A Prospective Study of Smoking and Risk of Synchronous Colorectal Cancers

Rare synchronous colorectal carcinoma with three pathological subtypes: A case report and review of the literature

BACKGROUND

Synchronous colorectal carcinomas (SCRC) are two or more primary colorectal carcinomas identified simultaneously or within 6 mo of the initial presentation in a single patient. Their incidence is low and the number of pathological types of SCRC is usually no more than two. It is very unusual that the pathological findings of a patient with SCRC show more than two different pathological subtypes. Here, we report a rare case of SCRC with three pathological subtypes.

CASE SUMMARY

A 75-year-old woman who had no previous medical history or family history was admitted to the hospital because of intermittent hematochezia for more than a month. Colonoscopy displayed an irregularly shaped neoplasm of the rectum, a tumor-like lesion causing intestinal stenosis in the descending colon, and a polypoidal neoplasm in the ileocecum. Subsequently, she underwent total colectomy, abdominoperineal resection for rectal cancer, and ileostomy. After operation, the pathological report showed three pathological subtypes including well-differentiated adenocarcinoma of the ascending colon, moderately differentiated adenocarcinoma of the descending colon, and mucinous adenocarcinoma of the rectum. She is now recovering well and continues to be closely monitored during follow-up.

CONCLUSION

Preoperative colonoscopy examination, imaging examination, and extensive intraoperative exploration play important roles in reducing the number of missed lesions.

Developing prognostic nomograms to predict overall survival and cancer-specific survival in synchronous multiple primary colorectal cancer based on the SEER database

BACKGROUND

Synchronous multiple primary colorectal cancer (SMPCC) is a rare subtype of CRC, characterized by the presence of two or more primary CRC lesions simultaneously or within 6 months from the detection of the first lesion. We aim to develop a novel nomogram to predict OS and CSS for SMPCC patients using data from the SEER database.

METHODS

The clinical variables and survival data of SMPCC patients between 2004 and 2018 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Appropriate inclusion and exclusion criteria were established to screen the enrolled patients. Univariate and multivariate Cox regression analyses were used to identify the independent risk factors for OS and CSS. The performance of the nomogram was evaluated using the concordance index (C-index), calibration curves, and the area under the curve (AUC) of a receiver operating characteristics curve (ROC). A decision curve analysis (DCA) was generated to compare the net benefits of the nomogram with those of the TNM staging system.

RESULTS

A total of 6772 SMPCC patients were enrolled in the study and randomly assigned to the training (n = 4670) and validation (n = 2002) cohorts. Multivariate Cox analysis confirmed that race, marital status, age, histology, tumor position, T stage, N stage, M stage, chemotherapy, and the number of dissected LNs were independent prognostic factors.The C-index values for OS and CSS prediction were 0.716 (95% CI 0.705-0.727) and 0.718 (95% CI 0.702-0.734) in the training cohort, and 0.760 (95% CI 0.747-0.773) and 0.749 (95% CI 0.728-0.769) in the validation cohort. The ROC and calibration curves indicated that the model had good stability and reliability. Decision curve analysis revealed that the nomograms provided a more significant clinical net benefit than the TNM staging system.

CONCLUSION

We developed a novel nomogram for clinicians to predict OS and CSS, which could be used to optimize the treatment in SMPCC patients.

A Rare Case of Synchronous Esophageal and Pancreatic Malignancy

The incidence of double primary tumors has been rising over the past few decades. Synchronous pancreatic and esophageal carcinomas are rarely reported in the literature. In this case report, we present an 86-year-old man who developed synchronous double cancers of the pancreas and esophagus. He has a past medical history of hypertension and prior nicotine dependence and was admitted for abdominal pain and weight loss. Laboratory data on admission were normal except for the serum carbonic anhydrase 19-9 (54 U/mL, reference range: 0-34 U/mL) and carcinoembryonic antigen (712.4 ng/mL, reference range: less than <5.0 ng/mL). Abdominal ultrasonography revealed a 2.3 cm lesion at the head of the pancreas. A CT scan with contrast was highly suspicious for pancreatic head malignancy. The patient underwent endoscopical ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) that showed a large non-obstructing ulcerating mass at the gastroesophageal junction (GEJ) as well as a pancreatic head mass. Histological findings from the obtained tissue demonstrated pancreatic adenocarcinoma and intestinal-type adenocarcinoma of the esophagus with an invasion of lamina propria, and diagnosis of double cancers of the pancreas and esophagus was made. In conclusion, our case report represents the fifth documented case of dual primary malignancy of the esophagus and pancreas. This highlights that, despite their rarity, primary distant malignancies in patients with pancreatic cancer is an entity that clinicians should be more cognizant about especially among the male smoker/ex-smoker patient population, specifically given that the current data demonstrate that the prognosis of double cancers primarily depends on the prognosis of the pancreatic carcinoma.

