Cancer prevention with aspirin in hereditary colorectal cancer (Lynch syndrome), 10-year follow-up and registry-based 20-year data in the CAPP2 study: a double-blind, randomised, placebo-controlled trial

BACKGROUND

Lynch syndrome is associated with an increased risk of colorectal cancer and with a broader spectrum of cancers, especially endometrial cancer. In 2011, our group reported long-term cancer outcomes (mean follow-up 55·7 months [SD 31·4]) for participants with Lynch syndrome enrolled into a randomised trial of daily aspirin versus placebo. This report completes the planned 10-year follow-up to allow a longer-term assessment of the effect of taking regular aspirin in this high-risk population.

METHODS

In the double-blind, randomised CAPP2 trial, 861 patients from 43 international centres worldwide (707 [82%] from Europe, 112 [13%] from Australasia, 38 [4%] from Africa, and four [<1%] from The Americas) with Lynch syndrome were randomly assigned to receive 600 mg aspirin daily or placebo. Cancer outcomes were monitored for at least 10 years from recruitment with English, Finnish, and Welsh participants being monitored for up to 20 years. The primary endpoint was development of colorectal cancer. Analysis was by intention to treat and per protocol. The trial is registered with the ISRCTN registry, number ISRCTN59521990.

FINDINGS

Between January, 1999, and March, 2005, 937 eligible patients with Lynch syndrome, mean age 45 years, commenced treatment, of whom 861 agreed to be randomly assigned to the aspirin group or placebo; 427 (50%) participants received aspirin and 434 (50%) placebo. Participants were followed for a mean of 10 years approximating 8500 person-years. 40 (9%) of 427 participants who received aspirin developed colorectal cancer compared with 58 (13%) of 434 who received placebo. Intention-to-treat Cox proportional hazards analysis revealed a significantly reduced hazard ratio (HR) of 0·65 (95% CI 0·43-0·97; p=0·035) for aspirin versus placebo. Negative binomial regression to account for multiple primary events gave an incidence rate ratio of 0·58 (0·39-0·87; p=0·0085). Per-protocol analyses restricted to 509 who achieved 2 years' intervention gave an HR of 0·56 (0·34-0·91; p=0·019) and an incidence rate ratio of 0·50 (0·31-0·82; p=0·0057). Non-colorectal Lynch syndrome cancers were reported in 36 participants who received aspirin and 36 participants who received placebo. Intention-to-treat and per-protocol analyses showed no effect. For all Lynch syndrome cancers combined, the intention-to-treat analysis did not reach significance but per-protocol analysis showed significantly reduced overall risk for the aspirin group (HR=0·63, 0·43-0·92; p=0·018). Adverse events during the intervention phase between aspirin and placebo groups were similar, and no significant difference in compliance between intervention groups was observed for participants with complete intervention phase data; details reported previously.

INTERPRETATION

The case for prevention of colorectal cancer with aspirin in Lynch syndrome is supported by our results.

FUNDING

Cancer Research UK, European Union, MRC, NIHR, Bayer Pharma AG, Barbour Foundation.

Obesity, Aspirin, and Risk of Colorectal Cancer in Carriers of Hereditary Colorectal Cancer: A Prospective Investigation in the CAPP2 Study

PURPOSE

In the general population, increased adiposity is a significant risk factor for colorectal cancer (CRC), but whether obesity has similar effects in those with hereditary CRC is uncertain. This prospective study investigated the association between body mass index and cancer risk in patients with Lynch syndrome (LS).

PATIENTS AND METHODS

Participants with LS were recruited to the CAPP2 study, in which they were randomly assigned to receive aspirin 600 mg per day or aspirin placebo, plus resistant starch 30 g per day or starch placebo (2 × 2 factorial design). Mean intervention period was 25.0 months, and mean follow-up was 55.7 months.

RESULTS

During follow-up, 55 of 937 participants developed CRC. For obese participants, CRC risk was 2.41× (95% CI, 1.22 to 4.85) greater than for underweight and normal-weight participants (reference group), and CRC risk increased by 7% for each 1-kg/m(2) increase in body mass index. The risk of all LS-related cancers in obese people was 1.77× (95% CI, 1.06 to 2.96; P = .03) greater than for the reference group. In subgroup analysis, obesity was associated with 3.72× (95% CI, 1.41 to 9.81) greater CRC risk in patients with LS with MLH1 mutation, but no excess risk was observed in those with MSH2 or MSH6 mutation (P = .5). The obesity-related excess CRC risk was confined to those randomly assigned to the aspirin placebo group (adjusted hazard ratio, 2.75; 95% CI, 1.12 to 6.79; P = .03).

CONCLUSION

Obesity is associated with substantially increased CRC risk in patients with LS, but this risk is abrogated in those taking aspirin. Such patients are likely to benefit from obesity prevention and/or regular aspirin.

Malnutrition risk predicts surgical outcomes in patients undergoing gastrointestinal operations: Results of a prospective study

BACKGROUND & AIMS

Patients undergoing gastrointestinal operations are at risk of malnutrition which may increase the chance of adverse surgical outcomes. This prospective study aimed at correlating nutritional status of patients having gastrointestinal operations with their short-term surgical outcomes captured by a territory-wide Surgical Outcomes Monitoring and Improvement Program.

METHODS

The preoperative malnutrition risk of Chinese adult patients undergoing elective/emergency ultra-major/major gastrointestinal operations in two surgical departments over a 12-month period were assessed by Chinese version of Malnutrition Universal Screening Tool. Their perioperative risk factors and clinical outcomes, including length of hospital stay, mortality and morbidity, were retrieved from the above mentioned program. Correlation of malnutrition risk with clinical outcomes was assessed by logistic regression analysis after controlling for known confounders.

