Risk factors and clinical characteristics of early-onset colorectal cancer vs. late-onset colorectal cancer: a case-case study

#CRCandMe: results of a pre-post quasi-experimental study of a mass media campaign to increase early-onset colorectal cancer awareness in Utah and Wisconsin

Overall colorectal cancer (CRC) incidence and mortality have been decreasing for several decades; however, since the early 1990s CRC incidence rates have nearly doubled among adults aged under 50 years. This study pilot-tested a community-based mass-media campaign aimed at improving knowledge and awareness of early-onset CRC in this population. The campaign (#CRCandMe) was deployed from June to September 2023 in Utah and Wisconsin. To evaluate its success (reach) and inform future campaigns, key performance indicators were defined (e.g., impressions, website traffic). To evaluate change in knowledge in the target population, the knowledge and awareness of participants recruited via consumer panels was assessed at baseline (n=235) and follow-up (n=161). The number of correct answers for each of seven knowledge items was calculated at baseline (pre-intervention) and follow-up (post-intervention). McNemar's test was employed to assess significant differences in the seven knowledge items between the two timepoints. The campaign delivered over 26.7 million impressions and nearly 43,000 clicks. A 15-second video ad received 221,985 plays, with 57,270 users watching to completion. Pre-survey results revealed that while 74% of participants were able to correctly identify CRC signs, only 18% could identify risk factors. Knowledge scores slightly improved from baseline to follow-up, with statistically significance for the question related to CRC signs (P=0.0004). This study demonstrated wide reach and may inform future larger-scale interventions and public health initiatives aimed at reducing CRC incidence and improving health outcomes for at-risk adults aged under 50 years.

Comparison analysis of the burden and attributable risk factors of early-onset and late-onset colorectal cancer in China from 1990 to 2019

OBJECTIVES

The project intended to analyze the impact of burden and related risk factors of late-onset colorectal cancer (LOCRC) and early-onset colorectal cancer (EOCRC) in China, thus offering essential references for optimizing prevention and control strategies.

METHOD

Global Burden of Disease Study was employed to describe burden changes of EOCRC and LOCRC in China during 1990-2019, containing the numbers of incidence, deaths, prevalence, and disability-adjusted life years (DALYs), and to compare attributable deaths and DALYs risk factors in varying age and sex segments.

RESULTS

The numbers and corresponding crude rates of incidence, deaths, prevalence, and DALYs of EOCRC and LOCRC in China during 1990-2019 demonstrated an upward trend across all age categories, with males being dramatically predominant. Overall, over time, the impact of a low-calcium diet and a low-fiber diet on mortality and DALY rates decreased, while the impact of other risk factors increased. In terms of gender, the risk factors affecting males changed greatly, with smoking, inadequate milk intake, and the low whole-grain diet being the main factors in 2019, while in 1990, the main factors were the low-calcium diet, smoking, and inadequate milk intake.

CONCLUSION

The burden of colorectal cancer in China is concerning. Patients grouped by diagnostic age exhibit different characteristics, indicating the need for high-quality research in the future to achieve personalized medicine tailored to different population characteristics.

Exploring 6 years of colorectal cancer surgery in rural Italy: insights from 648 consecutive patients unveiling successes and challenges

The multidisciplinary management of patients suffering from colorectal cancer (CRC) has significantly increased survival over the decades and surgery remains the only potentially curative option for it. However, despite the implementation of minimally invasive surgery and ERAS pathway, the overall morbidity and mortality remain quite high, especially in rural populations because of urban - rural disparities. The aim of the study is to analyze the characteristics and the surgical outcomes of a series of unselected CRC patients residing in two similar rural areas in Italy. A total of 648 consecutive patients of a median age of 73 years (IQR 64-81) was enrolled between 2017 and 2022 in a prospective database. Emergency admission (EA) was recorded in 221 patients (34.1%), and emergency surgery (ES) was required in 11.4% of the patients. Tumor resection and laparoscopic resection rates were 95.0% and 63.2%, respectively. The median length of stay was 8 days. The overall morbidity and mortality rates were 23.5% and 3.2%, respectively. EA was associated with increased median age (77.5 vs. 71 ys, p < 0.001), increased mean ASA Score (2.84 vs. 2.59; p = 0.002) and increased IV stage disease rate (25.3% vs. 11.5%, p < 0.001). EA was also associated with lower tumor resection rate (87.3% vs. 99.1%, p < 0.001), restorative resection rate (71.5 vs. 89.7%, p < 0.001), and laparoscopic resection rate (36.2 vs. 72.6%, p < 0.001). Increased mortality rates were associated with EA (7.2% vs. 1.2%, p < 0.001), ES (11.1% vs. 2.0%, p < 0.001) and age more than 80 years (5.8% vs. 1.9%, p < 0.001). In rural areas, high quality oncologic care can be delivered in CRC patients. However, the surgical outcomes are adversely affected by a still too high proportion of emergency presentation of elderly and frail patients that need additional intensive care supports beyond the surgical skill and alternative strategies for earlier detection of the disease.