Association Between Smoking and Molecular Subtypes of Colorectal Cancer

Background

Smoking is associated with colorectal cancer (CRC) risk. Previous studies suggested this association may be restricted to certain molecular subtypes of CRC, but large-scale comprehensive analysis is lacking.

Methods

A total of 9789 CRC cases and 11 231 controls of European ancestry from 11 observational studies were included. We harmonized smoking variables across studies and derived sex study-specific quartiles of pack-years of smoking for analysis. Four somatic colorectal tumor markers were assessed individually and in combination, including BRAF mutation, KRAS mutation, CpG island methylator phenotype (CIMP), and microsatellite instability (MSI) status. A multinomial logistic regression analysis was used to assess the association between smoking and risk of CRC subtypes by molecular characteristics, adjusting for age, sex, and study. All statistical tests were 2-sided and adjusted for Bonferroni correction.

Results

Heavier smoking was associated with higher risk of CRC overall and stratified by individual markers (P trend < .001). The associations differed statistically significantly between all molecular subtypes, which was the most statistically significant for CIMP and BRAF. Compared with never-smokers, smokers in the fourth quartile of pack-years had a 90% higher risk of CIMP-positive CRC (odds ratio = 1.90, 95% confidence interval = 1.60 to 2.26) but only 35% higher risk for CIMP-negative CRC (odds ratio = 1.35, 95% confidence interval = 1.22 to 1.49; P difference = 2.1 x 10-6). The association was also stronger in tumors that were CIMP positive, MSI high, or KRAS wild type when combined (P difference < .001).

Conclusion

Smoking was associated with differential risk of CRC subtypes defined by molecular characteristics. Heavier smokers had particularly higher risk of CRC subtypes that were CIMP positive and MSI high in combination, suggesting that smoking may be involved in the development of colorectal tumors via the serrated pathway.

Smoking and Colorectal Cancer Risk, Overall and by Molecular Subtypes: A Meta-Analysis

INTRODUCTION

The aim of this study was to provide the most comprehensive and up-to-date evidence on the association between cigarette smoking and colorectal cancer (CRC) risk.

METHODS

We conducted a systematic review and meta-analysis of epidemiological studies on the association between cigarette smoking and CRC risk published up to September 2018. We calculated relative risk (RR) of CRC according to smoking status, intensity, duration, pack-years, and time since quitting, with a focus on molecular subtypes of CRC.

RESULTS

The meta-analysis summarizes the evidence from 188 original studies. Compared with never smokers, the pooled RR for CRC was 1.14 (95% confidence interval [CI] 1.10-1.18) for current smokers and 1.17 (95% CI 1.15-1.20) for former smokers. CRC risk increased linearly with smoking intensity and duration. Former smokers who had quit smoking for more than 25 years had significantly decreased risk of CRC compared with current smokers. Smoking was strongly associated with the risk of CRC, characterized by high CpG island methylator phenotype (RR 1.42; 95% CI 1.20-1.67; number of studies [n] = 4), BRAF mutation (RR 1.63; 95% CI 1.23-2.16; n = 4), or high microsatellite instability (RR 1.56; 95% CI 1.32-1.85; n = 8), but not characterized by KRAS (RR 1.04; 95% CI 0.90-1.20; n = 5) or TP53 (RR 1.13; 95% CI 0.99-1.29; n = 5) mutations.

DISCUSSION

Cigarette smoking increases the risk of CRC in a dose-dependent manner with intensity and duration, and quitting smoking reduces CRC risk. Smoking greatly increases the risk of CRC that develops through the microsatellite instability pathway, characterized by microsatellite instability-high, CpG island methylator phenotype positive, and BRAF mutation.

Risk Factors and Incidence of Colorectal Cancer According to Major Molecular Subtypes

Background

Colorectal cancer (CRC) is a heterogeneous disease that can develop via 3 major pathways: conventional, serrated, and alternate. We aimed to examine whether the risk factor profiles differ according to pathway-related molecular subtypes.

Methods

We examined the association of 24 risk factors with 4 CRC molecular subtypes based on a combinatorial status of microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and BRAF and KRAS mutations by collecting data from 2 large US cohorts. We used inverse probability weighted duplication-method Cox proportional hazards regression to evaluate differential associations across subtypes.

