Changes in colorectal cancer incidence rates in young and older adults in the United States: what does it tell us about screening

Trends in the epidemiology of young-onset colorectal cancer: a worldwide systematic review

BACKGROUND

Recent data suggest that the risk of young-onset colorectal cancer (yCRC), in adults less than 50 years of age, is increasing. To confirm findings and identify contemporary trends worldwide, we conducted a systematic review of studies examining population-level trends in yCRC epidemiology.

METHODS

We searched MEDLINE (1946-2018), EMBASE (1974-2018), CINAHL (1982-2018), and Cochrane Database of Systematic Reviews (2005-2018) for studies that used an epidemiologic design, assessed trends in yCRC incidence or prevalence, and published in English. Extracted information included country, age cut-off for yCRC, and reported trends in incidence or prevalence (e.g. annual percent change [APC]). We pooled similarly reported trend estimates using random effects models.

RESULTS

Our search yielded 8695 articles and after applying our inclusion criteria, we identified 40 studies from 12 countries across five continents. One study assessed yCRC prevalence trends reporting an APCp of + 2.6 and + 1.8 among 20-39 and 40-49 year olds, respectively. 39 studies assessed trends in yCRC incidence but with substantial variability in reporting. Meta-analysis of the most commonly reported trend estimate yielded a pooled overall APCi of + 1.33 (95% CI, 0.97 to 1.68; p < 0.0001) that is largely driven by findings from North America and Australia. Also contributing to these trends is the increasing risk of rectal cancer as among 14 studies assessing cancer site, nine showed an increased risk of rectal cancer in adults less than 50 years with APCi up to + 4.03 (p < 0.001).

CONCLUSIONS

Our systematic review highlights increasing yCRC risk in North America and Australia driven by rising rectal cancers in younger adults over the past two decades.

The long-term outcomes in adolescent and young adult patients with colorectal cancer -A multicenter large-scale cohort study

Introduction: The prognosis of adolescent and young adult (AYA) patients with colorectal cancer (CRC) is still unclear. The aim of this study was to investigate the clinical features and prognosis in AYA patients compared with middle- aged patients.

Methods: Participants were identified from a clinical database of the multicenter cohort in Japan. The AYA group was defined as those <40 years of age, whereas the middle-aged group was defined in 10-year ranges around the median age of all patients. The primary outcome was the overall survival (OS), and the secondary outcome was the recurrence-free survival (RFS).

Results: A total of 502 patients were enrolled as the AYA group, and 7222 patients between 65 and 74 years of age were identified as the middle-aged group. The OS of colon cancer in stages II and III was significantly better in the AYA group (p = 0.033, 0.006, respectively) than in the middle-aged groups. There were no significant differences in the OS of rectal cancer in stages II and III between the two groups.

Conclusion: The prognosis of AYA patients with CRC was the same or better than that in middle-aged patients.

Projected estimates of cancer in Canada in 2020

BACKGROUND

Cancer projections to the current year help in policy development, planning of programs and allocation of resources. We sought to provide an overview of the expected incidence and mortality of cancer in Canada in 2020 in follow-up to the Canadian Cancer Statistics 2019 report.

METHODS

We obtained incidence data from the National Cancer Incidence Reporting System (1984-1991) and Canadian Cancer Registry (1992-2015). Mortality data (1984-2015) were obtained from the Canadian Vital Statistics - Death Database. All databases are maintained by Statistics Canada. Cancer incidence and mortality counts and age-standardized rates were projected to 2020 for 23 cancer types by sex and geographic region (provinces and territories) for all ages combined.

RESULTS

An estimated 225 800 new cancer cases and 83 300 cancer deaths are expected in Canada in 2020. The most commonly diagnosed cancers are expected to be lung overall (29 800), breast in females (27 400) and prostate in males (23 300). Lung cancer is also expected to be the leading cause of cancer death, accounting for 25.5% of all cancer deaths, followed by colorectal (11.6%), pancreatic (6.4%) and breast (6.1%) cancers. Incidence and mortality rates will be generally higher in the eastern provinces than in the western provinces.

INTERPRETATION

The number of cancer cases and deaths remains high in Canada and, owing to the growing and aging population, is expected to continue to increase. Although progress has been made in reducing deaths for most major cancers (breast, prostate and lung), there has been limited progress for pancreatic cancer, which is expected to be the third leading cause of cancer death in Canada in 2020. Additional efforts to improve uptake of existing programs, as well as to advance research, prevention, screening and treatment, are needed to address the cancer burden in Canada.

Colorectal Cancer in the Young: Epidemiology, Prevention, Management

Colorectal cancer (CRC) incidence rates in the United States overall have declined since the mid-1980s because of changing patterns in risk factors (e.g., decreased smoking) and increases in screening. However, this progress is increasingly confined to older adults. CRC occurrence has been on the rise in patients younger than age 50, often referred to as early-onset disease, since the mid-1990s. Young patients are more often diagnosed at an advanced stage and with rectal disease than their older counterparts, and they have numerous other unique challenges across the cancer management continuum. For example, young patients are less likely than older patients to have a usual source of health care; often need a more complex treatment protocol to preserve fertility and sexual function; are at higher risk of long-term and late effects, including subsequent primary malignancies; and more often suffer medical financial hardship. Diagnosis is often delayed because of provider- and patient-related factors, and clinicians must have a high index of suspicion if young patients present with rectal bleeding or changes in bowel habits. Educating primary care providers and the larger population on the increasing incidence and characteristic symptoms is paramount. Morbidity can further be averted by increasing awareness of the criteria for early screening, which include a family history of CRC or polyps and a genetic predisposition.

Cost-utility of colorectal cancer screening at 40 years old for average-risk patients

The incidence of colorectal cancer (CRC) is increasing in patients under the age of 50. The purpose of this study was to assess the cost-utility of available screening modalities starting at 40 years in the general population compared to standard screening at 50 years old. A decision tree modeling average-risk of CRC in the United States population was constructed for the cost per quality-adjusted life year (QALY) of the five most common and effective CRC screening modalities in average-risk 40-year olds versus deferring screening until 50 years old (standard of care) under a limited societal perspective. All parameters were derived from existing literature. We evaluated the incremental cost-utility ratio of each comparator at a willingness-to-pay threshold of $50,000/QALY and included multivariable probabilistic sensitivity analysis. All screening modalities assessed were more cost-effective with increased QALYs than current standard care (no screening until 50). The most favorable intervention by net monetary benefit was flexible sigmoidoscopy ($3284 per person). Flexible sigmoidoscopy, FOBT, and FIT all dominated the current standard of care. Colonoscopy and FIT-DNA were both cost-effective (respectively, $4777 and $11,532 per QALY). The cost-effective favorability of flexible sigmoidoscopy diminished relative to colonoscopy with increasing willingness-to-pay. Regardless of screening modality, CRC screening at 40 years old is cost-effective with increased QALYs compared to current screening initiation at 50 years old, with flexible sigmoidoscopy most preferred. Consideration should be given for a general recommendation to start screening at age 40 for average risk individuals.

Oxytocin Inhibition of Metastatic Colorectal Cancer by Suppressing the Expression of Fibroblast Activation Protein-α

Oxytocin (OXT) and its receptor (OXTR) are present in the gastrointestinal system and are involved in gastrointestinal tumorigenesis. However, the effect of OXTR signaling on the development of colorectal cancer (CRC) and its underlying mechanisms remain unexplored. To address these issues, we first examined the expressions of OXT, OXTR, and several cancer-associated proteins using colon “tissue chips” from a spectrum of malignant progression of the colon, which included normal colon tissue, chronic colitis, colorectal adenoma, and colorectal adenocarcinoma (CAC). The results showed that the expressions of OXT and OXTR decreased gradually with the malignant progression of the disease. Stimulation of CAC tissues with OXT increased OXTR expression while down-regulated FAPα and CCL-2 protein expressions in a concentration- and time-dependent manner. Moreover, cell invasion experiment showed that OXT treatment reduced the invasion ability of colon cancer cells and blocking OXTR with atosiban blocked OXT-reduced invasion ability of human colon cancer cell lines Ls174T and SW480. The results indicate that OXT has the potential to inhibit CRC development via down-regulating the immunosuppressive proteins FAPα and CCL-2. When the OXTR signaling is weakened, colon tissues may transform to CRC. These findings also highlight the possibility of applying OXT to inhibit CRC development directly.

Colorectal cancer incidence among young adults in England: Trends by anatomical sub-site and deprivation

BACKGROUND

Colorectal cancer incidence in the UK and other high-income countries has been increasing rapidly among young adults. This is the first analysis of colorectal cancer incidence trends by sub-site and socioeconomic deprivation in young adults in a European country.

