. Improving screening strategies is needed for early detection of CRC in Jordan.

Molecular and Clinicopathological Differences by Age at the Diagnosis of Colorectal Cancer

We compared the clinicopathological and molecular profiles between different age groups of sporadic colorectal cancer (CRC) patients (age <50, 56-60, 60-70, 70-80, and >80); 1475 CRC patients were enrolled after excluding 30 individuals with Lynch syndrome. The mutation spectra for APC, TP53, KRAS, PIK3CA, FBXW7, BRAF, NRAS, HRAS, TGFbR, Akt1, and PTEN were analyzed using polymerase chain reaction (PCR), followed by MassArray and microsatellite (MSI-high) analysis by performing genotyping. Male patients (74.1%) were significantly predominant to females (25.9%) in the older age group (70-80, >80). There was an insignificantly linear trend between TNM staging and age-onset of CRC diagnosis. Patients aged < 50 had 58.7% diseases in the advanced stages (Stage III: 36.5% and IV: 22.2% respectively), while this decreased to 40.2% (Stage III: 26.2% and IV; 14.0% respectively) in patients >80. The distributions of mutation frequency were similar in majority of the genes studied among different age groups. Additionally, patients aged <50 had significantly higher frequency of MSI-high, PTEN, and HRAS mutations than those of other groups. Age-onset at diagnosis significantly affected overall survival (HR = 1.46; 95% CI: 1.35-1.58), but not cancer-specific survival (HR = 1.08; 95% CI: 0.99-1.18) in multivariate analysis. In conclusion, molecular and clinicopathological differences were not as significant among different age groups of CRC patients as previously suspected.

Diet Quality and Colorectal Cancer Risk in the Women's Health Initiative Observational Study

Diet quality index scores on Healthy Eating Index 2010 (HEI-2010), Alternative HEI-2010, alternative Mediterranean Diet Index, and the Dietary Approaches to Stop Hypertension (DASH) index have been inversely associated with all-cause and cancer-specific death. This study assessed the association between these scores and colorectal cancer (CRC) incidence as well as CRC-specific mortality in the Women's Health Initiative Observational Study (1993-2012), a US study of postmenopausal women. During an average of 12.4 years of follow-up, there were 938 cases of CRC and 238 CRC-specific deaths. We estimated multivariate hazard ratios and 95% confidence intervals for relationships between quintiles of diet scores (from baseline food frequency questionnaires) and outcomes. HEI-2010 score (hazard ratios were 0.81, 0.77, and 0.73 with P values of 0.04, 0.01, and <0.01 for quintiles 3-5 vs. quintile 1, respectively) and DASH score (hazard ratios were 0.72, 0.74, and 0.78 with P values of <0.01, <0.01, and 0.03 for quintiles 3-5 vs. quintile 1, respectively), but not other diet scores, were associated with a lower risk of CRC in adjusted models. No diet scores were significantly associated with CRC-specific mortality. Closer adherence to HEI-2010 and DASH dietary recommendations was inversely associated with risk of CRC in this large cohort of postmenopausal women.

Epidemiological evidence on environmental tobacco smoke and cancers other than lung or breast

We reviewed 87 epidemiological studies relating environmental tobacco smoke (ETS) exposure to risk of cancer other than lung or breast in never smoking adults. This updates a 2002 review which also considered breast cancer. Meta-analysis showed no significant relationship with ETS for nasopharynx cancer, head and neck cancer, various digestive cancers (stomach, rectum, colorectal, liver, pancreas), or cancers of endometrium, ovary, bladder and brain. For some cancers (including oesophagus, colon, gall bladder and lymphoma) more limited data did not suggest a relationship. An increased cervix cancer risk (RR 1.58, 95%CI 1.29-1.93, n = 17 independent estimates), reducing to 1.29 (95%CI 1.01-1.65) after restriction to five estimates adjusting for HPV infection or sexual activity suggests a causal relationship, as do associations with nasosinus cancer observed in 2002 (no new studies since), and less so kidney cancer (RR 1.33, 95%CI 1.04-1.70, n = 6). A weaker association with total cancer (RR 1.13, 95%CI 1.03-1.35, n = 19) based on heterogeneous data is inconclusive. Inadequate confounder control, recall bias, publication bias, and occasional reports of implausibly large RRs in individual studies contribute to our conclusion that the epidemiological evidence does not convincingly demonstrate that ETS exposure causes any of the cancers studied.

Passive Smoking and Risk of Colorectal Cancer

We conducted this meta-analysis to explore the association between passive smoking and the risk of colorectal cancer. A literature search of online databases, including MEDLINE, EMBASE, the Cochrane Library, and Web of Science was performed up to June 30, 2015. A fixed-effects meta-analysis using Stata 12.0 was carried out to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for the associations. Eleven articles, including 6 case-control studies and 6 cohort studies, were included in our analysis according to inclusion and exclusion criteria. The pooled RR of all studies showed a statistically significant association between passive smoking and colorectal cancer (RR = 1.14; 95% CI = 1.05-1.24). Results of subgroup analysis showed a positive association between passive smoking and rectal cancer ((RR = 1.33; 95% CI = 1.15-1.53) and that male passive smokers were at greater risks of colorectal cancer (RR = 1.73; 95% CI = 1.37-2.19) than females. Results suggested that passive smoking is associated with an increased risk of colorectal cancer.

