The location of premalignant colorectal polyps under age 50: a further rationale for screening sigmoidoscopy

Early onset metastatic colorectal cancer in Australia

BACKGROUND

Colorectal cancer (CRC) incidence and mortality rates have been increasing among young patients (YP), for uncertain reasons. It is unclear whether YP have a distinct tumor biology or merit a different treatment approach to older patients (OP).

METHODS

We reviewed prospectively collected data from consecutive patients with metastatic CRC (MCRC) enrolled in the multi-site Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) Australian registry. Clinicopathological features, treatment and survival outcomes were compared between YP (<50 years) and OP (≥50 years).

RESULTS

Of 3692 patients diagnosed August 2009 - March 2023, 14 % (513) were YP. YP were more likely than OP to be female (52% vs. 40 %, P < 0.0001), have ECOG performance status 0-1 (94% vs. 81 %, P < 0.0001), to have a left-sided primary (72% vs. 63 %, P = 0.0008) and to have fewer comorbidities (90% vs. 60 % Charleston score 0, P < 0.0001). There were no differences in the available molecular status, which was more complete in YP. YP were more likely to have de novo metastatic disease (71% vs. 57 %, P < 0.0001). YP were more likely to undergo curative hepatic resection (27% vs. 17 %, P < 0.0001), to receive any chemotherapy (93% vs. 78 % (P < 0.0001), and to receive 3+ lines of chemotherapy (30% vs. 24 % (P < 0.0034)). Median first-line progression free survival (10.2 versus 10.6 months) was similar for YP vs OP, but overall survival (32.1 versus 25.4 months, HR = 0.745, P < 0.0001) was longer in YP.

CONCLUSION

Known prognostic variables mostly favored YP versus OP with newly diagnosed mCRC, who were also more heavily treated. Consistent with this, overall survival outcomes were improved. This data does not support that CRC in YP represent a distinct subset of mCRC patients, or that a modified treatment approach is warranted.

Randomized controlled trial of effects of a familiarization video and patient-controlled Entonox inhalation on patient stress levels and clinical efficacy of flexible sigmoidoscopy without analgesia or sedation for investigation of fresh rectal bleeding

BACKGROUND AND AIM

Flexible sigmoidoscopy (FS) without analgesia or sedation can be unpleasant for patients, resulting in unsatisfactory examinations. Prior familiarization videos (FVs) and intra-procedural Entonox inhalation have shown inconsistent effects. This study investigated their effects on undesirable participant factors (anxiety, stress, discomfort, pain, satisfaction, later unpleasant recall of procedure, and vasovagal reactions) and clinical effectiveness (extent of bowel seen, lesions detected, and procedural/recovery times).

METHODS

This cluster-randomized single-center study evaluated 138 participants undergoing FS. There were 46 controls, 49 given access to FV, and 43 access to both FV and self-administered Entonox. Participant factors were measured by self-administered questionnaires, independent nurse assessments, and heart rate variability (HRV) metrics.

RESULTS

Questionnaires showed that the FV group was slightly more tense and upset before FS, but knowledge of Entonox availability reduced anxiety. Nonlinear HRV metrics confirmed reduced intra-procedural stress response in the FV/Entonox group compared with controls and FV alone (P < 0.05). Entonox availability allowed more bowel to be examined (P < 0.001) but increased procedure time (P < 0.05), while FV alone had no effect. FV/Entonox participants reported 1 month after FS less discomfort during the procedure. Other comparisons showed no significant differences between treatment groups, although one HRV metric showed some potential to predict vasovagal reactions.

CONCLUSIONS

Entonox availability significantly improved clinical effectiveness and caused a slight reduction in undesirable participant factors. The FV alone did not reduce undesirable participant factors or improve clinical effectiveness. Nonlinear HRV metrics recorded effects in agreement with stress reduction and may be useful for prediction of vasovagal events in future studies.

Assessing Guidelines on the Need for Colonoscopy After Initial Flexible Sigmoidoscopy in Young Patients With Outlet-Type Rectal Bleeding

BACKGROUND

Although young-age-of-onset colorectal cancer is increasing in incidence, lack of screening leads to symptomatic presentation, often with rectal bleeding. Because most cancers in patients younger than 50 years are left-sided, flexible sigmoidoscopy is a reasonable way of investigating bleeding in these patients.

OBJECTIVE

To predict which patients undergoing flexible sigmoidoscopy for outlet-type rectal bleeding need a full colonoscopy.