Obesity and early-onset colorectal cancer risk: emerging clinical evidence and biological mechanisms

Early-onset colorectal cancer (EOCRC) is defined as diagnosed at younger than 50 years of age and indicates a health burden globally. Patients with EOCRC have distinct risk factors, clinical characteristics, and molecular pathogenesis compared with older patients with CRC. Further investigations have identified different roles of obesity between EOCRC and late-onset colorectal cancer (LOCRC). Most studies have focused on the clinical characteristics of obesity in EOCRC, therefore, the mechanism involved in the association between obesity and EOCRC remains inconclusive. This review further states that obesity affects the carcinogenesis of EOCRC as well as its development and progression, which may lead to obesity-related metabolic syndrome, intestinal dysbacteriosis, and intestinal inflammation.

Red Flag Signs and Symptoms for Patients With Early-Onset Colorectal Cancer: A Systematic Review and Meta-Analysis

Importance

Early-onset colorectal cancer (EOCRC), defined as a diagnosis at younger than age 50 years, is increasing, and so-called red flag signs and symptoms among these individuals are often missed, leading to diagnostic delays. Improved recognition of presenting signs and symptoms associated with EOCRC could facilitate more timely diagnosis and impact clinical outcomes.

Objective

To report the frequency of presenting red flag signs and symptoms among individuals with EOCRC, to examine their association with EOCRC risk, and to measure variation in time to diagnosis from sign or symptom presentation.

Data Sources

PubMed/MEDLINE, Embase, CINAHL, and Web of Science were searched from database inception through May 2023.

Study Selection

Studies that reported on sign and symptom presentation or time from sign and symptom presentation to diagnosis for patients younger than age 50 years diagnosed with nonhereditary CRC were included.

Data Extraction and Synthesis

Data extraction and quality assessment were performed independently in duplicate for all included studies using Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guidelines. Joanna Briggs Institute Critical Appraisal tools were used to measure risk of bias. Data on frequency of signs and symptoms were pooled using a random-effects model.

Main Outcomes and Measures

Outcomes of interest were pooled proportions of signs and symptoms in patients with EOCRC, estimates for association of signs and symptoms with EOCRC risk, and time from sign or symptom presentation to EOCRC diagnosis.

Results

Of the 12 859 unique articles initially retrieved, 81 studies with 24 908 126 patients younger than 50 years were included. The most common presenting signs and symptoms, reported by 78 included studies, were hematochezia (pooled prevalence, 45% [95% CI, 40%-50%]), abdominal pain (pooled prevalence, 40% [95% CI, 35%-45%]), and altered bowel habits (pooled prevalence, 27% [95% CI, 22%-33%]). Hematochezia (estimate range, 5.2-54.0), abdominal pain (estimate range, 1.3-6.0), and anemia (estimate range, 2.1-10.8) were associated with higher EOCRC likelihood. Time from signs and symptoms presentation to EOCRC diagnosis was a mean (range) of 6.4 (1.8-13.7) months (23 studies) and a median (range) of 4 (2.0-8.7) months (16 studies).

Conclusions and Relevance

In this systematic review and meta-analysis of patients with EOCRC, nearly half of individuals presented with hematochezia and abdominal pain and one-quarter with altered bowel habits. Hematochezia was associated with at least 5-fold increased EOCRC risk. Delays in diagnosis of 4 to 6 months were common. These findings highlight the need to identify concerning EOCRC signs and symptoms and complete timely diagnostic workup, particularly for individuals without an alternative diagnosis or sign or symptom resolution.

