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.

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.

Selection Criteria in Colorectal Cancer Screening

The authors report the results of a risk questionnaire (RQ) used in a population-based screening program for colorectal cancer. The positive predictive value (PPV) for cancer or adenoma was evaluated for the Hemoccult test (HO) and for all RQ items (symptoms, personal and familial risk) in 8,114 cases, by univariate and multivariate analysis. A significant correlation with the presence of cancer or adenoma was observed for HO-positive tests, whereas a significant correlation was absent for most RQ variables. The use of an RQ in screening practice is disregarded since it does not improve the rate of cancer detection. Moreover, the increase in the detection rate of HO-negative adenomas does not justify the high rate (0.18) of screening responders selected for endoscopic diagnostic workup, a figure which influences negatively the overall compliance to screening.

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 <x<2,000 μm), or 'R0 longness' (x≥2,000 μm). The histological change from the primary lesion to the recurrent lesion was classified as 'No change pattern', from well- to moderately-differentiated (W/M) to an expanding lesion; as 'Change pattern', from W/M to an infiltrating lesion.

RESULTS

Re-recurrence-free survival was better in 'R0 longness' than 'R0 shortness' groups and showed that 'No change pattern' cases had considerably better prognosis than 'Change pattern' cases.

CONCLUSION

Ensuring a CRM >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.

Is there a place for organ preservation in infiltrating rectal cancer?

Neoadjuvant chemoradiotherapy followed by total mesorectal excision is currently the standard of care for locally advanced rectal cancers. However, this therapeutic approach does not take into account response to neoadjuvant treatment, which can go up to a pathologic complete response in 10-20% of the patients. Moreover, despite its efficacy in terms of local control and survival, radical surgery is associated with a significant risk of postoperative morbidity, anastomotic leakage, permanent stoma, impaired quality of life, bowel and genitourinary dysfunction. Based on these adverse events, new strategies of organ preservation have emerged recently. They include, in case of suspicion of complete tumor response, both "watch and wait" strategy and local excision of the residual scar. They seem attractive options, both for patients and surgeons, in terms of postoperative results. But few high-quality studies are available and fears remain regarding oncologic results and reproducibility of published results. Before these strategies can be recommended, large prospective randomized studies are still needed. The aim of this review is to discuss these two options for organ preservation, based on the current literature, with a special focus on oncologic outcomes.

Preventive cancer care for the elderly

There is a great need for effective cancer prevention programs for the elderly. Unfortunately, the elderly have been omitted from most studies of cancer prevention; little is currently known concerning the benefits, risks, and feasibility of most primary and secondary cancer prevention measures in this segment of the population. Available data justify annual casefinding activities in the office of the primary care physician for breast cancer in elderly women and colorectal cancer in elderly persons of both sexes. PAP smear screening is also indicated for elderly women who have had few or no PAP smear in the past. There is some evidence that the health beliefs and practices of elderly persons and their physicians may impede the utilization of available cancer prevention measures. Further research is needed to define the efficacy of cancer prevention measures for the elderly and to improve the delivery of these measures to the elderly population.

Systematic review and meta-analysis of rectal washout on risk of local recurrence for cancer

BACKGROUND

It has been shown that intraluminal washout (WO) can prevent local recurrence (LR) of rectal cancer. This meta-analysis was to evaluate the association of rectal WO and the risk of LR after anterior resection in patients with rectal cancer.

METHODS

The relevant studies were identified by a search of the MEDLINE, Embase, Wiley Online Library, and Cochrane Oral Health Group Specialized Register with no restrictions on October 18, 2013, and these studies were included in a systematic review and meta-analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in fixed effects model.

RESULTS

A total of nine studies were included in our study, yielding a total of 5519 patients, and pooled ORs for overall LR in corresponding subgroups were calculated. Rectal WO was associated with a lower risk for LR (240/4176, 5.75% versus 9.75%, 131/1343, OR = 0.53, 95% CI = 0.42-0.68, and P < 0.00001) in patients with anterior resection, having total mesorectal excisions (234/3942, 5.93% versus 9.34%, 97/1039, OR = 0.59, 95% CI = 0.46-0.75, and P < 0.00001), and after radical resection (RR; 122/2665, 4.99% versus 8.90%, 74/831, OR = 0.56, 95% CI = 0.41-0.78, and P = 0.0005), with an overall LR rate of 6.72% (371/5519). But, the stability of RRs is not high in the total mesorectal excisions or RR subgroup by sensitivity analysis.

CONCLUSIONS

The use of rectal WO decreases risks of LR in patients after anterior resection of cancer.

[The distal resection margin in rectal cancer surgery]

Spread of the tumor in the distal direction is an important factor that must be considered when performing organ-serving surgery for rectal cancer. Particular relevance it has acquired in recent years due to the general tendency to expand the indications for the preservation of natural reflex-apparatus in patients with medium- and lower-ampullar part of the rectum.