RESULTS

943 patients (58% male; mean age 65.9 ± 14.8 years) underwent gastrointestinal operations (40.3% emergency operation; 52.7% ultra-major procedures; 66.9% bowel resections) had analyzable data. 15.8% and 17.1% of patients were at medium and high risk of malnutrition, respectively. Malnutrition risk score according to the screening tool was an independent predictor of length of hospital stay, 30-day mortality, 60-day mortality and minor medical complications. Similar correlations were found for various sub-scores of malnutrition risk. Weight loss sub-score was predictive of 30-day mortality, 60-day mortality and minor medical complications. Body mass index was predictive of mortality (30- and 60- day) whereas the acute disease sub-score was predictive of length of hospital stay.

CONCLUSIONS

Preoperative malnutrition was an important predictor of poor clinical outcomes in patients undergoing gastrointestinal operations in Hong Kong.

Study protocol for "Moving Bright, Eating Smart"- A phase 2 clinical trial on the acceptability and feasibility of a diet and physical activity intervention to prevent recurrence in colorectal cancer survivors

Background

Colorectal cancer is the second most common cancer and cancer-killer in Hong Kong with an alarming increasing incidence in recent years. The latest World Cancer Research Fund report concluded that foods low in fibre, and high in red and processed meat cause colorectal cancer whereas physical activity protects against colon cancer. Yet, the influence of these lifestyle factors on cancer outcome is largely unknown even though cancer survivors are eager for lifestyle modifications. Observational studies suggested that low intake of a Western-pattern diet and high physical activity level reduced colorectal cancer mortality. The Theory of Planned Behaviour and the Health Action Process Approach have guided the design of intervention models targeting a wide range of health-related behaviours.

Methods/design

We aim to demonstrate the feasibility of two behavioural interventions intended to improve colorectal cancer outcome and which are designed to increase physical activity level and reduce consumption of a Western-pattern diet. This three year study will be a multicentre, randomised controlled trial in a 2x2 factorial design comparing the “Moving Bright, Eating Smart” (physical activity and diet) programme against usual care. Subjects will be recruited over a 12-month period, undertake intervention for 12 months and followed up for a further 12 months. Baseline, interim and three post-intervention assessments will be conducted.

Two hundred and twenty-two colorectal cancer patients who completed curative treatment without evidence of recurrence will be recruited into the study. Primary outcome measure will be whether physical activity and dietary targets are met at the end of the 12-month intervention. Secondary outcome measures include the magnitude and mechanism of behavioural change, the degree and determinants of compliance, and the additional health benefits and side effects of the intervention.

Discussion

The results of this study will establish the feasibility of targeting the two behaviours (diet and physical activity) and demonstrate the magnitude of behaviour change. The information will facilitate the design of a further larger phase III randomised controlled trial with colorectal cancer outcome as the study endpoint to determine whether this intervention model would reduce colorectal cancer recurrence and mortality.

Trial registration

ClinicalTrials.gov No: NCT01708824

Long-term effect of resistant starch on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial

BACKGROUND

Observational studies report that higher intake of dietary fibre (a heterogeneous mix including non-starch polysaccharides and resistant starches) is associated with reduced risk of colorectal cancer, but no randomised trials with prevention of colorectal cancer as a primary endpoint have been done. We assessed the effect of resistant starch on the incidence of colorectal cancer.

METHODS

In the CAPP2 study, individuals with Lynch syndrome were randomly assigned in a two-by-two factorial design to receive 600 mg aspirin or aspirin placebo or 30 g resistant starch or starch placebo, for up to 4 years. Randomisation was done with a block size of 16. Post-intervention, patients entered into double-blind follow-up; participants and investigators were masked to treatment allocation. The primary endpoint for this analysis was development of colorectal cancer in participants randomly assigned to resistant starch or resistant-starch placebo with both intention-to-treat and per-protocol analyses. This study is registered, ISRCTN 59521990.

FINDINGS

463 patients were randomly assigned to receive resistant starch and 455 to receive resistant-starch placebo. At a median follow-up 52·7 months (IQR 28·9-78·4), 53 participants developed 61 primary colorectal cancers (27 of 463 participants randomly assigned to resistant starch, 26 of 455 participants assigned to resistant-starch placebo). Intention-to-treat analysis of time to first colorectal cancer showed a hazard ratio (HR) of 1·40 (95% CI 0·78-2·56; p=0·26) and Poisson regression accounting for multiple primary events gave an incidence rate ratio (IRR) of 1·15 (95% CI 0·66-2·00; p=0·61). For those completing 2 years of intervention, per-protocol analysis yielded a HR of 1·09 (0·55-2·19, p=0·80) and an IRR of 0·98 (0·51-1·88, p=0·95). No information on adverse events was gathered during post-intervention follow-up.

INTERPRETATION

Resistant starch had no detectable effect on cancer development in carriers of hereditary colorectal cancer. Dietary supplementation with resistant starch does not emulate the apparently protective effect of diets rich in dietary fibre against colorectal cancer.

FUNDING

European Union, Cancer Research UK, Bayer Corporation, National Starch and Chemical Co, UK Medical Research Council, Newcastle Hospitals Trustees, Cancer Council of Victoria Australia, THRIPP South Africa, The Finnish Cancer Foundation, SIAK Switzerland, and Bayer Pharma.

Physical activity for cancer survivors: meta-analysis of randomised controlled trials

OBJECTIVE

To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer.

DESIGN

Meta-analysis of randomised controlled trials with data extraction and quality assessment performed independently by two researchers.

DATA SOURCES

Pubmed, CINAHL, and Google Scholar from the earliest possible year to September 2011. References from meta-analyses and reviews.

STUDY SELECTION

Randomised controlled trials that assessed the effects of physical activity in adults who had completed their main cancer treatment, except hormonal treatment.