METHODS

We examined age-specific national trends in colorectal cancer incidence among all adults (20-99 years) diagnosed during 1971-2014, using Joinpoint regression to analyse data from the population-based cancer registry for England. We fitted a generalised linear model to the incidence rates, with a maximum of two knots. We present the annual percentage change in incidence rates in up to three successive calendar periods, by sex, age, deprivation and anatomical sub-site.

RESULTS

Annual incidence rates among the youngest adults (20-39 years) fell slightly between 1971 and the early 1990s, but increased rapidly from then onwards. Incidence Rates (IR) among adults 20-29 years rose from 0.8 per 100,000 in 1993 to 2.8 per 100,000 in 2014, an average annual increase of 8%. An annual increase of 8.1% was observed for adults aged 30-39 years during 2005-2014. Among the two youngest age groups (20-39 years), the average annual increase for the right colon was 5.2% between 1991 and 2010, rising to 19.4% per year between 2010 (IR = 1.2) and 2014 (IR = 2.5). The large increase in incidence rates for cancers of the right colon since 2010 were more marked among the most affluent young adults. Smaller but substantial increases were observed for cancers of the left colon and rectum. Incidence rates in those aged 50 years and older remained stable or decreased over the same periods.

CONCLUSIONS

Despite the overall stabilising trend of colorectal cancer incidence in England, incidence rates have increased rapidly among young adults (aged 20-39 years). Changes in the prevalence of obesity and other risk factors may have affected the young population but more research is needed on the cause of the observed birth cohort effect. Extension of mass screening may not be justifiable due to the low number of newly diagnosed cases but clinicians should be alert to this trend.

Global patterns and trends in colorectal cancer incidence in young adults

OBJECTIVE

Early-onset colorectal cancer (CRC) is increasing in the USA despite rapid declines in older ages. Similar patterns are reported in Australia and Canada, but a comprehensive global analysis of contemporary data is lacking.

DESIGN

We extracted long-term data from Cancer Incidence in Five Continents and supplemental sources to report on worldwide CRC incidence rates and trends by age (20-49 years and ≥50 years) through diagnosis year 2012 or beyond (Australia, Finland, New Zealand, Norway, Sweden, USA).

RESULTS

During 2008-2012, age-standardised CRC incidence rates in adults <50 ranged from 3.5 per 100 000 (95% CI 3.2 to 3.9) in India (Chennai) to 12.9 (95% CI 12.6 to 13.3) in Korea. During the most recent decade of available data, incidence in adults <50 was stable in 14 of 36 countries; declined in Austria, Italy and Lithuania; and increased in 19 countries, nine of which had stable or declining trends in older adults (Australia, Canada, Denmark, Germany, New Zealand, Slovenia, Sweden, UK and USA). In Cyprus, Netherlands and Norway, inclines in incidence in young adults were twice as rapid as those in older adults (eg, Norway average annual per cent change (AAPC), 1.9 (95% CI 1.4 to 2.5) vs 0.5 (95% CI 0.3 to 0.7)). Among most high-income countries with long-term data, the uptick in early-onset disease began in the mid-1990s. The steepest increases in young adults were in Korea (AAPC, 4.2 (95% CI 3.4 to 5.0)) and New Zealand (AAPC, 4.0 (95% CI 2.1 to 6.0)).

CONCLUSION

CRC incidence increased exclusively in young adults in nine high-income countries spanning three continents, potentially signalling changes in early-life exposures that influence large bowel carcinogenesis.

Association of Polyps with Early-Onset Colorectal Cancer and Throughout Surveillance: Novel Clinical and Molecular Implications

Early-onset colorectal cancer (EOCRC) is an increasing and worrisome entity. The aim of this study was to analyze its association with polyps concerning prognosis and surveillance. EOCRC cases were compared regarding the presence or absence of associated polyps (clinical and molecular features), during a minimum of 7 years of follow-up. Of 119 cases, 56 (47%) did not develop polyps (NP group), while 63 (53%) did (P group). The NP group showed a predominant location of the CRC in the rectum (50%), of sporadic cases (54%), and diagnosis at advanced stages: Only P53 and SMARCB1 mutations were statistically linked to this group. The P group, including mainly early-diagnosed tumors, was linked with the most frequent and differential altered chromosomal regions in the array comparative genomic hybridization. The two most frequent groups according to the follow-up were the NP group (40%), and patients developing polyps in the first 5 years of follow-up (P < 5FU) (34%) (these last groups predominantly diagnosed at the earliest stage and with adenomatous polyps (45%)). EOCRC with polyps that developed during the entire follow-up (PDFU group) were mainly located in the right colon (53%), diagnosed in earlier stages, and 75% had a familial history of CRC. Patients developing polyps after the first 5 years (P > 5FU) showed a mucinous component (50%). Our results show that the absence or presence of polyps in EOCRC is an important prognostic factor with differential phenotypes. The development of polyps during surveillance shows that it is necessary to extend the follow-up time, also in those cases with microsatellite-stable EOCRC.

Old vs new: Risk factors predicting early onset colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second leading cause of all cancer related deaths in the United States and Europe. Although the incidence has been decreasing for individuals’ ≥ 50, it has been on the rise for individuals < 50.

AIM

To identify potential risk factors for early-onset CRC.

METHODS

A population-based cohort analysis using a national database, Explorys, screened all patients with an active electronic medical record from January 2012 to December 2016 with a diagnosis of CRC. Subgroups were stratified based on age (25 – 49 years vs ≥ 50 years). Demographics, comorbidities, and symptom profiles were recorded and compared between both age groups. Furthermore, the younger group was also compared with a control group consisting of individuals aged 25-49 years within the same timeframe without a diagnosis of CRC. Twenty-data points for CRC related factors were analyzed to identify potential risk factors specific to early-onset CRC.

RESULTS

A total of 68860 patients were identified with CRC, of which 5710 (8.3%) were younger than 50 years old, with 4140 (73%) between 40-49 years of age. Multivariable analysis was reported using odds ratio (OR) with 95%CI and demonstrated that several factors were associated with an increased risk of CRC in the early-onset group versus the later-onset group. These factors included: African-American race (OR 1.18, 95%CI: 1.09-1.27, P < 0.001), presenting symptoms of abdominal pain (OR 1.82, 95%CI: 1.72-1.92, P <0.001), rectal pain (OR 1.50, 95%CI: 1.28-1.77, P < 0.001), altered bowel function (OR 1.12, 95%CI: 1.05-1.19, P = 0.0005), having a family history of any cancer (OR 1.78, 95%CI: 1.67-1.90, P < 0.001), gastrointestinal (GI) malignancy (OR 2.36, 95%CI: 2.18-2.55, P < 0.001), polyps (OR 1.41, 95%CI: 1.08-1.20, P < 0.001), and obesity (OR 1.14, 95%CI: 1.08-1.20, P < 0.001). Comparing the early-onset cohort versus the control group, factors that were associated with an increased risk of CRC were: male gender (OR 1.34, 95%CI: 1.27-1.41), P < 0.001), Caucasian (OR 1.48, 95%CI: 1.40-1.57, P < 0.001) and African-American race (OR 1.25, 95%CI: 1.17-1.35, P < 0.001), presenting symptoms of abdominal pain (OR 4.73, 95%CI: 4.49-4.98, P < 0.001), rectal pain (OR 7.48, 95%CI: 6.42-8.72, P < 0.001), altered bowel function (OR 5.51, 95%CI: 5.19-5.85, P < 0.001), rectal bleeding (OR 9.83, 95%CI: 9.12-10.6, P < 0.001), weight loss (OR 7.43, 95%CI: 6.77-8.15, P < 0.001), having a family history of cancer (OR 11.66, 95%CI: 10.97-12.39, P < 0.001), GI malignancy (OR 28.67, 95%CI: 26.64-30.86, P < 0.001), polyps (OR 8.15, 95%CI: 6.31-10.52, P < 0.001), tobacco use (OR 2.46, 95%CI: 2.33-2.59, P < 0.001), alcohol use (OR 1.71, 95%CI: 1.62-1.80, P < 0.001), presence of colitis (OR 4.10, 95%CI: 3.79-4.43, P < 0.001), and obesity (OR 2.88, 95%CI: 2.74-3.04, P < 0.001).

CONCLUSION

Pending further investigation, these potential risk factors should lower the threshold of suspicion for early CRC and potentially be used to optimize guidelines for early screening.

Recent trends in the age at diagnosis of colorectal cancer in the US National Cancer Data Base, 2004-2015

BACKGROUND

The incidence of colorectal cancer (CRC) in adults younger than 50 years has increased in the United States over the past decades according to Surveillance, Epidemiology, and End Results data. National guidelines conflict over beginning screening at the age of 45 or 50 years.

