Trends in colorectal cancer incidence: a period and birth-cohort analysis in a well-defined French population

The mortality risk in patients with early onset colorectal cancer: the role of comorbidities

The global incidence of early-onset colorectal cancer (EO-CRC) is increasing. Although the mortality rate is relatively stable, some comorbidities have been associated with a higher mortality rate. This study estimated the mortality risk in patients with EO-CRC with various comorbidities using real-world data to identify the high-risk group using Cox proportional regression for overall and cancer-specific mortality. The incidence rate of EO-CRC significantly increased from 6.04 per 100,000 population in 2007 to 12.97 per 100,000 population in 2017. The five-year overall mortality rate was 101.50 per 1000 person year and the cancer-specific mortality rate was 94.12 per 1000 person year. Patients with cerebrovascular disease (CVD) had a higher mortality risk (hazard ratio (HR): 1.68; 95% confidence interval (CI): 1.25-2.28; p=0.0007). After subgroup analyses based on age, sex, clinical stage, and treatment type, patients with CVD had a higher overall mortality risk compared to non-CVD patients, except for patients undergoing surgery and chemotherapy. Patients with chronic kidney disease had a higher mortality risk in the early clinical stages (HR: 2.31; 95% CI: 1.08-4.96; p=0.0138). Patients who underwent radiotherapy had a higher overall mortality risk (HR: 1.38; 95% CI: 1.04-1.85; p=0.0285) than those without liver disease. Identifying specific comorbidity mortality risks in patients with EO-CRC allows for risk stratification when screening target groups and may lower disease mortality.

Statistical methods for measuring trends in colorectal cancer incidence in registries: A systematic review

Background

Monitoring cancer trends in a population is essential for tracking the disease’s burden, allocating resources, and informing public health policies. This review describes variations in commonly employed methods to estimate colorectal cancer (CRC) incidence trends.

Methods

We performed a systematic literature search in four databases to identify population-based studies reporting CRC incidence trends, published between January 2010 and May 2020. We extracted and described data on methods to estimate trends and assess model validity, and the software used.

Results

This review included 145 articles based on studies conducted in five continents. The majority (93%) presented visual summaries of trends combined with absolute, relative, or annual change estimates. Fourteen (10%) articles exclusively calculated the relative change in incidence over a given time interval, presented as the percentage of change in rates. Joinpoint regression analysis was the most commonly used method for assessing incidence trends (n= 65, 45%), providing estimates of the annual percentage change (APC) in rates. Nineteen (13%) studies performed Poisson regression and 18 (12%) linear regression analysis. Age-period-cohort modeling- a type of generalized linear models- was conducted in 18 (12%) studies. Thirty-nine (37%) of the studies modeling incidence trends (n=104, 72%) indicated the method used to evaluate model fitness. The joinpoint program (52%) was the statistical software most commonly used.

Conclusion

This review identified variation in the calculation of CRC incidence trends and inadequate reporting of model fit statistics. Our findings highlight the need for increasing clarity and transparency in reporting methods to facilitate interpretation, reproduction, and comparison with findings from previous studies.

A systematic review of methods to estimate colorectal cancer incidence using population-based cancer registries

Background

Epidemiological studies of incidence play an essential role in quantifying disease burden, resource planning, and informing public health policies. A variety of measures for estimating cancer incidence have been used. Appropriate reporting of incidence calculations is essential to enable clear interpretation. This review uses colorectal cancer (CRC) as an exemplar to summarize and describe variation in commonly employed incidence measures and evaluate the quality of reporting incidence methods.

Methods

We searched four databases for CRC incidence studies published between January 2010 and May 2020. Two independent reviewers screened all titles and abstracts. Eligible studies were population-based cancer registry studies evaluating CRC incidence. We extracted data on study characteristics and author-defined criteria for assessing the quality of reporting incidence. We used descriptive statistics to summarize the information.

Results

This review retrieved 165 relevant articles. The age-standardized incidence rate (ASR) (80%) was the most commonly reported incidence measure, and the 2000 U.S. standard population the most commonly used reference population (39%). Slightly more than half (54%) of the studies reported CRC incidence stratified by anatomical site. The quality of reporting incidence methods was suboptimal. Of all included studies: 45 (27%) failed to report the classification system used to define CRC; 63 (38%) did not report CRC codes; and only 20 (12%) documented excluding certain CRC cases from the numerator. Concerning the denominator estimation: 61% of studies failed to state the source of population data; 24 (15%) indicated census years; 10 (6%) reported the method used to estimate yearly population counts; and only 5 (3%) explicitly explained the population size estimation procedure to calculate the overall average incidence rate. Thirty-three (20%) studies reported the confidence interval for incidence, and only 7 (4%) documented methods for dealing with missing data.

Conclusion

This review identified variations in incidence calculation and inadequate reporting of methods. We outlined recommendations to optimize incidence estimation and reporting practices. There is a need to establish clear guidelines for incidence reporting to facilitate assessment of the validity and interpretation of reported incidence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01632-7.

Cryptosporidium and colorectal cancer: a review of epidemiology and possible association

Cryptosporidiosis is an important protozoan disease with serious public health implications. The contribution of Cryptosporidium to colorectal cancer is still vaguely studied, but little evidence from experimental and epidemiological studies has suggested a possible association. This review discusses the epidemiology of cryptosporidiosis and colorectal cancer and attempts to unravel the possible link between the two diseases using epidemiological, pathological, molecular, and immunological evidence. The review stressed the need to undertake more studies in this relatively neglected field.

Colorectal cancer among farmers in the AGRICAN cohort study

OBJECTIVES

Specific farming types and tasks have rarely been studied in relation to colorectal cancer (CRC). We evaluated associations between 5 types of livestock and 13 types of crops in relation to CRC and its subsites within the Agriculture and Cancer (AGRICAN) study.