Red meat intake may increase the risk of colon cancer in Japanese, a population with relatively low red meat consumption

Asian populations have changed from traditional to Westernized diets, with increased red meat intake. They are suggested to be particularly susceptible to the adverse effects of red meat on the development of colorectal cancers, however, few prospective studies of this putative link have been conducted. We examined associations between the consumption of red and processed meat and the risk of subsite-specific colorectal cancer by gender in a large Japanese cohort. During 1995-1998, a validated food frequency questionnaire was administered to 80,658 men and women aged 45-74 years. During 758,116 person-years of follow-up until the end of 2006, 1,145 cases of colorectal cancer were identified. Higher consumption of red meat was significantly associated with a higher risk of colon cancer among women [multivariate hazard ratios (95%CIs) for the highest versus lowest quintiles (HR): 1.48 (1.01, 2.17; trend p=0.03)], as was higher consumption of total meat among men [HR=1.44 (1.06, 1.98; trend p=0.07)]. By site, these positive associations were found for the risk of proximal colon cancer among women and for distal colon cancer among men. No association was found between the consumption of processed meat and risk of either colon or rectal cancer. In conclusion, red meat intake may modestly increase the risk of colon cancer in middle-aged Japanese, although the highest quintile of red meat consumption could be considered moderate by Western standards.

A decision aid to support informed choices about bowel cancer screening among adults with low education: randomised controlled trial

OBJECTIVE

To determine whether a decision aid designed for adults with low education and literacy can support informed choice and involvement in decisions about screening for bowel cancer.

DESIGN

Randomised controlled trial.

SETTING

Areas in New South Wales, Australia identified as socioeconomically disadvantaged (low education attainment, high unemployment, and unskilled occupations).

PARTICIPANTS

572 adults aged between 55 and 64 with low educational attainment, eligible for bowel cancer screening.

INTERVENTION

Patient decision aid comprising a paper based interactive booklet (with and without a question prompt list) and a DVD, presenting quantitative risk information on the possible outcomes of screening using faecal occult blood testing compared with no testing. The control group received standard information developed for the Australian national bowel screening programme. All materials and a faecal occult blood test kit were posted directly to people's homes.

MAIN OUTCOME MEASURES

Informed choice (adequate knowledge and consistency between attitudes and screening behaviour) and preferences for involvement in screening decisions.

RESULTS

Participants who received the decision aid showed higher levels of knowledge than the controls; the mean score (maximum score 12) for the decision aid group was 6.50 (95% confidence interval 6.15 to 6.84) and for the control group was 4.10 (3.85 to 4.36; P<0.001). Attitudes towards screening were less positive in the decision aid group, with 51% of the participants expressing favourable attitudes compared with 65% of participants in the control group (14% difference, 95% confidence interval 5% to 23%; P=0.002). The participation rate for screening was reduced in the decision aid group: completion of faecal occult blood testing was 59% v 75% in the control group (16% difference, 8% to 24%; P=0.001). The decision aid increased the proportion of participants who made an informed choice, from 12% in the control group to 34% in the decision aid group (22% difference, 15% to 29%; P<0.001). More participants in the decision aid group had no decisional conflict about the screening decision compared with the controls (51% v 38%; P=0.02). The groups did not differ for general anxiety or worry about bowel cancer.

CONCLUSIONS

Tailored decision support information can be effective in supporting informed choices and greater involvement in decisions about faecal occult blood testing among adults with low levels of education, without increasing anxiety or worry about developing bowel cancer. Using a decision aid to make an informed choice may, however, lead to lower uptake of screening. Trial registration ClinicalTrials.gov NCT00765869 and Australian New Zealand Clinical Trials Registry 12608000011381.

Digital rectal examination for prostate and rectal tumour: knowledge and experience of final year medical students

BACKGROUND

It is most pertinent that medical students are taught the necessary skills for digital rectal examination (DRE) before they become doctors.

OBJECTIVE

The study is to assess the knowledge and experience of final year medical students regarding DRE for prostate and rectal tumours.

METHODS

Well-structured questionnaire were administered to each of the final year medical students of Ladoke Akintola University of Technology a week to their final examinations.

RESULTS

Response was received from 127 (60%) of the students, 124 (97.6%) agreed that they have been taught DRE. Most of the students, 102 (80.3%), have done one to five DRE, three (2.4%) and have never performed DRE while none of the students have done more than ten DRE. Only in 49 (38.6%) of cases were the findings of the students on DRE always confirmed by a doctor. Nine students (7.1%) have never felt a clinical BPH and none had felt it more than five times. Sixty-six (52.0%) have never felt a malignant prostate and none of the students have felt it up to three times. Most of the students, 106 (83.5%), have never felt a rectal tumour on DRE Only five (3.9%) felt very confident of their ability to give an opinion based on their findings on DRE while 105 (82.7%) felt reasonably confident

CONCLUSIONS

The students have been taught DRE and a good number of them have performed it. Few of the DRE done by the students were cross-checked by a doctor. Most of the students have problems differentiating BPH from cancer of the prostate and many of them were not very confident of their findings on DRE.

