Utility of ctDNA in predicting response to neoadjuvant chemoradiotherapy and prognosis assessment in locally advanced rectal cancer: A prospective cohort study.

BACKGROUND: For locally advanced rectal cancer (LARC) patients who receive neoadjuvant chemoradiotherapy (nCRT), there are no reliable indicators to accurately predict pathological complete response (pCR) before surgery. For patients with clinical complete response (cCR), a "Watch and Wait" (W&W) approach can be adopted to improve quality of life. However, W&W approach may increase the recurrence risk in patients who are judged to be cCR but have minimal residual disease (MRD). Magnetic resonance imaging (MRI) is a major tool to evaluate response to nCRT; however, its ability to predict pCR needs to be improved. In this prospective cohort study, we explored the value of circulating tumor DNA (ctDNA) in combination with MRI in the prediction of pCR before surgery and investigated the utility of ctDNA in risk stratification and prognostic prediction for patients undergoing nCRT and total mesorectal excision (TME). METHODS AND FINDINGS: We recruited 119 Chinese LARC patients (cT3-4/N0-2/M0; median age of 57; 85 males) who were treated with nCRT plus TME at Fudan University Shanghai Cancer Center (China) from February 7, 2016 to October 31, 2017. Plasma samples at baseline, during nCRT, and after surgery were collected. A total of 531 plasma samples were collected and subjected to deep targeted panel sequencing of 422 cancer-related genes. The association among ctDNA status, treatment response, and prognosis was analyzed. The performance of ctDNA alone, MRI alone, and combining ctDNA with MRI was evaluated for their ability to predict pCR/non-pCR. Ranging from complete tumor regression (pathological tumor regression grade 0; pTRG0) to poor regression (pTRG3), the ctDNA clearance rate during nCRT showed a significant decreasing trend (95.7%, 77.8%, 71.1%, and 66.7% in pTRG 0, 1, 2, and 3 groups, respectively, P = 0.008), while the detection rate of acquired mutations in ctDNA showed an increasing trend (3.8%, 8.3%, 19.2%, and 23.1% in pTRG 0, 1, 2, and 3 groups, respectively, P = 0.02). Univariable logistic regression showed that ctDNA clearance was associated with a low probability of non-pCR (odds ratio = 0.11, 95% confidence interval [95% CI] = 0.01 to 0.6, P = 0.04). A risk score predictive model, which incorporated both ctDNA (i.e., features of baseline ctDNA, ctDNA clearance, and acquired mutation status) and MRI tumor regression grade (mrTRG), was developed and demonstrated improved performance in predicting pCR/non-pCR (area under the curve [AUC] = 0.886, 95% CI = 0.810 to 0.962) compared with models derived from only ctDNA (AUC = 0.818, 95% CI = 0.725 to 0.912) or only mrTRG (AUC = 0.729, 95% CI = 0.641 to 0.816). The detection of potential colorectal cancer (CRC) driver genes in ctDNA after nCRT indicated a significantly worse recurrence-free survival (RFS) (hazard ratio [HR] = 9.29, 95% CI = 3.74 to 23.10, P < 0.001). Patients with detectable driver mutations and positive high-risk feature (HR_feature) after surgery had the highest recurrence risk (HR = 90.29, 95% CI = 17.01 to 479.26, P < 0.001). Limitations include relatively small sample size, lack of independent external validation, no serial ctDNA testing after surgery, and a relatively short follow-up period. CONCLUSIONS: The model combining ctDNA and MRI improved the predictive performance compared with the models derived from individual information, and combining ctDNA with HR_feature can stratify patients with a high risk of recurrence. Therefore, ctDNA can supplement MRI to better predict nCRT response, and it could potentially help patient selection for nonoperative management and guide the treatment strategy for those with different recurrence risks.

Recurrence hazard of rectal cancer compared with colon cancer by adjuvant chemotherapy status: a nationwide study in Japan.