METHODS

AGRICAN cohort includes 181,842 agricultural workers living in 11 French geographical areas. Data on farming types and tasks was collected by self-administered questionnaires. We identified 2 609 CRC, 972 right colon, 689 left colon and 898 rectal incident cancer cases during follow-up from 2005 to 2015. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI).

RESULTS

Significantly increased CRC risk was observed for farmers producing horses (HR=1.18, 95% CI 1.06-1.31), sunflower (HR=1.23, 95% CI 1.03-1.45) and field vegetables (HR=1.18, 95% CI 1.02-1.36). Positive associations were also observed for pig, poultry and wheat/barley. Some associations were observed only for specific subsites: left colon cancer was associated with fruit growing (HR=1.36, 95% CI 1.09-1.70) and potato (HR=1.28, 95% CI 1.05-1.57). Tasks related to livestock (animal care, insecticide treatment, disinfection of milking equipment and building) or to crop (haymaking, sowing, pesticide treatment, seed treatment, harvesting) were also associated with CRC. Duration and size of farming types/task increased the risk for some of the associations. Analysis stratified by sex suggested an interaction with several farming types/task.

CONCLUSIONS

The current study showed original and positive findings for several farming types and tasks and CRC risk, overall and by subsites.

Targeting BRAF and RAS in Colorectal Cancer

Simple Summary

In colorectal cancer, mutations of the KRAS and BRAF genes are quite common and can contribute to the activation of cell signaling pathways that lead to cell proliferation and differentiation. These processes promote cancer growth, and in some cases, they may cause cells to develop resistance to certain types of treatment, notably EGFR inhibitors. We summarize recent knowledge regarding the effects of KRAS and BRAF mutations in the setting of colorectal cancer and discuss the new therapies under development.

Abstract

Colorectal cancer (CRC) is still one of the most frequent forms of cancer in the world in terms of incidence. Around 40% of CRC patients carry a mutation of the Kirsten rat sarcoma (KRAS) gene, while 10% have a mutation in the B-Raf proto-oncogene serine/threonine kinase (BRAF) gene. These mutations are responsible for dysregulation of the mitogen-associated protein kinase (MAPK) pathway, leading to the proliferation, differentiation, angiogenesis, and resistance to apoptosis of cells. Activation of the MAPK pathway results in adaptive therapeutic resistance, rendering EGFR inhibitors ineffective. This review aims to highlight the recent findings that have improved our understanding of KRAS and BRAF mutations in colorectal cancer and to describe new targeted therapies, used alone or in combination.

Cancer Incidence and Mortality Rates in Multiple Sclerosis: A Matched Cohort Study

OBJECTIVE

To determine whether cancer risk differs in people with and without multiple sclerosis (MS), we compared incidence rates and cancer-specific mortality rates in MS and matched cohorts using population-based data sources.

METHODS

We conducted a retrospective matched cohort study using population-based administrative data from Manitoba and Ontario, Canada. We applied a validated case definition to identify MS cases, then selected 5 controls without MS matched on birth year, sex, and region. We linked these cohorts to cancer registries, and estimated incidence of breast, colorectal, and 13 other cancers. For breast and colorectal cancers, we constructed Cox models adjusting for age at the index date, area-level socioeconomic status, region, birth cohort year, and comorbidity. We pooled findings across provinces using meta-analysis.

RESULTS

We included 53,983 MS cases and 269,915 controls. Multivariable analyses showed no difference in breast cancer risk (pooled hazard ratio [HR] 0.92 [95% confidence interval (CI) 0.78-1.09]) or colorectal cancer risk (pooled HR 0.83 [95% CI 0.64-1.07]) between the cohorts. Mortality rates for breast and colorectal did not differ between cohorts. Bladder cancer incidence and mortality rates were higher among the MS cohort. Although the incidence of prostate, uterine, and CNS cancers differed between the MS and matched cohorts, mortality rates did not.

CONCLUSION

The incidence of breast and colorectal cancers does not differ between persons with and without MS; however, the incidence of bladder cancer is increased. Reported differences in the incidence of some cancers in the MS population may reflect ascertainment differences rather than true differences.

Clinicopathological Characteristics and Outcome of Adolescent and Young Adult-Onset Microsatellite Stable Colorectal Cancer Patients

Purpose: Colorectal cancer (CRC) incidence is increasing in adults younger than 50 years. This study evaluated clinicopathological characteristics and outcome of adolescent and young adult (AYA)-onset sporadic CRC patients. Methods: Medical records of patients who were diagnosed adenocarcinoma of colon or rectum at Siriraj Hospital between 2007 and 2018 were retrospectively reviewed. The patients were classified into two groups: AYA-onset CRC (age 15-39 years) and adult-onset CRC (age >50 years). Associations between sporadic microsatellite stable (MSS) AYA-/adult-onset CRC and clinicopathological features and outcome were evaluated. Results: A total of 203 patients were diagnosed with AYA-onset CRC with no known history of familial CRC syndromes, 119 had data on mismatch repair status; 98 confirmed MSS CRC. AYA-onset CRC patients were commonly found with left-sided rather than right-sided tumors (77.1% vs. 22%) and late stage of disease (80.7% in stage III-IV vs. 19.3% in stage I-II). Compared with adult-onset CRC (218 patients), AYA-onset MSS CRC had more patients with female gender (p = 0.038), perineural invasion (p = 0.003), and signet ring cell/mucinous histology (p = 0.132). On univariate analysis, male gender and mucinous/signet ring cell histology had worse overall survival (OS) (p = 0.004 and p = 0.072, respectively) and remained significant in multivariate analysis for signet ring cell histology (p = 0.008). There was no difference in disease-free survival and OS between both age groups. Conclusions: Sporadic MSS AYA-onset CRC patients were associated with female gender and aggressive pathological characteristics. However, there was no difference in survival outcome between AYA-onset and adult-onset groups.