METHODS

This was a retrospective study of National Cancer Data Base data from 2004 to 2015. The Cochran-Armitage test for trend was used to assess changes in the proportion of cases diagnosed at an age younger than 50 years.

RESULTS

This study identified 130,165 patients diagnosed at an age younger than 50 years and 1,055,598 patients diagnosed at the age of 50 years or older. The proportion of the total number of patients diagnosed with CRC at an age younger than 50 years rose (12.2% in 2015 vs 10.0% in 2004; P < .0001). Younger adults presented with more advanced disease (stage III/IV; 51.6% vs 40.0% of those 50 years old or older). Among men, diagnosis at ages younger than 50 years rose only in non-Hispanic whites (P < .0001), whereas among women, Hispanic and non-Hispanic whites had increases in younger diagnoses over time (P < .05). All income quartiles had a proportional increase in younger adults over time (P < .001), with the highest income quartile having the highest proportion of younger cases. The proportion of younger onset CRC cases rose in urban areas (P < .001) but did not rise in rural areas.

CONCLUSIONS

The proportion of persons diagnosed with CRC at an age younger than 50 years in the United States has continued to increase over the past decade, and younger adults present with more advanced disease. These data should be considered in the ongoing discussion of screening guidelines.

Risk of Breast, Prostate, and Colorectal Cancer Diagnoses Among HIV-Infected Individuals in the United States

Background

Although people living with HIV or AIDS (PLWHA) are at higher risk for many cancers, breast, prostate, and colorectal cancer rates are lower in this patient population. Because these tumors are often screen-detected, these inverse associations could be driven by HIV-related differences in utilization of cancer screening.

Methods

We ascertained incident breast, prostate, and colorectal cancer in PLWHA using data from the HIV/AIDS Cancer Match Study (1996-2012). Comparisons with general population cancer rates were made using standardized incidence ratios (SIRs), overall and stratified by tumor stage/size, breast cancer estrogen receptor status, and colorectal site. We also examined the potential effect of study design and unmeasured confounding on inverse standardized incidence ratios.

Results

Compared with the general population, PLWHA had lower rates of invasive breast (SIR = 0.63, 95% confidence interval [CI] = 0.58 to 0.68), prostate (SIR = 0.48, 95% CI = 0.46 to 0.51), proximal colon (SIR = 0.67, 95% CI = 0.59 to 0.75), distal colon (SIR = 0.51, 95% CI = 0.43 to 0.59), and rectal cancers (SIR = 0.69, 95% CI = 0.61 to 0.77). Reduced risk persisted across tumor stage/size for prostate and colorectal cancers. Although distant-stage breast cancer rates were not reduced (SIR = 0.94, 95% CI = 0.73 to 1.20), HIV-infected women had lower rates of large (>5 cm) breast tumors (SIR = 0.65, 95% CI = 0.50 to 0.83). The magnitude of these inverse standardized incidence ratios could not plausibly be attributed to case underascertainment, out-migration, or unmeasured confounding.

Conclusions

Breast, prostate, and colorectal cancer rates are markedly lower among PLWHA, including rates of distant-stage/large tumors that are not generally screen-detected. This set of inverse HIV-cancer associations is therefore unlikely to be due primarily to differential screening and may instead represent biological relationships requiring future investigation.

Are temporal trends in colonoscopy among young adults concordant with colorectal cancer incidence?

Objective

In the United States, colorectal cancer incidence has increased in adults under age 55. Although debate remains about whether this rise is a result of increased detection because of more colonoscopy utilization, population-based trends in colonoscopy among this age group are unknown. We examined changes in colonoscopy rates, as well as colorectal cancer incidence, among adults aged 40–54, using nationally representative data.

Methods

Recent (past year) colonoscopy rates were computed among 53,175 respondents aged 40–54 in National Health Interview Survey data from 2000 through 2015 by five-year age group. Colorectal cancer incidence rates and incidence rate ratios were estimated from 18 population-based Surveillance Epidemiology and End Result registries during the same period.

Results

Among respondents aged 40–44, past-year colonoscopy rates were stable during 2000–2015, and ranged from 2.3% to 3.5% ( p-value for trend = 0.771). In contrast, colonoscopy rates increased from 2.5% in 2000 to 5.2% in 2015 among ages 45–49, and from 5.0% to 14.1% in ages 50–54 (test for trend p-values < 0.001). During 2000–2015, colorectal cancer incidence rates increased by 28% in people aged 40–44 (incidence rate ratio = 1.28, 95% CI 1.20, 2.37), 15% in those aged 45–49 (incidence rate ratio = 1.15, 95%CI 1.10, 1.21), and 17% in those aged 50–54 (incidence rate ratio = 1.17, 95%CI 1.13, 1.21), respectively.

Conclusion

Increases in colonoscopy rates were confined to ages 45–54, whereas colorectal cancer incidence rates rose in those aged 40–44, 45–49, and 50–54. Colonoscopy trends do not fully align with colorectal cancer incidence patterns.

Colon cancer as a subsequent malignant neoplasm in young adults

BACKGROUND

The incidence of colon cancer (CC) is rising in younger adults and can occur de novo or in patients previously treated for another cancer. To the authors' knowledge, the impact on survival of CC occurring as a subsequent malignant neoplasm (SMN) has not been described for younger patients, which the authors anticipate to be lower with SMNs than that of primary CC.

METHODS

Patients aged <50 years with CC in the 2004 through 2014 National Cancer Data Base were identified. Patients were stratified by primary or subsequent occurrence. The impact of SMN status on overall survival (OS) was evaluated.

RESULTS

Of 41,915 patients, 2852 (6.8%) had colon SMNs. More patients with colon SMNs were aged 40 to 49 years compared with patients with primary CC (83% vs 77%; P < .001). Patients with colon SMNs presented with earlier clinical and pathological T, N, and M classifications (all P < .001). Colon SMNs more commonly occurred in the right colon, whereas primary CC was found to have a higher prevalence in the sigmoid colon (P < .001). Patients with colon SMNs more frequently underwent total colectomy (17% vs 5%; P < .001), but received less chemotherapy (53% vs 65%; P < .001). When adjusted for demographic, tumor, and treatment characteristics, SMN status was associated with a 23% decreased OS compared with primary CC (95% CI, 1.14-1.31; P < .001). Chemotherapy offered a 33% improvement in OS (95% CI, 0.56-0.8; P < .001).

CONCLUSIONS

Colon SMNs in younger patients present at an earlier stage and are treated more aggressively surgically compared with primary CCs. Patients with SMNs of the colon have decreased survival, although chemotherapy offers a survival advantage. Further investigation is warranted to determine whether these disparities are due to the effects of cancer treatment or differences in tumor biology.

CP*Trends: An Online Tool for Comparing Cohort and Period Trends Across Cancer Sites

Cohort or period components of trends can provide a rationale for new research or point to clues on the effectiveness of control strategies. Graphical display of trends guides models that quantify the experience of a population. In this paper, a method for smoothing rates by single year of age and year is developed and displayed to show the contributions of period and cohort to trends. The magnitude of the contribution of period and/or cohort in a model for trends may be assessed by the percentage of deviance explained and the relative contributions of cohort (C) and period (P) individually, known as the C-P score. The method is illustrated using Surveillance, Epidemiology, and End Results data (1975-2014) on lung and bronchial cancer mortality in females and prostate and colorectal cancer incidence in males. Smoothed age-period and age-cohort rates provide a useful first step in studies of etiology and the impact of disease control without imposing a restrictive model. We found that, in this data set, cohort predominates for female lung and bronchial cancer and period predominates for male prostate cancer. However, the effects change with age for male colorectal cancer incidence, indicating an age shift in relevant exposures. These methods are applied on an interactive website for both incidence and mortality at over 20 cancer sites in the United States.

Colorectal cancer screening from 45 years of age: Thesis, antithesis and synthesis

Colorectal cancer incidence and mortality in patients younger than 50 years are increasing, but screening before the age of 50 is not offered in Europe. Advanced-stage diagnosis and mortality from colorectal cancer before 50 years of age are increasing. This is not a detection-bias effect; it is a real issue affecting the entire population. Three independent computational models indicate that screening from 45 years of age would yield a better balance of benefits and risks than the current start at 50 years of age. Experimental data support these predictions in a sex- and race-independent manner. Earlier screening is seemingly affordable, with minimal impediments to providing younger adults with colonoscopy. Indeed, the American Cancer Society has already started to recommend screening from 45 years of age in the United States. Implementing early screening is a societal and public health problem. The three independent computational models that suggested earlier screening were criticized for assuming perfect compliance. Guidelines and recommendations should be derived from well-collected and reproducible data, and not from mathematical predictions. In the era of personalized medicine, screening decisions might not be based solely on age, and sophisticated prediction software may better guide screening. Moreover, early screening might divert resources away from older individuals with greater biological risks. Finally, it is still unknown whether early colorectal cancer is part of a continuum of disease or a biologically distinct disease and, as such, it might not benefit from screening at all. The increase in early-onset colorectal cancer incidence and mortality demonstrates an obligation to take actions. Earlier screening would save lives, and starting at the age of 45 years may be a robust screening option.