BACKGROUND: Previous studies of stage III colon cancer using the hazard function demonstrated that the risk of recurrence in patients with adjuvant chemotherapy never exceeded that of patients without adjuvant chemotherapy. However, it is unclear whether the same can be said for rectal cancer patients and whether adjuvant chemotherapy reduces recurrence. This study aimed to compare the recurrence hazard of stage III rectal cancer with that of colon cancer by adjuvant chemotherapy status using the hazard function, a method that allows for the assessment of instantaneous risk of recurrence over time. METHODS: This retrospective nationwide study consisted of 10,356 patients with stage III colorectal cancer who underwent curative resection between January 1997 and December 2012 in Japan. Recurrence hazards of rectal and colon cancers were compared between patients treated with adjuvant chemotherapy and those who were not. Analyses in which recurrence was divided into local and distant recurrence were also performed. RESULTS: The hazard rate of recurrence in rectal cancer patients with adjuvant chemotherapy was consistently lower throughout the follow-up period, and the peak time of recurrence later, compared to patients without adjuvant chemotherapy (peaked at 15.7 vs. 7.1 months). Adjuvant chemotherapy also strongly suppressed distant recurrence but not local recurrence in rectal cancer patients. Similar results were observed in colon cancer patients. CONCLUSIONS: Our results using nationwide real-world data in Japan suggest that, similar to what is observed in colon cancer patients, adjuvant chemotherapy delays the peak of recurrence and suppresses distant recurrence in stage III rectal cancer patients.

Dietary Polyamines Intake and Risk of Colorectal Cancer: A Case-Control Study.

Polyamines (including putrescine, spermidine, and spermine) are small, cationic molecules that are necessary for cell proliferation and differentiation. Few studies have examined the association of dietary polyamines intake with colorectal cancer risk. The aim of this study was to evaluate total polyamines, putrescine, spermidine, and spermine intake in relation to colorectal cancer risk in China. In total, 2502 colorectal cancer cases and 2538 age-(5-year interval) and sex-matched controls were recruited from July 2010 to April 2019. Odds ratios (ORs) and 95% confidence intervals (CI) were calculated by multivariable unconditional logistic regression after adjustment for various potential confounding factors. Higher intake of total polyamine, putrescine and spermidine was significantly associated with reduced risk of colorectal cancer. The adjusted ORs for the highest compared with the lowest quartile of intake were 0.60 (95% CI 0.50, 0.72; Ptrend < 0.001) for total polyamines, 0.35 (95% CI 0.29, 0.43; Ptrend < 0.001) for putrescine and 0.79 (95% CI 0.66, 0.95; Ptrend = 0.001) for spermidine, respectively. However, higher intake of spermine was associated with increased risk of colorectal cancer, with an adjusted OR of 1.58 (95% CI 1.29, 1.93; Ptrend < 0.001). This data indicate that higher intake of total polyamines, putrescine and spermidine, as well as lower intake of spermine, is associated with a decreased risk of colorectal cancer.

Physical activity and mortality in patients with colorectal cancer: a meta-analysis of prospective cohort studies.

The association between physical activity (PA) and colorectal cancer (CRC) patients' survival is inconsistent. We conducted a systematic review and meta-analysis to summarize published articles on this issue. We performed a comprehensive search of the PubMed, Embase, and Web of Science databases for relevant articles through 28 February 2018. The summary hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using a random-effects model. Eighteen prospective cohort studies were included in the meta-analysis, with a total of 9257 cases of total mortality (TM) and 4015 cases of colorectal cancer-specific mortality (CRCSM) among 31 873 CRC survivors and 557 150 general populations. Among CRC survivors, the highest versus the lowest levels of prediagnosis PA showed decreased risks of TM (summary HR = 0.81, 95% CI: 0.76-0.87, I = 1.8%) and CRCSM (summary HR = 0.85, 95% CI: 0.77-0.98, I = 0), respectively. Significant risk reductions for TM and CRCSM were also demonstrated for postdiagnosis PA (HR = 0.63, 95% CI: 0.54-0.74; and HR = 0.64, 95% CI: 0.47-0.88, respectively). The inverse association between prediagnosis PA and cancer mortality was more pronounced for colon cancer than that for rectal cancer (P = 0.08). The summary HRs (95% CIs) of TM were 0.89 (0.83-0.97) and 0.79 (0.69-0.90) per 10 metabolic equivalent task-h/week increase in prediagnosis and postdiagnosis PA, respectively. Our meta-analysis provides comprehensive evidence that PA performed before or after cancer diagnosis is related to reduced mortality risk among CRC survivors.

