Overweight and obese patients do not seem to adequately recognize their own risk for colorectal cancer

Perceived risk of colorectal and breast cancers among women who are overweight or with obesity

Many overweight women or women with obesity do not acknowledge their high weight status and may be unaware of their elevated cancer risk. We explored the relationship between weight status and women's perceived risk of colorectal (CRC) and breast cancers, overall and by race/ethnicity, in a nationally representative sample.

Data was combined from NHIS 2005, 2010, and 2015 sample adult questionnaires and cancer control supplements. The analytic sample included females aged 18 years and over without reported history of cancer diagnosis. Multivariable logistic regression was performed and adjusted estimates for perceived risk of CRC and breast cancers were examined, stratified by body mass index and race/ethnicity. Data were reported using predicted marginal risk ratio (PMR).

Colorectal cancer risk perception remained lowest among Non-Hispanic (NH) Black women regardless of weight status (PMR = 0.53 obesity, 0.65 overweight, 0.55 normal) compared to NH White women after adjustment for all covariates. Hispanic women who were overweight or had obesity also saw themselves at lower risk of CRC compared to NH White women, however these findings were statistically insignificant. Breast cancer risk perception also remained low for NH Blacks and Hispanics at any weight compared with NH Whites.

Greater effort is needed to develop, disseminate, and widely adopt or institutionalize multilevel weight management interventions and programs. These programs increase awareness of excess weight as a risk factor for cancer and empower women in diverse communities to achieve and maintain a healthy weight by adopting healthy behaviors related to nutrition and physical activity.

Accuracy of self-perceived risk for common conditions

Background:

Accurate awareness of common disease risk is necessary to promote healthy lifestyles and to prevent unnecessary anxiety and evaluation. Our objective is to identify characteristics of patients who do not accurately perceive their risk of developing coronary heart disease (CHD), diabetes (DM), breast cancer (BC) and colorectal cancer (CRC).

Methods:

Using personalized disease risk reports and risk perception surveys, subjects (n = 4703) were classified as high or low/average risk and high or low/average perceived risk for each condition. Models were used to examine factors associated with risk under-estimation by high risk patients and risk over-estimation by low/average risk patients.

Results:

Patients at high risk for DM, BC and CRC often (60%−75% of the time) under-estimated their risk, while low/average risk patients overestimated their risk 13%−40% of the time. For CHD, under-estimation by high risk individuals approximated over-estimation by low/average individuals. Compared to normal weight patients at high risk for cancer, obese patients were more likely to under-estimate their risk for BC (OR 3.1, CI 1.9–5.0) and CRC (2.6, 1.5–4.5) as were overweight patients. Overweight and obese patients at low/average risk of DM or CHD were more likely than normal weight patients to over-estimate their risk. Low/average risk women were more likely than men to over-estimate their risk of DM (1.3, 1.1–1.5) and CHD (1.8, 1.5–2.1).

Conclusions:

Our data show that body mass index is the factor most consistently associated with incorrect risk perceptions for several common conditions.

American Society of Clinical Oncology position statement on obesity and cancer

Rates of obesity have increased significantly over the last three decades in the United States and globally. In addition to contributing to heart disease and diabetes, obesity is a major unrecognized risk factor for cancer. Obesity is associated with worsened prognosis after cancer diagnosis and also negatively affects the delivery of systemic therapy, contributes to morbidity of cancer treatment, and may raise the risk of second malignancies and comorbidities. Research shows that the time after a cancer diagnosis can serve as a teachable moment to motivate individuals to adopt risk-reducing behaviors. For this reason, the oncology care team--the providers with whom a patient has the closest relationships in the critical period after a cancer diagnosis--is in a unique position to help patients lose weight and make other healthy lifestyle changes. The American Society of Clinical Oncology is committed to reducing the impact of obesity on cancer and has established a multipronged initiative to accomplish this goal by 1) increasing education and awareness of the evidence linking obesity and cancer; 2) providing tools and resources to help oncology providers address obesity with their patients; 3) building and fostering a robust research agenda to better understand the pathophysiology of energy balance alterations, evaluate the impact of behavior change on cancer outcomes, and determine the best methods to help cancer survivors make effective and useful changes in lifestyle behaviors; and 4) advocating for policy and systems change to address societal factors contributing to obesity and improve access to weight management services for patients with cancer.

Public perception of cancer survival rankings

Past research has observed that certain subgroups (e.g., individuals who are overweight/obese) have inaccurate estimates of survival rates for particular cancers (e.g., colon cancer). However, no study has examined whether the lay public can accurately rank cancer survival rates in comparison with one another (i.e., rank cancers from most deadly to least deadly). A sample of 400 Indiana adults aged 18 to 89 years (M = 33.88 years) completed a survey with questions regarding perceived cancer survival rates. Most cancers were ranked accurately; however, breast and stomach cancer survival rankings were highly distorted such that breast cancer was perceived to be significantly more deadly and stomach cancer significantly less deadly than reality. Younger participants also overestimated the survival rate for pancreatic cancer. These distortions mirror past content analytic work demonstrating that breast, stomach, and pancreatic cancers are misrepresented in the news.

High knowledge about obesity and its health risks, with the exception of cancer, among Mexican individuals

Mexico has the second biggest prevalence in the world of obese adults (30%). We conducted a survey to determine knowledge concerning obesity co-morbidities. Three groups were surveyed with a questionnaire divided into three sections: demographic characteristics; knowledge and awareness in relation to obesity being a disease; causes of obesity and the health risks it represents; weight auto-perception and the subject's personal experiences regarding weight. In all groups we found high knowledge regarding that obesity is a disease and the causes of its development, as well as that it greatly increases the risk of presenting type 2 diabetes, high blood pressure and knee osteoarthritis. However, in all groups, there was a gap in knowledge regarding the risk obesity poses for the development of breast and colon cancer. Aggressive health promotion campaigns concerning obesity, which have been implemented recently in Mexico, must emphasize cancer as a potential outcome for obese patients.