Increasing Incidence of Young-Onset Colorectal Carcinoma A 3-Country Population Analysis

BACKGROUND

The overall incidence of colorectal carcinoma is declining in Western populations; however, single country series demonstrate an increase in young-onset (<50 years) colorectal carcinoma.

OBJECTIVE

The purpose of this study was to determine whether the pattern of increasing incidence of young-onset colorectal carcinoma is consistent across 3 Western populations.

DESIGN

This is a population incidence study.

SETTINGS

National cancer registries of New Zealand, Sweden, and Scotland were used.

PATIENTS

The incidence of colorectal carcinoma was calculated from population data for 3 countries over 2 to 4 decades.

MAIN OUTCOME MEASURES

The incidence of colorectal carcinoma was measured. Incidence rate ratios were determined and data were stratified by subsite (colon versus rectum), sex, and age (<50, 50-79, and ≥80 y).

RESULTS

Overall colorectal carcinoma rates declined in New Zealand, remained stable in Scotland, and increased in Sweden. In all 3 populations, there was an increasing incidence of rectal carcinoma in those aged <50 years. Young-onset rectal carcinoma increased in New Zealand (1995-2012: incidence rate ratio = 1.18 (men) and 1.13 (women)), with declining incidence in all other age groups. Colon carcinoma did not increase in the population aged <50 years, with the exception of distal colonic carcinoma in men. Overall, rectal carcinoma incidence increased (1970-2014) in Sweden; however, increases in those <50 years of age exceeded increases in other age groups (incidence rate ratio = 1.14 (males) and 1.12 (females)). Distal colon carcinoma increases were most marked in the population aged <50 years. In Scotland (1990-2014), young-onset rectal carcinoma incidence increased (incidence rate ratio = 1.23 (males) and 1.27 (females)), with a smaller increase in colon carcinoma.

LIMITATIONS

Limitations include its registry-based, population incidence research.

CONCLUSIONS

This study shows an increase in young-onset rectal carcinoma in 3 national populations; this observation may provide a focus for looking at the role of environmental influences on the etiology of this increase and therefore to explore strategies for prevention. See Video Abstract at http://links.lww.com/DCR/B194. AUMENTO DE LA INCIDENCIA DE CARCINOMA COLORRECTAL DE INICIO JOVEN: UN ANÁLISIS DE POBLACIÓN DE TRES PAÍSES: La incidencia global de carcinoma colorrectal está disminuyendo en las poblaciones occidentales. Sin embargo, las series de un solo país demuestran un aumento en el carcinoma colorrectal de inicio joven (pacientes menores de 50 años).Determinar si el patrón de incidencia en aumento de carcinoma colorrectal de inicio joven es consistente en tres poblaciones occidentales.Estudio de incidencias de población en tres países.Registros nacionales de cáncer de Nueva Zelanda, Suecia y Escocia.la incidencia de carcinoma colorrectal se calculó a partir de datos de población de tres países durante dos o a cuatro décadas.Incidencia de carcinoma colorrectal. Se determinaron las tasas de incidencia y los datos se estratificaron por subsitio (colon versus recto), además de sexo y edad (<50, 50-79 y ≥ 80).las tasas generales de carcinoma colorrectal disminuyeron en Nueva Zelanda, se mantuvieron estables en Escocia y aumentaron en Suecia. En las tres poblaciones, hubo una incidencia creciente de carcinoma rectal en pacientes menores de 50 años. El carcinoma rectal de inicio juvenil aumentó en Nueva Zelanda (1995-2012): tasa de incidencia de 1,18 [varones] y 1,13 [mujeres], con una disminución de la incidencia en todos los demás grupos de edad. El carcinoma de colon no aumentó en la población de < 50 años, con la excepción del carcinoma de colon distal en hombres. En general, la incidencia de carcinoma rectal aumentó (1970-2014) en Suecia; sin embargo, los aumentos en aquellos de <50 años excedieron los aumentos en otros grupos de edad: tasa de incidencia 1.14 [hombres] y 1.12 [mujeres]. Los aumentos del carcinoma de colon distal fueron más marcados en la población de < 50 años. En Escocia (1990-2014), la incidencia de carcinoma rectal de inicio juvenil aumentó: relación de tasa de incidencia 1.23 [hombres] y 1.27 [mujeres], con un aumento menor en el carcinoma de colon.Investigación de incidencia poblacional basada en registros nacionales.Este estudio muestra un aumento en el carcinoma rectal de inicio joven en tres poblaciones nacionales. Esta observación puede indicar un enfoque para la examinación de influencias ambientales en la etiología de este aumento y, por lo tanto, explorar estrategias para la prevención. Consulte Video Resumen en http://links.lww.com/DCR/B194. (Traducción-Dr Adrián Ortega).