Results

We documented 1175 CRC patients with molecular subtype data: subtype 1 (n = 498; conventional pathway; non-MSI-high, CIMP-low or negative, BRAF-wild-type, KRAS-wild-type), subtype 2 (n = 138; serrated pathway; any MSI status, CIMP-high, BRAF-mutated, KRAS-wild-type), subtype 3 (n = 367; alternate pathway; non-MSI-high, CIMP-low or negative, BRAF-wild-type, KRAS-mutated), and subtype 4 (n = 172; other marker combinations). Statistically significant heterogeneity in associations with CRC subtypes was found for age, sex, and smoking, with a higher hazard ratio (HR) observed for the subtype 2 (HR per 10 years of age = 2.64, 95% CI = 2.13 to 3.26; HR for female = 2.65, 95% CI = 1.60 to 4.39; HR per 20-pack-year of smoking = 1.29, 95% CI = 1.14 to 1.45) than other CRC subtypes (all P_{heterogeneity} < .005). A stronger association was found for adiposity measures with subtype 1 CRC in men and subtype 3 CRC in women and for several dietary factors with subtype 1 CRC, although these differences did not achieve statistical significance at α  level of .005.

Conclusions

Risk factor profiles may differ for CRC arising from different molecular pathways.

Common habitual behaviors and synchronous colorectal cancer risk: a retrospective case-control study

PURPOSE

The association of habitual behaviors with the prevalence of synchronous colorectal cancer (sCRC) is unknown. Here, we investigated whether these behaviors, which are known risk factors for colorectal polyps, may be related to sCRC risk.

METHODS

We enrolled 17,093 patients who underwent cancer treatment between January 1995 and December 2016 and examined the association of age, sex, familial history of hereditary colorectal cancer (CRC), and status of three common habitual behaviors (smoking and alcohol and coffee consumption) with the prevalence of sCRC.

RESULTS

Of the enrolled patients, 960 (5.6%) patients had sCRC. The independent risk factors for sCRC prevalence included advanced age, male sex, hereditary CRC, smoking, and daily alcohol consumption of more than one bottle (> 600 mL). Contrary to these factors, daily coffee consumption of more than one cup seemed to provide a protection from sCRC. In the Kaplan-Meier test, the significantly worse 5-year overall survival (OS) was noted in smokers with stage 0-III CRC. The effect of alcohol consumption on 5-year OS was significant in stages II and III. Compared with those without daily coffee consumption, patients with daily coffee consumption had significantly higher 5-year OS in stages I (93.0% vs. 86.4%), II (87.1% vs. 77.2%), III (71.5% vs. 61.9%), and IV (18.0% vs. 13.0%).

CONCLUSIONS

sCRC prevalence was significantly associated with habitual behaviors. Patients with smoking or with daily alcohol consumption of one bottle had higher sCRC prevalence than did those without these habits. Coffee consumption could be a protective factor for lowering sCRC risk.

The CIMP-high phenotype is associated with energy metabolism alterations in colon adenocarcinoma

BACKGROUND

CpG island methylator phenotype (CIMP) is found in 15-20% of malignant colorectal tumors and is characterized by strong CpG hypermethylation over the genome. The molecular mechanisms of this phenomenon are not still fully understood. The development of CIMP is followed by global gene expression alterations and metabolic changes. In particular, CIMP-low colon adenocarcinoma (COAD), predominantly corresponded to consensus molecular subtype 3 (CMS3, "Metabolic") subgroup according to COAD molecular classification, is associated with elevated expression of genes participating in metabolic pathways.

METHODS

We performed bioinformatics analysis of RNA-Seq data from The Cancer Genome Atlas (TCGA) project for CIMP-high and non-CIMP COAD samples with DESeq2, clusterProfiler, and topGO R packages. Obtained results were validated on a set of fourteen COAD samples with matched morphologically normal tissues using quantitative PCR (qPCR).

RESULTS

Upregulation of multiple genes involved in glycolysis and related processes (ENO2, PFKP, HK3, PKM, ENO1, HK2, PGAM1, GAPDH, ALDOA, GPI, TPI1, and HK1) was revealed in CIMP-high tumors compared to non-CIMP ones. Most remarkably, the expression of the PKLR gene, encoding for pyruvate kinase participating in gluconeogenesis, was decreased approximately 20-fold. Up to 8-fold decrease in the expression of OGDHL gene involved in tricarboxylic acid (TCA) cycle was observed in CIMP-high tumors. Using qPCR, we confirmed the increase (4-fold) in the ENO2 expression and decrease (2-fold) in the OGDHL mRNA level on a set of COAD samples.