Trends in Incidence and Stage at Diagnosis of Colorectal Cancer in Adults Aged 40 Through 49 Years, 1975-2015

This cancer epidemiology study uses SEER program data to describe trends in stage of incident colorectal cancer in adults aged 40-49 years between 1975 and 2015 to understand if apparent increases in incidence are due to earlier detection or true increases in risk.

Treatment patterns and survival differ between early-onset and late-onset colorectal cancer patients: the patient outcomes to advance learning network

PURPOSE

Our objective was to describe differences in treatment patterns and survival between early-onset (< 50 years old) and late-onset colorectal cancer (CRC) patients in community-based health systems.

METHODS

We used tumor registry and electronic health record data to identify and characterize patients diagnosed with adenocarcinoma of the colon or rectum from 2010 to 2014 at six US health systems in the patient outcomes to advance learning (PORTAL) network. We used logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) comparing the distribution of tumor characteristics and treatment patterns in early-onset versus late-onset CRC. Cox regression models were used to estimate adjusted hazard ratios (HRs) and CIs comparing survival between early- and late-onset CRC patients.

RESULTS

There were 1,424 early-onset and 10,810 late-onset CRC cases in our analyses. Compared to late-onset CRC, early-onset CRC was significantly associated with advanced-stage disease, high-grade histology, signet ring histology, and rectal or left colon location. After adjusting for differences in tumor and patient characteristics, early-onset patients were more likely than late-onset patients to have > 12 lymph nodes examined (OR 1.60, CI 1.37-1.87), to receive systemic therapy (chemotherapy or immunotherapy) within 6 months of diagnosis (OR 2.84, CI 2.40-3.37), and to have a reduced risk of CRC-specific death (HR 0.66, CI 0.56-0.79).

CONCLUSIONS

Early-onset CRC is associated with aggressive tumor characteristics, distal location, and systemic therapy use. Despite some adverse risk factors, these patients tend to have better survival than older onset patients.

Heterogeneity of colon and rectum cancer incidence across 612 SEER counties, 2000-2014

Recent analyses have suggested decreases over time in colorectal cancer incidence at older ages (≥55 years) but increases at younger ages (20-54 years). Understanding the geographic heterogeneity of incidence facilitates resource allocation for potential interventions and advances our knowledge of differential etiologies for these cancers. We performed age-period-cohort analysis using 2000-2014 county-level incidence from the Surveillance, Epidemiology, and End Results (SEER) database, estimating relative risk (RR) and age-adjusted annual percent change (Net Drifts) simultaneously for 612 counties via a hierarchical model, separately for colon and rectum cancer, stratified by age group (20-54 vs. 55-84). We also studied correlates of RR and Net Drift with various county-level characteristics. In all SEER counties, colon and rectum cancer incidence rates increased at ages 20-54, whereas rates decreased at ages 55-84. There was marked heterogeneity in both RR and Net Drift among states and counties for both cancer types. Maps of county RR and Net Drift revealed localized clusters in several states. For both cancer types, counties with high RR and unfavorable Net Drift tended to have higher prevalence of obesity and diabetes and to be of a lower socioeconomic status. Counties with higher overall screening rates tended to have lower Net Drifts for both cancer types. Increasing colorectal cancer incidence in the younger age group is geographically widespread, although there is significant heterogeneity in temporal trends and risk both within and between states. These geographic patterns correlate with different county-level characteristics depending on cancer type and age group.

Development and validation of a scoring system for advanced colorectal neoplasm in young Korean subjects less than age 50 years

BACKGROUND/AIM

Colorectal cancer incidence among patients aged ≤50 years is increasing. This study aimed to develop and validate an advanced colorectal neoplasm (ACRN) screening model for young adults aged <50 years in Korea.

METHODS

This retrospective cross-sectional study included 59,575 consecutive asymptomatic Koreans who underwent screening colonoscopy between 2003 and 2012 at a single comprehensive health care center. Young Adult Colorectal Screening (YCS) score was developed as an optimized risk stratification model for ACRN using multivariate analysis and was internally validated. The predictive power and diagnostic performance of YCS score was compared with those of Asia-Pacific Colorectal Screening (APCS) and Korean Colorectal Screening (KCS) scores.

RESULTS

41,702 and 17,873 subjects were randomly allocated into the derivation and validation cohorts, respectively, by examination year. ACRN prevalence was 0.9% in both cohorts. YCS score comprised sex, age, alcohol, smoking, obesity, glucose metabolism abnormality, and family history of CRC, with score ranges of 0 to 10. In the validation cohort, ACRN prevalence was 0.6% in the low-risk tier (score, 0-4), 1.5% in the moderate-risk tier (score, 5-7), and 3.4% in the high-risk tier (score, 8-10). ACRN risk increased 2.5-fold (95%CI, 1.8-3.4) in the moderate-risk tier and 5.8-fold (95%CI, 3.4-9.8) in the high-risk tier compared with the low-risk tier. YCS score identified better balanced accuracy (53.9%) than APCS (51.5%) and KCS (50.7%) scores and had relatively good discriminative power (area under the curve=0.660).

CONCLUSIONS

YCS score based on clinical and laboratory risk factors was clinically effective and beneficial for predicting ACRN risk and targeting screening colonoscopy in adults aged <50 years.

Historical perspective: Two decades of progress in treating metastatic colorectal cancer

Colorectal cancer is the third most commonly diagnosed cancer in the United States. While screening methods strive to improve rates of early stage detection, 25% of patients have metastatic disease at the time of diagnosis, with the most common sites being the liver, lung, and peritoneum. While once perceived as hopeless, the last two decades have seen substantial strides in the medical, surgical, and regional therapies to treat metastatic disease offering significant improvements in survival.

Trends in and Predictions of Colorectal Cancer Incidence and Mortality in China From 1990 to 2025

Colorectal cancer (CRC) has emerged as a major public health concern in China during the last decade. In this study, we investigated the disease burden posed by CRC and analyzed temporal trends in CRC incidence and mortality rates in this country. We collected CRC incidence data from the Cancer Incidence in Five Continents, Volume XI dataset and the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) of CRC by sex and age, from the 2016 Global Burden of Diseases Study. We used the average annual percentage change (AAPC) to quantify temporal trends in CRC incidence and mortality from 1990 to 2016 and found the ASIR of CRC increased from 14.25 per 100,000 in 1990 to 25.27 per 100,000 in 2016 (AAPC = 2.34, 95% confidence interval [CI] 2.29, 2.39). Cancer cases increased from 104.3 thousand to 392.8 thousand during the same period. The ASIR increased by 2.76% (95% CI 2.66%, 2.85%) and 1.70% (95% CI 1.64%, 1.76%) per year in males and females, respectively. The highest AAPC was found in people aged 15–49 years (2.76, 95% CI 2.59, 2.94). Cancer deaths increased from 81.1 thousand in 1990 to 167.1 thousand in 2016, while the ASMR remained stable (−0.04, 95% CI −0.13, 0.05), A mild increase (AAPC = 0.42, 95% CI 0.34, 0.51) was found among males and a significant decrease (AAPC = −0.75, 95% CI −0.90, −0.60) was found among females. Between 2016 and 2025, cancer cases and deaths are expected to increase from 392.8 and 167.1 thousand in 2016 to 642.3 (95% CI 498.4, 732.1) and 221.1 thousand (95% CI 122.5, 314.8) in 2025, respectively. Our study showed a steady increase in the CRC incidence in China over the past three decades and predicted a further increase in the near future. To combat this health concern, the prevention and management of known risk factors should be promoted through national polices. Greater priority should be given to CRC prevention in younger adults, and CRC screening should be widely adopted for this population.