Epidemiology and Mechanisms of the Increasing Incidence of Colon and Rectal Cancers in Young Adults.

In contrast to the decreasing incidence of colorectal cancer (CRC) in older populations, the incidence has nearly doubled in younger adults since the early 1990s. Approximately 1 in 10 new diagnoses of CRC are now made in individuals 50 years or younger. Patients' risk of CRC has been calculated largely by age and family history, yet 3 of 4 patients with early-onset CRC have no family history of the disease. Rapidly increasing incidence rates in younger people could result from generational differences in diet, environmental exposures, and lifestyle factors. We review epidemiologic trends in CRC, data on genetic and nongenetic risk factors, and new approaches for determining CRC risk. These may identify individuals likely to benefit from early screening and specialized surveillance.

Effectiveness, benefit harm and cost effectiveness of colorectal cancer screening in Austria.

BACKGROUND: Clear evidence on the benefit-harm balance and cost effectiveness of population-based screening for colorectal cancer (CRC) is missing. We aim to systematically evaluate the long-term effectiveness, harms and cost effectiveness of different organized CRC screening strategies in Austria. METHODS: A decision-analytic cohort simulation model for colorectal adenoma and cancer with a lifelong time horizon was developed, calibrated to the Austrian epidemiological setting and validated against observed data. We compared four strategies: 1) No Screening, 2) FIT: annual immunochemical fecal occult blood test age 40-75 years, 3) gFOBT: annual guaiac-based fecal occult blood test age 40-75 years, and 4) COL: 10-yearly colonoscopy age 50-70 years. Predicted outcomes included: benefits expressed as life-years gained [LYG], CRC-related deaths avoided and CRC cases avoided; harms as additional complications due to colonoscopy (physical harm) and positive test results (psychological harm); and lifetime costs. Tradeoffs were expressed as incremental harm-benefit ratios (IHBR, incremental positive test results per LYG) and incremental cost-effectiveness ratios [ICER]. The perspective of the Austrian public health care system was adopted. Comprehensive sensitivity analyses were performed to assess uncertainty. RESULTS: The most effective strategies were FIT and COL. gFOBT was less effective and more costly than FIT. Moving from COL to FIT results in an incremental unintended psychological harm of 16 additional positive test results to gain one life-year. COL was cost saving compared to No Screening. Moving from COL to FIT has an ICER of 15,000 EUR per LYG. CONCLUSIONS: Organized CRC-screening with annual FIT or 10-yearly colonoscopy is most effective. The choice between these two options depends on the individual preferences and benefit-harm tradeoffs of screening candidates.

Estrategia de autocuidado en los adultos mayores con cáncer colorrectal en la comunidad / Self-care strategy in elderly adults with colorrectal cancer in the community

Fundamento: la probabilidad de adquirir cáncer colorrectal en Cuba a lo largo de la vida es del cuatro al seis por ciento. Alrededor del 80 porciento de los casos son esporádicos, pero el 20 porciento tiene una influencia genética.Objetivo: evaluar la estrategia de autocuidado en los adultos mayores con cáncer colorrectal en la comunidad.Métodos: se realizó un estudio de intervención y desarrollo el cual muestra la estrategia de autocuidado en los adultos mayores con cáncer colorrectal en la comunidad contextualizada en el Policlínico Dr. Rudesindo Antonio García del Rijo del municipio y provincia Sancti Spíritus desde el 2007 hasta 2017. Variables utilizadas: nivel de información de los médicos de la familia, autocuidado, estado de salud, prolongación de la sobrevida, alivio del dolor. Se utilizó entrevista estructurada, a los adultos mayores con cáncer colorrectal para conocer la mejoría del estado de salud, después de aplicada la estrategia se compararon las proporciones poblacionales mediante prueba de McNemar. Resultados: se lograron cambios significativos en el nivel de información de los médicos de la familia, al finalizar el programa de capacitación se obtuvo 78,37 porciento, lo que muestra un nivel aceptable. El 36,62 porciento del estado de salud de los adultos mayores fue bueno; el autocuidado se alcanzó de forma aceptable en el 44,82 porciento. La prolongación de la sobrevida después de aplicada la estrategia fue de 49,13 porciento. El alivio del dolor fue de 76,72 porciento. Conclusiones: se logró la evaluación de la estrategia de autocuidados en los adultos mayores con cáncer colorrectal, que incluye acciones y actividades que favorecen el logro de cambios significativos en el autocuidado (AU)