Association Between Exposure to Environmental Tobacco Smoke at the Workplace and Risk for Developing a Colorectal Adenoma: A Cross-Sectional Study

Purpose

A colorectal adenoma (CRA) is a well-defined precursor to colorectal cancer (CRC). Additionally, smoking is a potent risk factor for developing a CRA, as well as CRC. However, the association between exposure to environmental tobacco smoke (ETS) and the risk for developing a CRA has not yet been fully evaluated in epidemiologic studies. We performed a cross-sectional analysis on the association between exposure to ETS at the workplace and the risk for developing a CRA.

Methods

The study was conducted on subjects who had undergone a colonoscopy at a health promotion center from January 2012 to December 2012. After descriptive analyses, overall and subgroup analyses by smoking status were performed by using a multivariate logistic regression.

Results

Among the 1,129 participants, 300 (26.6%) were diagnosed as having CRAs. Exposure to ETS was found to be associated with CRAs in all subjects (fully adjusted odds ratio [OR], 1.95; 95% confidence interval [CI], 1.08–2.44; P = 0.001). In the subgroup analysis, exposure to ETS in former smokers increased the risk for developing a CRA (fully adjusted OR, 4.44; 95% CI, 2.07–9.51; P < 0.001).

Conclusion

Exposure to occupational ETS at the workplace, independent of the other factors, was associated with increased risk for developing a CRA in all subjects and in former smokers. Further retrospective studies with large sample sizes may be necessary to clarify the causal effect of this relationship.

Trends in colorectal cancer incidence and related lifestyle risk factors in 15-49-year-olds in Canada, 1969-2010

BACKGROUND

While the overall incidence rate of colorectal cancer (CRC) in Canada has been decreasing, some countries show an increasing incidence in those under the age of 50. We examined the trends in CRC incidence and associated lifestyle risk factors in Canadians aged 15-49.

METHODS

Incidence data for colorectal, colon and rectum/rectosigmoid cancers were obtained for 1969-2010 from the Canadian Cancer Registry, and trends in age-standardized incidence rates (ASIRs) were examined by Joinpoint regression for three age groups (15-29, 30-39, 40-49 years) and by sex. Trends in the prevalence of some CRC risk factors were similarly examined from national health surveys for various periods ranging from 1970 to 2012.

RESULTS

In both sexes combined, ASIRs rose by 6.7%/year (1997-2010) for 15-29-year-olds, 2.4%/year (1996-2010) for 30-39-year-olds, and 0.8%/year (1997-2010) for 40-49-year-olds. Similar trends were observed by sex. The rise in ASIR was more rapid for cancers of the rectum/rectosigmoid compared to colon for all age groups. Risk factor trends varied: excess weight rose substantially, vegetables and fruit consumption increased slightly, physical inactivity rates declined but remained high, alcohol consumption changed little, and smoking rates declined. Data on red/processed meat consumption were unavailable.

CONCLUSION

The ASIR of CRC in young Canadians has increased since about the mid-1990s. The rising prevalence of excess weight in younger generations has likely played a role in the CRC trend, but more research is needed.

Dietary polyamine intake and colorectal cancer risk in postmenopausal women

BACKGROUND

Putrescine, spermidine, and spermine (i.e., polyamines) are small cationic amines synthesized by cells or acquired from the diet or gut bacteria. Polyamines are required for both normal and colorectal cancer (CRC) cell growth.

OBJECTIVE

We investigated the association between dietary polyamines and risk of CRC incidence and mortality.

DESIGN

The study was a prospective analysis in 87,602 postmenopausal women in the Women's Health Initiative Observational Study. Multivariate Cox regression was used to calculate HRs and 95% CIs.

RESULTS

Total dietary polyamine intake (mean ± SD: 289.2 ± 127.4 μmol/d) was not positively associated with CRC in fully adjusted models. Instead, intake ≥179.67 μmol/d was associated with reduced risk of CRC [HR (95% CI): 0.82 (0.68, 1.00), 0.81 (0.66, 0.99), 0.91 (0.74, 1.12), and 0.80 (0.62, 1.02) for quintiles 2-5, respectively, compared with quintile 1]. Reduced risk was not significant across all quintiles. Polyamines were not significantly associated with CRC-specific mortality in fully adjusted models. When stratified by risk factors for CRC, only body mass index (BMI) and fiber intake significantly modified the association between polyamine intake and CRC. In women with BMI (in kg/m²) ≤25 or fiber consumption above the median, polyamine intake was associated with significantly lower risk of CRC.

CONCLUSIONS

No positive association between dietary polyamines and CRC or CRC-specific mortality risk in women was observed. Instead, a protective effect of dietary polyamines was suggested in women with some CRC risk-lowering behaviors in particular. These results are consistent with emerging evidence that exogenous polyamines may be beneficial in colon health and warrant additional study.

Advances in the management of colorectal cancer: from biology to treatment

BACKGROUND

Colorectal cancer (CRC) is the third most common malignant neoplasm worldwide and the fourth leading cause of cancer-related deaths. This article reviews the epidemiology, risk factors, pathogenesis, and prognosis of CRC with special emphasis on advances in the management of CRC over the past decade.

