Present status and perspectives of colorectal cancer in Asia: Colorectal Cancer Working Group report in 30th Asia-Pacific Cancer Conference

Guideline- Versus Non-Guideline-Based Neoadjuvant Management of Clinical T4 Rectal Cancer

(1) Background: Practice guidelines recommend neoadjuvant treatment for clinical T4 rectal cancer. The primary objective of this retrospective study was to assess whether compliance with guidelines correlates with patient outcomes. Secondarily, we evaluated predictors of adherence to guidelines and mortality. (2) Methods: A total of 397 qualified rectal cancer (RC) patients from 2017 to 2020 at West China Hospital of Sichuan University were included. Patients were divided into two groups depending on adherence to neoadjuvant treatment guidelines. The main endpoints were overall survival (OS) and disease special survival (DSS). We analyzed factors associated with guideline adherence and mortality. (3) Results: Compliance with guidelines was only 39.55%. Patients' neoadjuvant therapy treated not according to the guidelines for clinical T4 RC was not associated with an overall survival (95.7% vs. 88.9%) and disease special survival (96.3% vs. 91.1%) benefit. Patients were more likely to get recommended therapy with positive patient compliance. Staging Ⅲ, medium/high differentiation and objective compliance were associated with increased risk of mortality. (4) Conclusions: Guideline adherence for clinical T4 RC in our system is low. Compliance with the relevant guidelines for neoadjuvant therapy seems not to lead to better overall survival for patients with clinical T4 RC.

Colorectal Cancer Treatment Characteristics and Concordance With Guidelines in Sri Lanka: Results From a Hospital-Based Cancer Registry

Colorectal cancer (CRC) ranks among the top five incident cancers in Sri Lanka (SL). Here, we describe disease characteristics and treatment patterns of patients with CRC in SL.

Despite being one of the top five incident cancers in Sri Lanka, there is a paucity of information on patient population and treatment patterns for colorectal cancer in Sri Lanka. This study conducted among 1,578 patients with colorectal cancer found a lack of concordance with treatment guidelines, including both underuse and overuse of clinical treatments. This study provides impetus for further investigation into colorectal cancer treatment and guideline concordance in Sri Lanka and other low- and middle-income nations, where limited research like this have been conducted.

Influence of Old Age on Risk of Lymph Node Metastasis and Survival in Patients With T1 Colorectal Cancer: A Population-Based Analysis

Background

We aimed at determining the influence of old age on lymph node metastasis (LNM) and prognosis in T1 colorectal cancer (CRC).

Methods

We collected data from eligible patients in Surveillance, Epidemiology, and End Results database between 2004 and 2015. Independent predictors of LNM were identified by logistic regression analysis. Cox regression analysis, propensity score-matched analysis, and competing risks analysis were used to analyze the associations between old age and lymph node (LN) status and to validate the prognostic value of old age on cancer-specific survival (CSS).

Results

In total, 10,092 patients were identified. Among them, 6,423 patients (63.6%) had greater than or equal to 12 examined lymph nodes (LNE ≥12), and 5,777 patients (57.7%) were 65 years or older. The observed rate of LNM was 4.6% (15 out of 325) in T1 CRC elderly patients, with tumor size <3 cm, well differentiated, with negative carcinoembryonic antigen (CEA) level, and adenocarcinoma. Logistic regression models demonstrated that tumor size ≥3 cm (odds ratio, OR = 1.316, P = 0.038), poorly differentiated (OR = 3.716, P < 0.001), older age (OR = 0.633 for ages 65–79 years, OR = 0.477 for age over 80 years, both P <0.001), and negative CEA level (OR = 0.71, P = 0.007) were independent prognostic factors. Cox regression analysis demonstrated that CSS was not significantly different between elderly patients undergoing radical resection with LNE ≥12 and those with LNE <12 (hazard ratio = 0.865, P = 0.153), which was firmly validated after a propensity score-matched analysis by a competing risks model.

Conclusions

The predictive value of tumor size, grading, primary site, histology, CEA level, and age for LNM should be considered in medical decision making about local resection. We found that tumor size was <3 cm, well differentiated, negative CEA level, and adenocarcinoma in elderly patients with T1 colorectal cancer which was suitable for local excision.

Acquiring Advanced Laparoscopic Colectomy Skills - The Issues

Colorectal surgery has been revolutionised towards minimally invasive surgery with the emergence of enhanced recovery protocol after surgery initiatives. However, laparoscopic colectomy has yet to be widely adopted, due mainly to the steep learning curve. We aim to review and discuss the methods of overcoming these learning curves by accelerating the competency level of the trainees without compromising patient safety. To provide this mini review, we assessed 70 articles in PubMed that were found through a search comprised the keywords laparoscopic colectomy, minimal invasive colectomy, learning curve and surgical education. We found England's Laparoscopic Colorectal National Training Programme (LAPCO-NTP) England to be by far the most structured programme established for colorectal surgeons, which involves pre-clinical and clinical phases that end with an assessment. For budding colorectal trainees, learning may be accelerated by simulator-based training to achieve laparoscopic dexterity coupled with an in-theatre proctorship by field experts. Task-specific checklists and video recordings are essential adjuncts to gauge progress and performance. As competency is established, careful case selections with the proctor are essential to maintain motivation and ensure safe performances. A structured programme to establish competency is vital to help both the proctor and trainee gauge real-time progress and performance. However, training systems both inside and outside the operating theatre (OT) are equally useful to achieve the desired performance.

The impact of APC polymorphisms on the transition from polyps to colorectal cancer (CRC)

OBJECTIVE

The purpose of this study was to investigate the function of APC polymorphisms (D1822V and E1317Q) on the transition from polyps to colorectal cancer (CRC).

METHODS

259 patients with polyps were included in the study. APC polymorphisms were genotyped via polymerase chain reaction (PCR) and subsequent sequencing. χ² test was performed to analyze the relationship of APC polymorphisms or CRC occurrence with clinical features. COX regression was used to find out risk factors for CRC. Hazard ratio (HR) and 95% confidence interval (CI) represented the risk of CRC.

RESULTS

Clinical information on sex, regular physical activity, smoking history, alcohol use and polyps types was recorded. Neither D1822V nor E1317Q polymorphism was associated with these factors. In following analysis, we found significant difference in the frequency of males between CRC and non-CRC patients (87.4% vs. 58.7%, P < 0.001). Distinct difference in the distribution of D1822V polymorphism was also observed between CRC and non-CRC patients (P = 0.001). In COX analysis, sex was identified as a risk factor for transition from polyps to CRC (HR = 2.442, 95%CI = 1.281-4.654). D1822V polymorphism tended to inhibit the transition process (HR = 0.286, 95%CI = 0.170-0.480). However, E1317Q seemed to have no significant effect on this process (HR = 1.042, 95%CI = 0.676-1.606).

CONCLUSION

In a word, APC D1822V polymorphism has strong effect on the transition from polyps to CRC.

A competing-risk nomogram to predict cause-specific death in elderly patients with colorectal cancer after surgery (especially for colon cancer)

Background

Clinically, when the diagnosis of colorectal cancer is clear, patients are more concerned about their own prognosis survival. Special population with high risk of accidental death, such as elderly patients, is more likely to die due to causes other than tumors. The main purpose of this study is to construct a prediction model of cause-specific death (CSD) in elderly patients using competing-risk approach, so as to help clinicians to predict the probability of CSD in elderly patients with colorectal cancer.

Methods

The data were extracted from Surveillance, Epidemiology, and End Results (SEER) database to include ≥ 65-year-old patients with colorectal cancer who had undergone surgical treatment from 2010 to 2016. Using competing-risk methodology, the cumulative incidence function (CIF) of CSD was calculated to select the predictors among 13 variables, and the selected variables were subsequently refined and used for the construction of the proportional subdistribution hazard model. The model was presented in the form of nomogram, and the performance of nomogram was bootstrap validated internally and externally using the concordance index (C-index).