Radiation risk of incident colorectal cancer by anatomical site among atomic bomb survivors: 1958-2009

Radiation effects on colorectal cancer rates, adjusted for smoking, alcohol intake and frequency of meat consumption and body mass index (BMI) by anatomical subsite (proximal colon, distal colon and rectum) were examined in a cohort of 105,444 atomic bomb survivors. Poisson regression methods were used to describe radiation-associated excess relative risks (ERR) and excess absolute rates (EAR) for the 1958-2009 period. There were 2,960 first primary colorectal cancers including 894 proximal, 871 distal and 1,046 rectal cancers. Smoking, alcohol intake and BMI were associated with subsite-specific cancer background rates. Significant linear dose-responses were found for total colon (sex-averaged ERR/Gy for 70 years old exposed at age 30 = 0.63, 95% confidence interval [CI]: 0.34; 0.98), proximal [ERR = 0.80, 95% CI: 0.32; 1.44] and distal colon cancers [ERR = 0.50, 95% CI: 0.04; 0.97], but not for rectal cancer [ERR = 0.023, 95% CI: -0.081; 0.13]. The ERRs for proximal and distal colon cancers were not significantly different (p = 0.41). The ERR decreased with attained age for total colon, but not for proximal colon cancer, and with calendar year for distal colon cancer. The ERRs and EARs did not vary by age at exposure, except for decreasing trend in EAR for proximal colon cancer. In conclusion, ionizing radiation is associated with increased risk of proximal and distal colon cancers. The ERR for proximal cancer persists over time, but that for distal colon cancer decreases. There continues to be no indication of radiation effects on rectal cancer incidence in this population.

Épidémiologie des tumeurs neuroendocrines intestinales

Les données disponibles concernant l’incidence et les facteurs pronostiques des tumeurs neuroendocrines (TNE) digestives sont souvent fragmentaires. Les TNE digestives sont rares et représentent environ 1 % des cancers digestifs. En France, l’incidence des TNE digestives malignes est estimée à 1,1/100 000 chez l’homme et à 0,9/100 000 chez la femme. L’incidence augmente au cours du temps. Du fait de leur longue survie, les TNE constituent, après le cancer colorectal, le cancer digestif dont la prévalence est la plus élevée. La plupart des TNE sont bien différenciées, les carcinomes neuroendocrines peu différenciés représentent moins de 20 % des TNE digestives. Parmi les TNE bien différenciées intestinales, les localisations les plus fréquentes sont l’intestin grêle et le colorectal. Plus de la moitié des TNE sont diagnostiquées au stade métastatique, principalement au niveau hépatique. Le degré de différenciation, le grade histologique, la localisation du primitif et le stade sont les principaux facteurs pronostiques. Les taux de survie relative à cinq ans étaient de 4,5 % pour les tumeurs peu différenciées versus plus de 55 % pour les TNE bien différenciées.

Prognostic factors and patterns of recurrence after emergency management for obstructing colon cancer: multivariate analysis from a series of 2120 patients

PURPOSE

At equal TNM stage, obstructing colon cancer (OCC) is associated with worse prognosis in comparison with uncomplicated cancer. Our aim was to identify prognostic factors of overall (OS) and disease-free survival (DFS) in patients treated for OCC.

METHODS

From 2000 to 2015, 2325 patients were treated for OCC in French surgical centers, members of the French National Surgical Association (AFC). Patients with palliative management were excluded. The main endpoints were OS and DFS. A multivariate analysis, using Cox proportional hazards regression model, was performed to determine independent prognostic factors.

RESULTS

The cohort included 2120 patients. The median of follow-up was 13.2 months. In multivariate analysis, age > 75 years, ASA score ≥ 3, ECOG score ≥ 3, right-sided colon cancer, presence of synchronous metastases, anastomotic leakage, and absence of adjuvant chemotherapy were independent OS factors. Age > 75 years, ASA score ≥ 3, right-sided colon cancer, presence of synchronous metastases, and absence of postoperative chemotherapy were independent factors of poor OS after exclusion of patients who died postoperatively. Age ≥ 75 years, ASA score ≥ 3, ECOG score ≥ 3, right-sided colon cancer, lymph node involvement, presence of vascular, lymphatic or perineural invasion, less than 12 harvested lymph nodes, and absence of adjuvant chemotherapy were independent DFS factors.

CONCLUSIONS

Management of OCC should take into account prognostic factors related to the patient (age, comorbidities), tumor location, and tumor stage. Adjuvant chemotherapy administration plays an important role. For patients undergoing initial defunctionning stoma, neoadjuvant chemotherapy could be an option to improve prognosis.

Increasing colorectal cancer incidence in individuals aged < 50 years-a population-based study

PURPOSE

Data on the incidence of colorectal cancer (CRC) is conflicting, and it is unknown if the incidence is constant, declining, or increasing. Proximal colon cancer is considered to be more common among older individuals, but recent data have shown that rectal cancer and distal colon cancer have been increasing in the younger population. The aim of this study was to determine the trends regarding CRC incidence and tumour location in Sweden.

METHODS

CRC statistics from the National Board of Health and Welfare 1995-2015 were used. CRC incidence rates by age group (< 50 years, 50-79 years, ≥ 80 years), sex, and tumour localisation (proximal colon, distal colon, or rectum) were calculated and analysed using Poisson regression.

RESULTS

The age-standardised incidence of CRC increased in Sweden during the study period. This increase was significant (P < 0.0001) for colon cancer during the study period for all age groups regardless of tumour localisation. The greatest increase (27-52% per decade) in the colon cancer incidence rate was seen among men and women < 50 years of age. The incidence rate for rectal cancer increased for men < 50 years (P < 0.0001), decreased for both men and women aged ≥ 80 years (P < 0.005), and did not change for the remaining groups.

CONCLUSIONS

The CRC incidence in Sweden, in particular colon cancer, is increasing regardless of tumour localisation for individuals < 50 years of age. This paper supports the implementation of population-based colorectal cancer screening. A diagnostic workup should be performed in symptomatic individuals < 50 years of age.

Colorectal Cancer in the Young: Does Screening Make Sense?

PURPOSE OF REVIEW

Colorectal cancer (CRC) screening is recommended to reduce CRC mortality. This review outlines key factors to consider when recommending screening, including disease burden, screening benefits and harms, and remaining knowledge gaps.

