Physical activity and risk of large bowel cancer in the Framingham Study. Prospective study of colorectal cancer risk and physical activity, diabetes, blood glucose and BMI: exploring the hyperinsulinaemia hypothesis Body size and composition and colon cancer risk in men. Leisure-time physical activity, body size, and colon cancer in women. Nurses' Health Study Research Group. Physical Activity, Obesity, and Risk for Colon Cancer and Adenoma in Men Influence of body mass index on outcomes and treatment‐related toxicity in patients with colon carcinoma Waist circumference as a measure for indicating need for weight management Varying sensitivity of waist action levels to identify subjects with overweight or obesity in 19 populations of the WHO MONICA Project. Clinical and pathological characteristics of sporadic colorectal carcinomas with DNA replication errors in microsatellite sequences. Risk factors for fatal colon cancer in a large prospective study. Postoperative adjuvant chemotherapy or BCG for colon cancer: results from NSABP protocol C-01. Impact of body mass index on outcomes and treatment-related toxicity in patients with stage II and III rectal cancer: findings from Intergroup Trial 0114.
We examined the relation between self-reported physical activity  and  large bowel cancer  in a prospect i ve cohort of men and women who participated in the Framingham Study .  Self- assessment s of physical activity were available from the fourth biennial examination on a total of 1906 men and 2308 women aged 30 to 62 yr in 1954 . The cohort was followed for up to 28 yr and yielded 152 cases ( 73 men , 79 women ) of large bowel cancer . Inactivity was associated with an increased risk of large bowel cancer among men but not among women . The relative risk estimates for large bowel cancer among men in the middle and lowest tertiles of a physical activity index ( compared with the highest tertile ) were 1.4 ( 95 % confidence intervals , 0.8 - 2.6 ) and 1.8 ( 1.0 - 3.2 ) , respectively . Among women the comparable estimates were 1.2 ( 0.7 - 2.1 ) and 1.1 ( 0.6 - 1.8 ) , respectively . These findings were unchanged after adjustment for body mass index , serum cholesterol , alcohol , and other potentially confounding variables . The narrow range of physical activity and the minimal heavy activity reported by women in this cohort may have limited our ability to detect an association between physical activity  and large bowel cancer among women A sedentary lifestyle , obesity , and a Westernized diet have been implicated in the aetiology of both colorectal cancer and non-insulin dependent diabetes mellitus , leading to the hypothesis that hyperinsulinaemia may promote colorectal cancer . We prospect ively examined the association between colorectal cancer risk and factors related to insulin resistance and hyperinsulinaemia , including BMI , physical activity , diabetes mellitus , and blood glucose , in a cohort of 75 219 Norwegian men and women . Information on incident cases of colorectal cancer was made available from the Norwegian Cancer Registry . ReportedPvalues are two-sided . During 12 years of follow up , 730 cases of colorectal cancer were registered . In men , but not in women , we found a negative association with leisure-time physical activity ( Pfor trend = 0.002 ) , with an age-adjusted RR for the highest versus the lowest category of activity of 0.54 ( 95 % CI = 0.37–0.79 ) . Women , but not men , with a history of diabetes were at increased risk of colorectal cancer ( age-adjusted RR = 1.55 ; 95 % CI = 1.04–2.31 ) , as were women with non-fasting blood glucose ≥8.0 mmol l–1(age-adjusted RR = 1.98 ; 95 % CI = 1.31–2.98 ) compared with glucose < 8.0 mmol l–1 . Overall , we found no association between BMI and risk of colorectal cancer . Additional adjustment including each of the main variables , marital status , and educational attainment did not material ly change the results . We conclude that the inverse association between leisure-time physical activity and colorectal cancer in men , and the positive association between diabetes , blood glucose , and colorectal cancer in women , at least in part , support the hypothesis that insulin may act as a tumour promoter in colorectal carcinogenesis . © 2001 Cancer Research Campaign BACKGROUND Several studies of male colon cancer have found positive associations with body size and composition . It is uncertain whether this relationship is due to non-adipose mass , adipose mass , distribution of adipose mass such as central adiposity , or all three . METHODS In a prospect i ve cohort study of men aged 27 - 75 at recruitment in 1990 - 1994 , body measurements were taken by interviewers .  