Results

Dataset of 19,789 patients who met the inclusion criteria were eventually selected for analysis. The five-year cumulative incidence of CSD was 31.405% (95% confidence interval [CI] 31.402–31.408%). The identified clinically relevant variables in nomogram included marital status, pathological grade, AJCC TNM stage, CEA, perineural invasion, and chemotherapy. The nomogram was shown to have good discrimination after internal validation with a C-index of 0.801 (95% CI 0.795–0.807) as well as external validation with a C-index of 0.759 (95% CI 0.716–0.802). Both the internal and external validation calibration curve indicated good concordance between the predicted and actual outcomes.

Conclusion

Using the large sample database and competing-risk analysis, a postoperative prediction model for elderly patients with colorectal cancer was established with satisfactory accuracy. The individualized estimates of CSD outcome for the elderly patients were realized.

The Rise of Colorectal Cancer in Asia: Epidemiology, Screening, and Management

PURPOSE OF REVIEW

Colorectal cancer (CRC) remains the third most commonly diagnosed cancer globally, and its incidence and mortality rates have been on the rise in Asia. In this paper, we summarize the recent trends and screening challenges of CRC in this region.

RECENT FINDINGS

In 2018, Asia had the highest proportions of both incident (51.8%) and mortality (52.4%) CRC cases (all genders and ages) per 100,000 population in the world. In addition, there has been a rising trend of this disease across Asia with some regional geographic variations. This rise in CRC can be attributed to westernized dietary lifestyle, increasing population aging, smoking, physical inactivity, and other risk factors. In curbing the rising trend, Japan, South Korea, Singapore, and Taiwan have launched nationwide population-based screening programs. CRC screening across this region has been found to be effective and cost-effective compared with no screening at all. The emergence of new therapies has caused a reduction in case fatality; however, these new options have had a limited impact on cure rates and long-term survival due to the great disparity in treatment capacity/resources and screening infrastructures among Asian countries with different degrees of economic development. CRC is still rising in Asia, and implementation of screening is necessary for moderate- to high-incidence countries and construction of treatment capacity is the priority task in low-incidence and low-income countries. Unless countries in Asia implement CRC screening, the incidence and mortality rates of this disease will continue to rise especially with the rapidly rising population growth, economic development, westernized lifestyle, and increasing aging.

Provider Costs of Treating Colorectal Cancer in Government Hospital of Malaysia

Background

The incidence of colorectal cancer (CRC) is rapidly rising in several Asian countries, including Malaysia, but there is little data on health care provider costs in this region. The aim of this study was to estimate the cost of CRC management from the perspective of the health care provider, based on standard operating procedures.

Methods

A combination of top-down approach and activity-based costing was applied. The standard operating procedure (SOP) for CRC was developed for each stage according to national data and guidelines at the University of Malaya Medical Centre (UMMC). The unit cost was calculated and incorporated into the treatment pathway in order to obtain the total cost of managing a single CRC patient according to the stage of illness. The cost data were represented by means and standard deviation and the results were demonstrated by tabulation. All cost data are presented in Malaysian Ringgit (RM). The cost difference between early stage (Stage I) and late stage (Stage II–IV) was analysed using independent t-test.

Results

The cost per patient increased with stage of CRC, from RM13,672 (USD4,410.30) for stage I, to RM27,972 (USD9,023.20) for Stage IV. The early stage had statistically significant lower cost compared to late stage t(2) = −4.729, P = 0.042. The highest fraction of the cost was related to surgery for Stage I, but was superseded by oncology day care treatment for Stages II–IV. CRC is a costly illness. From a provider perspective, the highest cost was found in Stages III and IV. The early stages conserved more resources than did the advanced stages of cancer.

Conclusion

Early diagnosis and management of CRC, therefore, not only affects oncologic prognosis, but has implications for health care costs. This adds further justification to develop and implement CRC screening programmes in Malaysia.

miR-7-5p regulates the proliferation and migration of colorectal cancer cells by negatively regulating the expression of Krüppel-like factor 4

Previous studies have demonstrated that microRNA-7-5p (miR-7-5p) functions as a tumor suppressor in certain types of human cancer. However, the role of miR-7-5p in colorectal cancer (CRC) remains to be investigated. Using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), the present study demonstrated that miR-7-5p was downregulated in CRC tissues and cell lines. In addition, low miR-7-5p expression is able to predict a poor 5-year overall survival rate for patients with CRC. In vitro studies revealed that miR-7-5p overexpression inhibits cell proliferation and migration. Furthermore, Krüppel-like factor 4 (KLF4), an oncogene in CRC, was validated as a direct target of miR-7-5p. KLF4 expression was negatively correlated with miR-7-5p expression in CRC tissues. Notably, KLF4 overexpression rescued the suppressive effects of miR-7-5p on CRC cell proliferation and migration. In summary, the results of this study demonstrated that miR-7-5p inhibits CRC proliferation and migration by targeting KLF4, which suggests that miR-7-5p is a potential molecular target for the treatment of human CRC.

Nomogram Predicting Survival After Recurrence in Patients With Stage I to III Colon Cancer: A Nationwide Multicenter Study

BACKGROUND

Although a number of studies have been conducted to investigate factors affecting colon cancer recurrence and patient overall survival after surgical treatment, no prognostic risk models have been proposed for predicting survival specifically after postsurgical recurrence.

OBJECTIVE

We aimed to identify factors affecting the survival of the patients with recurrent colon cancer and to construct a nomogram for predicting their survival.

DESIGN

This was a retrospective study.

SETTINGS

This study used the Japanese Study Group for Postoperative Follow-Up of Colorectal Cancer database, which contains retrospectively collected data of all consecutive patients with stage I to III colorectal cancer who underwent surgical curative resection between 1997 and 2008 at 23 referral institutions.

PATIENTS

A total of 2563 patients with stage I to III colon cancer who experienced recurrence after surgery were included in the present study.

MAIN OUTCOME MEASURES

A nomogram predicting survival was constructed using a training cohort composed of patients from 15 hospitals (n = 1721) using a Cox regression hazard model analysis. The clinical applicability of this nomogram was validated in patients from the 8 remaining hospitals (the validation cohort; n = 842).

RESULTS

Eight factors (age, location of the primary tumor, histopathological type, positive lymph node status, presence of peritoneal metastasis, number of organs involved in the first recurrence, treatment for recurrence, and the interval between initial surgery and recurrence) were identified as nomogram variables. Our nomogram showed good calibration, with concordance indexes of 0.744 in the training cohort and 0.730 in the validation cohort. The survival curves stratified by the risk score calculated by the nomogram were almost identical for the training and validation cohorts.

LIMITATIONS

The study was conducted using the data until 2008, and more advanced chemotherapeutic agents and multidisciplinary therapies that might have improved the outcomes predicted by our nomogram were not available. In addition, treatment strategies for recurrence might differ between countries.

CONCLUSIONS

Our nomogram, which is based on a nationwide multicenter study, is the first statistical model predicting survival after recurrence in patients with stage I to III colon cancer. It promises to be of use in postoperative colon cancer surveillance. See Video Abstract at http://links.lww.com/DCR/A687.