CONCLUSIONS

We demonstrated the association between CIMP-high status and the energy metabolism changes at the transcriptomic level in colorectal adenocarcinoma against the background of immune pathway activation. Differential methylation of at least nine CpG sites in OGDHL promoter region as well as decreased OGDHL mRNA level can potentially serve as an additional biomarker of the CIMP-high status in COAD.

Cancer risk among young men with weight gain after smoking cessation: A population-based cohort study

BACKGROUND

Smoking cessation may help the current smokers to reduce cancer risk. However, weight gain following smoking cessation may attenuate the protective association of cessation with cancer.

PATIENTS AND METHODS

Our study included 1,278,794 men who were aged 20-39 years and underwent two consecutive health examinations by the National Health Insurance Service, without previous diagnosis of cancer. Participants were categorized into continual smokers, quitters with different degree of body weight change, and never smokers based on the biennial national health screening program (2002-2003 and 2004-2005) and were followed from January 1, 2006 to December 31, 2015. Cox proportional hazard models and restricted cubic spline model was used to evaluate the association of post-cessation weight change and cancer risk after adjustment for potential confounders.

RESULTS

During the 10 years of follow-up, the analyses included 1,278,794 men with 21,494 cancer incidences. Compared to continual smokers, quitters without weight gain of 2.0 kg had significantly lower risk of obesity-related cancer (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.79-0.97), smoking-related cancer (HR, 0.90; 95% CI, 0.83 to 0.98), and gastrointestinal cancer (HR, 89; 95% CI, 0.80 to 0.98). Weight gain among quitters attenuated the risk reduction of cancer compared to continual smoking. Among quitters, weight gain up to 5.0 kg with smoking cessation showed protective association with cancer risk among quitters without weight gain.

CONCLUSION

Excessive weight gain with smoking cessation among quitters was not associated with reduced risk of several cancer types. This association should be taken into account when recommending smoking cessation to prevent cancer.

Smoking and Risk of Colorectal Cancer Sub-Classified by Tumor-Infiltrating T Cells

Background

Evidence indicates not only carcinogenic effect of cigarette smoking but also its immunosuppressive effect. We hypothesized that the association of smoking with colorectal cancer risk might be stronger for tumors with lower anti-tumor adaptive immune response.

Methods

During follow-up of 134 981 participants (3 490 851 person-years) in the Nurses' Health Study and Health Professionals Follow-up Study, we documented 729 rectal and colon cancer cases with available data on T-cell densities in tumor microenvironment. Using the duplication-method Cox regression model, we examined a differential association of smoking status with risk of colorectal carcinoma subclassified by densities of CD3+ cells, CD8+ cells, CD45RO (PTPRC)+ cells, or FOXP3+ cells. All statistical tests were two-sided.

Results

The association of smoking status with colorectal cancer risk differed by CD3+ cell density (Pheterogeneity = .007). Compared with never smokers, multivariable-adjusted hazard ratios for CD3+ cell-low colorectal cancer were 1.38 (95% confidence interval = 1.09 to 1.75) in former smokers and 1.59 (95% confidence interval = 1.14 to 2.23) in current smokers (Ptrend = .002, across smoking status categories). In contrast, smoking status was not associated with CD3+ cell-high cancer risk (Ptrend = .52). This differential association appeared consistent in strata of microsatellite instability, CpG island methylator phenotype, or BRAF mutation status. There was no statistically significant differential association according to densities of CD8+ cells, CD45RO+ cells, or FOXP3+ cells (Pheterogeneity > .04, with adjusted α of 0.01).

Conclusions

Colorectal cancer risk increased by smoking was stronger for tumors with lower T-lymphocyte response, suggesting an interplay of smoking and immunity in colorectal carcinogenesis.

Methylation of tumor suppressor genes and risk factors of colorectal cancer

Although the diagnostic methods and treatment options are continuously optimized, the incidence and mortality of colorectal cancer (CRC) are still rising. Therefore, "preventive treatment of disease" is the key to solving this problem. In recent years, hypermethylation of promoter CpG islands (CGIs) in tumor suppressor genes has been a hot research topic because it is reversible and early events in the development of CRC, and affects drug resistance, disease treatment, and patient prognosis. CRC risk factors such as poor dietary choice, lack of physical activity, excessive drinking, and unhealthy weight can regulate promoter CGI hypermethylation, which will help develop new methylation-related cancer prevention strategies. This article mainly introduces the significance and regulatory mechanism of methylation of tumor suppressor genes and its relationship with risk factors in CRC.