DESIGN

Findings at colonoscopy were compared with published indications for colonoscopy after flexible sigmoidoscopy, which were as follows: 1) any number of advanced adenomas defined as a tubular adenoma of >9 mm diameter, a tubulovillous or villous adenoma of any size, or any adenoma with high-grade dysplasia; 2) 3 or more tubular adenomas of any size or histology; 3) any sessile serrated lesion; and 4) 20 or more hyperplastic polyps.

SETTING

Charity Hospital with volunteer specialists.

PATIENTS

Patients were included if they were younger than 57 years, had outlet-type rectal bleeding, and underwent flexible sigmoidoscopy at least to the descending colon followed by colonoscopy with biopsy of all resected lesions.

INTERVENTIONS

Flexible sigmoidoscopy and colonoscopy with excision of all removable lesions.

MAIN OUTCOME MEASURES

Findings at colonoscopy.

RESULTS

There were 66 patients who had a colonoscopy between 5 and 811 days after sigmoidoscopy and also had complete data. There were 43 men and 23 women with a mean age of 39.5 years. Analysis of flexible sigmoidoscopy criteria for finding proximal high-risk lesions on colonoscopy showed a sensitivity of 76.9%, a specificity of 67.9%, a positive predictive value of 37%, a negative predictive value of 92.3%, and an accuracy of 69.7%.

LIMITATIONS

A large number of exclusions for inadequate colonoscopy or inadequate data resulted in a reduced patient number in the study.

CONCLUSIONS

Our criteria for follow-up colonoscopy based on the findings at initial flexible sigmoidoscopy in young patients with outlet-type rectal bleeding are reliable enough to be used in routine clinical practice, provided this is audited. See Video Abstract.

GUA DE EVALUACIN PARA LA NECESIDAD DE COLONOSCOPIA DESPUS DE UNA SIGMOIDOSCOPIA FLEXIBLE INICIAL EN PACIENTES JVENES CON RECTORRAGIA

ANTECEDENTES:Si bien la edad de aparición temprana del cáncer colorrectal está aumentando en incidencia, la falta de pruebas de detección conduce a una presentación sintomática, a menudo con sangrado rectal. Debido a que la mayoría de los cánceres en pacientes menores de 50 años son del lado izquierdo, la sigmoidoscopia flexible es una forma razonable de investigar el sangrado en estos pacientes.OBJETIVO:Predecir qué pacientes sometidos a sigmoidoscopia flexible por rectorragia necesitan una colonoscopia completa.DISEÑO:Los resultados de la colonoscopia se compararon con las indicaciones publicadas para la colonoscopia después de una sigmoidoscopia flexible. Estos fueron: 1. Cualquier número de adenomas avanzados, definidos como un adenoma tubular > 9 mm, un adenoma tubulovelloso o velloso de cualquier tamaño, o cualquier adenoma con displasia de alto grado. 2. Tres o más adenomas tubulares de cualquier tamaño o histología. 3. Cualquier lesión serrada sésil. 4. Veinte o más pólipos hiperplásicos.ENTORNO CLINICO:Hospital de Caridad con especialistas voluntarios.PACIENTES:Menores de 57 años, con rectorragia, sometidos a sigmoidoscopia flexible al menos hasta el colon descendente, seguida de colonoscopia con biopsia de todas las lesiones resecadas.INTERVENCIONES:sigmoidoscopia flexible y colonoscopia con escisión de todas las lesiones removibles.PRINCIPALES MEDIDAS DE VALORACIÓN:Hallazgos en la colonoscopia.RESULTADOS:66 casos a los que se les realizó una colonoscopia entre 5 y 811 días después de la sigmoidoscopia, que también tenían datos completos. 43 hombres y 23 mujeres con una edad media de 39,5 años. El análisis de los criterios de sigmoidoscopia flexible para encontrar lesiones proximales de alto riesgo en la colonoscopia mostró una sensibilidad del 76,9 %, una especificidad del 67,9 %, un valor predictivo positivo del 37 %, un valor predictivo negativo del 92,3 % y una precisión del 69,7 %.LIMITACIONES:Gran número de exclusiones por colonoscopia inadecuada o datos inadecuados que causan un número reducido de pacientes en el estudio.CONCLUSIÓN:Nuestros criterios para la colonoscopia de seguimiento basados en los hallazgos de la sigmoidoscopia flexible inicial en pacientes jóvenes con rectorragia son lo suficientemente confiables para ser utilizados en la práctica clínica habitual, siempre que se audite. (Traducción- Dr. Ingrid Melo ).