Targeted Sequencing of Circulating Tumor DNA to Monitor Genetic Variants and Therapeutic Response in Metastatic Colorectal Cancer

Substantial improvements have been made in the management of metastatic colorectal cancer (mCRC) in the last two decades, but disease monitoring remains underdeveloped. Circulating tumor DNA (ctDNA) is a promising prognostic and predictive biomarker; however, ctDNA as a marker for mCRC patients is not well established, and there is still no consensus about how to utilize it most cost-effectively. In this study, we aim to investigate plasma ctDNA levels as a biomarker for therapeutic response of mCRC patients. We performed next-generation sequencing (NGS) by using a 12-gene panel to identify genetic variants in 136 tumor tissue and ctDNA samples from 32 mCRC patients. Genetic variants were detected in approximately 70% of samples, and there was a high concordance (85%) between tumor tissue and plasma ctDNA. We observed ctDNA changes in 18 follow-up patients, including the emergence of new variants. Changes in ctDNA levels significantly correlated with tumor shrinkage (P = 0.041), and patients with a ctDNA decrease >80% after treatment had a longer progression-free survival compared with patients with a ctDNA decrease of <80% (HR, 0.22; P = 0.015). The objective response rate among patients with a ctDNA decrease of >80% was better than those with a ctDNA decrease <80% (OR, 0.026; P = 0.007). In conclusion, this study demonstrates that monitoring of genetic ctDNA variants can serve as a valuable biomarker for therapeutic efficacy in mCRC patients, and that using a moderate-sized 12-gene NGS panel may be suitable for such clinical monitoring. Mol Cancer Ther; 17(10); 2238-47. ©2018 AACR.

Additional chemotherapy and salvage surgery for poor response to chemoradiotherapy in rectal cancers

AIM

A proportion of locally advanced rectal cancer patients who receive neoadjuvant chemoradiotherapy (NACRT) are still unresectable. This study was undertaken to assess the outcomes of giving additional chemotherapy to rectal cancer patients with unresectable disease after NACRT.

METHODS

Patients with poor response to NACRT where mesorectal fascia was still involved on MRI and R0 resection was doubtful, received additional four cycles of chemotherapy with either CAPOX or FOLFIRINOX regimen, and the response was reevaluated with MRI and reassessed for surgical resection.

RESULTS

Between June 2012 and December 2014, 50 patients received additional chemotherapy with CAPOX regime (19%, 38%) or FOLFIRINOX (31%, 62%) after CRT. Median number of chemotherapy cycles received was four (range 2-8 cycles). Overall 34 (68%) patients underwent exploration and 31 (62%) underwent R0 resection. The median time to surgery following chemoradiation was 5 months (range 3-18 months). Complete pathological response was seen in seven (22%) patients.

CONCLUSION

Patients with poor response to NACRT may be further downstaged using additional chemotherapy so as to achieve R0 resection in 62% of cases.

Descriptive epidemiology of colorectal cancer in University Malaya Medical Centre, 2001 to 2010

BACKGROUND

Colorectal cancer is the second most frequent cancer in Malaysia. Nevertheless, there is little information on treatment and outcomes nationally. We aimed to determine the demographic, clinical and treatment characteristics of colorectal cancer patients treated at the University Malaya Medical Centre (UMMC) as part of a larger project on survival and quality of life outcomes.

MATERIALS AND METHODS

Medical records of 1,212 patients undergoing treatment in UMMC between January 2001 and December 2010 were reviewed. A retrospective-prospective cohort study design was used. Research tools included the National Cancer Patient Registration form. Statistical analysis included means, standard deviations (SD), proportions, chi square, t-test/ ANOVA. P-value significance was set at 0.05.

RESULTS

The male: female ratio was 1.2:1. The mean age was 62.1 (SD12.4) years. Patients were predominantly Chinese (67%), then Malays (18%), Indians (13%) and others (2%). Malays were younger than Chinese and Indians (mean age 57 versus 62 versus 62 years, p<0.001). More females (56%) had colon cancers compared to males (44%) (p=0.022). Malays (57%) had more rectal cancer compared to Chinese (45%) and Indians (49%) (p=0.004). Dukes' stage data weres available in 67%, with Dukes' C and D accounting for 64%. Stage was not affected by age, gender, ethnicity or tumor site. Treatment modalities included surgery alone (40%), surgery and chemo/radiotherapy 32%, chemo and radiotherapy (8%) and others (20%).

CONCLUSIONS

Significant ethnic differences in age and site distribution, if verified in population-based settings, would support implementation of preventive measures targeting those with the greatest need, at the right age.

Long-Term Oncological Outcomes of Endoscopic Stenting as a Bridge to Surgery Versus Emergency Surgery for Malignant Colorectal Obstruction: A Comparative Study

AIM

With consideration of the theoretical link between the stent insertion and the increased risk of tumor cells spillaged, which may lead to distant metastases, there is a concern about long-term clinical outcomes after the usage of self-expanding metallic stents (SEMS) as a "bridge to surgery" in the malignant colorectal obstruction (MCO) treatment. This cohort study aimed to compare the long-term oncological outcomes of SEMS as a bridge to surgery (SEMS group) with those of emergency surgery (ES group) for MCO.

METHODS

Twenty-seven patients who underwent semielective curative resection after endoscopic SEMS insertion were included from October 2007 to December 2012 in the SEMS group were compared with 33 patients who underwent emergency curative surgery for MCO during the same period in the ES group. The clinical pathologic characteristics and the overall survival (OS) rate were compared between the two groups.

RESULTS

There were no significant differences in demographics, tumor stage, location, and histology between the SEMS and ES groups. The median OS times were 37 months for the SEMS group and 23 months for the ES group. The proportions of patients who received postoperative adjuvant chemotherapy were comparable (SEMS group versus ES group, 70.4% versus 45.5%; P = .138). There were no significant differences in terms of the long-term oncological outcome between two groups in the 3-year OS rate (55.6% versus 39.4%; P = .2119) and the 5-year OS rate (48.1% versus 36.4%; P = .3570).

CONCLUSIONS

Long-term oncological outcomes of the SEMS group were comparable to those of the ES group.

The pathological behaviors and prognostic factors of Chinese and Japanese colorectal cancers from general hospitals: a comparative study of the inpatients with surgical operation

Here, we collected the information of 17304 and 2014 inpatients with colorectal cancer (CRC) from general hospitals of China and Japan respectively, and analyzed microscopic and macroscopic aspects, even stratified by the age and gender. It was found that Chinese CRC patients showed younger prone, more rectal and ascending cancers, less sigmoid and transverse cancers, larger size, less invasion into lymphatic system or metastasis into lymph node, and poorer differentiation than Japanese ones (p < 0.05). TNM staging was employed as an independent factor for the prognosis of the CRC patients regardless of the country (p < 0.05). Female patients showed larger tumor size, easier invasion and metastasis into lymphatic system, and worse differentiation than males (p < 0.05). The younger patients displayed frequent invasion and metastasis into lymphatic system, and poor differentiation in comparison to elder ones (p < 0.05). These findings demonstrated that Japanese patients seemed to have more invasion and metastasis due to standard and precise operation and pathological diagnosis accuracy. Actually, Chinese patients had more aggressive pathological characteristics and a poorer prognosis. Therefore, it is essential to establish a routine screening methodology, a standard treatment system and postoperative diagnosis protocol for the prevention and therapeutics of Chinese CRC patients, especially for female and young patients.

Characterization of SLC22A18 as a tumor suppressor and novel biomarker in colorectal cancer

SLC22A18, solute carrier family 22, member 18, has been proposed to function as a tumor suppressor based on its chromosomal location at 11p15.5, mutations and aberrant splicing in several types of cancer and down-regulation in glioblastoma. In this study, we sought to demonstrate the significance of SLC22A18 as a tumor suppressor in colorectal cancer (CRC) and provide mechanistic bases for its function. We first showed that the expression of SLC22A18 is significantly down-regulated in tumor tissues using matched normal-tumor samples from CRC patients. This finding was also supported by publically accessible data from The Cancer Genome Atlas (TCGA). Functionally, SLC22A18 inhibits colony formation and induces of G2/M arrest consistent with being a tumor suppressor. Interestingly, suppression of KRAS by RNA interference promotes SLC22A18 expression, and expression of SLC22A18 in turn inhibits KRAS^G12D-mediated anchorage independent growth of NIH3T3 cells indicating a mutual negative interaction. Finally, we evaluated diagnostic and prognostic values of SLC22A18 using clinical and gene expression data from TCGA which revealed a significantly worse long-term prognosis for patients with low level SLC22A18 expression. In sum, we established SLC22A18 as a tumor suppressor in colon epithelial cells and propose that SLC22A18 is potentially a marker of diagnostic and prognostic values.