Symptom Burden and Time from Symptom Onset to Cancer Diagnosis in Patients with Early-Onset Colorectal Cancer: A Multicenter Retrospective Analysis

Background: The incidence of colorectal cancer (CRC) is decreasing in individuals >50 years due to organised screening but has increased for younger individuals. We characterized symptoms and their timing before diagnosis in young individuals. Methods: We identified all patients diagnosed with CRC between 1990-2017 in British Columbia, Canada. Individuals <50 years (n = 2544, EoCRC) and a matched cohort >50 (n = 2570, LoCRC) underwent chart review to identify CRC related symptoms at diagnosis and determine time from symptom onset to diagnosis. Results: Across all stages of CRC, EoCRC presented with significantly more symptoms than LoCRC (Stage 1 mean ± SD: 1.3 ± 0.9 vs. 0.7 ± 0.9, p = 0.0008; Stage 4: 3.3 ± 1.5 vs. 2.3 ± 1.7, p < 0.0001). Greater symptom burden at diagnosis was associated with worse survival in both EoCRC (p < 0.0001) and LoCRC (p < 0.0001). When controlling for cancer stage, both age (HR 0.87, 95% CI 0.8-1.0, p = 0.008) and increasing symptom number were independently associated with worse survival in multivariate models. Conclusions: Patients with EoCRC present with a greater number of symptoms of longer duration than LoCRC; however, time from patient reported symptom onset was not associated with worse outcomes.

Changing epidemiology of colorectal cancer - birth cohort effects and emerging risk factors

Incidence and mortality of colorectal cancer (CRC) are increasing worldwide, suggesting broad changes in the epidemiology of CRC. In this Review, we discuss the changes that are becoming evident, including trends in CRC incidence and mortality by age and birth cohort, and consider the contributions of early-life exposures and emerging risk factors to these changes. Importantly, incidence of CRC has increased among people born since the early 1950s in nearly all regions of the world. These so-called birth cohort effects imply the involvement of factors that influence the earliest stages of carcinogenesis and have effects across the life course. Accumulating evidence supports the idea that early-life exposures are important risk factors for CRC, including exposures during fetal development, childhood, adolescence and young adulthood. Environmental chemicals could also have a role because the introduction of many in the 1950s and 1960s coincides with increasing incidence of CRC among people born during those years. To reverse the expected increases in the global burden of CRC, participation in average-risk screening programmes needs to be increased by scaling up and implementing evidence-based screening strategies, and emerging risk factors responsible for these increases need to be identified.

Referral challenges for early-onset colorectal cancer: a qualitative study in UK primary care

BACKGROUND

The incidence of early-onset colorectal cancer (EOCRC) in adults aged <50 years has increased in several Western nations. National surveys have highlighted significant barriers to accessing timely care for patients with EOCRC, which may be contributing to a late stage of presentation in this population group.

AIM

To explore awareness of the increasing incidence of EOCRC, and to understand the potential barriers or facilitators faced by GPs when referring younger adults to secondary care with features indicative of EOCRC.

DESIGN & SETTING

Qualitative methodology, via virtual semi-structured interviews with 17 GPs in Northern Ireland.

METHOD

Reflective thematic analysis was conducted with reference to Braun and Clarke's framework.

RESULTS

Three main themes were identified among participating GPs: awareness, diagnostic, and referral challenges. Awareness challenges focused on perceptions of EOCRC being solely associated with hereditary cancer syndromes, and colorectal cancer being a condition of older adults. Key diagnostic challenges centred around the commonality of lower gastrointestinal complaints and overlap in EOCRC symptoms with benign conditions. Restrictions in age-based referral guidance and a GP 'guilt complex' surrounding over-referral to secondary care summarised the referral challenges. Young females were perceived as being particularly disadvantaged with regard to delays in diagnosis.

CONCLUSION

This novel research outlines potential reasons for the diagnostic delays seen in patients with EOCRC from a GP perspective, and highlights many of the complicating factors that contribute to the diagnostic process.

Clinico-Pathological Features, Outcomes and Impacts of COVID-19 Pandemic on Patients with Early-Onset Colorectal Cancer: A Single-Institution Experience

BACKGROUND

The rising incidence of colorectal cancer (CRC) among young patients is alarming. We aim to characterize the clinico-pathological features and outcomes of patients with early-onset CRC (EOCRC), as well as the impacts of COVID-19 pandemic.

