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

Anesthesia Service Use and the Uptake of Screening Colonoscopies

BACKGROUND

The Center for Medicare & Medicaid Services recently defined "screening colonoscopy" to include separately furnished anesthesia services.

OBJECTIVE

To examine the relationship between anesthesia service use and the uptake of screening colonoscopies.

STUDY DESIGN

We correlated metropolitan statistical area (MSA) level anesthesia service use rates, derived from the 2008, 2010, and 2012 Medicare and MarketScan claims data, with the presence of individual level guideline concordant screening colonoscopy using the Behavioral Risk Factor Surveillance System data for the same years.

MEASURES

Proportion of colonoscopies with anesthesia service was calculated at the MSA level. A guideline concordant screening colonoscopy was defined as a colonoscopy received within the past 10 years.

RESULTS

The average MSA level anesthesia service use rate in colonoscopy significantly increased from 25.34% in 2008 to 44.25% in 2012; but only a moderate increase in the rate of guideline concordant colonoscopies was observed, from 57.36% in 2008 to 65.32% in 2012. After adjusting for patient characteristics, we found a nonsignificant negative association between anesthesia service use rate and colonoscopy screening rate, with an odds ratio of 0.90 for receiving a guideline concordant colonoscopy for each percentage point increase in anesthesia service use rate (P=0.27). The relationship between anesthesia service use and the overall colorectal cancer screening rate followed the same pattern and was also not statistically significant.

CONCLUSIONS

No significant association between anesthesia service use and colonoscopy screening or colorectal cancer screening rates was found, suggesting that more evidence is needed to support the Center for Medicare & Medicaid Services rule change.

Rising Incidence of Colorectal Cancer Among Young Hispanics in Texas

GOALS

To investigate trends in colorectal cancer (CRC) incidence and survival among Hispanics in Texas.

BACKGROUND

The incidence of CRC is rising among young adults in the United States. Given Texas' large Hispanic population, investigating CRC trends in Texas may provide valuable insight into the future of CRC epidemiology in an ever-diversifying US population.

STUDY

Data from the Texas Cancer Registry (1995 to 2010) were used to calculate age-adjusted CRC rates based on the 2000 US standard population. Annual percentage change (APC) and 5-year cancer-specific survival (CSS) rates were reported by age, race/ethnicity, stage, and anatomic location.

RESULTS

Of 123,083 CRC cases, 11% occurred in individuals below 50 years old, 26% of whom were Hispanic. Incidence was highest among African Americans (AAs; 76.3/100,000), followed by non-Hispanic whites (NHWs; 60.2/100,000) and Hispanics (50.8/100,000). Although overall CRC incidence declined between 1995 and 2010 (APC, -1.8%; P<0.01), trends differed by age and race/ethnicity. Among individuals 50 years and above, the rate of decline was statistically significant among NHWs (APC, -2.4%; P<0.01) and AAs (APC, -1.3%; P<0.01) but not among Hispanics (APC, -0.6%; P=0.13). In persons aged 20 to 39 years, CRC incidence rose significantly among Hispanics (APC, 2.6%; P<0.01) and NHWs (APC, 2.4%; P<0.01), but not AAs (APC, 0.3%; P=0.75). CSS rates among Hispanics and NHWs were comparable across most age groups and cancer stages, whereas CSS rates among AAs were generally inferior to those observed among NHWs and Hispanics.

CONCLUSIONS

Although CRC incidence has declined in Texas, it is rising among young Hispanics and NHWs while declining more slowly among older Hispanics than among older NHWs and AAs.

Colorectal Cancer in Young African Americans: Is It Time to Revisit Guidelines and Prevention?

BACKGROUND & AIMS

Previous studies have suggested an increase in the incidence of colorectal cancer (CRC) in young adults (younger than 50 years). Among older people, African Americans have disproportionally higher CRC incidence and mortality. We assessed whether this CRC disparity also applies to CRC diagnosed among young people.

METHODS

Using the Surveillance, Epidemiology, and End Results cancer registries, a population-based cancer registry covering 25.6 % of the United States' African American population, we identified patients diagnosed with CRC between the years of 2000-2012. The age-adjusted rates for non-Hispanic whites (NHW), African Americans, and Asian-Pacific Islanders (API) were calculated for the age categories 20-24, 25-29, 30-34, 35-39, and 40-44.