Association Between Risk Factors for Colorectal Cancer and Risk of Serrated Polyps and Conventional Adenomas

BACKGROUND & AIMS

Serrated polyps (SPs) and conventional adenomas are precursor lesions for colorectal cancer (CRC), but they are believed to arise via distinct pathways. We characterized risk factor profiles for SPs and conventional adenomas in a post hoc analysis of data from 3 large prospective studies.

METHODS

We collected data from the Nurses' Health Study, the Nurses' Health Study 2, and the Health Professionals Follow-up Study on subjects who developed SPs or conventional adenomas. Our analysis comprised 141,143 participants who had undergone lower gastrointestinal endoscopy, provided updated diet and lifestyle data every 2-4 years, and were followed until diagnosis of a first polyp. We assessed 13 risk factors for CRC in patients with SPs or conventional adenomas and examined the associations according to histopathology features.

RESULTS

We documented 7945 SPs, 9212 conventional adenomas, and 2382 synchronous SPs and conventional adenomas during 18-20 years of follow-up. Smoking, body mass index, alcohol intake, family history of CRC, and height were associated with higher risk of SPs and conventional adenomas, whereas higher intake of vitamin D and marine omega-3 fatty acid were associated with lower risk. The associations tended to be stronger for synchronous SPs and conventional adenomas. Smoking, body mass index, and alcohol intake were more strongly associated with SPs than conventional adenomas (P for heterogeneity <.05), whereas physical activity and intake of total folate and calcium were inversely associated with conventional adenomas but not SPs. For SPs and conventional adenomas, the associations tended to be stronger for polyps in the distal colon and rectum, of 10 mm or larger or with advanced histology.

CONCLUSIONS

In an analysis of data from 3 large prospective studies, we found that although SPs and conventional adenomas share many risk factors, some factors are more strongly associated with one type of lesion than the other. These findings provide support for the etiologic heterogeneity of colorectal neoplasia.

Integrated analysis of colorectal cancer microRNA datasets: identification of microRNAs associated with tumor development

Colorectal cancer (CRC) is one of the leading cause of cancer death worldwide. Currently, no effective early diagnostic biomarkers are available for colorectal carcinoma. Therefore, there is a need to discover new molecules able to identify pre-cancerous lesions. Recently, microRNAs (miRNAs) have been associated with the onset of specific pathologies, thus the identification of miRNAs associated to colorectal cancer may be used to detect this pathology at early stages. On these bases, the expression levels of miRNAs were analyzed to compare the miRNAs expression levels of colorectal cancer samples and normal tissues in several miRNA datasets. This analysis revealed a group of 19 differentially expressed miRNAs. To establish the interaction between miRNAs and the most altered genes in CRC, the mirDIP gene target analysis was performed in such group of 19 differentially expressed miRNAs. To recognize miRNAs able to activate or inhibit genes and pathways involved in colorectal cancer development DIANA-mirPath prediction analysis was applied. Overall, these analyses showed that the up-regulated hsa-miR-183-5p and hsa-miR-21-5p, and the down-regulated hsa-miR-195-5p and hsa-miR-497-5p were directly related to colorectal cancer through the interaction with the Mismatch Repair pathway and Wnt, RAS, MAPK, PI3K, TGF-β and p53 signaling pathways involved in cancer development.

Alcohol, smoking and the risk of premalignant and malignant colorectal neoplasms

Colorectal cancer (CRC) is the third most common cancer worldwide and has a complex aetiology consisting of environmental and genetic factors. In this review, we evaluate the roles of alcohol and tobacco smoking in colorectal neoplasia. Alcohol intake and tobacco smoking are associated with modest, but significantly, increased risks of CRC, adenomatous and serrated polyps. There is consistent evidence of dose-response relationships for both alcohol and smoking, and risk of these neoplasms. Alcohol and smoking appear to be more strongly associated with colorectal polyp than CRC development, suggesting roles in the initiation of neoplastic growths. These lifestyle factors also seem more strongly related to adenomas and sessile serrated lesions than hyperplastic polyps, but further confirmation is required. The gastroenterology community has an important, yet currently underexploited, role to play addressing the modifiable factors associated with CRC and polyps. These behaviours include, but are not limited to, alcohol and smoking.