Kathleen Y. Wolin

Obesity and Cancer

The article examines the importance of managing weight to reduce risk for developing cancer and for survival among cancer patients and presents a set of strategies that can be useful to guide clinical advice to patients for whom weight control is an important adjunct to risk management or to improve quality of life and disease-free survival after diagnosis.

Physical activity and colon cancer prevention: a meta-analysis

Although an inverse association between physical activity and risk of colon cancer is well established, a formal estimate of the magnitude of this risk reduction that includes recent studies is not available. This analysis examines the association by sex and study design, restricting analyses to studies where data for colon cancer alone were available. The authors reviewed published studies through June 2008 examining the association between physical activity and risk of colon cancer. Heterogeneity and publication bias were evaluated and random effects models used to estimate relative risks (RR). Differences by sex and study design were evaluated. A total of 52 studies were included. An inverse association between physical activity and colon cancer was found with an overall relative risk (RR) of 0.76 (95% confidence interval (CI): 0.72, 0.81). For men, the RR was 0.76 (95% CI: 0.71, 0.82); for women, this was little different, (RR=0.79, 95% CI: 0.71, 0.88). The findings from case–control studies were stronger (RR=0.69, 95% CI: 0.65, 0.74) than for cohort studies (RR=0.83, 95% CI: 0.78, 0.88). This study confirms previous studies reporting an inverse association between physical activity and colon cancer in both men and women, and provides quantitative estimates of the inverse association.

Safe To Walk? Neighborhood Safety and Physical Activity Among Public Housing Residents

Background Despite its health benefits, physical inactivity is pervasive, particularly among those living in lower-income urban communities. In such settings, neighborhood safety may impact willingness to be regularly physically active. We examined the association of perceived neighborhood safety with pedometer-determined physical activity and physical activity self-efficacy. Methods and Findings Participants were 1,180 predominantly racial/ethnic minority adults recruited from 12 urban low-income housing complexes in metropolitan Boston. Participants completed a 5-d pedometer data-collection protocol and self-reported their perceptions of neighborhood safety and self-efficacy (i.e., confidence in the ability to be physically active). Gender-stratified bivariate and multivariable random effects models were estimated to account for within-site clustering. Most participants reported feeling safe during the day, while just over one-third (36%) felt safe at night. We found no association between daytime safety reports and physical activity among both men and women. There was also no association between night-time safety reports and physical activity among men (p = 0.23) but women who reported feeling unsafe (versus safe) at night showed significantly fewer steps per day (4,302 versus 5,178, p = 0.01). Perceiving ones neighborhood as unsafe during the day was associated with significantly lower odds of having high physical activity self-efficacy among both men (OR 0.40, p = 0.01) and women (OR 0.68, p = 0.02). Conclusions Residing in a neighborhood that is perceived to be unsafe at night is a barrier to regular physical activity among individuals, especially women, living in urban low-income housing. Feeling unsafe may also diminish confidence in the ability to be more physically active. Both of these factors may limit the effectiveness of physical activity promotion strategies delivered in similar settings.

Perceived racial/ethnic harassment and tobacco use among African American young adults.

We examined the association between perceived racial/ethnic harassment and tobacco use in 2129 African American college students in North Carolina. Age-adjusted and multivariate analyses evaluated the effect of harassment on daily and less-than-daily tobacco use. Harassed participants were twice as likely to use tobacco daily (odds ratio = 2.01; 95% confidence interval=1.94, 2.08) compared with those with no reported harassment experiences. Experiences of racial/ethnic harassment may contribute to tobacco use behaviors among some African American young adults.

Applying What We Know to Accelerate Cancer Prevention

Research says we already know how to prevent half of all cancers; now we need to put knowledge into action. Research says we already know how to prevent half of all cancers; now we need to put knowledge into action. More than half of the cancer occurring today is preventable by applying knowledge that we already have. Tobacco, obesity, and physical inactivity are the modifiable causes of cancer that generate the most disease. Cancer burden can be reduced by alterations in individual and population behaviors and by public health efforts as long as these changes are driven by sound scientific knowledge and social commitment to change. The obstacles to these efforts are societal and arise from the organization of institutions, including academia, and in the habits of daily life. To achieve maximal possible cancer prevention, we will need better ways to implement what we know and improved infrastructure that will better incentivize and support transdisciplinary, multilevel research and successful intervention.

Physical activity and risk of colon adenoma: A meta-analysis

Background:Little evidence is available on the relation of physical activity with colon adenomas, a colon cancer precursor.Methods:We conducted a systematic literature review and meta-analysis of published studies (in English) through April 2010, examining physical activity or exercise and risk or prevalence of colon adenoma or polyp. Random effects models were used to estimate relative risks (RRs) and corresponding confidence intervals (CIs). A total of 20 studies were identified that examined the association and provided RRs and corresponding 95% CIs.Results:A significant inverse association between physical activity and colon adenomas was found with an overall RR of 0.84 (CI: 0.77–0.92). The association was similar in men (RR=0.81, CI: 0.67–0.98) and women (RR=0.87, CI: 0.74–1.02). The association appeared slightly stronger in large/advanced polyps (RR=0.70, CI: 0.56–0.88).Conclusion:This study confirms previous reports of a significant inverse association of physical activity and colon adenoma, and suggests that physical activity can have an important role in colon cancer prevention.