METHODS

A review of the published English literature was conducted using the search engines PubMed, Medline, EMBASE, and Google Scholar. A total of 127 relevant publications were identified for further review.

RESULTS

Most CRC are sporadic and are due to genetic instability and multiple somatic mutations. Approximately 80% of cancers are diagnosed at the early stage and are curable. The pathologic stage at presentation is the most important predictor of outcome after resection of early stage cancer. Surgery is the primary treatment modality for localized CRC. Advances in (neo)adjuvant chemotherapy and radiation have reduced the disease recurrence and increased survival in high risk diseases. Although recent advancements in combination chemotherapy and target agents have increased the survival of incurable CRC, it is remarkable that only selected patients with advanced CRC can be cured with multimodality therapy.

CONCLUSION

Over the past decade, there has seen substantial progress in our understanding of and in the management of CRC.

Primary and secondary prevention of colorectal cancer

INTRODUCTION

Cancer is a worldwide problem as it will affect one in three men and one in four women during their lifetime. Colorectal cancer (CRC) is the third most frequent cancer in men, after lung and prostate cancer, and is the second most frequent cancer in women after breast cancer. It is also the third cause of death in men and women separately, and is the second most frequent cause of death by cancer if both genders are considered together. CRC represents approximately 10% of deaths by cancer. Modifiable risk factors of CRC include smoking, physical inactivity, being overweight and obesity, eating processed meat, and drinking alcohol excessively. CRC screening programs are possible only in economically developed countries. However, attention should be paid in the future to geographical areas with ageing populations and a western lifestyle.19,20 Sigmoidoscopy screening done with people aged 55–64 years has been demonstrated to reduce the incidence of CRC by 33% and mortality by CRC by 43%.

OBJECTIVE

To assess the effect on the incidence and mortality of CRC diet and lifestyle and to determine the effect of secondary prevention through early diagnosis of CRC.

METHODOLOGY: A comprehensive search of Medline and Pubmed articles related to primary and secondary prevention of CRC and subsequently, a meta-analysis of the same blocks are performed.

RESULTS

225 articles related to primary or secondary prevention of CRC were retrieved. Of these 145 were considered valid on meta-analysis: 12 on epidemiology, 56 on diet and lifestyle, and over 77 different screenings for early detection of CRC. Cancer is a worldwide problem as it will affect one in three men and one in four women during their lifetime. There is no doubt whatsoever which environmental factors, probably diet, may account for these cancer rates. Excessive alcohol consumption and cholesterol-rich diet are associated with a high risk of colon cancer. A diet poor in folic acid and vitamin B6 is also associated with a higher risk of developing colon cancer with an overexpression of p53. Eating pulses at least three times a week lowers the risk of developing colon cancer by 33%, after eating less meat, while eating brown rice at least once a week cuts the risk of CRC by 40%. These associations suggest a dose–response effect. Frequently eating cooked green vegetables, nuts, dried fruit, pulses, and brown rice has been associated with a lower risk of colorectal polyps. High calcium intake offers a protector effect against distal colon and rectal tumors as compared with the proximal colon. Higher intake of dairy products and calcium reduces the risk of colon cancer. Taking an aspirin (ASA) regularly after being diagnosed with colon cancer is associated with less risk of dying from this cancer, especially among people who have tumors with COX-2 overexpression.16 Nonetheless, these data do not contradict the data obtained on a possible genetic predisposition, even in sporadic or non-hereditary CRC. CRC is susceptible to screening because it is a serious health problem given its high incidence and its associated high morbidity/mortality.

CONCLUSIONS

(1) Cancer is a worldwide problem. (2) A modification of diet and lifestyle could reduce morbidity and mortality. (3) Early detection through screening improves prognosis and reduces mortality.

Smoking increases rectal cancer risk to the same extent in women as in men: results from a Norwegian cohort study

Background

Smoking has recently been established as a risk factor for rectal cancer. We examined whether the smoking-related increase in rectal cancer differed by gender.

Methods

We followed 602,242 participants (49% men), aged 19 to 67 years at enrollment from four Norwegian health surveys carried out between 1972 and 2003, by linkage to Norwegian national registries through December 2007. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by fitting Cox proportional hazard models and adjusting for relevant confounders. Heterogeneity by gender in the effect of smoking and risk of rectal cancer was tested with Wald χ².

Results

During a mean follow-up of 14 years, 1,336 men and 840 women developed invasive rectal cancer. Ever smokers had a significantly increased risk of rectal cancer of more than 25% for both men (HR = 1.27, 95% CI = 1.11-1.45) and women (HR = 1.28, 95% CI = 1.11-1.48) compared with gender-specific never smokers. Men smoking ≥20 pack-years had a significantly increased risk of rectal cancer of 35% (HR = 1.35, 95% CI = 1.14-1.58), whereas for women, it was 47% (HR = 1.47, 95% CI = 1.13-1.91) compared with gender-specific never smokers. For both men and women, we observed significant dose–response associations between the risk of rectal cancer for four variables [Age at smoking initiation in years (both p_trend <0.05), number of cigarettes smoked per day (both p_trend <0.0001), smoking duration in years (p_trend <0.05, <0.0001) and number of pack-years smoked (both p_trend <0.0001)]. The test for heterogeneity by gender was not significant between smoking status and the risk of rectal cancer (Wald χ², p -value; current smokers = 0.85; former smokers = 0.87; ever smokers = 1.00).