RECENT FINDINGS

In response to increasing rates of CRC incidence among younger (age < 50 years) adults, the American Cancer Society published guidelines in May 2018 recommending average-risk CRC screening beginning at age 45 (vs. 50) years. Rates of young-onset CRC have increased in the USA since the early 1990s. However, there is very little empirical evidence of screening effectiveness in younger adults, and few studies have reported harms of routine screening in this age group. Further, we know little about the natural history of CRC in younger adults. Uncertainty surrounding the efficacy of CRC screening in younger adults suggests the benefits may be small. Precision cancer screening-or modified screening regimens based on risk-may improve the balance of screening benefits and harms beyond conventional age-based strategies.

Establishing a research agenda for early-onset colorectal cancer

In this month's Editorial Caitlin C. Murphy and Amit Singal discuss the increasing incidence of early-onset colorectal cancer in patients under the age of 50.

[Analysis of the age-period-cohort effect on mortality from colorectal cancer in Rio de Janeiro State, Brazil, from 1980 to 2014]

The aim of this study was to estimate the contribution of the effect of age, period, and birth cohort on mortality from colorectal cancer. The study analyzed data on deaths from this cancer in individuals over 35 years of age in Rio de Janeiro State, Brazil, obtained from the Mortality Information System (SIM) from 1980 to 2014. Mortality rates were calculated by gender and age bracket. The effect of age, period, and birth cohort was estimated by the method that uses estimable functions: deviations, curves, and drift in the Epi library of the R software. Standardized mortality rates from colorectal cancer were 27.37/100,000 men and 21.83/100,000 women in 2014. The data showed an increase in mortality from this cancer from 1980 to 2014, and mortality rates were higher in men than in women after the 1990s. Age effect was observed with an increase in the rates and aging. Generational analysis showed lower risk of death in older versus younger cohorts, possibly related to the adoption of the Western lifestyle. This scenario underscores the need for screening strategies aimed at early diagnosis and treatment of precursor lesions.

The shifting epidemiology of colorectal cancer in sub-Saharan Africa

The perception that colorectal cancer is rare in sub-Saharan Africa is widely held; however, it is unclear whether this is due to poor epidemiological data or to lower disease rates. The quality of epidemiological data has somewhat improved, and there is an ongoing transition to western dietary and lifestyle practices associated with colorectal cancer. The impact of these changes on the incidence of colorectal cancer is not as evident as it is with other non-communicable diseases such as diabetes. In this Viewpoint, we discuss the epidemiology of colorectal cancer in sub-Saharan Africa. Colorectal cancer in this region frequently occurs at an early age, often with distinctive histological characteristics. We detail the crucial need for hypothesis-driven research on the risk factors for colorectal cancer in this population and identify key research gaps. Should colorectal cancer occur more frequently than assumed, then commensurate allocation of resources will be needed for diagnosis and treatment.

A Systematic Literature Review and Meta-Regression Analysis on Early-Life Energy Restriction and Cancer Risk in Humans

Background

In animal models, long-term moderate energy restriction (ER) is reported to decelerate carcinogenesis, whereas the effect of severe ER is inconsistent. The impact of early-life ER on cancer risk has never been reviewed systematically and quantitatively based on observational studies in humans.

Objective

We conducted a systematic review of observational studies and a meta-(regression) analysis on cohort studies to clarify the association between early-life ER and organ site-specific cancer risk.

Methods

PubMed and EMBASE (1982 –August 2015) were searched for observational studies. Summary relative risks (RRs) were estimated using a random effects model when available ≥3 studies.

Results

Twenty-four studies were included. Eleven publications, emanating from seven prospective cohort studies and some reporting on multiple cancer endpoints, met the inclusion criteria for quantitative analysis. Women exposed to early-life ER (ranging from 220–1660 kcal/day) had a higher breast cancer risk than those not exposed (RR_{RE all ages} = 1.28, 95% CI: 1.05–1.56; RR_{RE for 10–20 years of age} = 1.21, 95% CI: 1.09–1.34). Men exposed to early-life ER (ranging from 220–800kcal/day) had a higher prostate cancer risk than those not exposed (RR_RE = 1.16, 95% CI: 1.03–1.30). Summary relative risks were not computed for colorectal cancer, because of heterogeneity, and for stomach-, pancreas-, ovarian-, and respiratory cancer because there were <3 available studies. Longer duration of exposure to ER, after adjustment for severity, was positively associated with overall cancer risk in women (p = 0.02). Ecological studies suggest that less severe ER is generally associated with a reduced risk of cancer.

Conclusions

Early-life transient severe ER seems to be associated with increased cancer risk in the breast (particularly ER exposure at adolescent age) and prostate. The duration, rather than severity of exposure to ER, seems to positively influence relative risk estimates. This result should be interpreted with caution due to the limited number of studies and difficulty in disentangling duration, severity, and geographical setting of exposure.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Conditional net survival: Relevant prognostic information for colorectal cancer survivors. A French population-based study

BACKGROUND

Traditionally, survival estimates have been reported as survival from the time of diagnosis. A patient's probability of survival changes according to time elapsed since the diagnosis and this is known as conditional survival. The aim was to estimate 5-year net conditional survival in patients with colorectal cancer in a well-defined French population at yearly intervals up to 5 years.

METHODS

Our study included 18,300 colorectal cancers diagnosed between 1976 and 2008 and registered in the population-based digestive cancer registry of Burgundy (France). We calculated conditional 5-year net survival, using the Pohar Perme estimator, for every additional year survived after diagnosis from 1 to 5 years.