Background: the probability of acquiring colorectal cancer in Cuba throughout life is four to six percent. Approximately 80 percent of cases are sporadic, but 20 percent have a genetic influence. Objective: to evaluate the strategy of self-care in the elderly with colorectal cancer in the community. Method: intervention and development study was carried out, which shows the strategy of self-care in older adults with colorectal cancer in the community contextualized in the Dr. Rudesindo Antonio García del Rijo Polyclinic of the Municipality and Province of Sancti Spíritus in the period 2007-2017. The used variables were level of information of family doctors, self-care, health status, prolongation of survival, pain relief. Structured interview to older adults with colorectal cancer was used to know the improvement of the state of health, after applying the strategy, population proportions were compared by McNemar test. Results: significant changes were achieved in the level of information of family doctors at the end of the training program obtained 78.37 percent which shows an acceptable level. 36.62 percent of the health status of the elderly was good; self-care was achieved in an acceptable way in 44.82 percent. The prolongation of the survival after applying the strategy was 49.13 percent. The pain relief was 76.72 percent. Conclusions: the evaluation of the self-care strategy in the elderly with colorectal cancer was achieved, which includes actions and activities that favor the achievement of significant changes in self-care (AU)

Serum enterolactone concentrations are low in colon but not in rectal cancer patients.

The dietary lignan metabolite, enterolactone, has been suggested to have anti-cancer functions, and high serum enterolactone concentrations have been associated with decreased risk of breast and prostate cancers. We hypothesized that serum enterolactone concentrations as a marker of plant-based foods are associated with decreased risk in colorectal cancer (CRC). We measured serum enterolactone glucuronide and sulfate concentrations by liquid chromatography-tandem mass spectrometry in 115 CRC patients and 76 sex- and age-matched controls and analyzed the results with respect to tumor parameters, clinical parameters, and systemic inflammatory markers. Patients with colon cancer had significant lower serum enterolactone glucuronide and sulfate concentrations than controls (glucuronide: median 3.14 nM vs. 6.32 nM, P < 0.001; sulfate: median 0.13 nM vs. 0.17 nM, P = 0.002), whereas rectal cancer patients had similar enterolactone levels as controls (glucuronide: median 5.39 nM vs. 6.32 nM, P = 0.357; sulfate: median 0.19 nM vs. 0.17 nM, P = 0.452). High serum enterolactone concentrations were associated with low tumor grade, high serum creatinine levels, and concomitant diabetes. In summary, our results suggest that serum enterolactone concentrations are decreased in colon but not in rectal cancer. Further investigations are required to assess whether this reflects an altered lignan metabolism by the colon microbiome.

Rectal Cancer: 20% Risk Reduction Thanks to Dietary Fibre Intake. Systematic Review and Meta-Analysis.

The aim of this systematic review and meta-analysis was to evaluate the association between dietary fibre intake and rectal cancer (RC) risk. In January 2019, a structured computer search on PubMed/Medline, Excerpta Medica dataBASE (EMBASE) and Scopus was performed for studies reporting the results of primary research evaluating dietary fibre intake in women and men as well as the risk of developing RC. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations were followed. Highest vs. lowest fibre concentrations was compared. The Egger test was used to estimate publication bias. Heterogeneity between studies was evaluated with I2 statistics. The search strategy identified 912 papers, 22 of which were included in our meta-analysis. Having evaluated a total of 2,876,136 subjects, the results suggest a protective effect of dietary fibre intake on RC prevention. The effect Size (ES) was [0.77 (95% CI = 0.66-0.89), p-value = 0.001)]. Moderate statistical heterogeneity (Chi2 = 51.36, df = 21, I2 = 59.11%, p-value = 0.000) was found. However, no publication bias was found, as confirmed by Egger's linear regression test (Intercept -0.21, t = -0.24, p = 0.816). The findings suggest that dietary fibre intake could be protective against RC, with a clinically relevant reduction of RC risk. Identifying preventive measures to avoid the development of RC, especially by following a healthy lifestyle including healthy diet, is pivotal.