Fat mass and fat-free mass ( FFM ) were estimated from bioelectrical impedance analysis . Waist circumference and waist-to-hips ratio ( WHR ) estimated central adiposity . Incident colon cancers were ascertained via the population cancer registry . Altogether , 16,556 men contributed 145,433 person-years and 153 colon cancers . RESULTS Rate ratios ( RRs ) comparing men in the fourth quartile with those in the first quartile were as follows : FFM 2.3 [ 95 % confidence interval ( CI ) 1.4 - 3.7 ] ; height 1.9 ( 95 % CI 1.1 - 3.1 ) ; waist circumference 2.1 ( 95 % CI 1.3 - 3.5 ) ; WHR 2.1 ( 95 % CI 1.3 - 3.4 ) ; fat mass 1.8 ( 95 % CI 1.1 - 3.0 ) ; and body mass index 1.7 ( 95 % CI 1.1 - 2.8 ) . When continuous measures of FFM and WHR were modeled together , the RR for FFM per 10 kg was 1.37 ( 95 % CI 1.04 - 1.80 ) and the RR for WHR per 0.1 unit was 1.65 ( 95 % CI 1.28 - 2.13 ) . After adjustment for FFM and WHR , the RRs for fat mass and body mass index were no longer statistically significant . CONCLUSION Male colon cancer appears to be related to body size and composition by two different pathways , via central adiposity and via non-adipose mass BACKGROUND Physical inactivity and high body mass index ( weight in kilograms divided by height in square meters ) have been linked to increased risk of  colon cancer .  However , none of the few prospect i ve studies in women has shown a statistically significant reduction in colon cancer incidence or mortality associated with increased leisure-time physical activity . PURPOSE In this prospect i ve study , we asked whether leisure-time physical activity , body mass index , or body fat distribution could significantly influence the risk of colon cancer in women . METHODS The participants in this study were enrolled in the Nurses ' Health Study , which began in 1976 . Every 2 years , the women provided additional personal information and information on medical risk factors and major medical events . The time spent per week at a variety of leisure-time physical activities was determined , and the time spent at each activity was multiplied by its typical energy expenditure , expressed in terms of metabolic equivalents or METs . The result ing values for each woman were added to yield an MET-hours-per-week score . Reported diagnoses of colon cancer were confirmed by review of hospital records and pathology reports . Relative risks and associated 95 % confidence intervals were calculated . RESULTS In multivariate analyses that included body mass index , women who expended more than 21 MET-hours per week on leisure-time physical activity had a relative risk of colon cancer of 0.54 ( 95 % confidence interval [ CI ] = 0.33 - 0.90 ) in comparison with women who expended less than 2 MET-hours per week . Women who had a body mass index greater than 29 kg/m2 had a relative risk of colon cancer of 1.45 ( 95 % CI = 1.02 - 2.07 ) in comparison with women who had a body mass index less than 21 kg/m2 . A tendency toward higher colon cancer risk was observed for increasing waist-to-hip ratio ( relative risk = 1.48 [ 95 % CI = 0.88 - 2.49 ] for comparison of the highest quintile ratio [ > 0.833 ] to the lowest [ < 0.728 ] ) . CONCLUSIONS AND IMPLICATION S The significant inverse association between  leisure-time physical activity  and incidence of colon cancer in women in this study is consistent with what has been found in men . Recommendations to increase physical activity and maintain lean body weight should receive greater emphasis as part of a feasible approach to the prevention of colon cancer Westernization or industrialization leads to an increase in rates of colon cancer , which is the second leading cause of malignant death in the United States [ 1 ] . Although the precise causes of colon cancer remain unclear , a diet high in red meat or animal fat and low in fruits and vegetables appears to increase the risk for this malignancy [ 2 , 3 ] . It is perhaps less well recognized that an inverse association between physical activity and risk for colon cancer has been seen in studies of occupational activity only [ 4 - 12 ] and of both job-related and recreational activity [ 13 - 23 ] . In addition , many studies have found an association between body mass and elevated risk for colon cancer in men ; this association is weaker in women [ 24 - 33 ] . The fact that the association is stronger in men suggests that the abdominal distribution of adiposity typical in men may be an important component of enhanced risk . More limited evidence suggests that height , which may be a proxy for a person 's net energy intake during childhood and adolescence , is related to a higher risk for colon cancer [ 33 - 35 ] . We examine the association between physical activity , obesity , and attained height in relation to risk for colon cancers and their precursory adenomas in a large cohort of male health professionals in the United States . Waist and hip circumferences were available for a subcohort of the study population . We address the hypotheses that physical inactivity , obesity , and height increase the risk for colon cancer and adenoma independently of each other and of diet , and that the abdominal pattern of obesity is an additional independent risk factor . Methods Study Population The Health Professionals