RESULTS

CRC age-adjusted incidence is increasing among all three racial groups and was higher for African Americans compared to NHW and API across all years 2000-2012 (P < 0.001). Stage IV CRC was higher in African Americans compared with NHW, while there was higher stage III CRC in API compared with NHWs.

CONCLUSION

CRC incidence is increasing among the young in all racial groups under study. This increase in frequency of CRC is true among young African American adults who display highly advanced tumors in comparison with other races. While the present attention to screening seems to have decreased CRC prevalence in individuals older than 50, special attention needs to be addressed to young African American adults as well, to counter the observed trend, as they have the highest incidence of CRC among young population groups by race/ethnicity.

Increasing Incidence of Colorectal Cancer, Starting at a Younger Age for Rectal Compared to Colon Cancer in Brunei Darussalam

BACKGROUND

Colorectal cancer (CRC) is the most common gastrointestinal malignancy and is a significant cause of mortality. Its incidence is generally increasing in Asia. Reports from the West have indicated that the incidence of rectal cancer is increasing in the younger population. This study assessed the time trend of CRC in Brunei Darussalam specifically assessing the different age groups at which the incidences start to increase.

MATERIALS AND METHODS

The National Cancer registry was reviewed (1991 to 2014). The age standardized rate (ASR) and the age specific incidence rates (ASIRs) for three time periods (1991-1998), (1999-2006) and (2007-2014) were calculated.

RESULTS

The mean age of diagnosis was 59.3±14.6 years old, incidences being slightly higher amongst men (57.6%) and Malays (67.1%). The most common tumor type was adenocarcinoma (96.4%). Rectal cancers accounted for 35.2% (n=372/1,056) of all cancers of the large bowel; more men were affected than women. The proportion of rectal cancer was also high among the indigenous group. In the three time periods, the ASR for CRC increased from 16 per 100,000 (1991-1998) to 19.6 per 100,000 (1999-2006) and 24.3 per 100,000 (2007-2014). The ASIRs for CRC increased markedly between the time periods 1998-2006 and 2007-2014, beginning in the 40-44 years age group. For rectal cancers, the ASIRs started to increase in the 25-29 age group onward whereas for colon cancers, the increase was observed at a later age, starting from the 45-49 age group.

CONCLUSIONS

Our study showed an increase in the incidence of CRC including in the younger age groups. The increase was seen earlier in rectal cancer compared to colon cancer. These data mirror the trends reported from the West.

Different risk factors for advanced colorectal neoplasm in young adults

AIM: To compare the risk of developing advanced colorectal neoplasm (ACRN) according to age in Koreans.

METHODS: A total of 70428 Koreans from an occupational cohort who underwent a colonoscopy between 2003 and 2012 at Kangbuk Samsung Hospital were retrospectively selected. We evaluated and compared odds ratios (OR) for ACRN between the young-adults (YA < 50 years) and in the older-adults (OA ≥ 50 years). ACRN was defined as an adenoma ≥ 10 mm in diameter, adenoma with any component of villous histology, high-grade dysplasia, or invasive cancer.

RESULTS: In the YA group, age (OR = 1.08, 95%CI: 1.06-1.09), male sex (OR = 1.26, 95%CI: 1.02-1.55), current smoking (OR = 1.37, 95%CI: 1.15-1.63), family history of colorectal cancer (OR = 1.46, 95%CI: 1.01-2.10), diabetes mellitus related factors (OR = 1.27, 95%CI: 1.06-1.54), obesity (OR = 1.23, 95%CI: 1.03-1.47), CEA (OR = 1.04, 95%CI: 1.01-1.09) and low-density lipoprotein-cholesterol (OR = 1.01, 95%CI: 1.01-1.02) were related with an increased risk of ACRN. However, age (OR = 1.08, 95%CI: 1.06-1.09), male sex (OR = 2.12, 95%CI: 1.68-2.68), current smoking (OR = 1.38, 95%CI: 1.12-1.71), obesity (OR = 1.34, 95%CI: 1.09-1.65) and CEA (OR = 1.05, 95%CI: 1.01-1.09) also increased the risk of ACRN in the OA group.

CONCLUSION: The risks of ACRN differed based on age group. Different colonoscopic screening strategies are appropriate for particular subjects with risk factors for ACRN, even in subjects younger than 50 years.

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.

Characteristics of and risk factors for colorectal neoplasms in young adults in a screening population

AIM: To investigate prevalence and risk factors for colorectal neoplasms in adults aged < 50 years, for whom screening is not recommended.