Does adherence to the World Cancer Research Fund/American Institute of Cancer Research cancer prevention guidelines reduce risk of colorectal cancer in the UK Women's Cohort Study?

Evidence on adherence to diet-related cancer prevention guidelines and associations with colorectal cancer (CRC) risk is limited and conflicting. The aim of this cohort analysis is to evaluate associations between adherence to the World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR) 2007 recommendations and incident CRC. The UK Women's Cohort Study comprises over 35 372 women who filled in a FFQ at baseline in 1995. They were followed up for CRC incidence for a median of 17·4 years, an individual score linking adherence to eight of the WCRF/AICR recommendations was constructed. Cox proportional hazards regression provided hazard ratios (HR) and 95 % CI for the estimation of CRC risk, adjusting for confounders. Following exclusions, 444 CRC cases were identified. In the multivariate-adjusted model, women within the second and third (highest) categories of the WRCF/AICR score had HR of 0·79 (95 % CI 0·62, 1·00) and 0·73 (95 % CI 0·48, 1·10), respectively, for CRC compared with those in the lowest, reference category. The overall linear trend across the categories was not significant (P=0·17). No significant associations were observed between the WCRF/AICR score and proximal colon, distal colon and rectal cancers separately. Of the individual score components, a BMI within the normal weight range was borderline significantly protective only for rectal cancer in the fully adjusted model. In view of the likely different causes of CRC subtypes, further research is needed to identify the optimal dietary patterns associated with reducing colon and rectal cancer risk, respectively.

Guía de práctica clínica. Diagnóstico y prevención del cáncer colorrectal. Actualización 2018 / Clinical practice guideline. Diagnosis and prevention of colorectal cancer. 2018 Update

[{"text": "Este documento actualiza las recomendaciones realizadas por la Sociedad Española de Medicina Familiar y Comunitaria y la Asociación Española de Gastroenterología para el diagnóstico y la prevención del cáncer colorrectal (CCR). Para establecer la calidad de la evidencia y los niveles de recomendación de las intervenciones se ha utilizado la metodología basada en el sistema GRADE (Grading of Recommendations Assessment, Development and Evaluation). Este documento establece intervalos de demora óptimos en función de los síntomas y el test de SOH inmunológico (SOHi) y recomienda reducir las barreras para la confirmación diagnóstica en los pacientes con síntomas. En cuanto al cribado en población de riesgo medio, se proponen estrategias para conseguir la implantación universal del cribado poblacional basado en SOHi bienal e incrementar la participación de la población diana, incluyendo la implicación de atención primaria. Esta guía de práctica clínica recomienda el cribado universal del síndrome de Lynch mediante la inmunohistoquímica de las proteínas reparadoras o la inestabilidad de microsatélites en los CCR incidentes y el uso de paneles de genes en los pacientes con poliposis adenomatosas. También actualiza las estrategias para reducir la incidencia y la mortalidad tanto de CCR como de otros tumores asociados a los síndromes hereditarios. En cuanto al CCR familiar no hereditario y la vigilancia tras resección de CCR, adenomas y lesiones serradas, se establecen recomendaciones en función del riesgo atribuible y la reducción del riesgo de la intervención propuesta. Finalmente, en el documento se incluyen recomendaciones respecto a los intervalos de vigilancia en la enfermedad inflamatoria intestinal y la actitud ante la displasia.", "_i": "es"}, {"text": "This document updates the recommendations made by the Spanish Society of Family and Community Medicine and the Spanish Association of Gastroenterology for the diagnosis and prevention of colorectal cancer (CRC). In order to evaluate the quality of the evidence and determine the recommendation levels of the interventions, we used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. This document establishes optimal delay intervals based on symptoms and the faecal immunochemical test (FIT) and recommends reducing the barriers for diagnostic confirmation in symptomatic subjects. With regard to CRC screening in the average-risk population, we propose strategies to achieve the universal implementation of organised CRC screening programmes based on biennial FIT and to increase the participation of the target population, including the involvement of Primary Healthcare. This Clinical Practice Guideline recommends universal screening for Lynch syndrome with mismatch repair proteins immunohistochemistry or microsatellite instability in incident CRCs and the use of gene panels in patients with adenomatous polyposis. It also updates the strategies to reduce the incidence and mortality of both CRC and other tumours associated with hereditary syndromes. Regarding non-hereditary familial CRC and surveillance after resection of adenomas, serrated lesions or CRC, we established the recommendations based on the attributable risk and the risk reduction of the proposed intervention. Finally, the document includes recommendations regarding surveillance intervals in inflammatory bowel disease and the attitude towards dysplasia.", "_i": "en"}]