Depression, Fatigue, and QoL in Colorectal Cancer Patients During and After Treatment

In this study, we sought to explore the prevalence of depression and fatigue in colorectal cancer patients during and after treatment to examine how these variables affect quality of life (QoL). In total, 170 patients with colorectal cancer participated in this study. The study population was divided into two groups: one receiving treatment and another that had finished treatment. The results showed that depression and fatigue measurements were higher in patients receiving treatment. Depression was a strong and significant predictor of QoL in both groups, whereas fatigue was not, with the exception of the symptom score. These findings underscore the importance of early detection and management of depression and fatigue during the treatment and survival stages of patients with colorectal cancer. Our findings indicate that health care professionals should provide appropriate nursing intervention to decrease depression and fatigue and enhance patient QoL.

Metformin Is Associated With Slightly Reduced Risk of Colorectal Cancer and Moderate Survival Benefits in Diabetes Mellitus: A Meta-Analysis

To systematically assess the effect of metformin on colorectal cancer (CRC) risk and mortality in type 2 diabetes mellitus (T2DM) patients. We conducted a systematic search of PubMed, Web of Science, and the Cochrane Library databases for relevant articles before August 2015. Two investigators identified and extracted data independently. We adopted adjusted estimates to calculate summary estimates with 95% confidence interval (CI) using either a fixed-effects or a random-effects model. Subgroup and sensitivity analyses were conducted to evaluate the robustness of the pooled results. The risk of publication bias was assessed by examining funnel plot asymmetry as well as Begg test and Egger test. Fifteen studies on CRC incidence and 6 studies on CRC survival were finally included in our meta-analysis. The pooled odds ratio (OR) of observational studies illustrated that a slight 10% reduction of CRC incidence was associated with metformin use (OR = 0.90, 95% CI: 0.85-0.96). Furthermore, the pooled hazard ratio (HR) revealed an improved survival outcome for metformin users in CRC patients compared to nonusers (HR = 0.68, 95% CI: 0.58-081). There was no publication bias across studies. Our meta-analysis demonstrated that metformin therapy could slightly reduce CRC incidence and moderately improve the survival outcomes in patients with T2DM. More prospective studies are warranted to certify this protective association.

The changing epidemiology of Asian digestive cancers: From etiologies and incidences to preventive strategies

Digestive cancers are a major health burden in Asia. Due to the presence of similar "infection-inflammation-cancer" pathways in the carcinogenesis process, eradicating infective pathogens or attenuating relevant inflammatory signaling pathways may reduce digestive cancer incidences and improve patient outcomes. The aim of this paper is to review the recent evidence regarding the epidemiology of three major digestive cancers in Asia: stomach cancer, liver cancer, and colorectal cancer. We focused on the incidence trends, the major etiologies, and especially the potential preventive strategies.

Disparities in prevalence, location, and shape characteristics of colorectal neoplasia between South Korean and U.S. patients

BACKGROUND

Colon cancer screening is being introduced in many countries, but standard Western screening approaches may not be appropriate for Asian societies if differences in colon cancer epidemiology exist. Comparative analysis of colorectal neoplasia patterns in South Korean and Western subjects has implications for appropriate screening approaches in non-Western societies.

METHODS

The results of concurrent screening colonoscopies performed in average-risk patients 50 to 69 years old in 2 teaching hospitals, Kyung Hee University Hospital (Seoul, South Korea) and Virginia Mason Medical Center (Seattle, Wash), were compared with respect to prevalence, histologic features, anatomic distribution, and shape characteristics of colorectal neoplasia.

RESULTS

The U.S. (n = 3460) and South Korean (n = 2193) cohorts were similar with regard to the prevalence of adenomas (28.5% vs 29.8%, respectively, P = .312) and advanced neoplasia (6.4% vs 5.4%, respectively, P = .102), but the proportion of proximal adenomas was greater in the U.S. cohort (62.8% vs 45.9%, P < .001). The prevalence of adenomas and advanced neoplasia was similar in male patients, but there was a greater prevalence of neoplasia (23.5% vs 18.8%, P = .006) and advanced neoplasia (5.1% vs 2.7%, P < .001) in U.S. women than South Korean women. When large (≥10 mm) adenomas were considered, proximal location and nonpolypoid (flat) shape were more common in the U.S. cohort (79.4% vs 37.1%, P = .003 and 43.5% vs 12.3%, P < .001, respectively). The overall prevalence of large flat adenomas in the U.S. cohort was 5 times that of the South Korean cohort (2.6% vs 0.5%, P < .001). Adjustment for sex ratio discrepancies (48.3% men in the U.S. cohort vs 60.8% in the South Korean cohort, P < .001) did not result in any significant changes in the conclusions.

CONCLUSION

Compared with Westerners, South Koreans have a more distal distribution of adenomas and advanced neoplasia and lower prevalence of large flat adenomas. South Korean women have a lower prevalence of colorectal neoplasia than Western women. Such disparities suggest that Western screening strategies cannot be directly adopted by other countries, but need to be customized by society.

Nomogram prediction of metachronous colorectal neoplasms in patients with colorectal cancer

OBJECTIVE

To construct a predictive model of postoperative colorectal neoplasm development using a nomogram.

BACKGROUND

Although patients with colorectal cancer (CRC) are known to be at high risk of developing metachronous adenoma or CRC, no statistical model for predicting the incidence of postoperative colorectal lesions has been reported.

METHODS

A total of 309 CRC patients who underwent surgical resection received regular endoscopic follow-up to detect the development of metachronous adenoma or adenocarcinoma. The patients were divided into the derivation set (n = 209) and the validation set (n = 100). The nomogram to predict the 3- and 5-year adenoma-free survival rates was constructed using the derivation set, and a calibration plot and concordance index (c-index) were calculated. The predictive utility of the nomogram was validated in the validation set.

RESULTS

Sex, age, and number of synchronous lesions at the time of surgery for primary CRC were adopted as variables for the nomogram. The nomogram showed moderate calibration, with a c-index of 0.709 in the derivation set and 0.712 in the validation set.

CONCLUSIONS

A nomogram based on sex, age, and number of synchronous lesions at the time of surgery has the ability to predict postoperative adenoma-free survival.

Regorafenib plus best supportive care versus placebo plus best supportive care in Asian patients with previously treated metastatic colorectal cancer (CONCUR): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

In the international randomised phase 3 CORRECT trial (NCT01103323), regorafenib significantly improved overall survival versus placebo in patients with treatment-refractory metastatic colorectal cancer. Of the 760 patients in CORRECT, 111 were Asian (mostly Japanese). This phase 3 trial was done to assess regorafenib in a broader population of Asian patients with refractory metastatic colorectal cancer than was studied in CORRECT.

METHODS

In this randomised, double-blind, placebo-controlled, parallel-group, phase 3 trial done in 25 hospitals in mainland China, Hong Kong, South Korea, Taiwan, and Vietnam, we recruited Asian patients aged 18 years or older with progressive metastatic colorectal cancer who had received at least two previous treatment lines or were unable to tolerate standard treatments. Patients had to have an Eastern Cooperative Oncology Group performance status of 0 or 1, life expectancy of at least 3 months, and adequate bone marrow, liver, and renal function, without other uncontrolled medical disorders. We randomly allocated patients (2:1; with a computer-generated unicentric randomisation list [prepared by the study funder] and interactive voice response system; block size of six; stratified by metastatic site [single vs multiple organs] and time from diagnosis of metastatic disease [<18 months vs ≥18 months]) to receive oral regorafenib 160 mg once daily or placebo on days 1-21 of each 28 day cycle; patients in both groups were also to receive best supportive care. Participants, investigators, and the study funder were masked to treatment assignment. The primary endpoint was overall survival, and we analysed data on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT01584830.