Screening for cancer in adults

With careful selection of procedures, frequencies and risk groups, the periodic screening of adults for cancer can be a highly cost-effective medical activity. This paper summarizes the evidence of effectiveness of screening, the expected reduction in mortality, the risks and costs of screening, and the cost-effectiveness of screening strategies for cancer of the breast, colon, lung, cervix, endometrium and oral cavity. Some of the most pressing questions to be discussed concern the value of mammography, the frequency of the Pap smear, sigmoidoscopy, the value of chest X-rays and sputum cytology in the detection of lung cancer, and the current status of screening for cancers of the endometrium and oral cavity.

The relationship between family physician density and health related outcomes: the Canadian evidence

This paper analyzes if and to what extent the density of family physicians influences health related outcomes in Canada. The density of family physicians in a given region is assumed to serve as proxy for the access to and availability of desirable primary care services. We use self-reported general and mental health status as our overall health outcome measures. We also use several quality of care indicators reflecting whether or not an individual received influenza immunization, mammography, pap smear, and colorectal cancer screening if at high-risk. The empirical results of this study suggest that an additional family physician per 10,000 population has a statistically significant impact in the order of 2% to 4% on self-reported general health status, as well as, other quality of care outcomes. We also find important socioeconomic and demographic factors, such as income, education and immigrant status, influencing health related outcomes considered in this study. Understanding the influence of physician density and socioeconomic factors on health related outcomes are important considerations for health policy and planning.

Long-term oncologic results of patients with distal rectal cancer treated by local excision with or without adjuvant treatment

AIM

The aim of this study is to review long-term oncologic results of local excision (LE) and to investigate the validity and feasibility of LE as a treatment option for distal rectal cancer.

MATERIALS AND METHODS

Seventy-six patients who underwent LE for distal rectal adenocarcinoma with curative intent from 1991 to 2000 at Severance Hospital Yonsei University Medical Center, Seoul, Korea were enrolled in this study.

RESULTS

Preoperative transrectal ultrasonography revealed 3 cases of uT0, 55 cases of uT1 and 18 cases of uT2. Postoperative pathologic examination revealed 10 cases of pT0 (where no residual cancer cells remained), 11 cases of pTis, 37 cases of pT1, 16 cases of pT2, and 2 cases of pT3. Eleven out of 37 patients with pT1 tumors received adjuvant radiation therapy. Among 16 patients with pT2 tumor, 7 undertook salvage operation and 8 received adjuvant therapy. The median follow-up period was 84.9 months. Local recurrence was observed in six patients. The 5-year local recurrence-free survival rate (LFS) was 89.4% in the pT1 group and 75.0% in the pT2 group (p = 0.012). Among the patients with pT1 cancer, those who received adjuvant radiation therapy demonstrated a 5-year LFS of 100%, compared to those who did not, 76.0% (p = 0.038).

CONCLUSION

Our results imply a potential role of LE and adjuvant radiation as an option for the treatment of distal rectal cancer, and that even for pT1 carcinoma, LE alone might not be a valid modality.

Diet and vitamin or mineral supplementation and risk of rectal cancer in Canada

The study examines the relation of diet and vitamin or mineral supplementation with risk of rectal cancer. Mailed questionnaires were completed by 1 380 newly diagnosed patients with histologically confirmed rectal cancer and 3 097 population controls between 1994 and 1997 in seven Canadian provinces. Measurement included information on socio-economic status, lifestyle, diet and vitamin or mineral supplementation. We derived odds ratios and 95% confidence intervals through unconditional logistic regression. Total of consumption of vegetables, fruit and whole-grain products did not reduce the risk of rectal cancer. Consumption of cruciferous vegetables was inversely associated with risk of rectal cancer among women only, as did chicken intake among men. The strongest dietary association with increased rectal cancer risk appeared in males with increasing total fat intake and in females with bacon intake. Vitamin and mineral supplementation showed significant inverse associations with rectal cancer in women only. These findings suggest that dietary risk factors for rectal cancer in women may differ from those in men.

[Colorectal cancer chemoprevention]

Colorectal cancer (CRC) is the second most common malignancy in the world and a leading cause of cancer death. Prevention can lead to decreased incidence of this neoplasm. Chemoprevention may be one option. The article presents a summary of the main information on CRC chemoprevention based on internet database MEDLINE.