Conclusions

Smoking increases the risk of rectal cancer to the same extent in women as in men.

Double-contrast-enhanced sonography for diagnosis of rectal lesions with pathologic correlation

OBJECTIVES

Transabdominal sonography with a gastrointestinal contrast agent has been widely used in China for investigation of digestive disorders. Double-contrast-enhanced sonography combines a gastrointestinal luminal contrast agent with an intravenous contrast agent for imaging of lesions. The purpose of this pilot study was to assess the value of double-contrast-enhanced sonography for preoperative diagnosis of rectal lesions.

METHODS

We conducted a prospective single-center study using double-contrast-enhanced sonography of rectal lesions. Patients were administered both rectal and intravenous contrast agents, and imaging was performed transabdominally, transanally, and transrectally. Morphologic characteristics and perfusion parameters were compared between histologically proven adenocarcinomas, adenomas, and inflammatory masses. Perfusion parameters were analyzed with time-intensity curves, measuring the contrast arrival time, time to peak, peak intensity, and area under the curve of the lesions and normal rectal tissue.

RESULTS

From January 2009 to September 2012, 420 patients were recruited, with 227 patients meeting inclusion/exclusion criteria and having 232 rectal lesions analyzed (172 rectal adenocarcinomas, 45 adenomas, and 15 inflammatory masses). Adenocarcinomas had variable enhancement patterns. Adenomas were all hypoenhanced in a homogeneous pattern. Inflammatory masses had a hyperenhanced rim with no central enhancement. Time-intensity curve perfusion parameters (arrival time, time to peak, peak intensity, and area under the curve) of rectal adenocarcinomas, adenomas, and inflammatory masses were significantly different compared to normal rectal tissue (P < .05). The differences in the arrival time, peak intensity, and time to peak among the different lesions were also significant (P < .05).

CONCLUSIONS

Double-contrast-enhanced sonographic assessment of morphologic enhancement patterns combined with vascularity parameters may help differentiate benign and malignant rectal lesions.

Smoking, lower gastrointestinal endoscopy, and risk for colorectal cancer

BACKGROUND

Lower gastrointestinal endoscopy can decrease colorectal cancer risk strongly through detection and removal of adenomas. Thus, we aimed to investigate whether utilization of lower gastrointestinal endoscopy modifies the effect of lifetime smoking exposure on colorectal cancer risk in a population-based case-control study.

METHODS

In this study from Southern Germany including 2,916 patients with colorectal cancer and 3,044 controls, information about lifetime smoking and other risk factors was obtained from standardized interviews. Self-reported endoscopies were validated by medical records. Multivariate logistic regression was performed to investigate associations of smoking with colorectal cancer risk after stratification by utilization of lower gastrointestinal endoscopy in the preceding 10 years.

RESULTS

Median age of patients and controls was 69 and 70 years, respectively. Former regular smoking was associated with increased colorectal cancer risk in the group with no previous endoscopy [adjusted OR, 1.50; 95% confidence interval (CI), 1.28-1.75], whereas no association was found in the group with preceding endoscopy (OR, 1.05; CI, 0.83-1.33; P for interaction <0.01). Lower gastrointestinal endoscopy did not modify the association of smoking and colorectal cancer risk among current smokers and among the more recent quitters.

CONCLUSIONS

Our results suggest that the increased risk of colorectal cancer among former regular smokers is essentially overcome by detection and removal of adenomas at lower gastrointestinal endoscopy. However, risk of colorectal cancer was increased if smoking was continued into higher adult age.

IMPACT

The strong protective effect of lower gastrointestinal endoscopy may be compromised by continued smoking. Smoking cessation may increase the efficacy of lower gastrointestinal endoscopy.

Sex disparities in the association of lung adenocarcinoma with colorectal cancer

Background: Most cancers share common risk factors. It might provide evidence of shared risk factors with cancers by investigating cross-country and cross-township comparisons.

Methods: The data were obtained from International Association of Cancer Registries/World Health Organization and the National Cancer Registration Program of Taiwan. Age standardized incidence rates were calculated among gastric cancer, colorectal cancer and lung adenocarcinoma in 19 countries from 1995 to 1998. The Pearson correlations were also compared among 3 types of cancers for both sexes.

Results: The incidence rates of gastric and colorectal cancer throughout different countries show male dominance with a male-to-female sex ratio of around 2 and 1.5, respectively. Significant cross-country correlations in colorectal cancer (r=0.918, p<0.001), gastric cancer (r=0.985, p<0.001) and lung adenocarcinoma (r=0.685, p=0.001) were observed between men and women. There was a significant international correlation between colorectal cancer and lung adenocarcinoma in men (r=0.526, p=0.021), but not in women. In cross-township comparisons of Taiwan, there were significant correlations in colorectal cancer (r=0.451, p<0.001), gastric cancer (r=0.486, p<0.001), and lung adenocarcinoma (r=0.217, p<0.001) between men and women. There were links of lung adenocarcinoma and gastric cancer (r=0.122, p=0.024) and colorectal cancer (r=0.128, p=0.018) in women, and lung adenocarcinoma and colorectal cancer in men (r=0.276, p<0.001).