RESULTS

There were 34 randomised controlled trials, of which 22 (65%) focused on patients with breast cancer, and 48 outcomes in our meta-analysis. Twenty two studies assessed aerobic exercise, and four also included resistance or strength training. The median duration of physical activity was 13 weeks (range 3-60 weeks). Most control groups were considered sedentary or were assigned no exercise. Based on studies on patients with breast cancer, physical activity was associated with improvements in insulin-like growth factor-I, bench press, leg press, fatigue, depression, and quality of life. When we combined studies on different types of cancer, we found significant improvements in body mass index (BMI), body weight, peak oxygen consumption, peak power output, distance walked in six minutes, right handgrip strength, and quality of life. Sources of study heterogeneity included age, study quality, study size, and type and duration of physical activity. Publication bias did not alter our conclusions.

CONCLUSIONS

Physical activity has positive effects on physiology, body composition, physical functions, psychological outcomes, and quality of life in patients after treatment for breast cancer. When patients with cancer other than breast cancer were also included, physical activity was associated with reduced BMI and body weight, increased peak oxygen consumption and peak power output, and improved quality of life.

Long-term effect of aspirin on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial

BACKGROUND

Observational studies report reduced colorectal cancer in regular aspirin consumers. Randomised controlled trials have shown reduced risk of adenomas but none have employed prevention of colorectal cancer as a primary endpoint. The CAPP2 trial aimed to investigate the antineoplastic effects of aspirin and a resistant starch in carriers of Lynch syndrome, the major form of hereditary colorectal cancer; we now report long-term follow-up of participants randomly assigned to aspirin or placebo.

METHODS

In the CAPP2 randomised trial, carriers of Lynch syndrome were randomly assigned in a two-by-two factorial design to 600 mg aspirin or aspirin placebo or 30 g resistant starch or starch placebo, for up to 4 years. Randomisation was in blocks of 16 with provision for optional single-agent randomisation and extended postintervention double-blind follow-up; participants and investigators were masked to treatment allocation. The primary endpoint was development of colorectal cancer. Analysis was by intention to treat and per protocol. This trial is registered, ISRCTN59521990.

RESULTS

861 participants were randomly assigned to aspirin or aspirin placebo. At a mean follow-up of 55·7 months, 48 participants had developed 53 primary colorectal cancers (18 of 427 randomly assigned to aspirin, 30 of 434 to aspirin placebo). Intention-to-treat analysis of time to first colorectal cancer showed a hazard ratio (HR) of 0·63 (95% CI 0·35-1·13, p=0·12). Poisson regression taking account of multiple primary events gave an incidence rate ratio (IRR) of 0·56 (95% CI 0·32-0·99, p=0·05). For participants completing 2 years of intervention (258 aspirin, 250 aspirin placebo), per-protocol analysis yielded an HR of 0·41 (0·19-0·86, p=0·02) and an IRR of 0·37 (0·18-0·78, p=0·008). No data for adverse events were available postintervention; during the intervention, adverse events did not differ between aspirin and placebo groups.

INTERPRETATION

600 mg aspirin per day for a mean of 25 months substantially reduced cancer incidence after 55·7 months in carriers of hereditary colorectal cancer. Further studies are needed to establish the optimum dose and duration of aspirin treatment.

FUNDING

European Union; Cancer Research UK; Bayer Corporation; National Starch and Chemical Co; UK Medical Research Council; Newcastle Hospitals trustees; Cancer Council of Victoria Australia; THRIPP South Africa; The Finnish Cancer Foundation; SIAK Switzerland; Bayer Pharma.

Effects of adrenaline in human colon adenocarcinoma HT-29 cells

AIMS

Stress has been implicated in the development of cancers. Adrenaline levels are increased in response to stress. The effects of adrenaline on colon cancer are largely unknown. The aims of the study are to determine the effects of adrenaline in human colon adenocarcinoma HT-29 cells and the possible underlying mechanisms involved.

MAIN METHODS

The effect of adrenaline on HT-29 cell proliferation was determined by [(3)H] thymidine incorporation assay. Expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) were detected by Western blot. Matrix metalloproteinase-9 (MMP-9) activity and prostaglandin E(2) (PGE(2)) release were determined by zymography and enzyme immunoassay, respectively.

KEY FINDINGS

Adrenaline stimulated HT-29 cell proliferation. This was accompanied by the enhanced expression of COX-2 and VEGF in HT-29 cells. Adrenaline also upregulated MMP-9 activity and PGE(2) release. Adrenaline stimulated HT-29 cell proliferation which was reversed by COX-2 inhibitor sc-236. COX-2 inhibitor also reverted the action of adrenaline on VEGF expression and MMP-9 activity. Further study was performed to determine the involvement of β-adrenoceptors. The stimulatory action of adrenaline on colon cancer growth was blocked by atenolol and ICI 118,551, a β(1)- and β(2)-selective antagonist, respectively. This signified the role of β-adrenoceptors in this process. In addition, both antagonists also abrogated the stimulating actions of adrenaline on COX-2, VEGF expression, MMP-9 activity and PGE(2) release in HT-29 cells.

SIGNIFICANCE

These results suggest that adrenaline stimulates cell proliferation of HT-29 cells via both β(1)- and β(2)-adrenoceptors by a COX-2 dependent pathway.

A comprehensive training programme for nurse endoscopist performing flexible sigmoidoscopy in Hong Kong

AIMS

To describe the process and explore the feasibility of training a colorectal nurse in Hong Kong to perform flexible sigmoidoscopy.

BACKGROUND

Given the shortage and high turnover rate of medical staff, a pilot programme was designed to train and expand the role of colorectal nurse clinicians. It was hoped that such nurses could share some of the clinical duties of the medical staff. An advanced practice nurse was selected for the programme. One of the training components was the performance of flexible sigmoidoscopy.

DESIGN

This was a descriptive, case review study.

METHOD

A one-year-structured endoscopic training programme was designed for the nurse clinician. Weekly sessions were conducted by one of the trainers. The training process included the following: (1) procedural observation; (2) supervised withdrawal, advancement and manipulation of the sigmoidoscope and (3) a final assessment of the nurse's competency in performing sigmoidoscopy independently.