Nonsteroidal anti-inflammatory drugs and subsite-specific colorectal cancer incidence in the Iowa women's health study

BACKGROUND

Previous epidemiologic studies have shown that regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with decreased colorectal cancer risk. However, few studies have examined associations between NSAID use and subsite-specific colorectal cancer risks. Because tumors of the proximal and distal colon differ with respect to their genetic alterations, clinicopathologic features, and demographic distribution, further investigation of subsite-specific colorectal cancer risks may be rewarding.

METHODS

Data about aspirin and non-aspirin-NSAID use were recorded by self-report in 1992 among the initially cancer-free cohort of postmenopausal women in the Iowa Women's Health Study (n = 27,160). In total, 637 women developed colorectal cancer during the 11 years of follow-up, including 365 proximal colon, 132 distal colon, and 120 rectal cancer cases (11 overlapping and 9 not specified).

RESULTS

For colon cancer, the multivariable-adjusted hazard ratios (HR) for women reporting use of aspirin two to five times and six or more times weekly (compared with nonusers of aspirin) were 0.79 [95% confidence interval (95% CI), 0.59-1.04] and 0.76 (95% CI, 0.58-1.00), respectively. The corresponding HRs for non-aspirin NSAIDs were 0.63 (95% CI, 0.41-0.96) and 0.85 (95% CI, 0.63-1.15), respectively. For proximal colon cancer, the multivariable-adjusted HRs for women reporting use of aspirin or non-aspirin NSAIDs two or more times weekly (compared with nonusers of each) were 0.67 (95% CI, 0.51-0.87) and 0.71 (95% CI, 0.52-0.97), respectively. No statistically significant association was found between either distal colon or rectal cancer and aspirin or non-aspirin NSAID use.

DISCUSSION

Our study is consistent with a limited number of prior reports that have observed stronger associations between NSAID use and proximal versus distal colorectal cancer.

Subsite distribution of colorectal carcinoma and implications for screening; a retrospective audit of 1771 cases

BACKGROUND/AIMS

Recent epidemiologic studies mentioned a shift from left to right in colorectal cancer. We searched our hospital database to try to give an insight into the patient characteristics and also optimize the screening programs in our country.

METHODOLOGY

A total of 1771 colorectal cancer patients were identified and analyzed. Patients' gender, age, operation dates, tumor localization, resectability and T stage of the lesions, were recorded and comparisons were made. Second step of the study consisted of a questionnaire including 6 questions that were asked to 278 physicians to document current physician attitudes and practices regarding colorectal cancer screening, and to formulate appropriate interventions.

RESULTS

Most of our patients were older than 51 in our study and a higher percentage of cases had sigmoid and rectal cancer (67%). The chronological trends in anatomic subsite distribution of colorectal cancer showed that by changing years when left colon cancer percentage was increasing, rectum cancer percentage was decreasing. There was no age-dependent variation in the topographical distribution of colorectal cancer by changing years. Also there was no relation between sex differences and subsite distribution when the whole group was taken into consideration. Specialist physicians had a poor understanding of colorectal cancer screening and lacked the responsibility of the screening programs.

CONCLUSIONS

Data presented in this article do not support a progressive left to right shift in the distribution of colorectal carcinoma. Screening with fecal occult blood testing and sigmoidoscopy seems appropriate. Physician education may be an important step in screening before public awareness.

Physical activity, obesity, and risk of colon and rectal cancer in a cohort of Swedish men

We investigated the association between physical activity and colorectal cancer risk in a cohort of Swedish men. Information on physical activity was obtained at baseline in 1997 with a self-administered questionnaire from 45,906 men who were cancer-free at enrollment. During a mean follow-up of 7.1 years, 496 cases of colorectal cancer occurred. Leisure-time physical activity was inversely associated with colorectal cancer risk; the multivariate hazard ratio (HR) for 60 min or more per day of leisure-time physical activity compared with less than 10 min per day was 0.57 (95% CI 0.41-0.79; P for trend=0.001). Results were similar for colon (HR=0.56; 95% CI 0.37-0.83) and rectal cancer (HR=0.59; 95% CI 0.34-1.02). Home/housework activity was inversely associated with colon cancer risk (HR=0.68; 95% CI 0.48-0.96). No association was observed for work/occupational activity. These results support a role of physical activity in reducing the risk of colon and rectal cancer.

Dietary risk factors for colon and rectal cancers: a comparative case-control study

BACKGROUND

In Japan, the incidence rate of colon cancer has more rapidly increased than that of rectal cancer. The differential secular trends may be due to different dietary factors in the development of colon and rectal cancers.

METHODS

To compare dietary risk factors between colon and rectal cancers, we undertook a case-control study at Aichi Cancer Center Hospital, Japan. Subjects were 507 patients with newly diagnosed colon (n = 265) and rectal (n = 242) cancers, and 2,535 cancer-free outpatients (controls). Intakes of nutrients and food groups were assessed with a food frequency questionnaire, and multivariate-adjusted odds ratios (ORs) were estimated using unconditional logistic models.