[Comparative study of two rounds of colorectal cancer screening in 80, 000 targeted population in Haining].

Objective: To compare the results of two rounds of colorectal cancer screening in Haining, explore the long-term mechanism and interval time of screening during the prevention and control of colorectal cancer, and establish practical basis for the rational prevention and control strategies. Methods: Between 2007 to 2010 and 2013 to 2015, a total of 80, 000 cases who had completed two rounds of tumor screening were enrolled and analyzed. All cases comes from five towns in Haining. Results: The first round of screening was performed in 80 603 cases and 12.92% (n=10 417) were identified as high-risk population. Colonoscopy were completed in 7 796 subjects and 22.05%(n=1 719) of them were found at least one neoplastic lesions (polyps, adenoma or carcinoma). The population detection rate of all neoplasia was 21.33 per thousand. The detection rate of advanced neoplasia was 4.58% per colonoscopy and 4.43‰ in the population. A total of 357 advanced neoplasia including 296 advanced adenomas and 61 colorectal cancers were found, 330 of whom were applied to early treatment (92.44%). A total of 89 403 subjects participated the second round of screening. The detection rate of high-risk population in the second round (20.81%) was significantly higher than that in the first round (P<0.05). A total of 12 917 subjects completed colonoscopy and 31.97% (n=4 129) of them were found as least one neoplastic lesion. The population detection rate of all neoplasia was 46.18 ‰. Both in the subjects completed colonoscopy and in the screened population, the detection rate of all neoplasia were significantly (P<0.01) higher than that of the first round. The detection rate of advanced neoplasia (n=851) in both the subjects completed colonoscopy (6.59‰)and the total screened population (9.52‰) in the second round were also significantly (P<0.01) higher than that of the first round. The difference of early detection rates for the first (92.44%) and the second (97.53%) round screening were not statistically significant(P>0.05). Conclusions: The main technical indicators of the second round of colorectal cancer screening were significantly better than that of the first round, with significant screening effect. A screening interval of 5 years was suggested for the next round of colorectal cancer screening.

Calcium as a chemopreventive agent against colorectal neoplasm: does obesity play a role?

BACKGROUND: Concerning the chemopreventive potential of calcium against colorectal neoplasms, strong evidence from initial randomized controlled trials (RCTs) of colorectal adenoma has not been confirmed from the most recent large RCT. To explain the conflicting results, a new hypothesis was proposed that the benefit of calcium may be confined to lean individuals. METHODS: To test this hypothesis, we examined heterogeneity of the associations of calcium intake with adenoma and CRC, using data from the most recent meta-analyses of observational studies and conducting subgroup analysis by average body mass index (BMI) of study population. RESULTS: An inverse association of calcium intake with adenoma and CRC did not vary by population average BMI. By anatomical subsites of CRC, while there was no significant evidence of heterogeneity by population average BMI (P heterogeneity > 0.05), the benefit of calcium was confined to studies with population average BMI of ≥25 kg/m2 for both colon cancer and rectal cancer, contradicting the hypothesis. CONCLUSIONS: In our study-level meta-analysis, we found no evidence to support that the chemopreventive potential of calcium, if real, may be stronger in leaner individuals.

Challenges and successes in non-operative management of high-grade malignant bowel obstruction.