METHODS

We included all patients with pathologically confirmed diagnoses of CRC at Hospital Universitario La Paz from October 2016 to December 2021. The EOCRC cut-off age was 50 years old.

RESULTS

A total of 1475 patients diagnosed with CRC were included, eighty (5.4%) of whom had EOCRC. Significant differences were found between EOCRC and later-onset patients regarding T, N stage and metastatic presentation at diagnosis; perineural invasion; tumor budding; high-grade tumors; and signet ring cell histology, with all issues having higher prevalence in the early-onset group. More EOCRC patients had the RAS/ BRAF wild type. Chemotherapy was administered more frequently to patients with EOCRC. In the metastatic setting, the EOCRC group presented a significantly longer median OS. Regarding the COVID-19 pandemic, more patients with COVID-19 were diagnosed with metastatic disease (61%) in the year after the lockdown (14 March 2020) than in the pre-pandemic EOCRC group (29%).

CONCLUSIONS

EOCRC is diagnosed at a more advanced stage and with worse survival features in localized patients. More patients with EOCRC were diagnosed with metastatic disease in the year after the COVID-19 pandemic lockdown. The long-term consequences of COVID-19 are yet to be determined.

Young-onset colorectal cancer

In the past decades the incidence of colorectal cancer (CRC) in people under the age of 50 years has increased, which is referred to as early-onset CRC or young-onset CRC (YO-CRC). YO-CRC is expected to account for 11% of colon cancers and 23% of rectal cancers by 2030. This trend is observed in different parts of the world and in both men and women. In 20% of patients with YO-CRC, a hereditary cancer syndrome is found as the underlying cause; however, in the majority of patients no genetic predisposition is present. Beginning in the 1950s, major changes in lifestyle such as antibiotic use, low physical activity and obesity have affected the gut microbiome and may be an important factor in YO-CRC development. Owing to a lack of screening, patients with YO-CRC are often diagnosed with advanced-stage disease. Long-term treatment-related complications should be taken into account in these younger patients, making the more traditional sequential approaches of drug therapy not always the most appropriate option. To better understand the underlying mechanism and define relationships between environmental factors and YO-CRC development, long-term prospective studies are needed with lifestyle data collected from childhood.

Delphi Initiative for Early-Onset Colorectal Cancer (DIRECt) International Management Guidelines

BACKGROUND & AIMS

Patients with early-onset colorectal cancer (eoCRC) are managed according to guidelines that are not age-specific. A multidisciplinary international group (DIRECt), composed of 69 experts, was convened to develop the first evidence-based consensus recommendations for eoCRC.

METHODS

After reviewing the published literature, a Delphi methodology was used to draft and respond to clinically relevant questions. Each statement underwent 3 rounds of voting and reached a consensus level of agreement of ≥80%.

RESULTS

The DIRECt group produced 31 statements in 7 areas of interest: diagnosis, risk factors, genetics, pathology-oncology, endoscopy, therapy, and supportive care. There was strong consensus that all individuals younger than 50 should undergo CRC risk stratification and prompt symptom assessment. All newly diagnosed eoCRC patients should receive germline genetic testing, ideally before surgery. On the basis of current evidence, endoscopic, surgical, and oncologic treatment of eoCRC should not differ from later-onset CRC, except for individuals with pathogenic or likely pathogenic germline variants. The evidence on chemotherapy is not sufficient to recommend changes to established therapeutic protocols. Fertility preservation and sexual health are important to address in eoCRC survivors. The DIRECt group highlighted areas with knowledge gaps that should be prioritized in future research efforts, including age at first screening for the general population, use of fecal immunochemical tests, chemotherapy, endoscopic therapy, and post-treatment surveillance for eoCRC patients.

CONCLUSIONS

The DIRECt group produced the first consensus recommendations on eoCRC. All statements should be considered together with the accompanying comments and literature reviews. We highlighted areas where research should be prioritized. These guidelines represent a useful tool for clinicians caring for patients with eoCRC.

Risk and preventive factors of early-onset colorectal neoplasms: endoscopic and histological database analysis

BACKGROUND AND AIM

The incidence of early-onset colorectal neoplasms has been increasing in both Western and Eastern countries. However, the risks and preventive factors for these neoplasms in Eastern countries remain unclear.