METHODS: This cross-sectional study compared prevalence and characteristics of colorectal and advanced adenomas in patients aged < 50 years who underwent colonoscopy screening with subjects aged ≥ 50 years. To evaluate risk factors for colorectal and advanced adenoma in young adults, we used multivariable logistic regression models. Colorectal neoplasm characteristics were evaluated and compared with those in older patients.

RESULTS: Among 2819 patients included, prevalences of colorectal adenoma and advanced adenoma were 19.7% and 1.5%, respectively. As patient age increased, so did the prevalence of colorectal neoplasm. However, prevalence of advanced adenoma did not differ between age-groups 45-49 years and ≥ 50 years (OR = 0.43, 95%CI: 0.17-1.07, P = 0.070). In younger age-group (< 50 years), colorectal adenoma was significantly associated with older age, waist circumference (OR = 1.72, 95%CI: 1.15-2.55, P = 0.008), and current smoking (OR = 1.60, 95%CI: 1.07-2.41, P = 0.023). Alcohol consumption was an independent risk factor for colorectal advanced adenoma (OR = 3.69, 95%CI: 1.08-12.54, P = 0.037). Multiple neoplasms and large neoplasms (≥ 1 cm) were more prevalent in subjects ≥ 50 years.

CONCLUSION: Current screening strategies for colorectal cancer may need to be amended to account for patient age, especially in young subjects with abdominal obesity, current smoking and alcohol consumption.

Poor knowledge of colorectal cancer in Brunei Darussalam

BACKGROUND

Colorectal cancer (CRC) is the most common gastrointestinal cancer and the incidence is increasing in many developing countries. While it can be detected early and even prevented through screening and removal of premalignant lesions, there are barriers to screening which include low level of knowledge and awareness of CRC. This study assessed the level of knowledge of CRC in Brunei Darussalam.

MATERIALS AND METHODS

A total of 431 (262 male and 161 female) subjects participated in this questionnaire study. Subjects were scored on their knowledge of signs/symptoms (maximum 10 correct answers) and known risk factors for CRC (maximum 10 correct answers) and were categorised into poor (0-2), moderate (3-4) and satisfactory (5-10). Comparisons were made between the various patient factors.

RESULTS

Overall, 54.1% could not name any CRC signs/symptoms or associated risk factors. Most were not aware of any screening modalities. The overall scores for CRC signs/symptoms and risk factors were 1.3±1.39 (range 0-6) and 0.6±1.05 (range 0-5) respectively. Overall, the breakdown of scores was: poor (78.1%), moderate (20.3%) and satisfactory (6.2%) for signs/symptoms and poor (93.2%), moderate (6.2%) and satisfactory (0.7%) for risk factors. Higher level of education, female gender and non-Malay race were associated with higher scores for both signs/symptoms and knowledge of screening modality; however the overall scores were low.

CONCLUSIONS

Our study showed that the general knowledge of CRC in Brunei Darussalam is poor. Being female, with higher levels of education and non-Malay race were associated with higher scores, but they were still generally poor. More needs to be done to increase the public knowledge and awareness of CRC.

Characteristics of young colorectal cancer in Brunei Darussalam: an epidemiologic study of 29 years (1986-2014)

BACKGROUND

Colorectal cancer (CRC) is the most common gastrointestinal cancer and the incidence is increasing. CRC is more common with increasing age, but a proportion occurs in young adults, termed young CRC. This study assessed the incidence and the demographic of young CRC in Brunei Darussalam.

MATERIALS AND METHODS

All histologically proven CRC between 1986 and 2014 registered with the Department of Pathology cancer registry were reviewed and data extracted for analyses. Young CRC was defined as cancer in patients aged less than 45 years. The various population groups were categorized into locals (Malays, Chinese and Indigenous) and expatriates.

RESULTS

Over the study period, there were 1,126 histologically proven CRC (mean age 59.1 ± 14.7 years, Male 58.0%, Locals 91.8% and 8.2% expatriates). Young CRC accounted for 15.1% with the proportion declining over the years, from 29% (1986-1990) to 13.2% (2011-2014). The proportion of young CRC was highest among the indigenous (30.8%), followed by the expatriates (29.3%), Malays (14.3%) and lowest among the Chinese (10.8%). The mean age of young CRC was 35.9 ± 6.2; lowest among the indigenous (33.5 ± 6.7), expatriate (34.9 ± 6.0) groupd and the Malays (35.6 ± 6.5) compared to the Chinese (38.6 ± 4.6), a similar trend being observed in the non-young CRC groups. There were no difference between the genders and tumor locations (rectum or colon) between the young and the non-young CRC cases. Female young CRC was significantly younger than male (p<0.05) without any significant variation between the various population groups (p>0.05).