Malignant bowel obstruction (MBO) occurs in between 3% and 15% of patients with cancer, and portends a poor mean survival of four weeks for patients who are not able to undergo operative intervention. Surgical interventions may be fraught with complications since these patients typically have compromised nutritional status and progressive metastatic disease burden, with tumor type and degree of aggressiveness affecting outcomes. MBO is a dynamic and difficult process to treat, with adequate pain control being limited by unpredictable enteral absorption and need for prolonged parenteral analgesia (given limited enteral access) with its inherent risks. To explore these difficulties, we report the case of a 43-year-old patient who presented with multi-level MBO from metastatic rectal carcinoma, and explore the challenges and successes of symptom management in a non-operative MBO.

Importance of surgical margins in rectal cancer.

Distal resection margin (DRM) and circumferential resection margin (CRM) are two important considerations in rectal cancer management. Although guidelines recommend a 2 cm DRM, studies have shown that a shorter DRM is adequate, especially in patients receiving neoadjuvant chemoradiation. Standardization of total mesorectal excision has greatly improved quality of CRM. Although more patients are undergoing sphincter-saving procedures, abdominoperineal resection is indicated for very distal tumors, and pelvic exenteration is often necessary for tumors involving pelvic organs.

Evaluating the effect of clinical care pathways on quality of cancer care: analysis of breast, colon and rectal cancer pathways.

PURPOSE: Substantial gaps exist between clinical practice and evidence-based cancer care, potentially leading to adverse clinical outcomes and decreased quality of life for cancer patients. This study aimed to evaluate the usefulness of clinical pathways as a tool for improving quality of cancer care, using breast, colon, and rectal cancer pathways as demonstrations. METHODS: Newly diagnosed patients with invasive breast, colon, and rectal cancer were enrolled as pre-pathway groups, while patients with the same diagnoses treated according to clinical pathways were recruited for post-pathway groups. RESULTS: Compliance with preoperative core biopsy or fine-needle aspiration, utilization of sentinel lymph node biopsy, and proportion of patients whose tumor hormone receptor status was stated in pathology report were significantly increased after implementation of clinical pathway for breast cancer. For colon cancer, compliance with two care processes was significantly improved: surgical resection with anastomosis and resection of at least 12 lymph nodes. Regarding rectal cancer, there was a significant increase in compliance with preoperative evaluation of depth of tumor invasion, total mesorectal excision treatment of middle- or low-position rectal cancer, and proportion of patients who had undergone rectal cancer surgery whose pathology report included margin status. Moreover, total length of hospital stay was decreased remarkably for all three cancer types, and postoperative complications remained unchanged following implementation of the clinical pathways. CONCLUSIONS: Clinical pathways can improve compliance with standard care by implementing evidence-based quality indicators in daily practice, which could serve as a useful tool for narrowing the gap between clinical practice and evidence-based care.

Colorectal Chemoprevention.

With over 1 million cases diagnosed worldwide each year - incidence which seems to rise with the progressive westernization of lifestyles in Asian and African populations - colorectal cancer is the third most commonly diagnosed cancer in both men and women. Colorectal neoplasms and/or pre-neoplasms can be prevented by interfering with the various steps of oncogenesis, which begins with uncontrolled epithelial cell replication, continues with the formation of adenomas and eventually evolves into malignancy. The knowledge described herein will help to reduce and prevent this malignancy, which is one of the most frequent neoplasms in some developed countries. Genetics, experimental and epidemiologic studies suggest that colorectal cancer results from complex interactions between inherited susceptibility and environmental factors. Primary prevention involves the identification of genetic, biologic, and environmental factors that are etiologic or pathogenic in the development of cancer, and subsequent complete or significant interference with their effects on carcinogenesis.

Adequate Margins to Prevent Local Re-recurrence of Rectal Cancer: Viewpoint of Pathological Findings.

BACKGROUND: A sufficient surgical margin is critical for preventing re-recurrence and achieving R0 status after resection of a local recurrence of rectal cancer (LRRC). PATIENTS AND METHODS: Re-recurrence-free survival was analyzed in 110 cases of LRRC according to histological type of primary lesion. The circumferential resection margin (CRM) was classified as 'R1' (x=0 µm), 'R0 shortness' (0 µm 2,000 µm during resection of LRRC is more likely to prevent re-recurrence. Cases with poorly differentiated carcinoma from the primary lesion to the recurrent lesion tend to have poor prognoses.