RESULTS

The initial 5-year net survival estimates varied between 89% for stage I and 9% for advanced stage cancer. The corresponding 5-year net survival for patients alive after 5 years was 95% and 75%. Stage II and III patients who survived 5 years had a similar probability of surviving 5 more years, respectively 87% and 84%. For survivors after the first year following diagnosis, five-year conditional net survival was similar regardless of age class and period of diagnosis.

CONCLUSIONS

For colorectal cancer survivors, conditional net survival provides relevant and complementary prognostic information for patients and clinicians.

Trends in site- and sex-specific cancer mortality between 1979 and 2010 in Belgium compared with Europe using WHO data

BACKGROUND

Cancer mortality constitutes a major health burden in Europe. Trends are different for men and women, and across Europe. This study aims to map out Belgian cancer mortality trends for the most common cancer types in both sexes between 1979 and 2010, and to link these with trends in cancer mortality and smoking prevalence across Europe.

METHODS

Mortality and population data were obtained from the World Health Organization Mortality Database. Age-standardized mortality rates were calculated by direct standardization using the European Standard Population.

RESULTS

Belgian mortality decreased for the most common cancer sites between 1979 and 2010, except for female lung cancer. Yet, Belgian male lung and female breast cancer rates remain high compared with the remainder of Western Europe. For some cancer sites, mortality trends are similar among the European Regions (e.g. stomach cancer), yet for others trends are divergent (e.g. colorectal cancer).

CONCLUSIONS

Generally, cancer mortality shows a favorable trend in Belgium and Europe. Yet, female lung cancer mortality rates are increasing in Belgium. Furthermore, Belgium still has higher male lung and female breast cancer mortality rates compared with the European regional averages. Considering this and the current smoking prevalence, enduring tobacco control efforts should be made.

PIK3CA mutations predict recurrence in localized microsatellite stable colon cancer

PIK3CA, which encodes the p110α catalytic subunit of PI3Kα, is one of the most frequently altered oncogenes in colon cancer (CC), but its prognostic value is still a matter of debate. Few reports have addressed the association between PIK3CA mutations and survival and their results are controversial. In the present study, we aimed to clarify the prognostic impact of PIK3CA mutations in stage I-III CC according to mismatch repair status. Fresh frozen tissue samples from two independent cohorts with a total of 826 patients who underwent curative surgical resection of CC were analyzed for microsatellite instability and screened for activating point mutations in exon 9 and 20 of PIK3CA by direct sequencing. Overall, 693 tumors (84%) exhibited microsatellite stability (MSS) and 113 samples (14%) harbored PIK3CA mutation. In the retrospective training cohort (n = 433), patients with PIK3CA-mutated MSS tumors (n = 47) experienced a significant increased 5-year relapse-free interval compared with PIK3CA wild-type MSS tumors (n = 319) in univariate analysis (94% vs. 68%, Log-rank P = 0. 0003) and in multivariate analysis (HR = 0.12; 95% confidence interval, 0.029-0.48; P = 0.0027). In the prospective validation cohort (n = 393), the favorable prognostic impact of PIK3CA mutations in MSS tumors (n = 327) was confirmed (83% vs. 67%, Log-rank P = 0.04). Our study showed that PIK3CA mutations are associated with a good prognosis in patients with MSS stage I-III CC.

Cost-effectiveness analysis of panitumumab plus mFOLFOX6 compared with bevacizumab plus mFOLFOX6 for first-line treatment of patients with wild-type RAS metastatic colorectal cancer

OBJECTIVE

To investigate the cost-effectiveness of panitumumab plus mFOLFOX6 (oxaliplatin, 5-fluorouracil and leucovorin) compared with bevacizumab plus mFOLFOX6 in first-line treatment of patients with wild-type RAS metastatic colorectal cancer (mCRC).

DESIGN

A semi-Markov model was constructed from a French health collective perspective, with health states related to first-line treatment (progression-free), disease progression with and without subsequent active treatment, resection of metastases, disease-free after successful resection and death.

METHODS

Parametric survival analyses of patient-level progression-free and overall survival data from the only head-to-head clinical trial of panitumumab and bevacizumab (PEAK) were performed to estimate transitions to disease progression and death. Additional data from PEAK informed the amount of each drug consumed, duration of therapy, subsequent therapy use, and toxicities related to mCRC treatment. Literature and French public data sources were used to estimate unit costs associated with treatment and duration of subsequent active therapies. Utility weights were calculated from patient-level data from panitumumab trials in the first-, second- and third-line settings. A life-time perspective was applied. Scenario, one-way, and probabilistic sensitivity analyses were performed.

RESULTS

Based on a head-to-head clinical trial that demonstrates better efficacy outcomes for patients with wild-type RAS mCRC who receive panitumumab plus mFOLFOX6 versus bevacizumab plus mFOLFOX6, the incremental cost per life-year gained was estimated to be €26,918, and the incremental cost per quality-adjusted life year (QALY) gained was estimated to be €36,577. Sensitivity analyses indicate the model is robust to alternative parameters and assumptions.

CONCLUSIONS

The incremental cost per QALY gained indicates that panitumumab plus mFOLFOX6 represents good value for money in comparison to bevacizumab plus mFOLFOX6 and, with a willingness-to-pay ranging from €40,000 to €60,000, can be considered cost-effective in first-line treatment of patients with wild-type RAS mCRC.

Microangiopathy is common in submucosal vessels of the colon in patients with diabetes mellitus

OBJECTIVES

The pathophysiology behind gastrointestinal dysmotility in diabetes mellitus is unknown. Both esophageal dysmotility and gastroparesis have been shown to be associated with retinopathy, suggesting that microangiopathy is important in the common etiology. The aim of the present study was to examine whether patients with diabetes exhibit microangiopathy in the colon, and if present, to correlate microangiopathy with the clinical picture.