METHODS

The data of 5580 patients who underwent colonoscopy between 2016 and 2021 were retrospectively evaluated. The primary outcome was advanced colorectal neoplasm (ACRN), defined as advanced adenomas (adenoma ≥10 mm, or with high-grade dysplasia or villous component) or adenocarcinoma. The clinical factors associated with ACRNs were determined for each age category (≤50 and >50 years), and the differences between the two categories were assessed. Odds ratios adjusted for age and sex were calculated.

RESULTS

Among 1001 patients (age ≤50 years), ACRN was found in 94 (9.4%). In this younger category, male sex (adjusted odds ratio [aOR]:2.34, 95% confidence interval [CI]:1.51-3.63) and a family history of colorectal cancer (aOR:2.14, 95% CI:1.17-3.89) were significantly associated with higher odds of developing ACRNs. ACRNs were detected in 726 (15.9%) of 4579 patients (age >50 years). In the older age category, smoking (aOR:1.32, 95% CI:1.08-1.63) was significantly associated with a higher risk of ACRNs. Exercise of >3.5 metabolic equivalent of task (METs) (aOR,0.80; 95% CI:0.67-0.96) was significantly associated with a lower risk of ACRNs.

CONCLUSION

The development of early-onset ACRNs was primarily associated with congenital factors, whereas that of late-onset ACRNs was associated with acquired ones. Colonoscopy is recommended for young male patients, particularly for those with a family history of colorectal cancer.

People with early-onset colorectal cancer describe primary care barriers to timely diagnosis: a mixed-methods study of web-based patient reports in the United Kingdom, Australia and New Zealand

BACKGROUND

People with early-onset colorectal cancer, under the age of 50, are more likely to experience diagnostic delay and to be diagnosed at later stages of the disease than older people. Advanced stage diagnosis potentially requires invasive therapeutic management at a time of life when these patients are establishing intimate relationships, raising families, building careers and laying foundations for financial stability. Barriers to timely diagnosis at primary care level have been identified but the patient perspective has not been investigated.

METHODS

Personal accounts of cancer care are increasingly accessed as rich sources of patient experience data. This study uses mixed methods, incorporating quantitative content analysis and qualitative thematic analysis, to investigate patients' accounts of early-onset colorectal cancer diagnosis published on prominent bowel cancer support websites in the United Kingdom, Australia and New Zealand.

RESULTS

Patients' perceptions (n = 273) of diagnostic barriers at primary care level were thematically similar across the three countries. Patients perceived that GPs' low suspicion of cancer due to age under 50 contributed to delays. Patients reported that their GPs seemed unaware of early-onset colorectal cancer and that they were not offered screening for colorectal cancer even when 'red flag' symptoms were present. Patients described experiences of inadequate information continuity within GP practices and across primary, specialist and tertiary levels of care, which they perceived contributed to diagnostic delay. Patients also reported tensions with GPs over the patient-centredness of care, describing discord related to symptom seriousness and lack of shared decision-making.

CONCLUSIONS

Wider dissemination of information about early-onset colorectal cancer at primary care level is imperative given the increasing incidence of the disease, the frequency of diagnostic delay, the rates of late-stage diagnosis and the dissatisfaction with patient experience reported by patients whose diagnosis is delayed. Patient education about diagnostic protocols may help to pre-empt or resolve tensions between GPs' enactment of value-based care and patients' concerns about cancer. The challenges of diagnosing early-onset colorectal cancer are significant and will become more pressing for GPs, who will usually be the first point of access to a health system for this growing patient population.

Clinical Delays and Comparative Outcomes in Younger and Older Adults with Colorectal Cancer: A Systematic Review

Outcome disparities between adults <50 with colorectal cancer (CRC) and older adults may be explained by clinical delays. This study synthesized the literature comparing delays and outcomes between younger and older adults with CRC. Databases were searched until December 2021. We included studies published after 1990 reporting delay in adults <50 that made comparisons to older adults. Comparisons were described narratively and stage between age groups was meta-analyzed. 39 studies were included representing 185,710 younger CRC patients and 1,422,062 older patients. Sixteen delay intervals were compared. Fourteen studies (36%) found significantly longer delays among younger adults, and nine (23%) found shorter delays among younger patients. Twelve studies compared time from symptom onset to diagnosis (N younger = 1538). Five showed significantly longer delays for younger adults. Adults <50 years also had higher odds of advanced stage (16 studies, pooled OR for Stage III/IV 1.76, 95% CI 1.52-2.03). Ten studies compared time from diagnosis to treatment (N younger = 171,726) with 4 showing significantly shorter delays for younger adults. All studies showing longer delays for younger adults examined pre-diagnostic intervals. Three studies compared the impact of delay on younger versus older adult. One showed longer delays were associated with advanced stage and worse survival in younger but not older adults. Longer delays among younger adults with CRC occur in pre-diagnostic intervals.