RESULTS

We found a decreasing risk of colon cancer with increasing intakes of calcium and insoluble dietary fiber; the multivariate ORs across quartiles of intake were 1.00, 0.90, 0.80, and 0.67 (trend p = 0.040), and 1.00, 0.69, 0.64, and 0.65 (trend p = 0.027), respectively. For rectal cancer, a higher consumption of carotene and meat was associated with a reduced risk; the corresponding ORs were 1.00, 1.10, 0.71, and 0.70 for carotene (trend p = 0.028), and 1.00, 0.99, 0.68, and 0.72 for meat (trend p = 0.036). Carbohydrate intake was positively correlated with the risk of rectal cancer (ORs over quartiles: 1.00, 1.14, 1.42, and 1.54; trend p = 0.048). This association was stronger in women, while fat consumption was inversely correlated with the risk of female colon and rectal cancers.

CONCLUSIONS

Dietary risk factors appear to considerably differ between colon and rectal cancers.

Risk factors for tumour present in a circumferential line of resection after excision of rectal cancer

Background

Transected tumour in a circumferential line of resection after excision of rectal cancer carries a high likelihood of local recurrence. The aim of this study was to identify independent risk factors for transected tumour and to examine their temporal variability.

Methods

Data were drawn from a comprehensive, prospective hospital registry of all resections for rectal cancer from January 1971 to July 2004. Transected tumour was defined as tumour present histologically in a line of resection and was assessed in all specimens.

Results

Transection occurred in 129 of 1613 patients (8·0 (95 per cent confidence interval 6·7 to 9·4) per cent). The following variables were independently associated with transected tumour: tumour perforation, a non-restorative operation, tumour adherence, non-standardized operative technique, preoperative radiotherapy, male sex, histological involvement of an adjacent organ or tissue, high-grade tumour and venous invasion. The mean number of risk factors per patient per year and the annual percentage of patients with transection varied distinctly over the history of the database.

Conclusion

The varying prevalence of risk factors, both within and between hospitals and patient series, should be taken into account if the rate of transection is to be regarded as an index of the quality of surgery.

Screening und Prävention kolorektaler Karzinome

Das kolorektale Karzinom (KRK) ist die dritthäufigste Tumorerkrankung in den industrialisierten Ländern. Mortalität und Inzidenz des Kolonkarzinoms können durch Screeningverfahren effektiv gesenkt werden. Vor dem Screening muss der Risikostatus des Patienten erfasst werden. Für Personen ohne Risikofaktoren ist ein KRK-Screening ab dem 50. Lebensjahr sinnvoll. Abhängig von der individuellen Situation des Patienten sind mehrere Screeningverfahren möglich. Die vollständige Koloskopie bietet die höchste Sensitivität und Spezifität zur Detektion von Adenomen und Karzinomen im Colon und sollte daher primär angeboten werden. Alternativ sind die Sigmoidoskopie und der Test auf okkultes Blut möglich. Trotz vielversprechender Entwicklungen auf dem Gebiet der Schnittbildverfahren kann die virtuelle Koloskopie aktuell nicht zum Screening empfohlen werden.

Magnesium intake and reduced risk of colon cancer in a prospective study of women

A recent prospective study among Swedish women suggested an inverse association of dietary magnesium intake with incidence of colorectal cancer. The authors assessed this association in a cohort of 35,196 Iowa women initially free of cancer and aged 55-69 years in 1986. Intakes of magnesium and other nutrients were assessed by food frequency questionnaire at baseline. Over 17 years of follow-up through 2002, 1,112 women developed colorectal cancer. After adjustment for age, energy, other nutrients, and risk factors for colorectal cancer, the hazard ratios of colorectal cancer across quintiles of magnesium intake were 1.00, 0.96, 0.83, 0.87, and 0.80 (95% confidence interval: 0.62, 1.03; p(trend) = 0.06). The association was largely absent for rectal cancer but, for colon cancer, the hazard ratios were 1.00, 1.00, 0.88, 0.85, and 0.77 (95% confidence interval: 0.58, 1.03; p(trend) = 0.04). These findings offer further evidence that a diet high in magnesium may reduce the occurrence of colon cancer among women. If replicated by other observational studies, a clinical trial would be needed to determine whether it is magnesium, specifically, and not other aspects of the contributing foods, that may offer benefit.