RESULTS

In total, 119 outpatients (58 male and 61 female) with a mean age of 57·02 years (SD 14·6 years; range: 18-83 years) underwent flexible sigmoidoscopy by the nurse over 11 months. The mean procedural time was 9·38 minutes (SD 3·5 minutes; range 3-26 minutes). The procedure was terminated prematurely if it could not be tolerated by the patient or if the bowel preparation was inadequate. The mean depth of insertion was 53·5 cm (SD 12·2 cm; range 6-60 cm). In total, 82 patients had a normal exam, 32 patients had abnormalities. There were no procedural complications, and no patient required an unplanned hospital admission after the procedure.

CONCLUSION

In Queen Mary Hospital, nurses can be trained to perform flexible sigmoidoscopy in a safe and effective manner.

RELEVANCE TO CLINICAL PRACTICE

Nurse endoscopists could increase the use of flexible sigmoidoscopy in colorectal cancer screening and can also enhance the professional development of colorectal nurses.

A comprehensive training programme for nurse endoscopist performing flexible sigmoidoscopy in Hong Kong

AIMS

To describe the process and explore the feasibility of training a colorectal nurse in Hong Kong to perform flexible sigmoidoscopy.

BACKGROUND

Given the shortage and high turnover rate of medical staff, a pilot programme was designed to train and expand the role of colorectal nurse clinicians. It was hoped that such nurses could share some of the clinical duties of the medical staff. An advanced practice nurse was selected for the programme. One of the training components was the performance of flexible sigmoidoscopy.

DESIGN

This was a descriptive, case review study.

METHOD

A one-year-structured endoscopic training programme was designed for the nurse clinician. Weekly sessions were conducted by one of the trainers. The training process included the following: (1) procedural observation; (2) supervised withdrawal, advancement and manipulation of the sigmoidoscope and (3) a final assessment of the nurse's competency in performing sigmoidoscopy independently.

RESULTS

In total, 119 outpatients (58 male and 61 female) with a mean age of 57·02 years (SD 14·6 years; range: 18-83 years) underwent flexible sigmoidoscopy by the nurse over 11 months. The mean procedural time was 9·38 minutes (SD 3·5 minutes; range 3-26 minutes). The procedure was terminated prematurely if it could not be tolerated by the patient or if the bowel preparation was inadequate. The mean depth of insertion was 53·5 cm (SD 12·2 cm; range 6-60 cm). In total, 82 patients had a normal exam, 32 patients had abnormalities. There were no procedural complications, and no patient required an unplanned hospital admission after the procedure.

CONCLUSION

In Queen Mary Hospital, nurses can be trained to perform flexible sigmoidoscopy in a safe and effective manner.

RELEVANCE TO CLINICAL PRACTICE

Nurse endoscopists could increase the use of flexible sigmoidoscopy in colorectal cancer screening and can also enhance the professional development of colorectal nurses.

Hopefulness predicts resilience after hereditary colorectal cancer genetic testing: a prospective outcome trajectories study

Background -

Genetic testing for hereditary colorectal cancer (HCRC) had significant psychological consequences for test recipients. This prospective longitudinal study investigated the factors that predict psychological resilience in adults undergoing genetic testing for HCRC.

Methods -

A longitudinal study was carried out from April 2003 to August 2006 on Hong Kong Chinese HCRC family members who were recruited and offered genetic testing by the Hereditary Gastrointestinal Cancer Registry to determine psychological outcomes after genetic testing. Self-completed questionnaires were administered immediately before (pre-disclosure baseline) and 2 weeks, 4 months and 1 year after result disclosure. Using validated psychological inventories, the cognitive style of hope was measured at baseline, and the psychological distress of depression and anxiety was measured at all time points.

Results -

Of the 76 participating subjects, 71 individuals (43 men and 28 women; mean age 38.9 ± 9.2 years) from nine FAP and 24 HNPCC families completed the study, including 39 mutated gene carriers. Four patterns of outcome trajectories were created using established norms for the specified outcome measures of depression and anxiety. These included chronic dysfunction (13% and 8.7%), recovery (0% and 4.3%), delayed dysfunction (13% and 15.9%) and resilience (76.8% and 66.7%). Two logistic regression analyses were conducted using hope at baseline to predict resilience, with depression and anxiety employed as outcome indicators. Because of the small number of participants, the chronic dysfunction and delayed dysfunction groups were combined into a non-resilient group for comparison with the resilient group in all subsequent analysis. Because of low frequencies, participants exhibiting a recovery trajectory (n = 3 for anxiety and n = 0 for depression) were excluded from further analysis. Both regression equations were significant. Baseline hope was a significant predictor of a resilience outcome trajectory for depression (B = -0.24, p < 0.01 for depression); and anxiety (B = -0.11, p = 0.05 for anxiety).

Conclusions -

The current findings suggest that hopefulness may predict resilience after HCRC genetic testing in Hong Kong Chinese. Interventions to increase the level of hope may be beneficial to the psychological adjustment of CRC genetic testing recipients.

COGENT (COlorectal cancer GENeTics): an international consortium to study the role of polymorphic variation on the risk of colorectal cancer

It is now recognised that a part of the inherited risk of colorectal cancer (CRC) can be explained by the co-inheritance of low-penetrance genetic variants. The accumulated experience to date in identifying these variants has served to highlight difficulties in conducting statistically and methodologically rigorous studies and follow-up analyses. The COGENT (COlorectal cancer GENeTics) consortium includes 20 research groups in Europe, Australia, the Americas, China and Japan. The overarching goal of COGENT is to identify and characterise low-penetrance susceptibility variants for CRC through association-based analyses. In this study, we review the rationale for identifying low-penetrance variants for CRC and our proposed strategy for establishing COGENT.

Effect of aspirin or resistant starch on colorectal neoplasia in the Lynch syndrome

BACKGROUND

Observational and epidemiologic data indicate that the use of aspirin reduces the risk of colorectal neoplasia; however, the effects of aspirin in the Lynch syndrome (hereditary nonpolyposis colon cancer) are not known. Resistant starch has been associated with an antineoplastic effect on the colon.