CONCLUSIONS

Our study showed that the young CRC accounted for 15.1% of all CRC with declining trend observed over recent years. Young CRC was more common among indigenous, expatriates and Malays and least common among the Chinese. There were no differences in the gender and tumor locations.

Colorectal cancer in young patients: is it a distinct clinical entity?

BACKGROUND

The incidence of colorectal cancer in young patients is increasing. It remains unclear if the disease has unique features in this age group.

METHODS

This was a single-center, retrospective cohort study which included patients diagnosed with colorectal cancer at age ≤40 years in 1997-2013 matched 1:2 by year of diagnosis with consecutive colorectal cancer patients diagnosed at age >50 years during the same period. Patients aged 41-50 years were not included in the study, to accentuate potential age-related differences. Clinicopathological characteristics, treatment, and outcome were compared between groups.

RESULTS

The cohort included 330 patients, followed for a median time of 65.9 months (range 4.7-211). Several significant differences were noted. The younger group had a different ethnic composition. They had higher rates of family history of colorectal cancer (p = 0.003), hereditary colorectal cancer syndromes (p < 0.0001), and inflammatory bowel disease (p = 0.007), and a lower rate of polyps (p < 0.0001). They were more likely to present with stage III or IV disease (p = 0.001), angiolymphatic invasion, signet cell ring adenocarcinoma, and rectal tumors (p = 0.02). Younger patients more frequently received treatment. Young patients had a worse estimated 5-year disease-free survival rate (57.6  vs. 70 %, p = 0.039), but this did not retain significance when analyzed by stage (p = 0.092). Estimated 5-year overall survival rates were 59.1 and 62.1 % in the younger and the control group, respectively (p = 0.565).

CONCLUSIONS

Colorectal cancer among young patients may constitute a distinct clinical entity. Further research is needed to validate our findings and define the optimal approach in this population.

SATB1 expression is correlated with β-catenin associated epithelial-mesenchymal transition in colorectal cancer

SATB1, a global gene regulator, has been implicated in the growth and metastasis of multiple cancers, including colorectal cancer. While the understanding about the role of SATB1 in CRC remains limited. The aim of our study is to investigate the expression of SATB1 in CRC, and the relationship between SATB1 expression pattern and clinicopathological variables. A further aim is to analyze the correlation between SATB1 expression and epithelial-mesenchymal transition in CRC. Immunohistochemical expression of SATB1, β-catenin, E-cadherin, CK20, Vimentin, SMA, and desmin were assessed in a cohort of 200 patients using tissue microarrays. SATB1 was expressed in 133 (66.5%) CRC primary lesions, 14 (28%) adjacent colorectal mucosa specimens, and 60 (75%) corresponding lymph node metastases. The expression level of SATB1 was significantly higher in lymph node metastases than in CRC primary lesions and normal mucosa (P = 0.000). High expression of SATB1 in CRC was strongly correlated with poor differentiation of tumor tissues (P = 0.000). High expression of SATB1 was significantly correlated with aberrant expression of β-catenin (P = 0.0005), low expression of E-cadherin (P = 0.000) and CK20 (P = 0.000) and with high expression of Vimentin (P = 0.001). No SMA or desmin protein was expressed in the CRC cells. Our results suggested that high expression of SATB1 is significantly correlated with poor differentiation of CRC. SATB1 might promote the epithelial-mesenchymal transition by increasing the aberrant expression of β-catenin.

Effect of Age on Survival Outcome in Operated and Non-Operated Patients with Colon Cancer: A Population-Based Study

Objective

To know the effect of age on survival outcome in operated and non-operated patients with colon cancer.

Methods

From the Surveillance, Epidemiology, and End Results database, we identified 123,356 patients with colon cancer who were diagnosed between 1996 and 2005, grouped them as older or younger than 40 years and analyzed their 5-year cancer-specific survival (CSS) data, along with some risk factors, using Kaplan–Meier methods and multivariable Cox regression models.