Colorectal Cancer Incidence and Mortality Rates Among New York City Adults Ages 20-54 years during 1976-2015

Colorectal cancer (CRC) incidence rates are rising in younger Americans and mortality rates are increasing among younger white Americans. We used New York State Cancer Registry data to examine New York City CRC incidence and mortality trends among adults ages 20–54 years by race from 1976 to 2015. Annual percent change (APC) was considered statistically significant at P less than .05 using a two-sided test. CRC incidence increased among those ages 20–49 years, yet blacks had the largest APC of 2.2% (1993–2015; 95% confidence interval [CI] = 1.4% to 3.1%) compared with 0.5% in whites (1976–2015; 95% CI = 0.2% to 0.7%). Among those aged 50–54 years, incidence increased among blacks by 0.8% annually (1976–2015; 95% CI = 0.4% to 1.1%), but not among whites. CRC mortality decreased among both age and race groups. These findings emphasize the value of local registry data to understand trends locally, the importance of timely screening, and the need for clinicians to consider CRC among all patients with compatible signs and symptoms.

To Screen or Not to Screen Adults 45-49 Years of Age: That is the Question

Should we adopt the recently published American Cancer Society (ACS) recommendations to screen adults at 45 years of age? The main reasons for adopting the recommendation include the increase of colorectal cancer (CRC) in the young, especially late-stage tumors. Screening at 45 years is also supported by predictive modeling, which the ACS employed using updated and improved models as compared to those previously used by the United States Preventive Services Task Force. Reasons against adopting include concerns with the models as well as diversion of scarce screening resources away from high-risk populations. Readers are provided with opposing viewpoints regarding the ACS recommendation.

Time trends of incidence and mortality in colorectal cancer in Changning District, Shanghai, 1975-2013

OBJECTIVE

To evaluate the incidence and mortality of colorectal cancer (CRC) and the estimated patient's age, diagnostic duration and birth cohort effects in patients of Changning District, Shanghai.

METHODS

Age-standardized rates (ASRs) of CRC over eight intervals of 5 years from 1975 to 2013 were determined. Joinpoint regression analysis was used to determine the changes in annual incidence and mortality trends. Age-period-cohort analysis was performed to investigate their effects on the incidence and mortality trends of CRC.

RESULTS

For incidence, the ASRs of 14.14 per 100 000 and 11.81 per 100 000 during 1975-1979 increased to 32.11 per 100 000 and 26.25 per 100 000 in men and women during 2008-2013. For mortality, ASRs of 9.40 per 100 000 and 8.76 per 100 000 increased to 14.80 per 100 000 and 11.92 per 100 000 in men and women, respectively, from 1975-1979 to 2010-2013. Joinpoint regression analysis found an increasing incidence (average annual percentage change [AAPC] 2.18% for men and 1.65% for women) and mortality (AAPC 1.47% for men and 0.97% for women) of CRC throughout the entire period. The incidence and mortality trends of CRC were significantly affected by birth cohorts.

CONCLUSIONS

The increasing incidence and mortality of CRC are largely affected by the effects of birth cohorts. The increased incidence of CRC may be attributed to changes in lifestyle and diet, while that in mortality trends may be resulted from increasing incidence, an aging population and changing lifestyles.

An Adjusted Level of Adenoma Detection Rate is Necessary for Adults Below 50 Years Old

BACKGROUND

Although adenoma prevalence is lower in younger people compared with screening-aged adults 50 years old and above, there is no adjustment recommendation for the target adenoma detection rate (ADR) in young people. Herein, we estimated a different target ADR for adults below 50 years old based on screening colonoscopy findings.

MATERIALS AND METHODS

Asymptomatic, average-risk adults below 50 years old who underwent screening colonoscopy were enrolled at 12 endoscopy centers in Korea between February 2006 and March 2012. Screening colonoscopies were stratified into low or high ADR groups with ADR levels of 20% and 25%, respectively.

RESULTS

The ADRs from 12 endoscopy centers ranged from 12.1% to 43.8% (median ADR, 24.1%) based on 5272 young adults receiving screening colonoscopies. Using 20% as an ADR level, the risks for metachronous adenoma and advanced adenoma were significantly higher in the low ADR group than the high ADR group (35.4% vs. 25.7%, P<0.001; 8.3% vs. 3.7%, P=0.001, respectively). However, using ADR level of 25%, the risk for metachronous neoplasia was similar in the high and low ADR groups in young adults according to screening colonoscopy. In subgroup analysis, similar findings were found in males, but not in females.

CONCLUSIONS

Optimal target ADR may be different between younger and older populations, and the adoption of a 20% target ADR could be used as a performance indicator for young populations.

Trends in colorectal cancer incidence among younger adults-Disparities by age, sex, race, ethnicity, and subsite

Millennials (ages 18-35) are now the largest living generation in the US, making it important to understand and characterize the rising trend of colorectal cancer incidence in this population, as well as other younger generations of Americans. Data from the New Jersey State Cancer Registry (n = 181 909) and Surveillance, Epidemiology, and End Results program (n = 448 714) were used to analyze invasive CRC incidence trends from 1979 to 2014. Age, sex, race, ethnicity, subsite, and stage differences between younger adults (20-49) and screening age adults (≥50) in New Jersey (NJ) were examined using chi-square; and, we compared secular trends in NJ to the United States (US). Whites, men, and the youngest adults (ages 20-39) are experiencing greater APCs in rectal cancer incidence. Rates among younger black adults, overall, were consistently higher in both NJ and the US over time. When compared to older adults, younger adults with CRC in NJ were more likely to be: diagnosed at the late stage, diagnosed with rectal cancer, male, non-white, and Hispanic. Invasive CRC incidence trends among younger adults were found to vary by age, sex, race, ethnicity, and subsite. Large, case-level, studies are needed to understand the role of genetics, human papillomavirus (HPV), and cultural and behavioral factors in the rise of CRC among younger adults. Provider and public education about CRC risk factors will also be important for preventing and reversing the increasing CRC trend in younger adults.

Bowel preparation quality scales for colonoscopy

Colorectal cancer (CRC) is the third most common cancer and second leading cause of cancer-related death in the United States. Colonoscopy is widely preferred for CRC screening and is the most commonly used method in the United States. Adequate bowel preparation is essential for successful colonoscopy CRC screening. However, up to one-quarter of colonoscopies are associated with inadequate bowel preparation, which may result in reduced polyp and adenoma detection rates, unsuccessful screens, and an increased likelihood of repeat procedure. In addition, standardized criteria and assessment scales for bowel preparation quality are lacking. While several bowel preparation quality scales are referred to in the literature, these differ greatly in grading methodology and categorization criteria. Published reliability and validity data are available for five bowel preparation quality assessment scales, which vary in several key attributes. However, clinicians and researchers continue to use a variety of bowel preparation quality measures, including nonvalidated scales, leading to potential confusion and difficulty when comparing quality results among clinicians and across clinical trials. Optimal clinical criteria for bowel preparation quality remain controversial. The use of validated bowel preparation quality scales with stringent but simple scoring criteria would help clarify clinical trial data as well as the performance of colonoscopy in clinical practice related to quality measurements.

Bowel preparation quality scales for colonoscopy

Colorectal cancer (CRC) is the third most common cancer and second leading cause of cancer-related death in the United States. Colonoscopy is widely preferred for CRC screening and is the most commonly used method in the United States. Adequate bowel preparation is essential for successful colonoscopy CRC screening. However, up to one-quarter of colonoscopies are associated with inadequate bowel preparation, which may result in reduced polyp and adenoma detection rates, unsuccessful screens, and an increased likelihood of repeat procedure. In addition, standardized criteria and assessment scales for bowel preparation quality are lacking. While several bowel preparation quality scales are referred to in the literature, these differ greatly in grading methodology and categorization criteria. Published reliability and validity data are available for five bowel preparation quality assessment scales, which vary in several key attributes. However, clinicians and researchers continue to use a variety of bowel preparation quality measures, including nonvalidated scales, leading to potential confusion and difficulty when comparing quality results among clinicians and across clinical trials. Optimal clinical criteria for bowel preparation quality remain controversial. The use of validated bowel preparation quality scales with stringent but simple scoring criteria would help clarify clinical trial data as well as the performance of colonoscopy in clinical practice related to quality measurements.

Is increased colorectal screening effective in preventing distant disease?

BACKGROUND

Screening in the average risk population for colorectal cancer (CRC) is expected to reduce the incidence of distant (i.e., metastatic) CRCs at least as much as less advanced CRCs. Indeed, since 2000, during which time colonoscopy became widely used as a screening tool, the overall incidence of CRC has been reduced by 29%.

OBJECTIVE

The purpose of the current study was to determine whether the reduction of incidence rates is the same for all stages of disease.

METHODS

We evaluated incidence data from the Surveillance, Epidemiology, and End Results (SEER) program from 2000-2014 for Localized, Regional, and Distant disease. Joinpoint models were compared to assess parallelism of trends. Data were stratified by race, age, tumor location, and sex to determine whether these subgroupings could explain overall trends.