METHODS

In a randomized, placebo-controlled trial, we used a two-by-two design to investigate the effects of aspirin, at a dose of 600 mg per day, and resistant starch (Novelose), at a dose of 30 g per day, in reducing the risk of adenoma and carcinoma among persons with the Lynch syndrome.

RESULTS

Among 1071 persons in 43 centers, 62 were ineligible to participate in the study, 72 did not enter the study, and 191 withdrew from the study. These three categories were equally distributed across the study groups. Over a mean period of 29 months (range, 7 to 74), colonic adenoma or carcinoma developed in 141 participants. Of 693 participants randomly assigned to receive aspirin or placebo, neoplasia developed in 66 participants receiving aspirin (18.9%), as compared with 65 receiving placebo (19.0%) (relative risk, 1.0; 95% confidence interval [CI], 0.7 to 1.4). There were no significant differences between the two groups with respect to the development of advanced neoplasia (7.4% and 9.9%, respectively; P=0.33). Among the 727 participants receiving resistant starch or placebo, neoplasia developed in 67 participants receiving starch (18.7%), as compared with 68 receiving placebo (18.4%) (relative risk, 1.0; 95% CI, 0.7 to 1.4). Advanced adenomas and colorectal cancers were evenly distributed in the two groups. The prevalence of serious adverse events was low, and the events were evenly distributed.

CONCLUSIONS

The use of aspirin, resistant starch, or both for up to 4 years has no effect on the incidence of colorectal adenoma or carcinoma among carriers of the Lynch syndrome. (Current Controlled Trials number, ISRCTN59521990.)

Refinement of the basis and impact of common 11q23.1 variation to the risk of developing colorectal cancer

The common single-nucleotide polymorphism (SNP) rs3802842 at 11q23.1 has recently been reported to be associated with risk of colorectal cancer (CRC). To examine this association in detail we genotyped rs3802842 in eight independent case-control series comprising a total of 10 638 cases and 10 457 healthy individuals. A significant association between the C allele of rs3802842 and CRC risk was found (per allele OR = 1.17; 95% confidence interval [CI]: 1.12-1.22; P = 1.08 x 10(-12)) with the risk allele more frequent in rectal than colonic disease (P = 0.02). In combination with 8q21, 8q24, 10p14, 11q, 15q13.3 and 18q21 variants, the risk of CRC increases with an increasing numbers of variant alleles for the six loci (OR(per allele) = 1.19; 95% CI: 1.15-1.23; P(trend) = 7.4 x 10(-24)). Using the data from our genome-wide association study of CRC, LD mapping and imputation, we were able to refine the location of the causal locus to a 60 kb region and screened for coding changes. The absence of exonic mutations in any of the transcripts (FLJ45803, LOC120376, C11orf53 and POU2AF1) mapping to this region makes the association likely to be a consequence of non-coding effects on gene expression.

A genome-wide association study identifies colorectal cancer susceptibility loci on chromosomes 10p14 and 8q23.3

To identify colorectal cancer (CRC) susceptibility alleles, we conducted a genome-wide association study. In phase 1, we genotyped 550,163 tagSNPs in 940 familial colorectal tumor cases (627 CRC, 313 high-risk adenoma) and 965 controls. In phase 2, we genotyped 42,708 selected SNPs in 2,873 CRC cases and 2,871 controls. In phase 3, we evaluated 11 SNPs showing association at P < 10(-4) in a joint analysis of phases 1 and 2 in 4,287 CRC cases and 3,743 controls. Two SNPs were taken forward to phase 4 genotyping (10,731 CRC cases and 10,961 controls from eight centers). In addition to the previously reported 8q24, 15q13 and 18q21 CRC risk loci, we identified two previously unreported associations: rs10795668, located at 10p14 (P = 2.5 x 10(-13) overall; P = 6.9 x 10(-12) replication), and rs16892766, at 8q23.3 (P = 3.3 x 10(-18) overall; P = 9.6 x 10(-17) replication), which tags a plausible causative gene, EIF3H. These data provide further evidence for the 'common-disease common-variant' model of CRC predisposition.

Disorientation and Reconstruction

This study examines psychosocial difficulties faced by Chinese patients with colorectal cancer, and attempts to identify factors that contribute to the meaning searching process that in turn brings about growth and transformation. Twenty-six patients with colorectal cancer were interviewed. Data were analyzed using the constant comparative method. Two domains of psychosocial disorientation states were identified, namely, cognitive disorientation and emotional disorientation. Factors that facilitate meaning searching were identified and categorized into personal factors and external factors. The areas of growth and transformation through meaning searching were presented with narratives. Findings from the present study not only shed light on psychosocial hindrances among colorectal cancer patients but also have the potential to inform the design of intervention strategies to bring about meaning-orientated transformation through cancer experiences.

Anastomotic leakage is associated with poor long-term outcome in patients after curative colorectal resection for malignancy

The impact of anastomotic leakage on long-term outcomes after curative surgery for colorectal cancer has not been well documented. This study aimed to investigate the effect of anastomotic leakage on survival and tumor recurrence in patients who underwent curative resection for colorectal cancer. Prospectively collected data of the 1,580 patients (904 men) of a median age of 70 years (range: 24-94), who underwent potentially curative resection for colorectal cancer between 1996 and 2004, were reviewed. Cancer-specific survival and disease recurrence were analyzed using Kaplan Meier method, and variables were compared with log rank test. Cox regression model was used in multivariate analysis. The cancer was situated in the colon and the rectum in 933 and 647 patients, respectively. Anastomotic leakage occurred in 60 patients (clinical leakage: n = 48; radiological leak: n = 12). The leakage rate was significantly higher in patients with surgery for rectal cancer (6.3 vs 2.0%, p < 0.001). The 5-year cancer-specific survivals were 56.9% in those with leakage and 75.9% in those without leakage (p = 0.012). The 5-year systemic recurrence rates were 48.4 and 22.6% in patients with and without anastomotic leak, respectively (p = 0.001), whereas the 5-year local recurrence rates were 12.9 and 5.7%, respectively (p = 0.009). Anastomotic leakage remained an independent factor associated with a worse cancer-specific survival (p = 0.043, hazard ratio: 1.63, 95% CI: 1.02-2.60) and a higher systemic recurrence rate (hazard ratio: 1.94, 95% CI: 1.23-3.06, p = 0.004) on multivariate analysis. In rectal cancer, anastomotic leakage was an independent factor for a higher local recurrence rate (hazard ratio: 2.55, 95% CI: 1.07-6.06, p = 0.034). In conclusion, anastomotic leakage is associated with a poor survival and a higher tumor recurrence rate after curative resection of colorectal cancer. Efforts should be undertaken to avoid this complication to improve the long-term outcome.