FINDINGS

Between April 29, 2012, and Feb 6, 2013, we screened 243 patients and randomly assigned 204 patients to receive either regorafenib (136 [67%]) or placebo (68 [33%]). After a median follow-up of 7·4 months (IQR 4·3-12·2), overall survival was significantly better with regorafenib than it was with placebo (hazard ratio 0·55, 95% CI 0·40-0·77, one-sided p=0·00016; median overall survival 8·8 months [95% CI 7·3-9·8] in the regorafenib group vs 6·3 months [4·8-7·6] in the placebo group). Drug-related adverse events occurred in 132 (97%) of 136 regorafenib recipients and 31 (46%) of 68 placebo recipients. The most frequent grade 3 or higher regorafenib-related adverse events were hand-foot skin reaction (22 [16%] of 136 patients in the regorafenib group vs none in the placebo group), hypertension (15 [11%] vs two [3%] of 68 patients in the placebo group), hyperbilirubinaemia (nine [7%] vs one [1%]), hypophosphataemia (nine [7%] vs none), alanine aminotransferase concentration increases (nine [7%] vs none), aspartate aminotransferase concentration increases (eight [6%] vs none), lipase concentration increases (six [4%] vs one [1%]), and maculopapular rash (six [4%] vs none). Drug-related serious adverse events occurred in 12 (9%) patients in the regorafenib group and three (4%) in the placebo group.

INTERPRETATION

This phase 3 trial is the second to show an overall survival benefit with regorafenib compared with placebo in patients with treatment-refractory metastatic colorectal cancer, substantiating the role of regorafenib as an important treatment option for patients whose disease has progressed after standard treatments. In this trial, preceding standard treatments did not necessarily include targeted treatments. Adverse events were generally consistent with the known safety profile of regorafenib in this setting.

FUNDING

Bayer HealthCare Pharmaceuticals.

Clinicopathological Characteristics of Serrated Polyposis Syndrome in Korea: Single Center Experience

Background/Aim. Serrated polyposis syndrome (SPS) is a rare condition characterized by multiple serrated polyps throughout the colon and rectum. The aim of this study was to evaluate the clinicopathological characteristics of SPS in Koreans. Methods. This retrospective analysis of prospectively collected data was performed using information from the endoscopy, clinical records, and pathology database system of Uijeongbu St. Mary's Hospital. Consecutive patients satisfying the updated 2010 World Health Organization criteria for SPS between June 2011 and May 2014 were enrolled. Results. Of the 17,552 patients who underwent colonoscopies during the study period, 11 (0.06%) met the criteria for SPS. The mean age of these patients was 55.6 years. Ten patients (91%) were males. None had a family history of CRC or a first-degree relative with SPS. Seven patients (64%) had synchronous advanced adenoma. One patient had coexistence of SPS with CRC that was diagnosed at the initial colonoscopy. Five patients (45%) had more than 30 serrated polyps. One of the patients underwent surgery and 10 underwent endoscopic resection. Conclusion. The prevalence of SPS in this study cohort was comparable to that in Western populations. Considering the high risk of CRC, correct diagnosis and careful follow-up for SPS are necessary.

Clinical impact of prophylactic antibiotic treatment for self-expandable metallic stent insertion in patients with malignant colorectal obstruction

Purpose. The aim of this study was to determine the efficacy of prophylactic antibiotics (PA) for reducing the infectious complications and the potential risk factors responsible for the infectious complications after stent insertion for malignant colorectal obstruction. Methods. We performed a retrospective review of 224 patients who underwent self-expandable metallic stent (SEMS) insertion for malignant colorectal obstruction from May 2004 to December 2012. Results. There were 145 patients in the PA group and 79 in non-PA group. The CRP level in PA group was significantly higher than that in non-PA. Abdominal tenderness and mechanical ileus were significantly more frequent in PA group than those in non-PA. The frequency of post-SEMS insertion fever, systemic inflammatory response syndrome (SIRS), and bacteremia was not significantly different between PA and non-PA groups. In multivariate analysis, the CRP level was risk factor related to post-SEMS insertion SIRS. However, in propensity score matching analysis, there was no independent risk factor related to post-SEMS insertion fever, SIRS, and bacteremia. Conclusion. The use of PA in patients with malignant colorectal obstruction may be not effective to prevent the development of infectious complications after SEMS insertion.

Prevalence and management of colorectal neoplasia in surgically treated esophageal cancer patients

AIMS

The existence of other primary tumors during the treatment of esophageal cancer patients has been an important issue. Our aim is to investigate the prevalence and management of colorectal neoplasia (CRN) in surgically treated esophageal cancer patients.

METHODS

Between 2002 and 2008, 93 patients with esophageal cancer were surgically treated. Seventy-three patients underwent subtotal esophagectomy and 20 underwent lower esophagectomy for esophageal cancer. Colonoscopy was available for detecting CRN before and after surgery.

RESULTS

Eighty-nine (95.7%) of the 93 patients were screened by colonoscopy preoperatively or within a year from the operation. Thirty-nine patients (43.8%) with CRN were synchronously identified: adenoma in 34 (38.2%) and adenocarcinoma in 5 patients (5.6%). Eleven adenomas with high grade-dysplasia and 8 adenomas with low grade-dysplasia were removed endoscopically. Three superficial adenocarcinomas were endoscopically removed before surgery, and 2 adenocarcinomas were surgically removed. Seventy-four patients (83.1%) were followed using colonoscopy, and 11 subsequent CRN, including 2 superficial adenocarcinomas, were endoscopically detected in 8 patients (10.8%). The size of esophageal cancer was larger in the patients with than without CRN (p = 0.036). The body mass index in esophageal cancer patients with CRN tended to be higher than in those without CRN (p = 0.065).

CONCLUSIONS

We noted that esophageal cancer is frequently associated with synchronous and/or metachronous colorectal cancer and adenomas. Colonoscopy is useful to detect and manage CRN before and after esophagectomy, although a few limitations exist.

Nomograms for predicting the prognosis of stage IV colorectal cancer after curative resection: a multicenter retrospective study

PURPOSE

Although stage IV colorectal cancer (CRC) encompasses a wide variety of clinical conditions with diverse prognoses, no statistical model for predicting the postoperative prognosis of stage IV CRC has been established. Thus, we here aimed to construct a predictive model for disease-free survival (DFS) and overall survival (OS) after curative surgery for stage IV CRC using nomograms.

METHODS

The study included 1133 stage IV CRC patients who underwent curative surgical resection in 19 institutions. Patients were divided into derivation (n = 586) and validation (n = 547) groups. Nomograms to predict the 1- and 3-year DFS rates and the 3- and 5-year OS rates were constructed using the derivation set. Calibration plots were constructed, and concordance indices (c-indices) were calculated. The predictive utility of the nomogram was validated in the validation set.

RESULTS

The postoperative carcinoembryonic antigen (CEA) level, depth of tumor invasion (T factor), lymph node metastasis (N factor), and number of metastatic organs were adopted as variables for the DFS-predicting nomogram, whereas the postoperative CEA level, T factor, N factor, and peritoneal dissemination were adopted for the nomogram to predict OS. The nomograms showed moderate calibration, with c-indices of 0.629 and 0.640 in the derivation set and 0.604 and 0.637 in the validation set for DFS and OS, respectively.

CONCLUSIONS

The nomograms developed were capable of estimating the probability of DFS and OS on the basis of only 4 variables, and may represent useful tools for postoperative surveillance of stage IV CRC patients in routine practice.

Paradigm shift in the management of rectal cancer

Surgery for rectal cancer in the pre-Total Mesorectal Excision (TME) era was associated with high local recurrence rates. The widespread adoption of the TME technique together with the addition of neoadjuvant oncological therapies have reduced local failure rates and improved survival for patients with rectal cancer. Advances in our knowledge, better understanding of tumour biology and refinement in minimal access techniques and equipment have significantly changed the management of rectal cancer. This paper reviews these changes and proposes a paradigm shift in how rectal cancer management is conceptualised and treated, such that the treatment of rectal cancer is separated into early tumours (potentially suitable for local excison), TME tumours (optimally managed by TME) and beyond TME tumours (optimally managed by multivisceral resection outside the TME plane).