RESULTS

Inconsistent with the expectations of a successful screening program, the reduction in incidence rates of distant CRCs from 2000-2014 has been slower than the reductions in incidence rates of both regional and localized CRCs. This trend is evident even when the data are stratified by age at diagnosis, sex, race, or tumor location.

CONCLUSIONS

The slower decrease in the incidence rate of distant disease is not consistent with a screening effect, that is, CRC screening may not be effective in preventing many distant CRCs. As a consequence, distant CRCs represent an increasing fraction of all CRCs, accounting for 21% of all CRCs in 2014. The analysis indicates that inadequate screening does not explain the slower decrease in incidence of distant CRCs. Consequently, we suggest that a subtype of CRC exists that advances rapidly, evading detection because screening intervals are too long to prevent it. Microsatellite unstable tumors represent a known subtype that advances more rapidly, and we suggest that another rapidly advancing subtype very likely exists that is microsatellite stable.

Colorectal cancer screening for average-risk adults: 2018 guideline update from the American Cancer Society

In the United States, colorectal cancer (CRC) is the fourth most common cancer diagnosed among adults and the second leading cause of death from cancer. For this guideline update, the American Cancer Society (ACS) used an existing systematic evidence review of the CRC screening literature and microsimulation modeling analyses, including a new evaluation of the age to begin screening by race and sex and additional modeling that incorporates changes in US CRC incidence. Screening with any one of multiple options is associated with a significant reduction in CRC incidence through the detection and removal of adenomatous polyps and other precancerous lesions and with a reduction in mortality through incidence reduction and early detection of CRC. Results from modeling analyses identified efficient and model-recommendable strategies that started screening at age 45 years. The ACS Guideline Development Group applied the Grades of Recommendations, Assessment, Development, and Evaluation (GRADE) criteria in developing and rating the recommendations. The ACS recommends that adults aged 45 years and older with an average risk of CRC undergo regular screening with either a high-sensitivity stool-based test or a structural (visual) examination, depending on patient preference and test availability. As a part of the screening process, all positive results on noncolonoscopy screening tests should be followed up with timely colonoscopy. The recommendation to begin screening at age 45 years is a qualified recommendation. The recommendation for regular screening in adults aged 50 years and older is a strong recommendation. The ACS recommends (qualified recommendations) that: 1) average-risk adults in good health with a life expectancy of more than 10 years continue CRC screening through the age of 75 years; 2) clinicians individualize CRC screening decisions for individuals aged 76 through 85 years based on patient preferences, life expectancy, health status, and prior screening history; and 3) clinicians discourage individuals older than 85 years from continuing CRC screening. The options for CRC screening are: fecal immunochemical test annually; high-sensitivity, guaiac-based fecal occult blood test annually; multitarget stool DNA test every 3 years; colonoscopy every 10 years; computed tomography colonography every 5 years; and flexible sigmoidoscopy every 5 years. CA Cancer J Clin 2018;68:250-281. © 2018 American Cancer Society.

The impact of the rising colorectal cancer incidence in young adults on the optimal age to start screening: Microsimulation analysis I to inform the American Cancer Society colorectal cancer screening guideline

BACKGROUND

In 2016, the Microsimulation Screening Analysis‐Colon (MISCAN‐Colon) model was used to inform the US Preventive Services Task Force colorectal cancer (CRC) screening guidelines. In this study, 1 of 2 microsimulation analyses to inform the update of the American Cancer Society CRC screening guideline, the authors re‐evaluated the optimal screening strategies in light of the increase in CRC diagnosed in young adults.

METHODS

The authors adjusted the MISCAN‐Colon model to reflect the higher CRC incidence in young adults, who were assumed to carry forward escalated disease risk as they age. Life‐years gained (LYG; benefit), the number of colonoscopies (COL; burden) and the ratios of incremental burden to benefit (efficiency ratio [ER] = ΔCOL/ΔLYG) were projected for different screening strategies. Strategies differed with respect to test modality, ages to start (40 years, 45 years, and 50 years) and ages to stop (75 years, 80 years, and 85 years) screening, and screening intervals (depending on screening modality). The authors then determined the model‐recommended strategies in a similar way as was done for the US Preventive Services Task Force, using ER thresholds in accordance with the previously accepted ER of 39.

RESULTS

Because of the higher CRC incidence, model‐predicted LYG from screening increased compared with the previous analyses. Consequently, the balance of burden to benefit of screening improved and now 10‐yearly colonoscopy screening starting at age 45 years resulted in an ER of 32. Other recommended strategies included fecal immunochemical testing annually, flexible sigmoidoscopy screening every 5 years, and computed tomographic colonography every 5 years.

CONCLUSIONS

This decision‐analysis suggests that in light of the increase in CRC incidence among young adults, screening may be offered earlier than has previously been recommended. Cancer 2018;124:2964‐73. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Colorectal cancer incidence has been increasing since the mid‐1990s in adults aged <50 years. A well‐established decision‐analytic modeling approach suggests that in light of this increasing incidence, the optimal age to start colorectal cancer screening is 45 years.

See also pages 2974‐85.

Characteristics and comparison of colorectal cancer incidence in Beijing with other regions in the world

Background

Population-based epidemiologic studies about colorectal cancer are lacking in China. This study aims to provide a basis for colorectal cancer screening and prevention, through analysis and comparisons the characteristics of the trends in colorectal cancer incidence in Beijing and selected representative regions.

RESULTS

The annual incidence rate in Beijing region increased significantly, from 9.40/100,000 in 1998 to 18.61/100,000 in 2012. The stratified rate showed that the incidence of distal colon adenocarcinoma increased substantially in men, especially in those aged > 75 years and residing in urban areas. Although the incidence rate in Beijing is still lower than in Shanghai, Jiashan, and Hong Kong in China, it is increasing rapidly. Further, the incidence rate in Beijing is lower than in New York, Oxford and Osaka, but higher than in Mumbai and Kyadondo. The incidence trend in Beijing is increasing especially in older groups, while in other regions such as New York, it is decreasing in these age groups.

Materials and Methods

Colorectal cancer incidence data were obtained from Beijing Cancer Registry and Cancer Incidence in Five Continents Plus database. All incidence rates were age-standardized according to Segi's world population. Incidence trends were characterized by calculating the annual percent changes using the Joinpoint Regression Program.

Conclusions

Compared with other regions, Beijing has a medium level of colorectal cancer incidence, however, it is increasing significantly. There are obvious differences in the cancer subsite, sex and age distributions between Beijing and other regions. Prevention and screening of colorectal cancer in Beijing should be strengthened.

Metachronous colon polyps in younger versus older adults: a case-control study

BACKGROUND AND AIMS

The incidence of colorectal cancer in the United States has decreased substantially in individuals aged 50 and older. In contrast, it is increasing in young adults. The polyp characteristics on baseline and follow-up colonoscopy in young adults are not well characterized. We describe the polyp characteristics on baseline and follow-up colonoscopy in adults <40 years and determined factors associated with the occurrence of metachronous, advanced neoplasia or high-risk (HR) polyp features. We compared the occurrence of metachronous advanced neoplasia in young adults with those 50 years and older to assess whether postpolypectomy surveillance guidelines seem appropriate for polyp-bearing adults less than age 40 years.

METHODS

Patients <40 years of age with >1 polyp removed on colonoscopy followed by a postpolypectomy colonoscopy were eligible. The primary outcome was the occurrence of advanced neoplasia or HR polyp features on follow-up colonoscopy. Secondary endpoints included factors associated with metachronous advanced neoplasia in young adults. The occurrence of metachronous advanced neoplasia in young adults was compared with a cohort of patients aged 50 years and older.

RESULTS

Included were 128 patients with a mean age of 34.9 years; 124 patients (97%) had adenomas and 7% had sessile serrated polyps (SSPs). Advanced neoplasia was seen in 35% of patients at baseline. The median follow-up time was 33.6 months. Metachronous advanced neoplasia was identified in 7% of patients on follow-up colonoscopy. Baseline factors associated with metachronous advanced neoplasia included the presence of an SSP (hazard ratio, 7.8; 95% CI, 1.09-56.3; P = .041) with a trend in those with advanced neoplasia (hazard ratio, 3.4; 95% confidence interval, .89-12.8; P = .072). The occurrence of metachronous advanced neoplasia did not differ between the young and older cohorts (7% vs 12.2%, P = .58); however, young adults were less likely to have HR polyp features on follow-up (8.6% vs 20.3%, P = .008).

CONCLUSIONS

More than 1 in 3 adults <40 years old undergoing colonoscopy had advanced neoplasia on baseline colonoscopy. The occurrence of metachronous advanced neoplasia in young adults is similar to older adults and appears to be associated with the size, pathology, and number of baseline polyps. Our data suggest young polyp-bearing adults may undergo postpolypectomy colonoscopy at intervals currently recommended by national guidelines. Confirmation in larger studies is warranted.