Focusing on colorectal cancer in young adults (Review)

Colorectal cancer (CRC) ranks as the third leading cause of cancer-related mortality worldwide. Recent years have witnessed an increase in the incidence of CRC among adults <50 years old on a global scale. The increased incidence is associated with several modifiable risk factors, including obesity, type II diabetes, physical inactivity and frequent antibiotic use. In younger individuals, haematochezia and abdominal pain are the most common symptoms, predominantly affecting the left-side colon. While certain cases of early-onset CRC (eoCRC) are associated with a genetic predisposition, the majority result from sporadic mutations in the genes APC, KRAS, BRAF and TP53, which trigger uncontrolled cell proliferation and tumour formation. Colorectal carcinogenesis involves three major pathways: The chromosomal instability (CIN), microsatellite instability and CpG island methylator phenotype pathways. Dysregulation of the CIN pathway accounts for 85% of sporadic cases of eoCRC. Notably, eoCRC exhibits a distinctive molecular profile, characterized by a decreased prevalence of BRAF mutations, an increased prevalence of KRAS mutations and LINE-1 hypomethylation, and involvement of the Microsatellite and Chromosomal Stable pathway. Prevention strategies for eoCRC primarily centre on lifestyle modifications and the development of screening programs targeting younger populations. Further exploration into the molecular mechanisms involved in the identification of novel risk factors associated with eoCRC is imperative. These efforts, in conjunction with the development of specific screening strategies, hold the potential to reduce morbidity and mortality in the future.

Metabolic risk factors link unhealthy lifestyles to the risk of colorectal polyps in China

Colorectal cancer is the second leading cause of global cancer-related deaths, and its precursor lesions are colorectal polyps (CAP). The study aimed to explore the effect of combinations of unhealthy lifestyles on CAP and investigate the mediation role of metabolic disorder in this process. A total of 1299 adults were recruited from a hospital in Jiangsu, China, including 811 cases and 488 adults without diseases. The information on demographic characteristics and lifestyles was collected through questionnaires and the medical record system. Serum biochemical parameters were determined using the automatic biochemical analyzer. Adjusted regression analysis showed that unhealthy lifestyles, including smoking, overnight meals, daily water intake, staying up late, and exercise associated with the risk of CAP. Furthermore, metabolic biomarkers, including BMI, triglycerides, and uric acid, were associated with the risk of CAP. Also, unhealthy lifestyle scores were positively associated with BMI, triglycerides, and CAP. The mediation effect of metabolic biomarkers, such as BMI and triglycerides on the association of unhealthy lifestyle scores with CAP was significant. Available data demonstrate the adverse effect of combinations of unhealthy lifestyle factors on CAP, and metabolic disorders to potentially mediate the association of unhealthy lifestyles with the risk of CAP.

Characteristics and Outcomes of Right- Versus Left-Sided Early-Onset Colorectal Cancer

BACKGROUND

Early-onset colorectal cancers are increasing in incidence. Studies reported more left-sided cancers in patients aged <50 years. Some advocate for screening via flexible sigmoidoscopy at age 40 years.

OBJECTIVE

The purpose of this study was to investigate characteristics and outcomes in sporadic right- and left-sided early-onset colorectal cancers.

DESIGN

This was a retrospective cohort study.

SETTINGS

This study was conducted at a single, tertiary care institution.

PATIENTS

This study included patients aged <50 years diagnosed with colorectal cancer between 2000 and 2018.

MAIN OUTCOME MEASURES

We analyzed patient demographics, tumor characteristics, and survival.

RESULTS

A total of 489 patients aged 20 to 49 years were identified from 2000 to 2018. The majority of patients were white (90%) and male (57%). The median age at diagnosis was 44 years, and 75% were diagnosed at age 40-49 years. There was a predominance of left-sided tumors (80%). The majority of patients presented with stage 3 (35%) and stage 4 (35%) disease. Right-sided tumors were more likely to have mucinous (24% vs 7.4%; p < 0.001) and signet-ring cell (4.4% vs 1.7%; p < 0.001) histology. There was no difference in age, sex, race, ethnicity, and stage at presentation. Right-sided tumors were associated with lower 5-year overall survival (44% vs 61%; p < 0.005) with the decrease in survival most prominent in right-sided stage 3 tumors (41% vs 72%; p < 0.0001) and in ages 40 to 49 years (43% vs 61%; p = 0.03). Sex, tumor location, increasing stage, and signet-ring cell histology were independent prognostic factors of overall survival. There was no difference in disease-free survival.

