Thousands Of UK Women's Cancers Due To Overweight And Obesity

Editor's Choice
Main Category: Obesity / Weight Loss / Fitness
Also Included In: Women's Health / Gynecology;  Cancer / Oncology;  Public Health
Article Date: 07 Nov 2007 - 9:00 PDT

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Overweight and obesity among UK women is causing an additional 6,000 cases of cancer each year, according to an article published in the British Medical Journal (BMJ). The report explains that obesity/overweight raises the risk of developing and dying from cancer.

According to a recent national survey, approximately 23% of UK women are obese, while 34% are overweight. The authors explain that obesity is known for causing excess mortality, however its effects on cancer is less well-known.

Researchers from Oxford University and Cancer Research UK examined the link between body mass index (BMI), the incidence and mortality of cancer, among 1.2 million British women aged 50-64. The women were recruited to the Million Women Study, a large cohort UK study.

The researchers measured BMI and related them to 17 specific types of cancer. The women were followed up for 5.4 years (average) for cancer incidence, and 7 years for cancer mortality.

The researchers defined as overweight a woman whose BMI was within the 25-29.9 range, and obese if her BMI was at least 30. The WHO (World Health Organization) criteria for overweight/obese is the same.

They factored in such variables as socioeconomic status, smoking status, age, alcohol consumption, physical activity, time passed since menopause, plus the use of HRT (hormone replacement therapy).

During the follow-up period a total of 17,203 cancer deaths and 45,037 new cancers occurred.

They found that the higher a woman's BMI the higher was her risk of developing all the cancers. Overall, the link between BMI and mortality was similar to that for incidence.

According to the data, a key factor in closely linking BMI and cancer risk among women is menopausal status. This is the case not only for cancers which are hormonally related (breast and endometrial cancers) but also for other common cancers which are not hormone-related, such as colorectal cancer and malignant melanoma.

The researchers extrapolated from the data they had at hand and estimate that 5% of all cancers among post-menopausal women in the UK are attributable to being obese/overweight.

The obesity/overweight impact in cancer risk was much greater for some cancers than for others, they explained. They concluded that half of all adenocarcinoma of the esophagus were attributable to overweight/obesity.

Accompanying Editorial

Eugenia Calle of the American Cancer Society warns that the global obesity epidemic does not seem to be losing any momentum. We urgently need to learn how obesity contributes to the formation and progression of tumors, and find new interventions to tackle the process.

"Cancer incidence and mortality in relation to body mass index in the Million Women Study: cohort study"
Gillian K Reeves, Kirstin Pirie, Valerie Beral, Jane Green, Elizabeth Spencer, Diana Bull
BMJ, doi:10.1136/bmj.39367.495995.AE (published 6 November 2007)
Click here to view abstract online

Written by׃ Christian Nordqvist
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