Leakage after resection and intraperitoneal anastomosis for colorectal malignancy: analysis of risk factors

PURPOSE

The study was designed to identify the risk factors associated with anastomotic leakage after an intraperitoneal large-bowel anastomosis in patients with colorectal malignancy.

METHODS

The prospectively collected data of patients who underwent colorectal resection for malignancy with primary anastomosis above the pelvic peritoneal reflection for malignancy between 1996 and 2004 were reviewed. Thirty-five variables were evaluated using univariate and multivariate analysis.

RESULTS

A total of 1,417 patients were studied and anastomotic leakage occurred in 25 patients (1.8 percent). Twenty-two patients (88 percent) required reoperation for anastomotic leakage. The hospital stay (28 vs. 10 days, P < 0.001) and mortality rate (32 vs. 4 percent, P < 0.001) of patients with anastomotic leakage were significantly increased compared with those without leakage. Multivariate analysis showed that American Society of Anesthesiologists Grade 3 to 5 (P = 0.04; odds ratio, 5.6; 95 percent confidence interval, 1.6-15.3) and emergency operation (P = 0.03; odds ratio, 4.6; 95 percent confidence interval, 1.9-9.8) were independent factors associated with anastomotic leakage. The risk of anastomotic leakage was 8.1 percent (odds ratio, 10.5; 95 percent confidence interval, 2.7-26.8) if both factors were present.

CONCLUSIONS

Intraperitoneal anastomosis after large-bowel resection is associated with a low leakage rate. Emergency surgery and a high American Society of Anesthesiologists grade are independent factors associated with an increased incidence of leakage. A temporary diverting stoma to protect the primary anastomosis or even avoidance of anastomosis could be considered for patients with the two risk factors present.

Laparoscopic and open anterior resection for upper and mid rectal cancer: an evaluation of outcomes

PURPOSE

This study was designed to compare the outcomes of laparoscopic anterior resection with open operation for mid and upper rectal cancer.

METHODS

A total of 265 patients who underwent elective laparoscopic or open anterior resection for cancer of the mid and upper rectum from June 2000 to December 2004 were included. Data about the patients' demographics, operative details, postoperative outcome, and disease status were collected prospectively. Comparison of the outcome between laparoscopic and open resection was performed.

RESULTS

The median age of the 265 patients was 69 (range, 27-91) years, and laparoscopic anterior resection was performed in 98 patients (37 percent). There was no difference in the age, gender, comorbidities, and level of tumor between the two groups. The operating time was longer in the laparoscopic group (200 vs. 127 minutes; P < 0.01), but the blood loss was less (200 vs. 250 ml; P = 0.027). The overall operative mortality was 1.8 percent, and the complication rate was 27.9 percent. Significantly more patients with early diseases (Stage I and Stage II) were operated with laparoscopic approach. There was no difference in the mortality or morbidity between the two groups. Anastomotic leakage occurred in five patients with open resection and one with laparoscopic resection (P = 0.418). Patients with laparoscopic resection had an earlier return of bowel function and earlier resumption of diet as well as a shorter median hospital stay (7 vs. 8 days; P < 0.001). With the median follow-up of the surviving patients for 21.2 months, the three-year local recurrence rates for those with open and laparoscopic resection were 4.9 and 3.3 percent, respectively (P = 0.513). In patients with Stage I and Stage II disease, the three-year cancer-specific survivals for open and laparoscopic resection were 89.8 and 88.6 percent, respectively (P = 0.882), whereas those of patients with Stage III disease were 65.6 and 55.5 percent, respectively (P = 0.911).

CONCLUSIONS

Laparoscopic anterior resection for mid and proximal rectal cancer is a safe option with short-term advantages compared with open operation. The oncologic outcomes of patients who underwent laparoscopic anterior resection were not compromised, with similar local recurrence rate and the cancer-specific survival rate as patients who underwent open resection.

Self-expanding metallic stent as a bridge to surgery versus emergency resection for obstructing left-sided colorectal cancer: a case-matched study

This study aimed to compare the outcomes of patients who suffered from obstructing left-sided colorectal cancer, treated with self-expanding metallic stent (SEMS) as a bridge to surgery, with those who underwent emergency operation. Twenty patients who had acute obstruction due to left-sided colorectal cancer underwent surgical resection after insertion of SEMS (group I) were matched to 40 patients with emergency colonic resection (group II). The two groups were compared for the incidence of primary anastomosis, stoma rate, hospital stay, duration of intensive care, postoperative morbidity, and mortality. Both groups had similar preoperative comorbidity and stage of disease, but the tumors in group I were more distally located (P < 0.001). In group I, one patient developed colon perforation and required Hartmann's operation. All the other patients underwent elective operation with primary anastomosis. In group II, primary anastomosis was performed in 29 patients (72.5%; P = 0.047). The operative mortality of group I and group II was 5% and 12.5%, respectively (P = 0.653). Significantly shorter median postoperative hospital stay and median stay in the intensive care unit (ICU) were observed in group I (9 days [range, 5-39 days] vs. 12 days [range, 8-49 days], P = 0.015 and 0 day [range, 0-17 days] vs. 0.5 day [range, 0-18 days], P = 0.022, respectively). There were no differences in hospital mortality (P = 0.653) or 30-day mortality (P = 0.653). Both groups had similar reoperation rates, surgical complications, and medical complications. When compared with emergency resection, insertion of SEMS as a bridge to surgery for obstructing left-sided colorectal cancer is associated with a higher rate of primary anastomosis as well as a better outcome in terms of hospital stay and stay in the ICU. The wider application of this treatment option for obstructing colorectal cancer warranted further studies.