Exercise in adult and pediatric hematological cancer survivors: an intervention review

Observational research has shown that the physical activity levels of survivors of hematological cancer are low, with deleterious health consequences. This review summarizes the research on exercise interventions in adult and pediatric hematological cancer survivors. We searched MEDLINE, SPORTDiscus, CINAHL, Embase, Cochrane and PEDro through September 2009 for exercise intervention studies in children and adults with any type of hematological cancer. In the 24 adult intervention studies reviewed, we found strong evidence (that is, ⩾3 high-quality studies and ⩾75% reporting a significant benefit) for a benefit on body composition. Weak, but promising, evidence (⩾3 high-quality studies, but <75% reporting a significant benefit) was found for cardiorespiratory fitness, fatigue, muscle strength, physical functioning and quality of life. In pediatric interventions (13 studies), we found strong evidence for a benefit on muscle strength and cardiorespiratory fitness, particularly, if training was conducted in the hospital setting. Evidence is weak for ankle dorsiflexion, physical functioning and body composition. No exercise-related risks were identified in adults or children studies. Though more randomized controlled trials are needed, a growing body of literature supports the notion that regular physical activity is safe and has potential benefits for both adult and pediatric hematological cancer survivors.

Implementing the Exercise Guidelines for Cancer Survivors

In 2009, the American College of Sports Medicine convened an expert roundtable to issue guidelines on exercise for cancer survivors. This multidisciplinary group evaluated the strength of the evidence for the safety and benefits of exercise as a therapeutic intervention for survivors. The panel concluded that exercise is safe and offers myriad benefits for survivors including improvements in physical function, strength, fatigue, quality of life, and possibly recurrence and survival. Recommendations for situations in which deviations from the US Physical Activity Guidelines for Americans are appropriate were provided. Here, we outline a process for implementing the guidelines in clinical practice and provide recommendations for how the oncology care provider can interface with the exercise and physical therapy community.

Time Course of Risk Factors in Cancer Etiology and Progression

Patients with cancer increasingly ask what they can do to change their lifestyles and improve outcomes. Risk factors for onset of cancer may differ substantially from those that modify survival with implications for counseling. This review focuses on recent data derived from population-based studies of causes of cancer and of patients with cancer to contrast risk factors for etiology with those that impact survival. For different cancer sites, the level of information to inform the timing of lifestyle exposures and risk of disease onset or progression after diagnosis is often limited. For breast cancer, timing of some exposures, such as radiation, is particularly important. For other exposures, such as physical activity, higher levels may prevent onset and also improve survival. For colon cancer, study of precursor polyps has provided additional insight to timing. Extensive data indicate that physical activity reduces risk of colon cancer, and more limited data suggest that exposure after diagnosis improves survival. Dietary factors including folate and calcium may also reduce risk of onset. More limited data on prostate cancer point to obesity increasing risk of aggressive or advanced disease. Timing of change in lifestyle for change in risk of onset and for survival is important but understudied among patients with cancer. Counseling patients with cancer to increase physical activity and avoid weight gain may improve outcomes. Advice to family members on lifestyle may become increasingly important for breast and other cancers where family history is a strong risk factor.

Leisure-time physical activity patterns and risk of colon cancer in women

Although physical activity has been consistently associated with lower risk of colon cancer, many details of the relationship remain unclear. We assessed the relation between physical activity and risk of colon cancer in 79,295 women aged 40–65 who were free of cancer, ulcerative colitis and Crohns disease and who reported their leisure‐time physical activity in 1986; 547 cases were identified through 2002. Women who expended more than 21.5 metabolic equivalent hr/week of physical activity had a relative risk (RR) of colon cancer of 0.77 (95% CI 0.58–1.01), compared to women who expended <2 metabolic equivalent hr/week. The association was stronger for distal than proximal tumors. Among women whose only reported activity was walking, there was a decreased risk of colon cancer in women walking 1–1.9 hr/week (RR = 0.69, 95% CI 0.47–1.03) compared to those who did not walk. Results were similar for increased amounts of walking, but there was no evidence of a dose response relation. Among women who participated in moderate or vigorous activity, increasing hours of activity were also associated with a decreased risk of colon cancer (p for trend = 0.01); women exercising >4 hr/week had a 40% lower risk of colon cancer than those exercising <1 hr/week (RR = 0.56, 95%CI 0.33–0.94). Long‐term physical activity was not associated with risk of colon cancer, but the number of cases was small. A significant inverse association exists between physical activity, including that of moderate intensity, such as walking, and risk of colon cancer in women that is more pronounced for distal tumors.