LIMITATIONS

This study was a retrospective review at a single institution.

CONCLUSIONS

The majority of early-onset colorectal cancers arise from age 40 to 49 years with a left-sided predominance but higher mortality in right-sided tumors. These findings provide further evidence in favor of recommending earlier initial screening colonoscopy for colorectal cancer. See Video Abstract at http://links.lww.com/DCR/B892 .

CARACTERSTICAS Y RESULTADOS DEL CNCER COLORRECTAL DE INICIO TEMPRANO DEL LADO DERECHO FRENTE AL IZQUIERDO

ANTECEDENTES:Los cánceres colorrectales de aparición temprana están aumentando en incidencia. Los estudios han informado una preponderancia de cánceres en el lado izquierdo en pacientes <50 años, lo que ha llevado a algunos a abogar por la detección con sigmoidoscopia flexible a los 40 años.OBJETIVO:El propósito de nuestro estudio fue investigar las características del tumor y los resultados de los pacientes en cánceres colorrectales esporádicos del lado derecho e izquierdo de aparición temprana.DISEÑO:Este fue un estudio de cohorte retrospectivo.ENTORNO CLÍNICO:Este estudio se realizó en una única institución de atención terciaria.PACIENTES:Pacientes <50 años diagnosticados de cáncer colorrectal entre 2000 y 2018.RESULTADO PRINCIPAL:Analizamos los datos demográficos de los pacientes, las características del tumor, la supervivencia general y la supervivencia libre de enfermedad.RESULTADOS:Se identificaron un total de 489 pacientes de entre 20 y 49 años entre 2000 y 2018. La mayoría de los pacientes eran blancos (90%) y varones (57%). La mediana de edad en el momento del diagnóstico fue de 44 años y el 75% se diagnosticó entre los 40 y los 49 años. Predominó los tumores del lado izquierdo (80%). La mayoría de los pacientes presentaban enfermedad en estadio 3 (35%) y estadio 4 (35%). Los tumores del lado derecho tenían más probabilidades de tener histología mucinosa (24% frente a 7,4%, p < 0,001) y de células en anillo de sello (4,4% frente a 1,7%, p < 0,001). No hubo diferencia en edad, sexo, raza, etnia, estadio AJCC en la presentación. Los tumores del lado derecho se asociaron con una menor supervivencia general a 5 años (44% frente al 61%, p < 0,005) con la disminución de la supervivencia más prominente en los tumores del lado derecho en estadio 3 (41% frente al 72%, p < 0,0001) y en edades 40-49 (43% vs 61%, p = 0.03). El sexo, la ubicación del tumor, el estadio AJCC en aumento y la histología de las células en anillo de sello fueron factores pronósticos independientes de la supervivencia general. No hubo diferencias significativas en la supervivencia libre de enfermedad.LIMITACIONES:Este estudio fue una revisión retrospectiva en una sola institución.CONCLUSIONES:La mayoría de los cánceres colorrectales de aparición temprana surgen entre los 40 y los 49 años con un predominio en el lado izquierdo pero una mayor mortalidad en los tumores del lado derecho. Estos hallazgos proporcionan evidencia adicional a favor de recomendar una colonoscopia de detección inicial más temprana para el cáncer colorrectal. Consulte Video Resumen en http://links.lww.com/DCR/B892 . (Traducción-Dr. Ingrid Melo ).

Understanding the Burden of Colorectal Adenomas in Patients Younger Than 50 Years: A Large Single-Center Retrospective Cohort Study

BACKGROUND

Colorectal cancer is increasing in young adults. Our understanding of the adenoma-carcinoma sequence in young patients aged <50 years is lacking. The yield obtained by lowering the age of screening colonoscopy remains unclear.

OBJECTIVE

The goal of this study was to understand the burden and histology of colorectal polyps in young adults and to explore predictors of adenoma detection in this population.

DESIGN

This is a retrospective cohort study.

SETTING

Colonoscopies were performed at a single university-affiliated tertiary care center.

PATIENTS

This study included adults aged <50 years who underwent a colonoscopy between 2014 and 2019. Patients with inflammatory bowel disease and genetic disorders were excluded.

MAIN OUTCOME MEASURES

Adenoma detection rates were analyzed according to age. Predictors of adenoma detection were investigated by multiple logistic regression.