Follow-up Study [ 36 ] was started in 1986 ; in that year , 51 529 male dentists , optometrists , osteopaths , podiatrists , pharmacists , and veterinarians in the United States between 40 and 75 years of age responded to a mailed question naire . They reported on their leisure-time physical activity ( described below ) ; current body weight ; weight at age 21 years ; height ; history of cancer and other medical conditions ; parental history of various diseases , including colorectal cancer ; and use of aspirin and other nonsteroidal anti-inflammatory medications . They also reported dietary and alcohol intake using a vali date d [ 37 , 38 ] , semi-quantitative food-frequency question naire . We mailed an optional question naire in 1987 to assess  waist and hip circumferences . In 1988 , 1990 , and 1992 , we up date d exposure information and ascertained newly diagnosed medical conditions and history of colonoscopy or sigmoidoscopy , including the indications for endoscopy : bleeding in stool , positive results from tests for occult fecal blood , abdominal pain , diarrhea or constipation , family history of colorectal cancer , routine screening without symptoms , or follow-up [ 39 ] . Most of the deaths in the cohort were reported by family members or by the postal system in response to the follow-up question naires . We also used the National Death Index to identify deaths among nonrespondents [ 40 ] . Assessment of Physical Activity The 1986 question naire included a section about mainly recreational or leisure-time physical activity . The reliability and validity of question naires design ed to assess physical activity have been investigated [ 41 - 43 ] . A question naire such as the one used in our cohort was evaluated in a cohort of U.S. nurses and was found to provide useful information [ 44 ] , and similar results were found during a similar validation study done within the Health Professionals cohort ( Chasan-Taber S. Personal communication ) . Participants reported the average time per week spent doing each of eight moderate and vigorous activities , choosing from among 10 possible responses that ranged from 0 minutes to 11 or more hours per week . The specific activities listed were walking or hiking outdoors ( including walking during golf ) ; jogging ( slower than 10 minutes/mile ) ; running ( 10 minutes/mile or faster ) ; bicycling ( including that done on a stationary machine ) ; lap swimming ; tennis , squash , or racquetball ; and calisthenics or rowing . In addition , each respondent reported the number of flights of stairs he climbed daily and his usual walking pace . The reported time spent at each activity per week was multiplied by its typical energy expenditure requirements expressed in metabolic equivalents ( METs ) [ 45 ] to yield a MET-hour score . One MET , which is the energy expended by sitting quietly , is equivalent to 3.5 mL of oxygen uptake per kilogram of body weight per minute for a 70-kg adult . For example , 1 hour per week of running contributed 10.2 MET-hours , 1 hour of tennis contributed 6 MET-hours , and 1 hour of walking at a moderate pace contributed 3.2 MET-hours . Body weight was excluded from the derivation of energy expenditure from physical activity to avoid confounding the expenditure variable by body weight . If more than one published intensity level was available for a given activity , the moderate or general MET value was chosen . An average MET value was assigned to the categories that listed more than one activity , such as rowing or calisthenics , and squash or racquetball . Assessment of Anthropometric Variables  Each man reported his current weight and height and his weight at age 21 years on the 1986 question naire . In 1987 , we mailed an optional question naire once to obtain additional exposure information , including body circumference measurements . We instructed each participant to measure ( to the nearest quarter inch ) his waist at the umbilicus and his hips at the largest circumference between the waist and thighs while st and ing and without measuring over bulky clothing [ 46 ] . We provided a tape measure and an illustration to help st and ardize the measurements . Sixty-five percent of the cohort responded . We used the Quetelet index ( kilograms/height in meters2 ) as a measure of total adiposity , waist-to-hip ratio to measure relative distribution of fat , and waist circumference to estimate total abdominal fat . Although the waist-to-hip ratio has been used more widely , waist circumference provides an estimate of absolute abdominal adiposity , the component most closely related to important metabolic abnormalities , including hyperinsulinemia , hypertension , and high triglyceride levels . To remove extraneous variation in the waist circumference because of height ( taller men tend to have larger waist circumferences due to their larger body size rather than to obesity ) , we adjusted waist for height using residual analysis [ 47 ] . We first regressed waist