METHODS

Consecutive patients subjected to colon surgery were identified in the southernmost districts of Skåne between January 2011 and May 2013. Medical records were scrutinized, and patients with a history of diabetes were noted. Gender, age, type of diabetes, treatment, complications, and other concomitant diseases were registered. Histopathologic re-evaluation of surgical biopsies with morphometric analyses of submucosal vessels in the colon was performed. Morphometric examination and clinical data were compared with non-diabetic patients.

RESULTS

Of 1135 identified patients during the time period studied, 95 patients with diabetes were recognized and included. Fifty-three non-diabetic, randomly chosen patients served as controls. The mean age was 71.8 ± 10.2 and 71.4 ± 9.5 years in diabetic and non-diabetic patients, respectively. Microangiopathy was found in 68.4% of diabetic patients and in 7.5% of non-diabetic patients (p < 0.001). The wall-to-lumen ratio was 0.31 (0.23-0.46) in patients with diabetes compared with 0.16 (0.12-0.21) in non-diabetic patients (p < 0.001). No clinical association with microangiopathy could be verified.

CONCLUSION

Microangiopathy in the colon is more common in diabetic than in non-diabetic patients. The clinical significance of microangopathy has yet to be clarified.

Colonoscopy reduced distal colorectal cancer risk and excess cancer risk associated with family history

PURPOSE

Colonoscopy efficacy at preventing proximal colorectal cancer (CRC) is questioned, and little is known about efficacy in high-risk versus medium-risk populations. We investigated the relationship between colonoscopy screening, family history of colorectal cancer (FHCC), and CRC risk by site.

METHODS

Among 92,078 women of the E3N prospective cohort, 692 CRCs have been diagnosed after a median follow-up of 15.4 years. Cox proportional hazard models estimated adjusted hazards ratios according to subsites of cancer and FHCC.

RESULTS

A personal history of colonoscopy (PHC; n = 37,470) was associated with decreased rectal and distal colon cancer risks (hazard ratio (HR) = 0.57; 95% Confidence Interval (CI) = 0.42-0.78 and HR = 0.37; 95% CI = 0.26-0.52, respectively), but not proximal colon cancer risk (HR = 0.87; 95% CI = 0.64-1.18). In women with no prior colonoscopy, those with FHCC had a 80% higher CRC risk than those without FHCC. In women with previous colonoscopy, CRC risk was similar in women with and without FHCC (p for interaction = 0.04).

CONCLUSIONS

Results showed colonoscopy ability to prevent distal cancers, but not proximal cancers in women. Colonoscopy screening also reduced the excess risk of women with FHCC to that of women with no FHCC.

Management of rectal cancer in France in a well-defined population

OBJECTIVE

The aim of this study was to draw a picture of diagnostic assessment and patterns of care for rectal cancer in France using population-based registries data.

METHODS

The study included a random sample of 669 cases of rectal cancers diagnosed in 2005.

RESULTS

Diagnostic assessment was performed by colonoscopy in 91.4% of the cases. An abdominal computed tomography was performed in 59.4% of the cases and chest computed tomography in 47.8%. An R0 resection was performed in 65.8% of cases and an R1/R2 resection in 16.1%. A rectal endosocography was performed in 40.4% and MRI in 10.4%. The sphincter was preserved in 73.6% of patients aged younger than 75 years of age and in 62.5% of those older than 75 years of age (P=0.002). In cases of R0 resection, neoadjuvant radiotherapy was performed in 47.8% of patients younger than 75 years of age and in 34.1% of older patients (P=0.007). Postoperative chemotherapy was administered in 23.9% of stage II and 67.8% of stage III resected patients.

CONCLUSION

The management of rectal cancers can be improved. Preoperative staging has not reached its full development; very few patients received neoadjuvant treatment, whereas adjuvant chemotherapy was often performed, although its benefit is still unclear. The management of elderly patients was less optimal than that of younger patients.

FOLFIRI® and bevacizumab in first-line treatment for colorectal cancer patients: safety, efficacy and genetic polymorphisms

BACKGROUND

Over 50% of colorectal cancer (CRC) patients develop metastases. The aim of this study was to evaluate efficacy and tolerance of first-line FOLFIRI® + bevacizumab (B) treatment for metastatic CRC, and to assess genetic polymorphisms as potential markers.

METHODS

Adult patients with histologically-proven, non-resectable metastatic CRC and ECOG ≤ 2 were included. 14-day cycles consisted of bevacizumab (5 mg/kg), irinotecan (180 mg/m2), bolus FU (400 mg/m2) and leucovorin (400 mg/m2), followed by 46-hour FU infusions (2400 mg/m2). Primary endpoint was response rate according to RECIST criteria. Secondary endpoints were overall (OS) and progression-free (PFS) survivals, response duration, and toxicity. Associations between clinical data, UGT1A1, thymidylate synthase, VEGFA polymorphisms and PFS, OS and toxicity were analyzed.

RESULTS

Sixty-two patients were enrolled (median age 68y). 59/62 patients were eligible and evaluable for response at 6 months: 28 showed partial response (47.5%; 95% CI; 34.3-60.9), 20 stable disease (33.9%) and 11 progression (18.6%). Grade 3/4 toxicities were as follows: neutropenia 16.1%; diarrhea 11.3%; nausea-vomiting 1.6%. Median response duration was 9.5 months (range 2.7-20); median PFS 10.3 months (range 8.8-11.7); and median OS 25.7 months (range 20.2-29.7). 11/59 initially unresectable patients were resectable after treatment. VEGFA polymorphism (rs25648) was associated with better OS (HR: 3.61; 95% CI: 1.57-8.30).