Conclusions: There were associations between lung adenocarcinoma and colorectal cancer between and in both sexes in Taiwan, but not in cross-country comparisons. The results suggest that some factor, like genes, may be important as determinants for the association between lung adenocarcinoma and colorectal cancer.

A comparative overview of general risk factors associated with the incidence of colorectal cancer

Cancers found in colorectal region remain largely localized to the large intestine and rectum. They are derived from the epithelium and are considered to be among the most frequently detected cancers. They are known to occur in approximately 5 % population of the Western world. After metastasis, a patient's 5-year postsurgical survival chances unfortunately fall from 90 to 10 % or even less. Adenocarcinoma, the most common cell type of colon cancer, alone constitutes 95 % of the cases. Lymphoma and squamous cell carcinoma can also be found in some cases. Because 5 % of persons are predisposed to development of colorectal cancer, this disease has often been addressed as an important public health issue. Factors that are known in particular to increase a person's risk to develop this cancer are as follows: an individual's age, dietary habits, any complaint of obesity, diabetes, previous history of cancer or intestinal polyps, personal habit of alcohol consumption and smoking, family history of colon cancer, race, sex, and ethnicity. Since the risk of colorectal cancer is increasing steadily in Kashmir, India, like in some other corners of Asia, exhaustive efforts are being made to find the association of above given and other risk factors with the development of this gastrointestinal tract cancer. Adoption of Western life style, diet mimicry, together with a habit of having physically inactive life style and consumption of red meat in particular can be blamed as being active players to a considerable extent.

Risk of colorectal cancer associated with active smoking among female teachers

PURPOSE

The objective of this study was to examine the risk of colorectal cancer associated with active smoking among members of the California Teachers Study (CTS), a large cohort of female public school employees for whom highly detailed smoking information is available.

METHODS

The analysis was conducted among the 122,264 CTS participants who lived in California at cohort entry in 1995/1996, had no prior history of colorectal cancer, and provided detailed smoking information. 1,205 cases of invasive colorectal cancer prospectively diagnosed in 1995-2009 were identified from the California Cancer Registry, including 650 in the proximal colon, 267 in the distal colon, and 288 in the rectum. Hazard ratios and 95% confidence intervals were estimated using Cox proportional hazards models, stratified by age at cohort entry, and adjusted for race/ethnicity.

RESULTS

Compared to never smokers, current smokers had an approximately 30% increased risk of colorectal cancer. Overall, a slightly elevated risk was also noted for former smokers. Among former smokers, risks appeared to remain elevated for up to 20 years following cessation. Risks among former and current smokers increased with greater intensity and duration of smoking. Little evidence for heterogeneity in risk was noted for colon versus rectal cancer or for different subsites within the colon.

CONCLUSIONS

These results provide convincing evidence that heavy and/or long-term smoking is a risk factor for cancers of the colon and rectum. Such evidence should be considered when updating screening guidelines to include targeting people with long active smoking histories.

The increased risk of colon cancer due to cigarette smoking may be greater in women than men

BACKGROUND

Smoking is a recently established risk factor for colon cancer. We wanted to explore the hypothesis that women may be more susceptible to smoking-attributed colon cancer than men as one of the possible explanations for the high colon cancer risk of Norwegian women.

METHODS

We followed 602,242 participants aged 19 to 67 years at enrollment in 1972-2003, by linkage to national registries through December 2007. We used Cox proportional hazard models to estimate HRs and 95% confidence intervals (CI).

RESULTS

During a mean follow-up of 14 years, altogether 3,998 (46% women) subjects developed colon cancer. Female ever-smokers had a 19% (HR = 1.19, 95% CI = 1.09-1.32) and male ever-smokers an 8% (HR = 1.08, CI = 0.97-1.19) increased risk of colon cancer compared with never smokers. For all the four dose-response variables examined, female ever-smokers in the most exposed category of smoking initiation, (HR = 1.48, 95% CI = 1.21-1.81), of daily cigarette consumption (HR = 1.28, 95% CI = 1.06-1.55), of smoking duration (HR = 1.47, 95% CI = 1.11-1.95), and of pack-years of smoking (HR = 1.33, 95% CI = 1.11-1.57) had a significantly increased risk of more than 20% for colon cancer overall and of more than 40% for proximal colon cancer, compared with never smokers. A test for heterogeneity by gender was statistically significant only for ever smoking and risk of proximal colon cancer (Wald χ(2), P = 0.02).

CONCLUSIONS

Female smokers may be more susceptible to colon cancer and especially to proximal colon cancer than male smokers.

IMPACT

Women who smoke are more vulnerable to colon cancer than men.

Effects of smoking and antioxidant micronutrients on risk of colorectal cancer

BACKGROUND & AIMS

Antioxidant intake has been reported to increase the risk of colorectal cancer (CRC) for smokers, yet reduce the risk for nonsmokers. We investigated the association between tobacco smoking and risk of colon or rectal cancer, and whether dietary and supplemental intake of the antioxidant vitamins A, C, E, β-carotene, selenium, zinc, and manganese affects the risk of CRC among smokers.