Recurrent NOMO1 Gene Deletion Is a Potential Clinical Marker in Early-Onset Colorectal Cancer and Is Involved in the Regulation of Cell Migration

Simple Summary

The incidence of EOCRC (age < 50 years at diagnosis) with unknown causes is rising worldwide, necessitating the mechanistical analysis of its molecular basis. The NOMO1 gene is deleted in a high number of EOCRC tumors compared to LOCRC. In this work, we aimed to test the NOMO1 gene mutational profile in EOCRC tumors and to characterize the effect of NOMO1 loss in different CRISPR/cas9-edited cell lines, as well as in murine models. Here, we show that the NOMO1 gene can be inactivated not only by deletion but also by pathogenic mutations in EOCRC. Our results indicate that NOMO1 loss could be a passenger mutation in the development of EOCRC, although it contributes significantly to colon cancer cell migration.

Abstract

The incidence of early-onset colorectal cancer (EOCRC; age younger than 50 years) has been progressively increasing over the last decades globally, with causes unexplained. A distinct molecular feature of EOCRC is that compared with cases of late-onset colorectal cancer, in EOCRC cases, there is a higher incidence of Nodal Modulator 1 (NOMO1) somatic deletions. However, the mechanisms of NOMO1 in early-onset colorectal carcinogenesis are currently unknown. In this study, we show that in 30% of EOCRCs with heterozygous deletion of NOMO1, there were pathogenic mutations in this gene, suggesting that NOMO1 can be inactivated by deletion or mutation in EOCRC. To study the role of NOMO1 in EOCRC, CRISPR/cas9 technology was employed to generate NOMO1 knockout HCT-116 (EOCRC) and HS-5 (bone marrow) cell lines. NOMO1 loss in these cell lines did not perturb Nodal pathway signaling nor cell proliferation. Expression microarrays, RNA sequencing, and protein expression analysis by LC–IMS/MS showed that NOMO1 inactivation deregulates other signaling pathways independent of the Nodal pathway, such as epithelial–mesenchymal transition and cell migration. Significantly, NOMO1 loss increased the migration capacity of CRC cells. Additionally, a gut-specific conditional NOMO1 KO mouse model revealed no subsequent tumor development in mice. Overall, these findings suggest that NOMO1 could play a secondary role in early-onset colorectal carcinogenesis because its loss increases the migration capacity of CRC cells. Therefore, further study is warranted to explore other signalling pathways deregulated by NOMO1 loss that may play a significant role in the pathogenesis of the disease.

Review article: obesity and colorectal cancer

BACKGROUND

Obesity is a growing global public health problem. More than half the European and North American population is overweight or obese. Colon and rectum cancers are still the second leading cause of cancer death worldwide, and epidemiological data support an association between obesity and colorectal cancers (CRCs).

AIM

To review the literature on CRC epidemiology in obese subjects, assessing the effects of obesity, including childhood or maternal obesity, on CRC, diagnosis, management, and prognosis, and discussing targeted prophylactic measures.

METHOD

We searched PubMed for obesity/overweight/metabolic syndrome and CRC. Other key words included 'staging', 'screening', 'treatment', 'weight loss', 'bariatric surgery' and 'chemotherapy'.

RESULTS

In Europe, about 11% of CRCs are attributed to overweight and obesity. Epidemiological data suggest that obesity is associated with a 30%-70% increased risk of colon cancer in men, the association being less consistent in women. Visceral fat or abdominal obesity seems to be of greater concern than subcutaneous fat obesity, and any 1 kg/m² increase in body mass index confers more risk (hazard ratio 1.03). Obesity might increase the likelihood of recurrence or mortality of the primary cancer and may affect initial management, including accurate staging. The risk maybe confounded by different factors, including lower adherence to organised CRC screening programmes. It is unclear whether bariatric surgery helps reduce rectal cancer risk.