Colorectal cancer in the young: a possible role for immune surveillance?

BACKGROUND

Younger patients with colorectal cancer (CRC) generally have better survival in spite of worse clinical and pathological features.

METHODS

Twenty-six patients under 50 years operated for primary CRC were enrolled and matched 1:2:2 according to stage, tumor site and gender with 52 patients from 50 to 70 years and 52 patients over 70 years old.

RESULTS

Patients under 50 years had a significantly longer overall, cancer specific and disease free survival (p = .001, p = .007 and p = .05, respectively). However, they had more frequently lymphovascular invasion (p = .006) and they more frequently developed metachronous CRC at follow-up (p = .03). Nevertheless, preoperative lymphocytes blood count/white blood count (LBC/WBC) ratio inversely correlated with age at operation (rho = -.21, p = .04) and it predicted CRC recurrence with an accuracy of 70%, p < .001 (threshold value LBC/WBC = 0.21%) and better overall, cancer specific and disease free survival (p < .0001 for all). At multivariate analysis, stage and LBC/WBC ratio resulted independent predictors of disease free survival (p = .0001 and p = .01, respectively).

CONCLUSIONS

Patients under 50 years had a significantly longer survival with a higher LBC/WBC ratio. These results could suggest a possible role of immunosurveillance in neoplastic control.

Update on Hereditary Colorectal Cancer: Improving the Clinical Utility of Multigene Panel Testing

Colorectal cancer (CRC), one of the most common cancers, is a major public health issue globally, especially in Westernized countries. Up to 35% of CRCs are thought to be due to heritable factors, but currently only 5% to 10% of CRCs are attributable to high-risk mutations in known CRC susceptibility genes, predominantly the mismatch repair genes (Lynch syndrome) and adenomatous polyposis coli gene (APC; familial adenomatous polyposis). In this era of precision medicine, high-risk mutation carriers, when identified, can be offered various risk management options that prevent cancers and improve survival, including risk-reducing medication, screening for early detection, and surgery. The practice of clinical genetics is currently transitioning from phenotype-directed single gene testing to multigene panels, now offered by numerous providers. For CRC, the genes included across these panels vary, ranging from well established, clinically actionable susceptibility genes with quantified magnitude of risk, to genes that lack extensive validation or have less evidence of association with CRC and, therefore, have minimal clinical utility. The current lack of consensus regarding inclusion of genes in CRC panels presents challenges in patient counseling and management, particularly when a variant in a less validated gene is identified. Furthermore, there remain considerable challenges regarding variant interpretation even for the well established CRC susceptibility genes. Ironically though, only through more widespread testing and the accumulation of large international data sets will sufficient information be generated to (i) enable well powered studies to determine if a gene is associated with CRC susceptibility, (ii) to develop better models for variant interpretation and (iii) to facilitate clinical translation.

Subsite- and stage-specific colorectal cancer trends in Estonia prior to implementation of screening

BACKGROUND

The occurrence of colorectal cancer (CRC) in Estonia has been characterised by increasing incidence, low survival and no screening. The study aimed to examine long-term incidence and survival trends of CRC in Estonia with specific focus on subsite and stage.

METHODS

We analysed CRC incidence and relative survival using Estonian Cancer Registry data on all cases of colorectal cancer (ICD-10 C18-21) diagnosed in 1995-2014. TNM classification was used to categorise stage.

RESULTS

Age-standardized incidence of colon cancer increased both in men and women at a rate of approximately 1% per year. Significant increase was seen for right-sided tumours, but not for left-sided tumours. Rectal cancer incidence increased significantly only in men and anal cancer incidence only in women. Age-standardized five-year relative survival for colon cancer increased from 50% in 1995-1999 to 59% in 2010-2014; for rectal cancer, from 38% to 56%. Colon cancer survival improved significantly for left-sided tumours (from 51% to 62%) and stage IV disease (from 6% to 15%). For rectal cancer, significant survival gain was seen for stage II (from 58% to 75%), stage III (from 34% to 70%) and stage IV (from 1% to 12%).

CONCLUSION

In the pre-screening era in Estonia, increase in colon cancer incidence was limited to right-sided tumours. Large stage-specific survival gain, particularly for rectal cancer, was probably due to better staging and advances in multimodality treatment. Nonetheless, more than one quarter of new CRC cases are diagnosed at stage IV, emphasising the need for an efficient screening program.

Rectal cancer survival in the United States by race and stage, 2001 to 2009: Findings from the CONCORD-2 study

BACKGROUND

In the first CONCORD study, 5-year survival for patients with diagnosed with rectal cancer between 1990 and 1994 was <60%, with large racial disparities noted in the majority of participating states. We have updated these findings to 2009 by examining population-based survival by stage of disease at the time of diagnosis, race, and calendar period.

METHODS

Data from the CONCORD-2 study were used to compare survival among individuals aged 15 to 99 years who were diagnosed in 37 states encompassing up to 80% of the US population. We estimated net survival up to 5 years after diagnosis correcting for background mortality with state-specific and race-specific life table. Survival estimates were age-standardized with the International Cancer Survival Standard weights. We present survival estimates by race (all, black, and white) for 2001 through 2003 and 2004 through 2009 to account for changes in collecting the data for Surveillance, Epidemiology, and End Results Summary Stage 2000.

RESULTS

There was a small increase in 1-year, 3-year, and 5-year net survival between 2001-2003 (84.6%, 70.7%, and 63.2%, respectively), and 2004-2009 (85.1%, 71.5%, and 64.1%, respectively). Black individuals were found to have lower 1-year, 3-year, and 5-year survival than white individuals in both periods; the absolute difference in survival between black and white individuals declined only for 5-year survival. Black patients had lower 5-year survival than whites at each stage at the time of diagnosis in both time periods.

CONCLUSIONS

There was little improvement noted in net survival for patients with rectal cancer, with persistent disparities noted between black and white individuals. Additional investigation is needed to identify and implement effective interventions to ensure the consistent and equitable use of high-quality screening, diagnosis, and treatment to improve survival for patients with rectal cancer. Cancer 2017;123:5037-58. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Increasing colorectal cancer incidence trends among younger adults in Canada

Recent analyses in the United States have shown an overall decrease in the incidence of colorectal cancer despite contrasting increases in younger age groups. We examined whether these cohort trends are occurring in Canada. Age-specific trends in colon and rectal cancer incidence in Canada from the National Cancer Incidence Reporting System (1969-1992) and the Canadian Cancer Registry (1992-2012) were analyzed. We estimated annual percent changes (APC) with the Joinpoint Regression Program from the Surveillance Epidemiology, and End Results Program. Birth cohort effects were estimated using 5-year groups starting in 1888. Age-specific prevalence of class I, II and III obesity in Canada was examined from the National Population Health Survey (1994-2001) and the Canadian Community Health Survey (2001-2011). The reductions in CRC incidence among Canadians are limited to older populations. While reductions among younger age groups (20-29year olds (yo), 30-39yo and 40-50yo) were observed between 1969 and 1995, rates have returned to and surpassed historical levels (APCs 20-29yo colon cancer=6.24%, APCs 20-29yo rectal cancer=1.5%). Recent birth cohorts (1970-1990) have the highest incidence rate ratios ever recorded. Ecologic trends in obesity prevalence among these birth cohorts in Canada are suggestive of an impact on increasing incidence trends. Furthermore, obesity prevalence estimates suggest that these trends may continue to increase justifying further examination of the etiologic associations and biological impacts of excess adipose tissue among younger populations. While population-based screening of younger age groups deserves careful consideration, these concerning observed trends warrant public health action to address the growing obesity epidemic.

Predictive relevance of lymphovascular invasion in T1 colorectal cancer before endoscopic treatment

BACKGROUND AND AIM

 The depth of tumor invasion is currently the only reliable predictive risk factor for lymph node metastasis before endoscopic treatment for colorectal cancer. However, the most important factor to predict lymph node metastasis has been suggested to be lymphovascular invasion rather than the depth of invasion. Thus, the aim of this study was to investigate the predictive relevance of lymphovascular invasion before endoscopic treatment.

METHODS

 The data on pT1 colorectal cancers that were resected endoscopically or surgically from 2007 to 2015 were retrospectively reviewed. The cases were categorized into two groups: positive or negative for lymphovascular invasion. The following factors were evaluated by univariate and multivariate analyses: age and sex of the patients; location, size, and morphology of the lesion; and depth of invasion.