METHODS

Data on smoking habits and antioxidant intake were analyzed for 54,208 participants in the Danish Prospective Diet, Cancer and Health Study. Of these participants, 642 were diagnosed with colon cancer and 348 were diagnosed with rectal cancer. Hazard ratios and 95% confidence intervals were estimated using Cox proportional hazard models. Principal components were used to analyze intake of combinations of antioxidants.

RESULTS

Ever smoking increased the risk for CRC (hazard ratio, 1.19; 95% confidence interval, 1.03-1.37), especially for rectal cancer. Smoking for at least 20 years was associated with a 26% increase in risk of CRC, compared with never smokers, and smoking 20 g tobacco or more each day was associated with a 30% increase in risk. Smoking for more than 30 years, or more than 20 g tobacco each day, was associated with a 48% increase in risk of rectal cancer. We did not observe an interaction between smoking and antioxidant consumption on risk of CRC.

CONCLUSIONS

Tobacco smoking increases the risk for CRC. We did not observe that consumption of antioxidant micronutrients modulates the effects of smoking on CRC risk.

Estrogen plus progestin and colorectal cancer incidence and mortality

PURPOSE

During the intervention phase in the Women's Health Initiative (WHI) clinical trial, use of estrogen plus progestin reduced the colorectal cancer diagnosis rate, but the cancers were found at a substantially higher stage. To assess the clinical relevance of the findings, analyses of the influence of combined hormone therapy on colorectal cancer incidence and colorectal cancer mortality were conducted after extended follow-up.

PATIENTS AND METHODS

The WHI study was a randomized, double-blind, placebo-controlled clinical trial involving 16,608 postmenopausal women with an intact uterus who were randomly assigned to daily 0.625 mg conjugated equine estrogen plus 2.5 mg medroxyprogesterone acetate (n = 8,506) or matching placebo (n = 8,102). Colorectal cancer diagnosis rates and colorectal cancer mortality were assessed.

RESULTS

After a mean of 5.6 years (standard deviation [SD], 1.03 years) of intervention and 11.6 years (SD, 3.1 years) of total follow-up, fewer colorectal cancers were diagnosed in the combined hormone therapy group compared with the placebo group (diagnoses/year, 0.12% v 0.16%; hazard ratio [HR], 0.72; 95% CI, 0.56 to 0.94; P = .014). Bowel screening examinations were comparable between groups throughout. Cancers in the combined hormone therapy group more commonly had positive lymph nodes (50.5% v 28.6%; P < .001) and were at higher stage (regional or distant, 68.8% v 51.4%; P = .003). Although not statistically significant, there was a higher number of colorectal cancer deaths in the combined hormone therapy group (37 v 27 deaths; 0.04% v 0.03%; HR, 1.29; 95% CI, 0.78 to 2.11; P = .320).

CONCLUSION

The findings, suggestive of diagnostic delay, do not support a clinically meaningful benefit for combined hormone therapy on colorectal cancer.

APC and KRAS mutations in distal colorectal polyps are related to smoking habits in men: results of a cross-sectional study

BACKGROUND

The purpose of this study was (a) to evaluate the association between cigarette smoking and the prevalence of distal colorectal polyps and adenocarcinoma and (b) to analyse genetic alterations representing different molecular pathways of the colorectal carcinogenesis.

METHODS

A total of 623 asymptomatic male (mean age: 53 years; 50-65) car factory workers were included. Information on smoking habits and other lifestyle factors were collected followed by a 60 cm colonoscopy. APC and KRAS mutations and microsatellite status were determined in colorectal lesions (colorectal carcinoma (CRC), hyperplastic (HP) and adenomatous polyps (AP)). Data were analysed using unconditional multiple logistic regression models.

RESULTS

Smokers had a higher prevalence of AP (OR 2.1; 95% CI 1.2-3.6; p<0.05) and HP (OR 5.4; 95% CI 2.6- 11.1; p<0.05). No differences in CRC were observed. There was a dose-response relationship with the number of cigarettes smoked. The risk of developing AP or HP decreased after smoking cessation, even among heavy smokers (≥20 packs/year). KRAS mutations were more prevalent among smokers AP (OR 5.6; 95% CI 1.6-20.4; p=0.007). There was a trend of positive association with APC mutations (OR 3.5; 95% CI 0.9-4.4; p=0.096). APC and KRAS mutations were found in 36% and 61% of the HP of smokers, but were absent in non-smokers (p=0.89 and 0.78, respectively). There were no differences in MSI between smokers and non-smokers.

CONCLUSIONS

Cigarette smoking is associated with a higher risk of developing both HP and AP and a higher prevalence of mutations in APC and KRAS.

Identification and chemoprevention in subjects at moderate risk of colorectal cancer

The risk of developing colorectal cancer (CRC) depends on both genetic factors and lifestyle-related factors. Chemoprevention's true contribution is dependent on lifetime CRC risk. There are clinical situations where chemoprevention for CRC is undoubtedly useful. There are other situations where the risk of CRC seems to be only moderately increased and in these situations, the true contribution of chemoprevention is questionable. A few specific studies assessing the effect of chemopreventive agents in these situations are available. In the present article, we will try to better define these particular situations and discuss the risk quantification and the expected chemoprevention contribution.