Results

The younger group had significantly higher pathological grades (P<0.001), more mucinous and signet-ring histology (P<0.001), advanced AJCC stage (P<0.001), and were more likely to undergo surgery (P<0.001). For surgically treated patients, age did not significantly affect 5-year CSS (younger: 66.7%; older: 67.3%; P = 0.86). Further analysis showed that age was an independent prognostic factor in stage I–IV disease (stage I: P = 0.001; P<0.001 for stages II–IV, in both uni- and multivariate analyses), but not for patients with unknown disease stage (P = 0.52). For non-surgically treated patients, age significantly affected 5-year CSS (younger: 16.2%; older: 12.9%; P<0.001) in univariate analysis; and was an independent prognostic factor (P<0.001) in multivariate analysis.

Conclusion

The CSS rate for younger CC patients was at least as high as for older patients, although they presented with higher proportions of unfavorable factors and more advanced disease.

Risk of developing advanced colorectal neoplasia after removing high-risk adenoma detected at index colonoscopy in young patients: A KASID study

BACKGROUND AND AIM

Advanced adenoma (> 10 mm in diameter, villous structure, or high-grade dysplasia) in young patients may have different characteristics and prognosis compared with those in older patients. We aimed to compare the incidence of colorectal neoplasms in young patients with older patients after removing high-risk adenoma (advance adenoma or ≥ 3 adenomas).

METHODS

A retrospective, multicenter study was conducted at 13 university hospitals in Korea. The 1479 patients who removed high-risk adenoma at index colonoscopy and followed by surveillance colonoscopy ≥ 2.5 years after were included. The cumulative incidence of overall and advanced colorectal neoplasms was compared according to the age groups (group 1: < 50 years, group 2: 50-70 years, and group 3: ≥ 70 years).

RESULTS

The prevalence of advance adenoma detected at index colonoscopy was significantly higher in group 1 than in groups 2 and 3 (85.4%, 78.1%, and 77.2%, respectively; P = 0.035). The 5 years cumulative incidence of overall and advanced colorectal neoplasms were 61.9%, 67.9%, and 74.7% (P < 0.001), and 11.7%, 17.9%, and 27.1% (P = 0.001) in groups 1, 2, and 3, respectively. In multivariate analysis, age > 70 years was a significant risk factor for developing overall (hazard ratio [HR] 1.41, 95% confidence interval [CI] 1.12-1.82, P = 0.004) and advanced colorectal neoplasms (HR = 2.56, 95% CI 1.43-4.59, P = 0.002).

CONCLUSION

The cumulative incidence of overall and advanced colorectal neoplasms was significantly higher in older patients than in young patient groups. Age was a significant risk factor for developing colorectal neoplasms after removing high-risk adenoma.

Trends in colorectal cancer admissions and stage at presentation: impact of screening

BACKGROUND

Colorectal cancer (CRC) incidence is rising among patients under age 50. As such, we set out to determine the proportion of CRC-related hospital admissions and distribution of colon cancer by stage in different age groups.

METHODS

The NIS database for 2002-2012 was used to investigate trends of colorectal cancer resection by age, and the ACS NSQIP database for 2012-2013 was used to investigate contemporary stage at diagnosis for colon cancer in different age groups.

RESULTS

A total of 1,198,421 patients were admitted to a hospital with a diagnosis of CRC and captured by the NIS database. Although the number of hospitalized CRC patients decreased from 2002 to 2012, the observed decrease was predominant in patients older than 65 years (P < 0.01) and in colon cancer compared to rectal cancer patients (P < 0.01). The proportion of patients younger than 65 years increased from 32.8 % in 2002 to 41.1 % in 2012, and the proportion of patients under age 50 increased from 9 to 12 %. In the NSQIP database, the age <50 group also had a significantly higher proportion of advanced disease (stage III/IV) compared to patients age 50 and older (62.3 vs. 47.5 %, P < 0.01). In 2012, it was observed that most patients with rectal cancer were younger than 65 years (55.8 %).

CONCLUSION

There was a steady decrease in the number of hospitalized patients with colorectal cancer during the last decade, primarily attributable to a decrease in the older than 65 years age patients and colon cancer patients. The proportion of hospitalized patients age <50 is rising. In addition, patients younger than 50 years were more likely to have advanced disease compared to older patients.