Outcome of anterior resection for stage II rectal cancer without radiation: the role of adjuvant chemotherapy

BACKGROUND

This study aimed to evaluate the oncological outcome of patients who had Stage II rectal cancer and underwent curative nonsphincter-ablation surgery without adjuvant radiation.

PATIENTS AND METHODS

During the study period from August 1993 to December 2002, 224 patients (141 men) with Stage II cancer underwent curative anterior resection or Hartmann's procedure without adjuvant radiation. Data were collected prospectively. The oncologic outcomes of these patients were studied and the risk factors for recurrence and survival were analyzed.

RESULTS

The median age of the patients was 69 (range, 27-89) years and the median level of the tumor from the anal verge was 8 (range, 3-20) cm. Four patients (1.8 percent) died in the postoperative period and postoperative complications occurred in 74 patients (33 percent). The median follow-up time of the surviving patients was 43.6 months. The actuarial five-year recurrence rate was 25.4 percent, whereas the five-year actuarial local and systemic recurrence rates were 6.1 percent and 20 percent, respectively. On multivariate analysis, independent factors associated with a higher recurrence rate included lymphovascular invasion, perineural invasion, and absence of chemotherapy. The overall and cancer-specific survival rates of the patients were 71.1 percent and 81.1 percent, respectively. On multivariate analysis, only adjuvant chemotherapy (P = 0.024; hazard ratio = 6.04; 95 percent confidence interval, 1.27-28.74) and the absence of lymphovascular invasion (P = 0.002; hazard ratio = 3.77; 95 percent confidence interval, 1.63-8.77) were independent factors associated with significantly better cancer-specific survival.

CONCLUSION

A low local recurrence rate can be achieved in patients with Stage II rectal cancer treated with nonsphincter-ablation surgery without adjuvant radiation. Postoperative chemotherapy is associated with a lower recurrence rate and higher survival rates. Further study is warranted to define the role of adjuvant chemotherapy in patients with rectal cancer.

Bowel preparation for colonoscopy: a randomized controlled trial comparing polyethylene glycol solution, one dose and two doses of oral sodium phosphate solution

OBJECTIVES

To compare three bowel preparation regimens for colonoscopy in terms of the quality of preparation, the side effects and patient acceptance.

METHODS

A total of 299 patients who underwent colonoscopy were randomized to three bowel preparation regimens: polyethylene glycol solution (n = 106), or a single dose (n = 92) or two doses (n = 101) of sodium phosphate solution. The colonoscopists who recorded the quality of bowel preparation were blind to the preparation regimens. The discomforts associated with bowel preparation and patient acceptance of the preparation were also recorded.

RESULTS

Two doses of sodium phosphate solution achieved significantly better bowel preparation than polyethylene solution or a single dose of sodium phosphate solution (p < 0.05). Although two doses of sodium phosphate solution was associated with more dizziness and anal irritation, patients preferred preparation with sodium phosphate solution than with polyethylene glycol solution. Of the 69 patients in the sodium phosphate solution groups who had prior experience of bowel preparation using polyethylene glycol solution, 55 patients (80%) stated that they preferred sodium phosphate solution.

CONCLUSION

Two doses of sodium phosphate solution achieved better bowel preparation than polyethylene glycol solution and was more acceptable to patients. A single dose of sodium phosphate did not achieve similar bowel preparation to two doses of the solution.

MSH2 c.1452-1455delAATG is a founder mutation and an important cause of hereditary nonpolyposis colorectal cancer in the southern Chinese population

Hereditary nonpolyposis colorectal cancer (HNPCC) accounts for approximately 2% of all colorectal cancer (CRC) cases and is the most common hereditary CRC syndrome. We have previously reported a high incidence of microsatellite instability (MSI) and germline mismatch repair (MMR) gene mutations in young Hong Kong Chinese with CRC. Ongoing studies at the Hereditary Gastrointestinal Cancer Registry in Hong Kong have revealed a unique germline MSH2 c.1452-1455delAATG mutation that has not been reported in other ethnic groups. Detailed analysis showed that this specific MSH2 mutation constituted 21% of all germline MMR gene mutations and 36% of all MSH2 germline mutations identified. We designed a specific PCR-based diagnostic test on paraffin-embedded tissues and identified this germline mutation in 2 (1.5%) of 138 consecutive patients with early-onset CRC (<46 years of age at diagnosis). Haplotype analysis was performed using 11 microsatellite markers located between D2S391 and D2S123. All 10 families had the same disease haplotype, suggesting a founder effect. These 10 families all originated from the Chinese province of Guangdong, which historically included Hong Kong. It is the most populous of the Chinese provinces, with a population of >93 million. Further analysis suggested that this founder mutation may date back to between 22 and 103 generations ago. The identification of this MSH2 founder mutation has important implications for the design of mutation-detection strategies for the southern Chinese population. Since there were major emigrations from Hong Kong and Guangdong province during the 19th and 20th centuries, this finding is also significant for Chinese communities worldwide.