Colorectal cancer screening and prevention in women

Colorectal cancer (CRC) is the third most common cause of cancer in women. Screening for CRC increases early detection of cancer and premalignant polyps and decreases morbidity from this disease. However, adherence to the screening guidelines continues to remain inadequate both at the physician and patient levels. Several factors are of special importance to women. Presence of prior gynecological malignancies may increase the risk of CRC in women. Furthermore, new studies have shown other factors such as obesity and smoking to increase the risk of CRC in women. This article highlights issues unique to women with regards to CRC and outlines special considerations for determining screening intervals in women, identifies factors that make screening more difficult in women, and reviews studies that identify preventative strategies which, together with screening, may reduce the burden of CRC.

Disparities in treatment and survival of white and Native American patients with colorectal cancer: a SEER analysis

BACKGROUND

Minority groups with colorectal cancer have not experienced the decline in incidence and mortality that has been reported in whites. We sought to determine whether differences exist in treatment and survival between white and Native American patients with colorectal cancer because little has been written about this specific minority group.

STUDY DESIGN

The Surveillance Epidemiology and End Results (SEER) database for colorectal cancer was used to compare treatment and survival in whites (colon, n = 137,949; rectum, n = 46,843) and Native Americans (colon, n = 872; rectum, n = 316). Cox proportional hazards models were used to compare cancer-specific survival in Native Americans with whites, adjusted for stage, sex, age and year of diagnosis, socioeconomic status, and treatment.

RESULTS

Native Americans presented at younger ages than whites for both colon and rectal cancer (p < 0.001). They were diagnosed at more advanced stages of disease than whites for only colon cancer. No significant differences were detected in the proportion of patients recommended for surgery between the two groups, for either cancer at any stage (all p > 0.05). Native Americans with rectal cancer were more likely to receive radiation than whites (p < 0.001), but they received less sphincter-preserving surgery (60.0% vs 65.4%; p = 0.045). Native Americans with colon cancer fared significantly worse than whites (hazard ratio = 1.20; 95% CI = 1.08 to 1.34), but there is no difference in cancer-free survival between races for rectal cancer.

CONCLUSIONS

Compared with whites, Native Americans with colon cancer have worse cancer-specific survival.

Racial differences in colorectal cancer incidence and mortality in the Women's Health Initiative

BACKGROUND

Colorectal cancer (CRC) incidence and mortality rates are higher in African-Americans as compared with other racial/ethnic groups. The women's health initiative (WHI) study sample was used to determine whether differences in CRC risk factors explain racial/ethnic differences in incidence and mortality.

METHODS

The WHI is a longitudinal study of postmenopausal women recruited from 40 centers. Baseline questionnaires were used to collect sociodemographic and health status information. All CRC diagnoses were centrally adjudicated. Cox regression models were used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for invasive CRC by race/ethnicity.

RESULTS

The study sample included 131,481 (83.7%) White, 14,323 (9.1%) African-American, 6,362 (4.1%) Hispanic, 694 (0.4%) Native American and 4,148 (2.6%) Asian/Pacific Islanders. After a mean follow-up of 10.8 years (SD 2.9), CRC incidence was the highest in African-Americans (annualized rate = 0.14%), followed by Whites and Native Americans (0.12% each), Asian/Pacific Islanders (0.10%), and Hispanics (0.08%). After adjustment for age and trial assignment, Hispanics had a lower risk compared with Whites, HR 0.73 (95% CI: 0.54-0.97) (P = 0.03), and African-Americans had a marginally greater risk, HR 1.16 (95% CI: 0.99-1.34), P = 0.06. Multivariable adjustment attenuated the difference in incidence between African-Americans and Whites (HR 0.99, 95% CI: 0.82-1.20), while strengthening the lower HR for Hispanics (HR 0.68, 95% CI: 0.48-0.97).

CONCLUSIONS

African-American/White differences in CRC risk are likely due to sociodemographic/cultural factors other than race.

IMPACT

A number of modifiable exposures could be a focus for reducing CRC risk in African-Americans.

Cigarette smoking and colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition study

BACKGROUND & AIMS

There has been consistent evidence for a relationship between smoking and colorectal cancer (CRC), although it is not clear whether the colon or rectum is more sensitive to the effects of smoking. We investigated the relationships between cigarette smoking and risk of CRC and tumor location.

METHODS

We analyzed data from 465,879 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) study; 2741 developed CRC during the follow-up period (mean, 8.7 years). Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

The risk of colon carcinoma was increased among ever smokers (HR, 1.18; 95% CI, 1.06-1.32) and former cigarette smokers (HR, 1.21; 95% CI, 1.08-1.36), compared with never smokers; the increased risk for current smokers was of borderline significance (HR, 1.13; 95% CI, 0.98-1.31). When stratified for tumor location, the risk of proximal colon cancer was increased for former (HR, 1.25; 95% CI, 1.04-1.50) and current smokers (HR, 1.31; 95% CI, 1.06-1.64), but the risks for cancers in the distal colon or rectum were not. Subsite analyses showed a nonsignificant difference between the proximal and distal colon (P = .45) for former smokers and a significant difference for current smokers (P = .02). For smokers who had stopped smoking for at least 20 years, the risk of developing colon cancer was similar to that of never smokers.