on height using multiple linear regression and then added the residual to the average waist size ( 37.4 inches ) for a man of average height ( 70 inches ) to convert this measure back to the initial scale . This conversion created for each man a st and ardized waist circumference unconfounded by height . We evaluated the precision of self-reported anthropometric measures among 123 cohort members who were part of a dietary validation study [ 46 ] . Trained technicians paid the sub study participants two visits , approximately 6 months apart , to measure current weight and waist and hip circumferences . The Pearson correlation between self-report and the average of the technicians ' two measurements was 0.97 for weight , 0.95 for waist circumference , 0.88 for hip circumference , and 0.69 for waist-to-hip ratio . The men 's self- measurements of their waist circumferences were 0.36 inches greater , their self- measurements of hip circumferences were 0.78 inches smaller , and their self- measurements of weight were 2.3 pounds less than the technician 's measurements . Identification of Patients with Colorectal Cancers In 1988 , 1990 , and 1992 , we asked each participant whether cancer had been diagnosed during the previous 2 years . The response rate to the follow-up question naires was 94 % through 31 January 1992 . When a participant ( or a decedent 's next-of-kin ) reported a diagnosis of cancer of the colon or rectum , we sought permission to obtain hospital records and pathology reports . A study physician , blinded to exposure information , review ed all medical records received and extracted data about histologic type , anatomic location , and stage of the cancer . Proximal colon cancers were defined as those from the cecum to and including the splenic flexure , and distal colon cancers were defined as those in the descending and sigmoid colon . We confirmed 249 new cases of colorectal adenocarcinoma ( excluding carcinoma in situ ) , 90 % by medical records and the remainder with corroborating information about diagnosis and treatment from the cohort member . Two hundred three cancers were in the colon and 46 were in the rectum . Identification of Patients with Colorectal Adenomas and Controls Because more than 90 % of the adenomas were diagnosed during endoscopic procedures for screening or for unrelated gastrointestinal conditions , we restricted the adenoma analysis to men who had had a colonoscopy or sigmoidoscopy .  This was done to reduce the potential for detection bias . Most procedures were sigmoidoscopies ; thus , we analyzed only adenomas of the distal colorectum . Although we did not examine proximal colon adenomas , this should not have biased inferences for the distal colorectum . However , different causes for proximal adenomas may exist . A total of 12 879 men who did not meet any of the exclusion criteria ( see Data Analysis ) reported having had an endoscopy between 1986 and 1992 . In 1993 , we sent a mailing to a r and om sample of 200 controls ( men who reported negative results from an endoscopy ) to confirm that they did not have adenomas . After one mailing , 140 ( 70 % ) controls granted us permission to review the medical records of their endoscopic procedure ; none had an unreported , histologically confirmed adenoma . We were able to recontact 96 % of the men who reported a diagnosis of polyp , and we received medical records in response to more than 96 % of the requests sent to medical record departments , Obesity is a risk factor for the development of colon carcinoma . The influence of body mass index ( BMI ) on long‐term outcomes and treatment‐related toxicity in patients with colon carcinoma has not been well characterized Abstract Objective : To test the hypothesis that a single measurement , waist circumference , might be used to identify people at health risk both from being overweight and from having a central fat distribution . Design : A community derived r and om sample of men and women and a second , validation sample . Setting : North Glasgow . Subjects : 904 men and 1014 women ( first sample ) ; 86 men and 202 women ( validation sample ) . Main outcome measures : Waist circumference , body mass index , waist : hip ratio . Results : Waist circumference > /=94 cm for men and > /=80 cm for women identified subjects with high body mass index ( > /=25 kg/m2 ) and those with lower body mass index but high waist : hip ratio ( > /=0.95 for men , > /=0.80 women ) with a sensitivity of > 96 % and specificity > 97.5 % . Waist circumference > /=102 cm for men or > /=88 cm for women identified subjects with body mass index > /=30 and those with lower body mass index but high waist : hip ratio with a sensitivity of > 96 % and specificity > 98 % , with only about 2 % of the sample being misclassified . Conclusions : Waist circumference could be used in health promotion programmes to identify individuals who should seek and be offered weight management . Men with waist circumference > /=94 cm and women