Oral administration of butyrivibrio fibrisolvens, a butyrate-producing bacterium, decreases the formation of aberrant crypt foci in the colon and rectum of mice

Butyrivibrio fibrisolvens, a butyrate-producing ruminal bacterium, was evaluated for use as a probiotic to prevent colorectal cancer. Oral administration to Jcl:ICR mice of a new strain of B. fibrisolvens (MDT-1) that produces butyrate at a high rate (10(9) cfu/dose) increased the rate of butyrate production by fecal microbes, suggesting that MDT-1 can grow in the gut. The number of colorectal aberrant crypt foci (ACF), putative preneoplastic lesions induced by 1,2-dimethylhydrazine, was reduced after MDT-1 administration (10(9) cfu/dose, 3 times/wk for 4 wk). The number of aberrant crypts (ACs), number of foci having 3 or 4 ACs per focus, and the percentage of mice having 3 or 4 ACs per focus were also reduced, suggesting that the progress of lesions was suppressed by MDT-1. Interestingly, the MDT-1 cell homogenate did not have a similar beneficial effect. MDT-1 had low beta-glucuronidase activity, and administration of MDT-1 reduced the beta-glucuronidase activity in the colorectal contents. The numbers of natural killer (NK) and NKT cells in the spleen were markedly enhanced in response to MDT-1. Decreased beta-glucuronidase activity and increased numbers of NK and NKT cells and butyrate production may explain in part why MDT-1 administration suppressed ACF formation. These results suggest that colorectal cancer may be prevented or suppressed by the utilization of MDT-1 as a probiotic. Administration of MDT-1 had no harmful effect on the health of mice at least for 3 mo.

Inappropriate colorectal cancer screening: findings and implications

OBJECTIVES

Inclusion of colorectal cancer screening as a performance measure in the Veterans Health Administration (VHA) health system appears to have improved screening rates but may have also increased inappropriate screening. Our aim was to ascertain whether the fecal occult blood test (FOBT) was being ordered appropriately.

METHODS

We examined records of 500 consecutive primary care patients at a single VHA facility for whom FOBT had been ordered to determine whether the FOBT was appropriate and, if not, the reason why.

RESULTS

We found that 18% of the sample had severe comorbid illness, 13% had signs or symptoms of gastrointestinal blood loss, 7% had a history of colorectal neoplasia or inflammatory bowel disease (high risk), 5% had undergone colonoscopy within prior 5 yr, and 3% were younger than 50 yr of age. Overall, 35% of the patients had at least one reason that the FOBT was inappropriate and at least 19% of the patients should not have undergone any colorectal cancer test for screening or diagnosis.

CONCLUSIONS

The FOBT order was inappropriate in a third of the sample, most commonly because of a documented life-limiting comorbidity. In addition, data suggested that FOBT was being used for diagnosis instead of screening. Screening patients unlikely to live long enough to develop and die from colorectal cancer provides no benefit and places these individuals at unjustifiable risk. Additionally, inappropriate screening utilizes resources that could be used to improve screening and follow-up for eligible individuals.

Colorectal cancer screening in average risk individuals

Colorectal cancer is the third leading type of cancer, and the second leading cause of cancer-related death in the United States. Prevention of colorectal cancer should be achievable by screening programs that detect adenomas in asymptomatic patients and lead to their removal. In this manuscript, we review the major screening modalities, the advantages and disadvantages of each approach, the data supporting their use, and various issues affecting the implementation of each test. Screening guidelines will be reviewed, and future techniques for colorectal cancer screening examined.

Diets, polymorphisms of methylenetetrahydrofolate reductase, and the susceptibility of colon cancer and rectal cancer

The aim of this study was to investigate the association of environmental factors (dietary folate, methionine and drinking status) and polymorphisms in the methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) gene, as well as the combination of these factors, with the risk of colon cancer and rectal cancer. A case-control study of 53 colon cancer patients, 73 rectal cancer patients and 343 healthy controls was conducted. Genotypes of C677T and A1298C polymorphisms were analyzed by PCR-RFLP. The dietary folate and methionine intakes were assessed using food-frequency questionnaires and food consumption tables. Unconditional logistic regression was applied to estimate the odds ratios (ORs) and their 95% confidence intervals (CIs). The frequency of MTHFR 677T and 1298C alleles in healthy population were 39.4 and 17.2%, respectively. After adjustment for specific variants, the MTHFR 677TT genotype showed a significantly reduced risk of colon cancer compared with the wild type (OR=0.22, 95% CI: 0.50-0.98), and 1298C allele-carrier showed an inverse association with the risk of rectal cancer compared to the wild type (OR=0.52, 95% CI: 0.28-0.98). Adequate intake of folate was a protective factor from colon cancer (OR=0.32, 95% CI: 0.12-0.88) and MTHFR C677T polymorphism showed a statistically significant effect (OR=0.25, 95% CI: 0.06-0.93), reducing the risk of colon cancer in groups that have an intake of folate exceeding 115.64ng per 1000kcal per day. This study suggests that MTHFR C677T and A1298C polymorphisms are associated with the reduced risk of colon and rectal cancers, respectively. Adequate folate intake shows an inverse association with the risk of colon cancer. There is a significant interaction between MTHFR C677T polymorphism and folate intake in reducing the risk of colon cancer.