RESULTS

A total of 4475 patients were analyzed. The mean age was 40.2 ± 8.0 years, 56.4% were female, and the mean BMI was 26.3 ± 5.5 kg/m2. A family history of colorectal cancer was reported in 23.8% of patients. The overall polyp and adenoma detection rates were 22% and 14%. The majority of polyps were adenomatous (58.9% of all polypectomies) and located in the left colon or rectum (61.4%). The detection rates of adenomas, advanced neoplasias, and adenocarcinomas were highest in patients aged 45 to 49 (19.3%, 4.8%, and 1.3%). On multivariate analysis, variables independently associated with adenoma detection included age (OR 1.08, 95% CI, 1.06-1.1), female sex (OR 1.80, 95% CI, 1.44-2.27), BMI (OR 1.01, 95% CI, 1.01-1.05), and having undergone a diagnostic colonoscopy (OR 1.81, 95% CI, 1.44-2.29). On subgroup analysis of patients aged 45 to 49, the same variables remained associated with adenoma detection except for age.

LIMITATIONS

The study was limited due to the retrospective nature with heterogenous data.

CONCLUSIONS

Adenoma detection in young adults aged 45 to 49 approaches the current adenoma detection of older adults. Predictors of adenoma detection in these young adults are female gender and BMI, which may help guide colorectal cancer screening guidelines in the future. See Video Abstract at http://links.lww.com/DCR/B843.

COMPRENDER DE LA CARGA DE LOS ADENOMAS COLORRECTALES EN PACIENTES AOS UN ESTUDIO DE COHORTE RETROSPECTIVO DE UN SOLO CENTRO

ANTECEDENTES:El cáncer colorrectal está aumentando en adultos jóvenes. No se conoce la secuencia adenoma-carcinoma en pacientes jóvenes <50 años. El rendimiento obtenido al reducir la edad de la colonoscopia de detección sigue sin estar claro.OBJETIVO:Comprender la carga y la histología de los pólipos colorrectales en adultos jóvenes y explorar los predictores de detección de adenomas en esta población.DISEÑO:Estudio de cohorte retrospectivo.AJUSTE:Las colonoscopias se realizaron en un único centro de atención terciario afiliado a la universidad.PACIENTES:Adultos jóvenes <50 años que se sometieron a una colonoscopia entre 2014-2019. Se excluyeron los pacientes con enfermedad inflamatoria intestinal y trastornos genéticos.PRINCIPALES MEDIDAS DE RESULTADO:Se analizaron las tasas de detección de adenomas según la edad. Los predictores de la detección de adenomas se investigaron mediante regresión logística múltiple.RESULTADOS:Se analizaron 4475 pacientes. La edad media fue de 40,2 ± 8,0 años, el 56,4% eran mujeres y el IMC medio fue de 26,3 ± 5,5 kg / m2. Se informó de antecedentes familiares de cáncer colorrectal en el 23,8% de los pacientes. Las tasas generales de detección de pólipos y adenomas fueron del 22% y el 14%, respectivamente. La mayoría de los pólipos eran adenomatosos (58,9% de todas las polipectomías) y estaban localizados en colon izquierdo o recto (61,4%). Las tasas de detección de adenomas, neoplasias avanzadas y adenocarcinomas fueron más altas en pacientes de 45 a 49 años (19,3%, 4,8% y 1,3%, respectivamente). En el análisis multivariado, las variables asociadas de forma independiente con la detección de adenomas incluyeron: edad (OR 1.08; IC del 95%: 1,06-1,1), sexo femenino (OR 1,80; IC del 95%: 1,44-2,27), IMC (OR 1,01; IC del 95%: 1,01-1,05)) y haber sido sometido a una colonoscopia diagnóstica (OR 1,81; IC 95% 1,44-2,29). En el análisis de subgrupos de pacientes de 45 a 49 años, las mismas variables permanecieron asociadas con la detección de adenomas, excepto la edad.LIMITACIONES:Carácter retrospectivo con datos heterogéneos.CONCLUSIONES:La detección de adenomas en adultos jóvenes de 45 a 49 años se acerca a la detección actual de adenomas en adultos mayores. Los predictores de la detección de adenomas en estos adultos jóvenes son el sexo femenino y el IMC, que pueden ayudar a guiar las pautas de detección del cáncer colorrectal en el futuro. Consulte Video Resumen en http://links.lww.com/DCR/B843. (Traducción-Dr. Hagerman).