Colorectal cancer in Chinese patients: current and emerging treatment options

Colorectal cancer is the second most common cancer in Hong Kong and its incidence is rising in economically developed Chinese cities, including Hong Kong and Shanghai. Several studies conducted in the People's Republic of China have characterized the unique molecular epidemiology of familial colorectal cancer syndromes and molecular biomarkers such as microsatellite instability and genetic mutations (eg, KRAS, NRAS, BRAF, PIK3CA, ERCC1) in Chinese populations. Interethnic differences in anticancer drug response and toxicity have been well described in many cancers, and this review examined the literature with regard to the tolerance of Chinese patients to commonly used chemotherapeutic regimens and targeted therapies for metastatic colorectal cancer. Studies on the pharmacogenomic differences in drug metabolizing and DNA repair enzymes between Chinese, North Asians, and Caucasian patients were also reviewed.

Colorectal cancer in Chinese patients: current and emerging treatment options

Colorectal cancer is the second most common cancer in Hong Kong and its incidence is rising in economically developed Chinese cities, including Hong Kong and Shanghai. Several studies conducted in the People's Republic of China have characterized the unique molecular epidemiology of familial colorectal cancer syndromes and molecular biomarkers such as microsatellite instability and genetic mutations (eg, KRAS, NRAS, BRAF, PIK3CA, ERCC1) in Chinese populations. Interethnic differences in anticancer drug response and toxicity have been well described in many cancers, and this review examined the literature with regard to the tolerance of Chinese patients to commonly used chemotherapeutic regimens and targeted therapies for metastatic colorectal cancer. Studies on the pharmacogenomic differences in drug metabolizing and DNA repair enzymes between Chinese, North Asians, and Caucasian patients were also reviewed.

Prognostic nomograms for predicting survival and distant metastases in locally advanced rectal cancers

Aim

To develop prognostic nomograms for predicting outcomes in patients with locally advanced rectal cancers who do not receive preoperative treatment.

Materials and Methods

A total of 883 patients with stage II–III rectal cancers were retrospectively collected from a single institution. Survival analyses were performed to assess each variable for overall survival (OS), local recurrence (LR) and distant metastases (DM). Cox models were performed to develop a predictive model for each endpoint. The performance of model prediction was validated by cross validation and on an independent group of patients.

Results

The 5-year LR, DM and OS rates were 22.3%, 32.7% and 63.8%, respectively. Two prognostic nomograms were successfully developed to predict 5-year OS and DM-free survival rates, with c-index of 0.70 (95% CI = [0.66, 0.73]) and 0.68 (95% CI = [0.64, 0.72]) on the original dataset, and 0.76 (95% CI = [0.67, 0.86]) and 0.73 (95% CI = [0.63, 0.83]) on the validation dataset, respectively. Factors in our models included age, gender, carcinoembryonic antigen value, tumor location, T stage, N stage, metastatic lymph nodes ratio, adjuvant chemotherapy and chemoradiotherapy. Predicted by our nomogram, substantial variability in terms of 5-year OS and DM-free survival was observed within each TNM stage category.

Conclusions

The prognostic nomograms integrated demographic and clinicopathological factors to account for tumor and patient heterogeneity, and thereby provided a more individualized outcome prognostication. Our individualized prediction nomograms could help patients with preoperatively under-staged rectal cancer about their postoperative treatment strategies and follow-up protocols.

Next-generation sequencing of colorectal cancers in chinese: identification of a recurrent frame-shift and gain-of-function Indel mutation in the TFDP1 gene

Abstract Re-sequencing of target genes is a highly effective approach for identifying mutations in cancers. Mutations, including indels (insertions, deletions, and the combination of the two), play important roles in carcinogenesis. Combining genomic DNA capture using high-density oligonucleotide microarrays (NimbleGen, Inc.) with next-generation high-throughput sequencing, we identified approximately 1600 indels for colorectal cancers in the Chinese population. Among them, 5 indels were localized to exonic regions of genes, including the TFDP1 (transcription factor Dp-1) gene. TFDP1 is an important transcription factor that coordinates with E2F proteins, thereby promoting transcription of E2F target genes and regulating the cell cycle and differentiation. We report here the identification of a recurrent frame-shift indel mutation (named indel84) in the TFDP1 gene in colorectal cancers by next-generation sequencing. We found in a validation set that TFDP1 indel84 is present in 70% of colorectal cancer (CRC) tissues. Wild-type TFDP1 encodes a protein of 410 amino acids with a potential DNA binding site at its N-terminal followed by several functional protein domains. The TFDP1 indel cDNA would generate an alternative TFDP1 protein missing the first 120 amino acids and potentially affecting the DNA binding domain. We further demonstrated that the TFDP1 indel84 mutation generated a gain-of-function phenotype by increasing cell proliferation, migration, and invasion of CRC cells. Our study identified a key molecular event for CRC that might have great diagnostic and therapeutic potentials.

Endoscopic resection as the first-line treatment for early colorectal cancer: comparison with surgery

INTRODUCTION

Endoscopic resection has emerged as an alternative therapeutic option for selected cases of early colorectal cancer. However, even now, few data are available on the comparative effectiveness of endoscopic versus surgical resection of early colorectal cancer. The aim of our study was to compare the clinical outcomes in patients with early colorectal cancer who underwent endoscopic resection and those who underwent surgical resection.

METHODS

292 early colorectal cancer lesions in 287 patients who were treated with either endoscopic resection or colorectal surgery (open or laparoscopic colorectal resection) between January 2005 and December 2010 were retrospectively analyzed. After excluding 54 deep submucosal lesions [and/or tumor budding (Grade 2 or 3)], a total of 168 lesions with mucosal/superficial submucosal invasion were treated by endoscopic resection, and 70 lesions with mucosal/superficial submucosal invasion were treated by colorectal surgery.

RESULTS

In the endoscopic resection group, the en bloc resection rate and the complete resection rate were 91.1 and 91.1%, respectively. In the colorectal surgery group, both the en bloc resection rate and the curative resection rate were 100%. However, using Log rank test in Kaplan-Meier curve, no significant difference in recurrence rate (including metachronous cancer) during the median follow-up period of 37 months (range, 6-98 months) was observed between the two groups (p = 0.647). In addition, a similar morbidity rate was observed for endoscopic resection compared with surgery (5.4 vs. 5.7%, p = 0.760). A significantly shorter hospital stay was observed in the endoscopic resection group than colorectal surgery group [median 2 days (range, 2-29) vs. median 10 days (range, 7-37), p < 0.001).

CONCLUSION

We suggest that endoscopic resection, being equally effective but less invasive than surgery, can be the first-line treatment for well selected early colorectal cancer.

Prevalence of synchronous colorectal neoplasms in surgically treated gastric cancer patients and significance of screening colonoscopy

BACKGROUND AND AIM

The existence of other primary tumors during the treatment and management of gastric cancer (GC) is an important issue. The present study investigated the prevalence and management of synchronous colorectal neoplasms (CRN) in surgically treated GC patients.

METHODS

Of 381 surgically treated GC patients, 332 (87.1%) underwent colonoscopy to detect CRN before surgery or within a year after surgery.

RESULTS

CRN were synchronously observed in 140 patients (42.2%). Adenoma was observed in 131 patients (39.4%). Endoscopic resection was done in 18 patients with adenoma. Colorectal cancer (CRC) was observed in 16 patients (4.8%), superficial CRC in 13 and advanced CRC in three patients. Endoscopic resection of superficial CRC was carried out in seven patients, whereas simultaneous surgical resection of CRC was done in nine patients. CRN were more frequently observed in men. CRC was more frequently observed in GC patients with distant metastasis, albeit without significance. The overall survival of GC patients with CRN or CRC was poorer than that of patients without CRN or CRC.