CONCLUSIONS

FOLFIRI® + bevacizumab is active with good response rate, long median OS, and a good safety profile. A VEGFA polymorphism might have a prognostic value in this malignancy.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT00467142 (registration date: April 25, 2007).

Sporadic carcinoma of the colon-rectum in young patients: a distinct disease? A critical review

INTRODUCTION

Colon carcinoma is rare in patients under 40 years but incidence is increasing. Results regarding outcome of this age group have been controversial and difficult to interpret. Some authors have reported a worse prognosis related to advanced stage at diagnosis and cancer-aggressive behavior. We tried to assess whether sporadic colon carcinoma in young patients is a distinct disease with different etiology and how this reflects on outcome.

METHODS

Most relevant papers published and indexed on PubMed in the last 20 years were reviewed. Epidemiological data were retrieved from the Surveillance, Epidemiology and End Results database and discussed.

DISCUSSION

Stage-specific analyses adjusted for age have demonstrated that prognosis is related to tumor stage regardless of age. Advanced stage is partly due to tumor biology and to delayed diagnosis. Younger patients show a better performance status that allows aggressive multimodal treatment.

CONCLUSION

Colon carcinoma in young adults appears to be a distinct disease characterized by biological aggressiveness, but prognosis is not worse due to a better performance status at time of surgical intervention.

[Site-specific colorectal cancer; how is it different?]

One of the most critical characteristics of colorectal cancer (CRC) is the difference between proximal (right-sided colon cancer, RCC) and distal (left-sided colon cancer, LCC) disease. The recent CRC studies showed the unique characteristics of RCC; RCCs were more prevalent in women than men and old patients, and the age difference between RCC and LCC was more apparent in women. Moreover, relatively poor protection against RCC by colonoscopy is a clearly hot issue for alarm. Thus, the left and right colon have been considered as dichotomous or even different organs in the view of molecular, histopathological, epidemiologic and clinical bases for over three decades. However, the evolutionary data suggesting linearity from the rectum to ascending colon beyond the simple right-left dichotomization in the views of cancer molecular features and site-specific clinicopathological differences, support the need for a paradigm shift to the colorectal continuum model rather than the traditional two-colon concept. This new multi-segmental or colorectal continuum hypothesis would provide both the better understanding of the complex etiology of colorectal carcinogenesis and the tailored preventive and therapeutic strategies for CRC including individualized CRC screening programs.

Long-term net survival in patients with colorectal cancer in France: an informative contribution of recent methodology

BACKGROUND

Net survival, the survival that might occur if cancer was the only cause of death, is a major epidemiological indicator. Recent findings have shown that the classical methods used for the estimation of net survival from cancer registry data, referred as to "relative-survival methods," provided biased estimates.

OBJECTIVES

The aim of this study was to provide, for the first time, long-term net survival rates for colorectal cancer by using a population-based digestive cancer registry.

DESIGN

This study is a population-based cancer registry analysis. The recently proposed unbiased nonparametric Pohar-Perme estimator was used.

PATIENTS

Overall, 14,715 colorectal cancers diagnosed between 1976 and 2005 and registered in the population-based digestive cancer registry of Burgundy (France) were included.

MAIN OUTCOME MEASURES

The primary outcome measured was cancer net survival, ie, the survival that might occur if all risks of dying of other causes than cancer were removed

RESULTS

: Ten-year net survival increased from 31% during the 1976 to 1985 period to 47% during the 1986 to 1995 period and then leveled out (48% during the 1996-2005 period). There was a major improvement in 10-year net survival after resection for cure and for stage I to III. It was striking for stage III cancers, for which 10-year net survival increased from 21% (1976-1985) to 49% (1996-2005). The corresponding net survivals were 70% and 87% for stage I and 49% and 65% for stage II. These trends can be related to the decrease in operative mortality, the increase in the proportion of patients resected for cure, and the improvement in stage at diagnosis. They were mainly seen between 1976 and 1995, explaining why survival leveled out after 1995.

LIMITATIONS

The study was limited by its retrospective and population-based nature.

CONCLUSIONS

Further improvements for colorectal cancer management can be expected from more effective treatments and from the implementation of organized cancer screening.

Trends in colorectal incidence by anatomic subsite from 1985 to 2005: a population-based study

BACKGROUND

Conflicting results on the shift of right-left ratio in colon cancer incidence have been reported. We examine incidence trends by subsite in a population-based study.

MATERIALS AND METHODS

Colorectal cancer cases diagnosed in the 1985-2005 period were identified through the Tuscany Cancer Registry. Colon subsite was defined as proximal and distal; gender, age at diagnosis, histology, and stage were analyzed. Average annual incidence and age-specific rates according to subsite were calculated.

RESULTS

A total of 21,160 colorectal cancer cases were extracted; in 18,311 cases, the subsite was identified: 6,916 rectal, 5,239 proximal, and 6,156 distal. A larger proportion of distal colon cancers presented as early stage when compared with proximal. Incidence of rectal and distal colon cancer remained stable, while proximal colon cancer incidence increased.

CONCLUSIONS

Proximal colon cancer incidence rate increased through the period. Temporal variations in the incidence rate by subsite could suggest different carcinogenic pathways of right- and left-sided colon cancer.

How many diseases are colorectal cancer?

The development of personalised therapy and mechanism-targeted agents in oncology mandates the identification of the patient populations most likely to benefit from therapy. This paper discusses the increasing evidence as to the heterogeneity of the group of diseases called colorectal cancer. Differences in the aetiology and epidemiology of proximal and distal cancers are reflected in different clinical behaviour, histopathology, and molecular characteristics of these tumours. This may impact response both to standard cytotoxic therapies and mechanism-targeted agents. This disease heterogeneity leads to challenges in the design of clinical trials to assess novel therapies in the treatment of "colorectal cancer."