Decisional consideration of hereditary colon cancer genetic test results among Hong Kong chinese adults

This study investigated the relationship between psychosocial factors and the decisional consideration of genetic testing of hereditary colon cancer. Attitudes and beliefs about genetic testing, anxiety and depression levels, coping style, and optimism were used as psychosocial independent variables. Sixty-two registrants (61% males and 39% females) of the Hereditary Gastrointestinal Cancer Registry of the Queen Mary Hospital in Hong Kong completed a mail survey. Mean age of the respondents was 42 years (SD = 9.92 years, range: 18-68 years). Correlational analyses and regression analyses were used to examine the relationships between the dependent and independent variables. Participants were concerned about the well-being and reactions of their significant others even more than their own well-being in their decisional consideration processes. Those who had higher perceived risks of being a mutated carrier and higher depression levels tended to emphasize more on the negative consequences of learning the test results and sharing them with relatives. Besides, those who believed that having cancer was attributable to personal (e.g., stress) rather than environmental factors considered that the negative consequences were relatively more important than the positive gains in sharing their results with relatives. Our participants tended to be relational or interdependent oriented in their decisional consideration processes related to genetic testing of colon cancer. This result is consistent with the established interdependent orientation of Chinese. Participants with higher risk perception focused more on the negative consequences of genetic testing. Psychological counseling might help these patients to cope with their concerns about being diagnosed as gene carriers after genetic testing.

Germline, somatic and epigenetic events underlying mismatch repair deficiency in colorectal and HNPCC-related cancers

High-frequency microsatellite instability (MSI-H) results from deficiency in nucleotide mismatch repair. It contributes significantly to carcinogenesis in the human colorectal mucosa. Here we study 41 colorectal and three other HNPCC-related cancers with MSI-H to provide comprehensive information on the mechanisms of inactivation of the two major proteins involved, hMLH1 and hMSH2. Seventeen of the patients had family histories meeting the criteria for Bethesda grades 1, 2 or 3. Of these familial cases, 14 (83%) had early-onset disease, defined on the basis of diagnosis prior to the age of 50, but in three the disease was of late onset (>50 years). A second subset of 20 patients had early onset disease without family history. The remaining seven patients were selected to allow comparisons with sporadic, late-onset disease, the molecular basis of which has been extensively reported elsewhere. We stratified the tumours initially on the basis of hMLH1 or hMSH2 protein deficiency, detected by immunohistochemistry, and then by analysis of germline and somatic mutation, mRNA transcription, loss of heterozygosity (LOH) at the hMLH1 and hMSH2 loci, and methylation status in two regions of the hMLH1 promoter. The functional significance of several of these changes in the MSI-H tumours was confirmed by comparisons with 16 tumours with low-frequency microsatellite instability and 56 tumours with stable microsatellites. As anticipated, patients with family histories usually showed germline mutation of hMSH2 or hMLH1. In many cases the residual normal allele was silenced in their tumours by loss of heterozygosity (LOH). The small subset of late-onset, sporadic cases confirmed the preponderance in this group of biallelic hMLH1 promoter methylation. In the early-onset, apparently sporadic subset there were 11 tumours with hMLH1 deficiency, five with hMSH2 deficiency and four with no detectable abnormality in expression of either protein. These showed a complex mixture of lesions, including germline and somatic mutations, promoter methylation, LOH, suppression of wild-type RNA by as yet undiscovered mechanisms, or no detectable abnormality in any of these parameters. Evidence is presented to indicate that methylation in proximal region of the hMLH1 promoter is a more reliable correlate of transcriptional silencing in colorectal cancers than methylation in upstream region. These observations have significant implications for management of patients with MSI-H tumours.

Phenotype and management of patients with familial adenomatous polyposis in Hong Kong: perspective of the Hereditary Gastrointestinal Cancer Registry

OBJECTIVES

To report on the phenotypic spectrum and clinical management of Chinese patients suffering from the rare autosomal dominant colorectal cancer syndrome of familial adenomatous polyposis.

DESIGN

Analysis of prospectively collected data from the database of a regional registry.

SETTING

The Hereditary Gastrointestinal Cancer Registry, Hong Kong.

PARTICIPANTS

One hundred and eight patients with proven familial adenomatous polyposis from 36 local Chinese families with the condition recruited to the Registry from 1995 to 2001.

INTERVENTIONS

Screening programme for at-risk family members, prophylactic surgery at presymptomatic diagnosis, and surveillance programme for extracolonic lesions in affected individuals.

MAIN OUTCOME MEASURES

Rate of colorectal cancer, type of surgical treatment, spectrum of extracolonic lesions, and management of the syndrome.

RESULTS

Fifty patients suffered from colorectal cancer with a mortality rate of 78.0%. The strategy of presymptomatic diagnosis by screening and appropriate prophylactic surgery reduced the incidence of colorectal cancer. Affected individuals were prone to develop potentially serious extracolonic lesions including thyroid cancer (5.7%), desmoid tumour (15.7%), gastroduodenal adenomas (7.1%), duodenal microadenoma (17.1%), and pouch polyposis (17.4%).

CONCLUSIONS

Screening and prophylactic surgery are effective ways to prevent colorectal cancer for patients with familial adenomatous polyposis. Lifelong regular surveillance is necessary to detect and manage extracolonic lesions. A dedicated registry is essential to coordinate clinical management and to compile data for furthering knowledge of this rare but complex syndrome.

Mutations of the BRAF gene in human cancer

Cancers arise owing to the accumulation of mutations in critical genes that alter normal programmes of cell proliferation, differentiation and death. As the first stage of a systematic genome-wide screen for these genes, we have prioritized for analysis signalling pathways in which at least one gene is mutated in human cancer. The RAS RAF MEK ERK MAP kinase pathway mediates cellular responses to growth signals. RAS is mutated to an oncogenic form in about 15% of human cancer. The three RAF genes code for cytoplasmic serine/threonine kinases that are regulated by binding RAS. Here we report BRAF somatic missense mutations in 66% of malignant melanomas and at lower frequency in a wide range of human cancers. All mutations are within the kinase domain, with a single substitution (V599E) accounting for 80%. Mutated BRAF proteins have elevated kinase activity and are transforming in NIH3T3 cells. Furthermore, RAS function is not required for the growth of cancer cell lines with the V599E mutation. As BRAF is a serine/threonine kinase that is commonly activated by somatic point mutation in human cancer, it may provide new therapeutic opportunities in malignant melanoma.