Effect of glutathione-S-transferase polymorphisms on the cancer preventive potential of isothiocyanates: an epidemiological perspective

Isothiocyanates (ITCs) are widely distributed in cruciferous vegetables and are biologically active against chemical carcinogenesis due to their ability to induce phase II conjugating enzymes. Among these is the glutathione-S-transferase (GST) family of enzymes, which in turn catalyzes the metabolism of ITCs, for which it has high substrate specificity. A recent body of epidemiologic data on the inverse association between cruciferous vegetable/ITC intake and cancers of the colo-rectum, lung and breast, also support that this protective effect is greater among individuals who possess the GSTM1 or T1 null genotype, and who would be expected to accumulate higher levels of ITC at the target tissue level, a pre-requisite for their enzyme-inducing effects. The association between ITC and cancer, and its modification by GST status, is most consistent for lung cancer and appears to be strongest among current smokers. Within limits, a comparison between groups which have been stratified by GST genotype may be less susceptible to confounding by other variables, given the random assortment of genes in gametogenesis. While a more complete understanding of the overall effects on health will need to take into account other components such as indoles and anti-oxidants, the interaction between ITC intake and GST genotype may provide a firmer basis to support a biologically significant role for ITC in cruciferous vegetables.

The ileo neo rectal anastomosis (INRA) in patients with familial adenomatous polyposis: clinical results at two years

BACKGROUND

Ileo neo rectal anastomosis (INRA) is a promising alternative for patients with familial adenomatous polyposis (FAP) to restorative proctocolectomy with its morbidity and unpredictable functional outcome to colectomy with ileo rectal anastomosis (IRA) with the continuing risk of rectal cancer. The aims of the present study were to evaluate the function of the neorectum, to assess the morbidity and complications of the operation and to determine the incidence of neorectal polyps.

METHODS

Data of all patients having INRA, including bowel function and complications, were prospectively recorded. The reservoir capacity was determined repeatedly by physiologic tests. The anal sphincter complex was assessed by manometry and ultrasound examination. Evaluation of the neorectal mucosa was performed by endoscopy.

RESULTS

Six patients underwent the INRA procedure for FAP. Median defaecation frequency two years postoperatively was 5.5/24 h (range 4-7) including 1/night (range 0-2). Endoscopic examination showed normal mucosa and no evidence of polyp formation in all patients.

CONCLUSION

INRA affords a good functional reservoir and is accompanied by few reservoir-related complications. At a minimum follow up period of two years, no growth of polyps in the neorectum occurred.

Meat consumption and K-ras mutations in sporadic colon and rectal cancer in The Netherlands Cohort Study

Case–cohort analyses were performed on meat and fish consumption in relation to K-ras mutations in 448 colon and 160 rectal cancers that occurred during 7.3 years of follow-up, excluding the first 2.3 years, and 2948 subcohort members of The Netherlands Cohort Study on diet and cancer. Adjusted incidence rate ratios and 95% confidence intervals were computed for colon and rectal cancer and for K-ras mutation status subgroups. Total fresh meat, most types of fresh meat and fish were not associated with colon or rectal cancer, neither overall nor with K-ras mutation status. However, several weak associations were observed for tumours with a wild-type K-ras, including beef and colon tumours, and an inverse association for pork with colon and rectal tumours; for meat products, an increased association was observed with wild-type K-ras tumours in the colon and possibly with G>A transitions in rectal tumours.

[Contribution of intraoperative radiotherapy in the control of local recurrences of rectal cancer]

Local recurrence (LR) is a major problem following curative resection of rectal cancer. Intraoperative radiation therapy (IORT) is considered an ideal boost technique for increasing the dose of radiation therapy within a restricted area without introducing a significant toxicity. The aim of this study is to present the results of a multimodality treatment containing external beam irradiation, chemotherapy, surgical resection, and IORT delivered by a movable linear accelerator (NOVAC7, Hitesys SpA, Italia), employed in a "traditional" operating room.

Amount, type, and timing of recreational physical activity in relation to colon and rectal cancer in older adults: the Cancer Prevention Study II Nutrition Cohort

Physical activity has consistently been associated with lower risk of colon cancer, but information is limited on the amount, type, and timing of activities. The relationship between physical activity and rectal cancer is unclear. We examined characteristics of recreational physical activity in relation to colon and rectal cancer in the Cancer Prevention Study II Nutrition Cohort of 70,403 men and 80,771 women (median age, 63 years); 940 colon and 390 rectal cancers were identified from enrollment in 1992 to 1993 through August 1999. The multivariate-adjusted rate ratios (95% confidence intervals) associated with any recreational physical activity compared with none were 0.87 (0.71-1.06) for colon cancer and 0.70 (0.53-0.93) for rectal cancer. Colon cancer risk decreased significantly with increasing total hours (P for trend without reference group = 0.007) and metabolic equivalent hours (P for trend = 0.006) per week of activities. No clear decrease in rectal cancer risk was seen with increasing hours per week of physical activity. Rate ratios (95% confidence intervals) were 0.72 (0.52-0.98) for <2 hours, 0.68 (0.47-0.97) for 2 to 3 hours, 0.59 (0.41-0.83) for 4 to 6 hours, and 0.83 (0.59-1.16) for >/=7 hours per week of physical activity compared with none. Past exercise, as reported in 1982, was not associated with risk of either colon or rectal cancer. We conclude that increasing amounts of time spent at recreational physical activity are associated with substantially lower risk of colon cancer and that recreational physical activity is associated with lower risk of rectal cancer in older men and women.