CONCLUSIONS

Despite a growing body of evidence linking obesity to CRC, many questions remain unanswered, including whether we should screen patients with obesity earlier or propose prophylactic bariatric surgery for certain patients with obesity.

Risk of Colorectal Cancer in Patients With Irritable Bowel Syndrome: A Meta-Analysis of Population-Based Observational Studies

Background and Aims

Evidence on the association between irritable bowel syndrome (IBS) and colorectal cancer (CRC) risk is inconsistent. Therefore, we aimed to examine whether IBS leads to an increased risk for CRC using a systematic review and meta-analysis approach.

Methods

PubMed, Embase, and Web of Science were systematically searched to identify all relevant literature published through July 30, 2021. The pooled risk ratios (RRs) and corresponding 95% confidence intervals (CIs) for CRC after diagnosis of IBS were computed using random-and fixed-effects models and stratified by age, follow-up time, gender, and study design. The quality of included studies was assessed by the Newcastle-Ottawa scale.

Results

We included six studies consisting of 1,085,024 participants. Overall, the risk of detecting CRC after the initial IBS diagnosis was significantly higher than non-IBS controls (RR = 1.52, 95% CI: 1.04-2.22, P = 0.032). The peak of elevated risk occurred within the first year of IBS diagnosis (RR = 6.84, 95% CI: 3.70-12.65, P < 0.001), and after 1 year, the risk of CRC was similar to that of the general population (RR = 1.02, 95% CI: 0.88-1.18, P = 0.813). Notably, we found that the RR of CRC was more significant in IBS patients younger than 50 years compared to those older than 50 years (RR = 2.03, 95% CI: 1.17-3.53, P = 0.012 vs. 1.28, 95%CI: 0.94-1.75, P = 0.118, respectively). Gender and study design did not affect the results.

Conclusion

The risk of CRC within one year of the initial IBS diagnosis was increased approximately six-fold, whereas the long-term risk was not increased. However, current evidence does not support that IBS leads to an increased incidence of CRC, and the early excess risk is more likely attributable to misclassification resulting from overlapping symptoms rather than causation. Clinicians must remain vigilant for the CRC risk in patients younger than 50 years with IBS-like symptoms to avoid delaying necessary screening.

Epidemiology and biology of early onset colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in men or women in the United States. Average-risk screening that begins at age 50 years has reduced incidence and mortality of CRC in those over 50 years of age, whereas CRC incidence in those under age 50 years (early onset colorectal cancer (eoCRC)) has recently and dramatically increased. In this review, we summarize the recent literature including risk factors for eoCRC, differences in clinicopathologic presentation and outcomes in eoCRC, and emerging evidence regarding the molecular pathways that are altered in eoCRC compared to later onset CRC (loCRC). Epidemiologic studies of eoCRC show predominance in distal colon and rectum, and association with several modifiable risk factors, including diabetes, obesity, diet, sedentary time, alcohol consumption and smoking. Data regarding potential risk factors of prior antibiotic exposure and microbiome alterations or direct carcinogen exposure are still emerging. Aggressive clinicopathologic features of eoCRC at presentation may be due to delay in diagnosis or more aggressive tumor biology. EoCRC outcomes are similar to loCRC when matched for stage, but overall mortality is greater due to higher frequency of advanced disease at a younger presentation, with more life-years lost. There are only few molecular evaluations of eoCRC to date, with findings of potential increase in TP53 and CTNNB1 somatic mutation and decrease in APC, KRAS and BRAF somatic mutation, compared to loCRC. Other findings include LINE-1 hypomethylation, absence of microsatellite instability (MSI-H), presence of chromosomal instability (CIN) or microsatellite and chromosomal stability (MACS). These studies are only now emerging and have not yet identified a specific molecular signature defining eoCRC. Further research evaluating genetic and molecular differences as well as environmental triggers for eoCRCs should provide a clearer understanding to inform targeted screening for pre-symptomatic at-risk younger individuals.

The Role of Diet and Lifestyle in Early-Onset Colorectal Cancer: A Systematic Review

Simple Summary

This systematic review sifted through the exogenous dietary and lifestyle risk factors associated with early-onset colorectal cancer, going through the putative involvement of these exogenous risk factors in epigenetic and microbiota modifications. Given the burden of early-onset colorectal cancer and its globally increasing trend with scant literature on its pathogenesis, we believe it would be of benefit to highlight the importance of further systematic and large studies. Indeed, dietary and lifestyle modification could complement colorectal screening for early-onset colorectal cancer prevention.