with waist circumference > /=80 cm should gain no further weight ; men with waist circumference > /=102 cm and women with waist circumference > /=88 cm should reduce their weight It has been suggested in the literature that cut-off points based on waist circumference ( waist action levels ) should replace cut-off points based on body mass index ( BMI ) and waist-to-hip ratio in identifying subjects with overweight or obesity . In this article , we examine the sensitivity and specificity of the cut-off points when applied to 19 population s with widely different prevalences of overweight . Our design was a cross-sectional study based on r and om population sample s. A total of 32,978 subjects aged 25 - 64 years from 19 male and 18 female population s participating in the second MONICA survey from 1987 to 1992 were included in this study . We found that at waist action level 1 ( waist circumference > or = 94 cm in men and > or = 80 cm in women ) , sensitivity varied between 40 % and 80 % in men and between 51 % and 86 % in women between population s when compared with the cut-off points based on BMI ( > or = 25 kg/m2 ) and waist-to-hip ratio ( > or = 0.95 for men , > or = 0.80 for women ) . Specificity was high ( > or = 90 % ) in all population s. At waist action level 2 ( waist circumference > or = 102 cm and > or = 88 cm in men and women , respectively , BMI > or = 30 kg/m2 ) , sensitivity varied from 22 % to 64 % in men and from 26 % to 67 % in women , whereas specificity was > 95 % in all population s. Sensitivity was in general lowest in population s in which overweight was relatively uncommon , whereas it was highest in population s with relatively high prevalence of overweight . We propose that cut-off points based on waist circumference as a replacement for cut-off points based on BMI and waist-to-hip ratio should be viewed with caution . Based on the proposed waist action levels , very few people would unnecessarily be advised to have weight management , but a varying proportion of those who would need it might be missed . The optimal screening cut-off points for waist circumference may be population specific DNA replication errors ( RERs ) in repeated nucleotide sequences due to defective mismatch repair genes have been reported in a subset of sporadic colorectal carcinomas and in the majority of tumors from patients with hereditary nonpolyposis colorectal cancer syndrome ( HNPCC ) . We detected  RER in 18 cases ( 13 % ) in a prospect i ve series of 137 sporadic stage II and III ( Dukes ' B and C ) colorectal carcinomas . The clinical and pathological features of the RER-positive cases differed from those without RER . The patients with RER-positive cancers tended to be somewhat younger ( 60 + /- 5 years , range 22 - 83 , versus 66 + /- 1 , range 27 - 90 , P = 0.2 with unequal variances ) and had a marked preponderance of tumors proximal to the splenic flexure ( 17/18 , 94 % , versus 41/119 , 34 % , P < 0.0001 ) . Only two RER-positive patients ( 11 % ) had a family history of colorectal cancer . In comparison to the 41 RER-negative proximal colonic cancers , RER-positive cancers had more frequent exophytic growth ( P = 0.04 ) , large size ( P = 0.03 ) , poor differentiation ( P = 0.0004 ) , extracellular mucin production ( P = 0.003 ) and Crohn's-like lymphoid reaction ( P = 0.003 ) , and a trend toward less frequent p53 gene product overexpression by immunohistochemistry ( 3/17 , 18 % , versus 18/41 , 44 % , P = 0.06 ) . We conclude that a subset of sporadic colorectal carcinomas has unique biological features that may indicate inherited germline mutation , de novo germline mutation , or somatic mutations of the mismatch repair genes involved in HNPCC BACKGROUND Diet , physical activity , obesity , aspirin use , and family history may all modify the risk of colon cancer , but few epidemiologic studies are large enough to examine these factors simultaneously . PURPOSE We prospect ively assessed the relationship of diet and other factors to risk of fatal colon cancer . METHODS Using data from Cancer Prevention Study II -- an ongoing prospect i ve mortality study --we studied 764,343 adults who , in 1982 , completed a question naire on diet and other risk factors and did not report cancer or other major illness . We assessed mortality through August 1988 and identified 1150 deaths from colon cancer ( 611 men and 539 women ) .  