CONCLUSIONS

Ever smokers have an increased risk of colon cancer, which appeared to be more pronounced in the proximal than the distal colon location.

Colorectal cancer: what should patients and families be told to lower the risk of colorectal cancer?

Colorectal cancer (CRC) is the second most common cause of cancer-related death in the United States. CRC, however, is potentially preventable, and several strategies may be employed to decrease the incidence of and mortality from CRC. Understanding of individual risk and adherence to screening and surveillance recommendations undoubtedly will reduce CRC-associated deaths. Several natural and synthetic chemopreventive agents may prove effective for both primary and secondary CRC chemoprevention. Finally, dietary modifications (ie, increased dietary fiber, fruits and vegetables, and decreased red meat) and other lifestyle changes (i.e., increased physical activity, weight maintenance, avoidance of smoking, and moderation of alcohol intake) also may lower the risk of developing CRC.

The comparison of the clinical manifestations and risk factors of colorectal cancer and adenomas: results from a colonoscopy-based study in southern Chinese

BACKGROUND AND AIMS

Colorectal cancer (CRC) is one of the most common gastrointestinal tumors in the world. This study aimed to compare the clinical manifestations and risk factors of CRC and adenomas in native patients of Guangzhou.

METHODS

Patients who underwent colonoscopy for the first time at Nanfang Hospital between July 2008 and July 2009 were recruited. Data on demographic information, main clinical manifestations, results of endoscopies and pathology, and possible risk factors of colorectal tumor were collected. Chi-square test and logistic regression were used to compare the clinical characteristics and risk factors for CRC and adenomas.

RESULTS

Hematochezia and body weight loss were more frequent in proximal and distal CRC groups, respectively (P ≤  0.05). Older age [odds ratio (OR), 1.079; 95% confidence interval (CI), 1.065-1.093], smoking status (OR, 1.712; 95% CI, 1.158-2.531), BMI =18.5-24.9 and  ≥ 25.0 (OR, 2.384; 95% CI, 1.250-4.549; OR, 2.162; 95% CI, 1.044-4.478, respectively) were significant risk factors for advanced adenoma, while female (OR, 0.638; 95% CI, 0.429-0.949) and using aspirin (OR, 0.188; 95% CI, 0.042-0.845) were significant protective factors. Hyperlipemia (OR, 0.109; 95% CI, 0.013-0.886) was identified as a protective factor for proximal CRC. Smoking (OR, 1.717; 95% CI, 1.093-2.696), drinking (OR, 1.817; 95% CI, 1.145-2.883), DM history (OR, 2.204; 95% CI, 1.044-4.652) were identified as independent risk factors for distal CRC, and using aspirin (OR, 0.190; 95% CI, 0.043-0.840) was a protective factor. Drinking (OR, 3.288; 95% CI, 1.546-6.994; OR, 1.862; 95% CI, 1.037-3.343, respectively) was an independent risk factor for both poorly to moderately differentiated CRC and well-differentiated CRC. Besides, DM (OR, 3.761; 95% CI, 1.615-8.762) and hypertension (OR, 0.384; 95% CI, 0.178-0.828) were identified as independent risk factor and protective factor for well-differentiated CRC, respectively.

CONCLUSIONS

Hematochezia and body weight loss were representative manifestations for distal and proximal CRC, respectively. For southern Chinese the most important influential factors for colorectal tumor are age, smoking, drinking, nutritional state, DM, hypertension, and the use of aspirin.

Does level of sedation impact detection of advanced neoplasia?

BACKGROUND AND AIMS

Two of the foremost issues in screening colonoscopy involve delivering quality and maximizing adenoma detection rates (ADR). Little is known about the impact of deep sedation on ADR. This study aims to compare the detection of advanced lesions during screening colonoscopy performed with moderate conscious sedation (MCS) versus deep sedation (DS).

METHODS

A retrospective cohort study was performed using the Clinical Outcomes Research Initiative database. Average risk screening colonoscopies performed January 2000 to December 2005 were examined for practice setting, patient demographics, and findings, including detection of a polyp >9 mm and suspected malignant lesions.

RESULTS

A total of 104,868 colonoscopies were examined, 97% of which were performed with MCS. Univariate analysis demonstrated that more polyps of any size were detected with MCS (38 vs. 34%, p < 0.0001) and more advanced lesions were found with DS compared with MCS (7 vs. 6%, p = 0.01). When exclusively examining sites that performed DS > 10% for all procedures, a more significant increase in advanced lesion detection when using DS was observed (7.5 vs. 5.7%, p = 0.003). When adjusted for age, gender, race/ethnicity, site, prep quality, and ASA group, DS was 25% more likely to detect an advanced lesion.

CONCLUSIONS

Our data suggest that use of DS may be associated with a higher rate of advanced lesion detection. However, this retrospective design has limitations that necessitate follow-up with prospective studies. These follow-up studies would be essential to support any change in the standard practices of sedation.