Temporal Epidemiological Assessment of Colorectal Cancer Incidence and Mortality in East Kazakhstan, 2004-2013

Colorectal cancer incidence and mortality in Kazakhstan are relatively high but exact statistics have hitherto been lacking and trends over time are unclear. The present study was therefore undertaken to retrospectively assess data for East Kazakhstan, accessed from the central registration office, for the period 2004-2013. Approximate age standardized data for incidence and mortality were generated and compared across age groups, gender and year. It was determined that during the studied period 3,417 new cases of colorectal cancer were registered and 2,259 died of this pathology. Average cancer cancer incidence and mortality over the ten years were 24.1/105 and 15.9/105 respectively, and the overall ratio of mortality/incidence (M/I) was 0.69:1 (range 0.58-0.73). Both incidence and mortality tended to remain constant in both males and females. The male to female ratios also did not significantly vary over time but a trend for improvement of the mortality to incidence ratio was observed, especially for rectum. Whether this might be related to screening remains unclear. These preliminary data indicate that whereas colorectal cancer continues to be important, change in environmental factors are not having a great impact on incidence in East Kazakhstan.

Colorectal cancer in young adults

The incidence and mortality rates of colorectal cancer (CRC) have been decreasing in adults over 50 years of age, however, these rates have been increasing in adults under 50. The majority of CRC in young adults is sporadic, and is likely due to behavioral and environmental causes, however the exact etiology still remains unclear. The minority of CRC in this population is due to inherited CRC syndromes. Young adults with CRC are often symptomatic (abdominal pain, rectal bleeding), and diagnosis is often delayed due to reasons such as under-utilized health care services, and physicians attributing symptoms to diagnoses other than CRC. Young adults with CRC often have more aggressive tumor characteristics, but they tend to have better survival rates when compared with older adults when matched for stage. Treatment is the same for young patients with CRC, however there are issues that arise in this population that do not necessarily affect older adults, such as the negative effect of chemotherapy/radiation on fertility. It is not clear that screening individuals for CRC at ages under 50 is beneficial or cost-effective. Further studies are needed regarding this topic.

Rising incidence of early-onset colorectal cancer in Australia over two decades: report and review

The average age at diagnosis for colorectal cancer (CRC) in Australia is 69, and the age-specific incidence rises rapidly after age 50 years. The incidence has stabilized or is declining in older age groups in Australia during recent decades, possibly related to the increased uptake of screening and high-risk surveillance. In the same time frame, a rising incidence of CRC in younger adults has been well-documented in the United States. This rise in incidence in the young has not been reported from other countries that share long-term exposure to westernised urban lifestyles. Using data from the Australian Institute of Health and Welfare, we examined trends in national incidence rates for CRC under age 50 years and observed that rates in people under age 40 years have been rising for the last two decades. We further performed a review of the literature regarding CRC in young adults to outline the extent of current understanding, explore potential risk factors such as obesity, alcohol, and sedentary lifestyles, and to identify the questions remaining to be addressed. Although absolute numbers might not justify a population screening approach, the dispersal of young adults with CRC across the primary health-care system decreases probability of their recognition. Patient and physician awareness, aided by stool and emerging blood-screening tests and risk profiling tools, have the potential to aid in identification of those young adults who would most benefit from a colonoscopy through early detection of CRCs or by removal of advanced polyps.

High expression of ROR2 in cancer cell correlates with unfavorable prognosis in colorectal cancer

The receptor tyrosine kinase-like orphan receptor 2 (ROR2) is a transmembrane protein that belongs to a conserved family of tyrosine kinase receptors involved in several functional processes. ROR2 is overexpressed in various types of solid tumors; however, the expression of ROR2, as well as its functional and prognostic significance has yet to be evaluated in colorectal cancer (CRC). In this study, one-step quantitative reverse transcription-polymerase chain reaction and immunohistochemical analysis using tissue microarrays were used to evaluate ROR2 expression in CRC and to investigate the association between ROR2 expression and patient prognosis. We observed that the expression of ROR2 mRNA and protein was significantly higher in CRC specimens compared with normal, tumor-adjacent tissues (both p<0.05). Cytoplasmic ROR2 expression was related to TNM stage (p=0.041) and lymph node metastasis (N) (p=0.015). Kaplan-Meier and multivariate analyses suggested that high cytoplasmic ROR2 expression (p=0.001), poor tumor differentiation (p=0.001), and advanced TNM stage (p=0.001) and high preoperative CEA level (p<0.001) were significantly associated with unfavorable survival of CRC patients. These results suggest that ROR2 expression is correlated with malignant attributes of CRC and may serve as an indicator for poor prognosis in patients with CRC.