CONCLUSION

Synchronous CRN were commonly associated with GC and screening colonoscopy should be offered to patients with GC.

Laparoscopic surgery decreases the surgical risks associated with hyperlipidemia in rectal cancer: a retrospective analysis of 495 patients

BACKGROUND

Epidemiologic studies provide evidence for a link between disorders of lipid metabolism and the risk for colorectal cancer, hyperlipidemia is a common feature of rectal cancer patients. However, information about the effects of hyperlipidemia on rectal cancer surgery is scarce.

OBJECTIVE

The aim of this study was to investigate whether hyperlipidemia affected short-term outcomes of rectal cancer surgery, and determine the preferable surgery method based on the comparison of laparoscopic surgery and open surgery.

METHODS

Clinical data of 495 rectal cancer patients who received traditional open or laparoscopic radical resection between March 2006 and December 2010 were retrospectively reviewed.

RESULTS

Compared with normal blood lipid group (n=232), hyperlipidemia group (n=263) showed increased intraoperative bleeding (P<0.001), prolonged time for resuming food intake (P<0.001), peritoneal drainage (P<0.001), and hospital stay (P=0.019). However, there was no difference in operation time. Compared with those receiving open surgery, patients receiving laparoscopic surgery exhibited less intraoperative bleeding (P<0.001), less time for resuming food intake (P<0.001), peritoneal drainage (P<0.001), and hospital stay (P<0.001), whereas more operation time was needed (P<0.001). Among patients receiving laparoscopic surgery, no differences were shown on hospital stay, time for resuming food intake, and peritoneal drainage between hyperlipidemia group and normal blood lipid group, although more intraoperative bleeding was still presented in the hyperlipidemia group (P<0.001).

CONCLUSION

Hyperlipidemia has adverse effects on rectal cancer surgery. Laparoscopic surgery can eliminate postoperative recovery retardation caused by hyperlipidemia.

Palliative treatment of malignant colorectal obstruction caused by advanced malignancy: a self-expanding metallic stent or surgery? A system review and meta-analysis

We conducted a meta-analysis to compare the outcomes of a self-expanding metallic stent (SEMS) vs. surgery for the palliative treatment of colorectal obstruction caused by advanced colorectal malignancy. The databases of MEDLINE, EMBASE, Cochrane controlled trials registry and the Chinese Wanfang were retrieved (updated to 31 August 2011) to identify eligible studies. We calculated the odds ratio or weighted mean difference and its corresponding 95 % confidence interval. In total, nine primary studies were included in this analysis. The success rate of SEMS placement was 93.9 %, with short-term and long-term complication rates of 26.2 and 16.1 %, respectively. Combined analyses revealed that the SEMS group had a similar risk of short-term complications as the surgical group (P = 0.22). Moreover, SEMS was not associated with a higher mortality risk than surgical intervention (P = 0.22) and it required a significantly shorter hospitalization time (P < 0.01); however, SEMS patients had a higher risk of long-term complications (P = 0.03). Because of great heterogeneities between patients and chemoradiotherapy, we did not analyze the survival times of the two groups. These results support the feasibility of SEMS as a palliative treatment for malignant colorectal obstruction caused by incurable malignancy, as it requires shorter hospitalization and is followed by quick recovery. However, the risk of long-term complications such as perforation and stent migration should be borne in mind.

Associations between lifestyles and neutrophil-lymphocyte and platelet-lymphocyte ratios in colorectal cancer

AIMS

To explore the etiology of the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) abnormalities in colorectal cancer.

METHODS

In total, 230 patients with histopathologically confirmed colorectal cancer from August 2009 to August 2011 were recruited to our study. The associations between lifestyles (smoking, alcohol and pickled food consumption) and pretreatment NLR and PLR were estimated using the Kruskal-Wallis tests and linear regression model.

RESULTS

The Kruskal-Wallis test showed a significant association between pickled food intake and pretreatment NLR but not PLR (P = 0.002, 0.057, respectively). Pairwise comparisons showed that, compared with those with a moderately frequent (2-3 times/week) and an infrequent (≤ once a week) intake of pickled food, high frequency (≥ four times/week) consumption of pickled food had a higher pretreatment NLR (P = 0.01, 0.007, respectively). Multivariate linear regression analysis showed pretreatment NLR increased significantly in high frequency (≥ four times/week) consumption of pickled food (P < 0.0001). No association between other lifestyle factors and pretreatment PLR was found.

CONCLUSIONS

A higher frequency intake of pickled food possibly contributes to higher NLR, which may reflect a systemic inflammatory response in colorectal cancer.

Cost-comparison of laparoscopic and open surgery for mid or low rectal cancer after preoperative chemoradiotherapy: data from a randomized controlled trial

BACKGROUND

The purpose of the present study was to compare the direct costs of laparoscopic surgery (LS) and open surgery (OS) in the treatment of mid or low rectal cancer after preoperative chemoradiotherapy in patients in Korea.

METHODS AND RESULTS

The records of 130 LS patients and 125 OS patients were reviewed. Hospital stay after surgery and overall complication rates within three months of surgery were not significantly different. The LS group had significantly higher median costs than the OS group ($7,467.30 vs. $5,667.00; P < 0.001). The median hospital costs during hospitalization for surgery were higher in the LS group ($7,436.60 vs. $5,626.60; P < 0.001), but hospital costs for management of early postoperative complications were similar. The higher direct costs of LS were mainly due to the more expensive consumables and equipment needed for LS.

CONCLUSIONS

Further study is needed to determine whether the higher direct costs of LS for rectal cancer are balanced by advantages of LS over OS, such as better short-term outcomes and cosmetic effect.

Quality of life in Malaysian colorectal cancer patients

INTRODUCTION

The rapidly increasing of incidence colorectal cancer (CRC) in Malaysia and the introduction of new treatments that prolong survival advocating treatment outcome measures such as patients' quality of life (QOL) are evaluated in this study. The study aims to determine QOL in CRC patients according to cancer stage and age.

METHODS

A cross-sectional study was performed from June to December 2011 at four public tertiary hospitals. The European Organization for Research and Treatment in Cancer (EORTC) Quality of Life Questionnaire Core-30 (EORTC QLQ C-30) questionnaire was used through face-to-face interview and the medical records of 160 respondents were reviewed.

RESULTS

The mean age of respondents was 58.47 ± 12.04 years with 57.5% of respondents being male and 42.5% female. The majority of respondents were in CRC stages III and IV. Median global health status (GHS) score was 83.33 (IQR 16.67). Sikhs and Indians had a higher median GHS score compared to other ethnicities (Kruskal-Wallis, χ(2)  = 12.12, p = 0.007). Emotional, cognitive and social functions were higher in respondents with earlier stage of disease (Kruskal-Wallis, χ2 = 6.06, 6.36, 10.58, p = 0.048, 0.042, 0.005). Median pain, dyspnea, diarrhea and financial implication scores were significantly higher in advanced stage of disease (Kruskal-Wallis, χ(2)  = 9.31, 6.26,6.77, 7.28, p = 0.010, 0.044,0.034,0.026). Median diarrhea score (p = 0.012) was significantly different between age groups.

DISCUSSION

Emotional, cognitive and social functions deteriorate with advanced stage of disease. Patients with advanced stage disease experience more pain, dyspnea, diarrhea and financial implications. A systematic screening program to detect cases as early as possible is essential nationwide.

Direct medical costs of care for Chinese patients with colorectal neoplasia: a health care service provider perspective

OBJECTIVES

To estimate the direct medical cost of colorectal neoplasia (CRN) from newly diagnosed to the completion of the tumour-specific treatment in the initial year of disease across stages and tumour primary sites.

METHODS

Only direct medical costs from the perspective of the health care service provider were incorporated in the cost analysis (in 2009 USD) using a bottom-up approach. Tumour-specific treatments of surgery, chemotherapy and radiotherapy data in the initial year of disease were identified from the 401 CRN adult patients by a review of their medical records. Service utilization for diagnosis, staging, pre-operative assessment and post-operative follow-up consultations was estimated from the recommendations of established surveillance and clinical practice guidelines.