Disparate age and sex distribution of sessile serrated lesions and conventional adenomas in an outpatient colonoscopy population-implications for colorectal cancer screening?

PURPOSE

Colorectal cancer (CRC) is increasingly diagnosed in individuals aged < 50 years, resulting in advocacy of screening from age 45 years. Despite existing knowledge associating CRC with conventional adenomas, the significance of sessile serrated lesions (SSLs) on the burden of CRC is less detailed. We aimed to provide contemporary estimates for SSL prevalence and examine patient and procedure factors associated with SSL detection.

METHODS

Retrospective observational study examining associations between SSL and conventional adenoma detection, polyp histopathology, patient, and procedure characteristics in an outpatient colonoscopy unit over 12 months.

RESULTS

From 2097 colonoscopies, SSL detection was 13.8% overall and 12.5% in patients < 50 years. SSLs were mostly proximal in location (64%), and SSL detection was significantly higher in females compared with males (16.2% vs. 11.7%, p = 0.003), particularly in those < 50 years (16.8% vs. 8.6%, p < 0.001). In multivariable analysis, SSL detection was associated with female sex (adjusted odds ratio [aOR] 1.48, 95% confidence interval [CI] 1.15-1.91), synchronous conventional adenoma detection (aOR 1.36, 95% CI 1.04-1.78) and BMI ≥ 25 kg/m² (aOR 1.34, 95% CI 1.02-1.77). Conventional adenoma detection was 33.6% and associated with age ≥ 50 years (aOR 3.57, 95% CI 2.84-4.47) and synchronous SSL detection (aOR 1.36, 95% CI 1.03-1.79).

CONCLUSIONS

We observed age and sex disparities in polyp types and prevalence in this outpatient colonoscopy population. SSLs were most prevalent in females aged < 50 years, suggesting a potential increased susceptibility of young females to SSLs and CRC. Our findings may have implications for the design of CRC screening programs.

Is colorectal neoplasia more aggressive in the young? A look at shifting guidelines

BACKGROUND

This study aimed to compare factors associated with CRC in patients younger than 50 and in those 50 and older, that required surgical resection due to malignancy or premalignant conditions.

METHODS

A retrospective chart review was conducted looking at patients who had bowel resection due to CRC or advanced polyps; individuals found to have hereditary tumors and inflammatory bowel disease were excluded. Data was analyzed with chi square test of association comparing proportions of patients in the two age groups.

RESULTS

A significantly higher proportion of the younger population had advanced stages of CRC. Data from this and other studies suggests that the colorectal tumors seen in patients under 50 have a higher virulence, and perhaps this is due to different tumor biology.

CONCLUSION

These findings illustrate how changes in screening guidelines reinforced by proper support from insurance providers/payors and a widespread aggressive educational campaign for patients and providers can benefit this increasingly vulnerable population.

Increasing Incidence of Left-Sided Colorectal Cancer in the Young: Age Is Not the Only Factor

BACKGROUND

Recent single-institution studies have shown that colorectal cancer (CRC) in patients < 50 is predominantly left-sided. The aims of this study were to 1 compare the incidence of left-sided CRC in patients under and over 50, 2 investigate this trend over time, and 3 examine whether racial differences exist in the anatomical distribution of CRC.

METHODS

We used the Nationwide Inpatient Sample to identify all patients with colon or rectal cancer who underwent a resection from 2000 to 2014. Logistic regression models were used to determine the odds of a patient having a left-sided CRC based on age and race.

RESULTS

A total of 1,547,589 patients underwent resection, with a mean age of 68.6. Overall, 65.1% of patients < 50 had a left-sided CRC compared with 47.2% of patients ≥ 50 (OR = 2.1; 95% CI 2.0, 2.1). The difference was greater as patients became older with 39.9% of patients > 70 having a left-sided CRC (< 50 vs ≥ 70; OR = 2.8; 95% CI 2.7, 2.9). The incidence of CRC in those under 50 increased over the study period due to an increase in left-sided tumors. The distribution of CRC varied with race, with African-Americans having a lower odds for left-sided CRC (OR = 0.89; 95% CI 0.87, 0.91) and Asians/Pacific Islanders having a higher odds (OR = 1.8; 95% CI 1.7, 1.9).

CONCLUSION

In the < 50 age group, the incidence of CRC is increasing, with majority of these tumors left-sided. Tumor location varies with both age and race.