RESULTS

 The positive and negative groups included 229 and 457 cases, respectively. Younger age ( P  < 0.01), smaller lesion size ( P  = 0.01), non-LST (LST: laterally spreading tumor) ( P  < 0.01), presence of depression ( P  < 0.01), and pT1b ( P  < 0.01) were associated with lymphovascular invasion. In multivariate analysis, younger age (comparing patients aged ≤ 64 years with those aged > 65 years, OR, 1.81; 95 %CI, 1.29 - 2.53), presence of depression (OR, 1.97; CI, 1.40 - 2.77), non-LST features (OR, 1.50; CI, 1.04 - 2.15), and pT1b (OR, 3.08; CI, 1.91 - 4.97) were associated with lymphovascular invasion.

CONCLUSION

 Younger age, presence of depression, T1b, and non-LST are associated with lymphovascular invasion. Therefore, careful pathological diagnosis and surveillance are necessary for lesions demonstrating any of these four factors.

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.

Comparison of Colonoscopy Surveillance Outcomes Between Young and Older Colorectal Cancer Patients

BACKGROUND

Young-onset colorectal cancer is uncommon, but the incidence is increasing. Despite several guidelines for colonoscopic surveillance following colorectal cancer resection, there is little consistency regarding the timing and age-adjusted strategies of surveillance colonoscopy after surgery of young-onset colorectal cancer. The aim of this study was to compare the outcomes of surveillance colonoscopy between sporadic colorectal cancer patients with young and older age after curative resection.

METHODS

We retrospectively reviewed 569 colorectal cancer patients who underwent curative resection between January 2006 and December 2010. The primary outcome was comparison of the development of metachronous advanced neoplasia during surveillance colonoscopy between young and older colorectal cancer patients.

RESULTS

There were 95 patients in the young age group and 474 patients in the older age group. The mean time interval from surgery to the development of metachronous advanced neoplasia was 99.2 ± 3.7 months in the young age group and 84.4 ± 2.5 months in the old age group (P = 0.03). In the multivariate analysis, age (OR, 3.56; P = 0.04) and family history of colorectal cancer (OR, 2.66; P = 0.008) were associated with the development of metachronous advanced neoplasia. None of the young patients without both family history of colorectal cancer and high-risk findings at index colonoscopy showed advanced neoplasia during the follow-up period.

CONCLUSIONS

Age and family history of colorectal cancer are independent risk factors for the occurrence of advanced neoplasia after curative colorectal cancer resection, suggesting age-adjusted strategies of surveillance colonoscopy.

Rectal Cancer in Asian vs. Western Countries: Why the Variation in Incidence?

OPINION STATEMENT

Colorectal cancer (CRC) is the third most common cancer worldwide. CRC has been thought to be less common in Asia compared to Western countries. However, the incidence rates of CRC in Asia are high and there is an increasing trend in the Asian population. Furthermore, colorectal cancer accounts for the greatest number of all incidences of CRC in Asia. The increasing adoption of a Western lifestyle, particularly in dietary habits, is likely the most important factor contributing to the rapid increase in colon cancer incidence; it is noteworthy that trends for rectal cancer were flat. The etiology of colon and rectal cancer is a bit different. The risks of distal colon and rectal cancers are more likely to be related to environmental factors, such as polluted surface water sources, alcohol consumption, and habitual smoking. The lack of great change in the incidence of rectal cancer might be due to weaker associations with such lifestyle factors. Therefore, it has been hypothesized that proximal and distal sections of the colon and rectum are two different organs in terms of function and genetic background. It may mean differences in differential sensitivities and exposures to carcinogens. However, despite the decrease in whole incidence, the CRC incidence in young adults in Western countries are reversely increasing, especially in rectal cancer, due to reasons largely unknown. Although the treatment algorithm is different between Asia and western countries, globally, the survival rate for patients with rectal cancer has risen during the past 10 years. Screening contributes a great deal to reducing the incidence and improving survival. Most countries in Asia, such as China, need nationwide registration and screening systems to provide better data.

Colorectal Cancer Mortality Rates in Adults Aged 20 to 54 Years in the United States, 1970-2014

This study uses National Center for Health Statistics data to analyze colorectal cancer mortality rates among US adults aged 20 to 54 years by race from 1970 through 2014.

Colorectal Cancer Incidence Patterns in the United States, 1974-2013

Background

Colorectal cancer (CRC) incidence in the United States is declining rapidly overall but, curiously, is increasing among young adults. Age-specific and birth cohort patterns can provide etiologic clues, but have not been recently examined.

Methods

CRC incidence trends in Surveillance, Epidemiology, and End Results areas from 1974 to 2013 (n = 490 305) were analyzed by five-year age group and birth cohort using incidence rate ratios (IRRs) and age-period-cohort modeling.

Results

After decreasing in the previous decade, colon cancer incidence rates increased by 1.0% to 2.4% annually since the mid-1980s in adults age 20 to 39 years and by 0.5% to 1.3% since the mid-1990s in adults age 40 to 54 years; rectal cancer incidence rates have been increasing longer and faster (eg, 3.2% annually from 1974-2013 in adults age 20-29 years). In adults age 55 years and older, incidence rates generally declined since the mid-1980s for colon cancer and since 1974 for rectal cancer. From 1989-1990 to 2012-2013, rectal cancer incidence rates in adults age 50 to 54 years went from half those in adults age 55 to 59 to equivalent (24.7 vs 24.5 per 100 000 persons: IRR = 1.01, 95% confidence interval [CI] = 0.92 to 1.10), and the proportion of rectal cancer diagnosed in adults younger than age 55 years doubled from 14.6% (95% CI = 14.0% to 15.2%) to 29.2% (95% CI = 28.5% to 29.9%). Age-specific relative risk by birth cohort declined from circa 1890 until 1950, but continuously increased through 1990. Consequently, compared with adults born circa 1950, those born circa 1990 have double the risk of colon cancer (IRR = 2.40, 95% CI = 1.11 to 5.19) and quadruple the risk of rectal cancer (IRR = 4.32, 95% CI = 2.19 to 8.51).

Conclusions

Age-specific CRC risk has escalated back to the level of those born circa 1890 for contemporary birth cohorts, underscoring the need for increased awareness among clinicians and the general public, as well as etiologic research to elucidate causes for the trend. Further, as nearly one-third of rectal cancer patients are younger than age 55 years, screening initiation before age 50 years should be considered.

Increasing Incidence of Colorectal Cancer in Adolescents and Young Adults Aged 15-39 Years in Western Australia 1982-2007: Examination of Colonoscopy History

Aims

To examine trends in colorectal cancer (CRC) incidence and colonoscopy history in adolescents and young adults (AYAs) aged 15–39 years in Western Australia (WA) from 1982 to 2007.

Design

Descriptive cohort study using population-based linked hospital and cancer registry data.

Method

Five-year age-standardized and age-specific incidence rates of CRC were calculated for all AYAs and by sex. Temporal trends in CRC incidence were investigated using Joinpoint regression analysis. The annual percentage change (APC) in CRC incidence was calculated to identify significant time trends. Colonoscopy history relative to incident CRC diagnosis was examined and age and tumor grade at diagnosis compared for AYAs with and without pre-diagnosis colonoscopy. CRC-related mortality within 5 and 10 years of incident diagnosis were compared for AYAs with and without pre-diagnosis colonoscopy using mortality rate ratios (MRRs) derived from negative binomial regression.

Results

Age-standardized CRC incidence among AYAs significantly increased in WA between 1982 and 2007, APC = 3.0 (95% CI 0.7–5.5). Pre-diagnosis colonoscopy was uncommon among AYAs (6.0%, 33/483) and 71% of AYAs were diagnosed after index (first ever) colonoscopy. AYAs with pre-diagnosis colonoscopy were older at CRC diagnosis (mean 36.7 ± 0.7 years) compared to those with no prior colonoscopy (32.6 ± 0.2 years), p < 0.001. At CRC diagnosis, a significantly greater proportion of AYAs with pre-diagnosis colonoscopy had well-differentiated tumors (21.2%) compared to those without (5.6%), p = 0.001. CRC-related mortality was significantly lower for AYAs with pre-diagnosis colonoscopy compared to those without, for both 5-year [MRR = 0.44 (95% CI 0.27–0.75), p = 0.045] and 10-year morality [MRR = 0.43 (95% CI 0.24–0.83), p = 0.043].

Conclusion

CRC incidence among AYAs in WA has significantly increased over the 25-year study period. Pre-diagnosis colonoscopy is associated with lower tumor grade at CRC diagnosis as well as significant reduction in both 5- and 10-year CRC-related mortality rates. These findings warrant further research into the balance in benefits and harms of targeted screening for AYA at highest risk.