RESULTS

Direct medical cost for the care of a newly diagnosed CRN was ranging from $1941 for low-risk polyp to $45 115 for stage IV colorectal cancer in the initial year of care. Costs of care showed a gradient increase from $1748 for low-risk colonic polyps to $42 899 for stage IV colon cancer, and from $2232 for low-risk rectal polyps to $48 453 for stage IV rectal cancers. Diagnostic/pre-operative assessment and treatment accounted for most of total costs of colorectal polyp (58.9-76.7%) and cancer (60.8-85.2%) care.

CONCLUSION

The results provided stage and site-specific estimations of the direct medical costs of CRN in a Chinese population that can assist policy decision making and facilitate health care service planning and cost-effectiveness evaluations.

Quality of life in Malaysian colorectal cancer patients: a preliminary result

OBJECTIVE

Rapidly increasing colorectal cancer (CRC) incidence in Malaysia and the introduction of cutting edge new treatments, which prolong survival, mean that treatment outcome measures meed to be evaluated, including consideration of patient's quality of life (QoL) assessment. There are limited data on QoL in CRC patients, especially in Malaysia. Therefore, this study was performed focusing on cancer stages and age groups.

METHODS

The cross sectional study was conducted from June to September 2011 at three public tertiary hospitals with the EORTC QLQ C-30 questionnaire in addition to face to face interview and review of medical records of 100 respondents.

RESULTS

The mean age was 57.3 (SD 11.9) years with 56.0% are males and 44.0% females, 62% of Malay ethnicity, 30% Chinese, 7% Indian and 1% Sikh. Majority were educated up to secondary level (42%) and 90% respondents had CRC stages III and IV. Mean global health status (GHS) score was 79.1 (SD 21.4). Mean scores for functional status (physical, emotional, role, cognitive, social) rangeds between 79.5 (SD 26.6) to 92.2 (SD 13.7). Mean symptom scores (fatigue, pain, nausea/vomiting, constipation, diarrhea, insomnia, dyspnoea, loss of appetite) ranged between 4.00 (SD 8.58) to 20.7 (SD 30.6). Respondents role function significantly deteriorates with increasing stage of the disease (p=0.044). Females had worse symptoms of pain (p=0.022), fatigue (p=0.031) and dyspnoea (p=0.031). Mean insomnia (p=0.006) and diarrhea (p=0.024) demonstrated significant differences between age groups.

CONCLUSION

QOL in CRC patients in this study was comparable to that in other studies done in developed countries. Pain, fatigue and dyspnoea are worse among female CRC patients. Given that functions deteriorates with advanced stage of the disease at diagnosis, a systematic screening programme to detect cases as early as possible is essential nationwide.

Colonic stenting vs emergent surgery for acute left-sided malignant colonic obstruction: A systematic review and meta-analysis

AIM: To investigate the effects of emergent preoperative self-expandable metallic stent (SEMS) vs emergent surgery for acute left-sided malignant colonic obstruction.

METHODS: Two investigators independently searched the MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials, as well as references of included studies to identify randomized controlled trials (RCTs) that compared two or more surgical approaches for acute colonic obstruction. Summary risk ratios (RR) and 95% CI for colonic stenting and emergent surgery were calculated.

RESULTS: Eight studies met the selection criteria, involving 444 patients, of whom 219 underwent SEMS and 225 underwent emergent surgery. Seven studies reported difference of the one-stage stoma rates between the two groups (RR, 0.60; 95% CI: 0.48-0.76; P < 0.0001). Only three RCTs described the follow-up stoma rates, which showed no significant difference between the two groups (RR, 0.80; 95% CI: 0.59-1.08; P = 0.14). Difference was not significant in the mortality between the two groups (RR, 0.91; 95% CI: 0.50-1.66; P = 0.77), but there was significant difference (RR, 0.57; 95% CI: 0.44-0.74; P < 0.0001) in the overall morbidity. There were no significant differences between the two groups in the anastomotic leak rate (RR, 0.60; 95% CI: 0.28-1.28; P = 0.19), occurrence of abscesses, including peristomal abscess, intraperitoneal abscess and parietal abscess (RR, 0.83; 95% CI: 0.36-1.95; P = 0.68), and other abdominal complications (RR: 0.67; 95% CI: 0.40-1.12; P = 0.13).

CONCLUSION: SEMS is not obviously more advantageous than emergent surgery for patients with acute left-sided malignant colonic obstruction.

Diabetes, metformin use, and colon cancer: a population-based cohort study in Taiwan

OBJECTIVE

A retrospective cohort study, using a population-based reimbursement database, was conducted for investigating the relationship between diabetes and colon cancer and assessing whether metformin had a protective effect.

METHODS

Overall, 493,704 men and 502,139 women, covered by the National Health Insurance, without colon cancer were followed from 2003 to 2005. Cox regression evaluated the adjusted relative risk (RR), considering confounders and detection examinations.

RESULTS

Even though diabetes patients had a significantly higher probability of receiving examinations that could lead to the detection of colon cancer, they had a significantly higher risk (24%) of this cancer after adjustment. Metformin users had a significantly lower risk (27%) of colon cancer. While comparing patients with diabetes for <1, 1-3, and ≥ 3 years to nondiabetes individuals, the adjusted RR (95% confidence interval) was 1.308 (1.020-1.679), 1.087 (0.900-1.313), and 1.185 (1.055-1.330) respectively. The higher risk among those with diabetes for <1 year suggested a possible reverse causality or a link with prediabetes. However, diabetes still might play some role in the development of colon cancer in those with diabetes for ≥ 3 years. The duration of metformin use showed an inverse trend, with a significant RR of 0.643 (0.490-0.845) in users for ≥ 3 years, when compared with nonusers. In addition, metformin may reduce colon cancer risk associated with chronic obstructive pulmonary disease (a surrogate for smoking).

CONCLUSIONS

Following adjustment for potential detection bias and other covariates, diabetes remains a significant risk factor for colon cancer. Metformin may protect against colon cancer.

No association between the USP7 gene polymorphisms and colorectal cancer in the Chinese Han population

Colorectal cancer (CRC), now the third most common cancer across the world, is known to aggregate in families. USP7 is a very important protein with an important role in regulating the p53 pathway, which is critical for genomic stability and tumor suppression. We here genotyped eight SNPs within the USP7 gene and conducted a case-control study in 312 CRC patients and 270 healthy subjects in the Chinese Han population. No significant associations were found for any single SNP and CRC risk. Our data eliminate USP7 as a potential candidate gene towards for CRC in the Han Chinese population.

Polyp surveillance after surgery for colorectal cancer

PURPOSE

Although it is known that those patients who have developed colorectal cancer (CRC) are at a higher risk to develop metachronous adenoma or CRC, no study has been performed to analyze the relationship between the risk factors and the time course for the formation of postoperative adenoma using survival analysis.

METHODS

One hundred seventy-six patients with CRC,who had received surgical resection, were endoscopically followed-up to detect the development of metachronous adenoma or adenocarcinoama. The association between the risk factors such as age, synchronous adenomas with index CRC or other clinicopathological variables and the formation of postoperative adenoma was assessed using the logrank test and the Cox proportional hazard model.

RESULTS

Age over 60, synchronous lesions at the time of surgery for primary CRCs and presence of diabetes mellitus(DM) as the associated disease were positively related to the formation of postoperative adenoma. Among those patients with the three risk factors, only 27.8% remained adenoma-free during 5 years after operation, whereas in the group without any risk factor, it was 90.4%.

CONCLUSIONS

From our data, age over 60, synchronous adenomas or CRCs and DM were the potential risk factors for the postoperative formation of adenoma or CRC, and they should be taken into consideration when defining the appropriate interval of postoperative colonoscopy.