Abstract

The incidence of early-onset colorectal cancer, defined as colorectal cancer occurring in young adults under the age of 50, is increasing globally. Knowledge of the etiological factors in young adults is far from complete. Questionable eoCRCs’ exogenous factors are represented by processed meat, sugary drinks, alcohol, Western dietary pattern, overweight and obesity, physical inactivity, and smoking, though with heterogeneous results. Therefore, we performed a systematic review to summarize the current evidence on the role of diet and lifestyle as eoCRC risk factors. We systematically searched PubMed, Scopus, and EMBASE up to July 2021, for original studies evaluating diet, alcohol, physical activity, BMI, and smoking in eoCRC and included twenty-six studies. Indeed, the exogenous factors could represent modifiable key factors, whose recognition could establish areas of future interventions through public health strategies for eoCRC primary prevention. Additionally, we discussed the role of additional non-modifiable risk factors, and of epigenetic regulation and microbiota as mediators of the eoCRC triggered by diet and lifestyle.

Clinical Characteristics and Outcomes of Colorectal Cancer in the ColoCare Study: Differences by Age of Onset

Early-onset colorectal cancer has been on the rise in Western populations. Here, we compare patient characteristics between those with early- (<50 years) vs. late-onset (≥50 years) disease in a large multinational cohort of colorectal cancer patients (n = 2193). We calculated descriptive statistics and assessed associations of clinicodemographic factors with age of onset using mutually-adjusted logistic regression models. Patients were on average 60 years old, with BMI of 29 kg/m², 52% colon cancers, 21% early-onset, and presented with stage II or III (60%) disease. Early-onset patients presented with more advanced disease (stages III-IV: 63% vs. 51%, respectively), and received more neo and adjuvant treatment compared to late-onset patients, after controlling for stage (odds ratio (OR) (95% confidence interval (CI)) = 2.30 (1.82-3.83) and 2.00 (1.43-2.81), respectively). Early-onset rectal cancer patients across all stages more commonly received neoadjuvant treatment, even when not indicated as the standard of care, e.g., during stage I disease. The odds of early-onset disease were higher among never smokers and lower among overweight patients (1.55 (1.21-1.98) and 0.56 (0.41-0.76), respectively). Patients with early-onset colorectal cancer were more likely to be diagnosed with advanced stage disease, to have received systemic treatments regardless of stage at diagnosis, and were less likely to be ever smokers or overweight.

Perioperative and oncologic outcomes in young and octogenarian patients with colorectal cancer: a comparison at the extremes

INTRODUCTION

In colorectal cancer (CRC), surgical outcomes in the young (< 50) and octogenarian populations are believed to be poor due to an aggressive phenotype in the former, and increased frailty in the latter. Given that age-related effects are inversely related between groups, we compared short- and long-term outcomes of young and octogenarian patients with CRC to determine the dominance of one age-related factor over another.

METHODS

A prospectively collected database from 2015 to 2020 of all CRC was analyzed. Cases were divided into metastatic and non-metastatic groups.

RESULTS

Among non-metastatic cases, there were 34 young and 113 octogenarian patients. Mean CEA was higher among octogenarians (11.2 vs 32.8 units/ml; p = 0.041). Octogenarians suffered from more comorbidities than younger counterparts, with increased rates of postoperative UTI (3.3% vs 10.3%; p = 0.246) and pneumonia (3.1% vs 8.8%; p = 0.331). There was no increased rate of reintervention or Clavien-Dindo scores. We noticed a statistically significant higher proportion of extramural vascular invasion (EMVI) (8.8% vs 32.3%; p = 0.003) among the young. When excluding octogenarians who had declined surgery, Kaplan-Meier analysis showed no difference in disease-free (p = 0.290) or overall survival (p = 0.111). Among metastatic cases, there were 21 young and 19 octogenarian patients. Young patients were treated more aggressively with chemotherapy (55.6% vs 12.5%; p = 0.040). There was however no difference in overall survival between groups (p = 0.610).

CONCLUSIONS

Octogenarians may have more comorbidities, but can achieve similar surgical outcomes with younger patients. There is no reason to suspect a more aggressive phenotype in younger patients.