Obese people increase the risk of developing cancer

  • Jan 23 , 2017

Overweight and obesity increase the risk of developing several cancers. Once cancer develops, individuals may be at increased risk of recurrence and poorer survival if they are overweight or obese. A statistically significant association between overweight or obesity and breast cancer recurrence or survival has been observed in the majority of the population.

However, adiposity has been shown to have less effect on prognosis in the clinical trial setting. Weight gain after breast cancer diagnosis may also be associated with decreased prognosis. New evidence suggests that overweight/obesity vs normal weight may increase the risk of poor prognosis among resected colon cancer patients and the risk of chemical recurrence in prostate cancer patients.

Furthermore, obese cancer patients are at increased risk for developing problems following surgery, including wound complication, lymphedema, second cancers, and the chronic diseases affecting obese individuals without cancer such as cardiovascular disease and diabetes.

Mechanisms proposed to explain the association between obesity and reduced prognosis include adipose tissue induced increased concentrations of estrogens and testosterone, insulin, bioavailable insulin-like growth factors, leptin, and cytokines. Additional proposed mechanisms include reduced immune functioning, chemotherapy dosing, and differences in diet and physical activity in obese and non-obese patients.

However, there have been no clinical trials on the effect of weight loss on recurrence or survival in overweight or obese cancer patients. In the absence of clinical trial data, normal weight, overweight, and obese patients should be advised to avoid weight gain through the cancer treatment process. In addition, weight loss is probably safe, and perhaps helpful, for overweight and obese cancer survivors who are otherwise healthy.

Photo Courtesy: The Visual MD

Being overweight has been linked to some cancers like:

  • Breast cancer
  • Colorectal cancer
  • Uterine cancer
  • Kidney cancer
  • Head and neck cancer
  • Esophageal cancer
  • Pancreatic cancer
  • Endometrium (lining of the uterus) cancer
  • Prostate cancer
  • Gallbladder cancer
  • Thyroid cancer

Weight management

If you are currently overweight or obese, it is best to start by taking steps to lose weight through nutrition and exercise. Aim to lose 5 per cent to 10 per cent of your body weight as your first goal. Although this amount may seem small, research shows that even losing 5 per cent to 10 per cent of your weight is beneficial. Most hospitals and health care organisations have professionals—such as dietitians—on staff who can provide weight management counselling and treatment.

Sometimes nutritional changes and increasing physical activity aren’t enough.

But there are other steps you can take.

  • A change in lifestyle - First, change behaviours to reduce the amount of food eaten and increase physical activity before considering other weight loss treatments. A registered dietitian, exercise physiologist, clinical psychologist, or doctor who specialises in weight loss can help.
  • Behaviour change support - For many, being overweight or obese is more complex than simply eating too much and exercising too little. It’s important to get support when you are trying to lose weight. Most weight loss programs include sessions with a dietitian or weight loss specialist to help you make healthy lifestyle changes and stick with them over time.
  • Medications - Weight loss drugs are usually only recommended when a combination of diet, exercise, and behaviour change support have not worked. Or, if you have other serious health conditions from being obese.
  • Surgery - Weight loss surgery, or bariatric surgery, is a term for a variety of procedures that make a person’s stomach smaller. This may be an option for people who have serious health condition related to obesity.