Physical activity and cancer prevention--data from epidemiologic studies

PURPOSE

The aim of this paper is to examine whether physical activity plays any role in the prevention of cancer.

METHODS

To accomplish this, data from published epidemiologic studies on the relation between physical activity and the risk of developing cancer were reviewed.

RESULTS

The data are clear in showing that physically active men and women have about a 30-40% reduction in the risk of developing colon cancer, compared with inactive persons. Although the data are sparse, it appears that 30-60 min.d(-1) of moderate- to vigorous-intensity physical activity is needed to decrease risk. There is a dose-response relation, with risk declining further at higher levels of physical activity. It is also clear that physical activity is not associated with the risk of developing rectal cancer. With regard to breast cancer, there is reasonably clear evidence that physically active women have about a 20-30% reduction in risk, compared with inactive women. It also appears that 30-60 min.d(-1) of moderate- to vigorous-intensity physical activity is needed to decrease the risk of breast cancer, and that there is likely a dose-response relation. For prostate cancer, the data are inconsistent regarding whether physical activity plays any role in the prevention of this cancer. There are relatively few studies on physical activity and lung cancer prevention. The available data suggest that physically active individuals have a lower risk of lung cancer; however, it is difficult to completely account for cigarette smoking. There is little information on the role of physical activity in preventing other cancers.

CONCLUSION

Physical activity is associated with lower risk of developing certain site-specific cancers, in particular colon and breast cancers.

Plant foods, fiber, and rectal cancer

BACKGROUND

Associations between colon and rectal cancer and intakes of vegetables, other plant foods, and fiber have stimulated much debate.

OBJECTIVE

We examined the association between rectal cancer and plant food and fiber intakes.

DESIGN

Data from 952 incident cases of rectal cancer were compared with data from 1205 population-based controls living in Utah or enrolled in the Kaiser Permanente Medical Care Program in northern California

RESULTS

Rectal cancer was inversely associated with intakes of vegetables (odds ratio: 0.72; 95% CI: 0.54, 0.98), fruit (0.73; 0.53, 0.99), and whole-grain products (0.69; 0.51, 0.94), whereas a high intake of refined-grain products was directly associated with an increased risk of rectal cancer (1.42; 1.04, 1.92). Similarly, relative to low fiber intakes, high intakes of dietary fiber reduced the risk of rectal cancer (0.54; 0.37, 0.78). The reduced risk of rectal cancer associated with vegetable (0.48; 0.29, 0.80), fruit (0.63; 0.38, 1.06), and fiber (0.40; 0.22, 0.71) intakes was strongest for persons who received the diagnosis after age 65 y. A threshold effect at approximately 5 servings of vegetables/d was needed to see a reduced risk of rectal cancer.

CONCLUSIONS

The results suggest that plant foods may be important in the etiology of rectal cancer in both men and women. Age at diagnosis appears to play an important role in the association.

Antioxidants, carotenoids, and risk of rectal cancer

Numerous properties suggest that antioxidants and carotenoids may be valuable chemopreventive agents. A population-based case-control study of 952 rectal cancer cases and 1,205 controls from Northern California and Utah was conducted between September 1997 and February 2002. Detailed diet history, medical history, and lifestyle factors interviews were conducted. Dietary antioxidants were not associated with rectal cancer risk in men. For women, relative to the highest level of intake, low intake of dietary lycopene (odds ratio (OR) = 1.7, 95% confidence interval (CI): 1.0, 2.8) or vitamin E (OR = 2.2, 95% CI: 1.1, 4.3) was associated with an increased risk of rectal cancer. Alpha-, beta-, and gamma-tocopherol were associated with an approximate twofold increased risk of rectal cancer in women. Associations were stronger for women aged > or = 60 years for vitamin E and tocopherols (alpha-tocopherol OR = 3.6, 95% CI: 1.4, 9.4; gamma-tocopherol OR = 5.3, 95% CI: 2.1, 13.2; delta-tocopherol OR = 1.9, 95% CI: 0.9, 4.0), except for beta-tocopherol, for which risk increased twofold for all women. Associations differed by estrogen status for beta-carotene, lycopene, and vitamin E. These results suggest that vitamin E and lycopene may modestly reduce the risk of rectal cancer in women.