Multivariate analyses were used to compare these case patients with 5746 matched control subjects drawn from the cohort . RESULTS Risk of fatal colon cancer decreased with more frequent consumption of vegetables and high-fiber grains ( P for trend = .031 in men and .0012 in women ) . The relative risk ( RR ) for the highest versus lowest quintile of vegetable intake was 0.76 in men ( 95 % confidence interval [ CI ] = 0.57 - 1.02 ) and 0.62 in women ( 95 % CI = 0.45 - 0.86 ) . Dietary consumption of vegetables and grains and regular use of aspirin were the only factors having an independent and statistically significant association with fatal colon cancer . Participants who consumed the least vegetables and grains and no aspirin had a higher risk compared with those who consumed the most vegetables and used aspirin 16 or more times per month . For men in the former category , the RR was 2.4 ( 95 % CI = 1.1 - 5.3 ) ; for women , it was 2.9 ( 95 % CI = 1.3 - 6.7 ) . Weaker associations were seen for physical inactivity , obesity , total dietary fat , and family history . No associations were seen with consumption of red meat or total or saturated fat in either sex , but this finding must be interpreted cautiously . CONCLUSIONS These findings support recommendations that increased consumption of vegetables and grains may reduce the risk of fatal colon cancer . Regular use of low doses of aspirin may prove to be an important supplemental measure Data are presented from 1,166 patients with Dukes B and C carcinoma of the colon who were entered into the National Surgical Adjuvant Breast and Bowel Project ( NSABP ) Protocol C-01 between November 1977 and February 1983 . Patients were r and omized to one of three therapeutic categories : 1 ) no further treatment following curative resection ( 394 patients ) ; 2 ) postoperative chemotherapy consisting of 5-fluorouracil , semustine , and vincristine ( 379 patients ) ; or 3 ) postoperative BCG ( 393 patients ) . The average time on study was 77.3 months . A comparison between patients receiving postoperative adjuvant chemotherapy and those treated with surgery alone indicated that there was an overall improvement in disease-free survival ( P = .02 ) and survival ( P = .05 ) in favor of the chemotherapy-treated group . At 5 years of follow-up , patients treated with surgery alone were at 1.29 times the risk of developing a treatment failure and at 1.31 times the likelihood of dying as were similar patients treated with combination adjuvant chemotherapy . Comparison of the BCG-treated group with the group treated with surgery alone indicated that there was no statistically significant difference in disease-free survival ( P = .09 ) . There was , however , a survival advantage in favor of the BCG-treated group ( P = .03 ) . At 5 years of follow-up , patients r and omized to the surgery-alone arm were at 1.28 times the risk of dying as were similar patients treated with BCG . Further investigation disclosed that this survival advantage in favor of BCG was a result of a diminution in deaths that were non-cancer related . When analyses were conducted on which events not related to cancer recurrence were eliminated , the survival difference between the BCG and control groups became nonsignificant ( P = .40 ) ; the cumulative odds at 5 years decreased from 1.28 to 1.10 . The findings from this study are the first from a r and omized prospect i ve clinical trial to demonstrate that a significant disease-free survival and survival benefit can be achieved with postoperative adjuvant chemotherapy in patients with Dukes B and C carcinoma of the colon who have undergone curative resection PURPOSE To study the relationship between body mass index ( BMI ) and rates of sphincter-preserving operations , overall survival , cancer recurrence , and treatment-related toxicities in patients with rectal cancer . PATIENTS AND METHODS We evaluated a nested cohort of 1,688 patients with stage II and III rectal cancer participating in a r and omized trial of postoperative fluorouracil-based chemotherapy and radiation therapy .  RESULTS Obese patients were more likely to undergo an abdominoperineal resection ( APR ) than normal-weight patients ( odds ratio , 1.77 ; 95 % CI , 1.27 to 2.46 ) . When analyzed by sex , increasing adiposity in men was a strong predictor of having an APR ( P < .0001 ) . Obese men with rectal cancer were also more likely than normal-weight men to have a local recurrence ( hazard ratio [ HR ] , 1.61 ; 95 % CI , 1.00 to 2.59 ) . In contrast , obesity was not predictive of cancer recurrence in women , nor was BMI predictive of overall mortality in either men or women . Underweight patients had an increased risk of death ( HR , 1.43 ; 95 % CI , 1.08 to 1.89 ) compared with normal-weight patients but no increase in cancer recurrences . Among all study participants , obese patients had a significantly lower rate of grade 3 to 4 leukopenia , neutropenia , and stomatitis and a lower rate of any grade 3 or worse toxicity when compared with normal-weight individuals . CONCLUSION Increasing BMI in male patients with rectal cancer is associated with a decreased likelihood of sphincter preservation and a higher chance of local recurrence . For both men and women , overweight and obese patients experience less toxicity associated with adjuvant chemoradiotherapy , suggesting that actual body weight dosing of fluorouracil for obese patients is justified
BACKGROUND Physical inactivity and obesity increase the risk of  colorectal cancer  but little is known about whether they influence prognosis after diagnosis .