LUGANO-MADRID – Body fat distribution in the trunk is more important than body weight when it comes to cancer risk in postmenopausal women, according to a study presented at the ESMO 2017 Congress in Madrid. (1)
The findings put a new spin on weight management priorities for women in this this age-group, who are prone to abdominal weight gain, said study investigator Line Mærsk Staunstrup, MSc, a PhD student with Nordic Bioscience and ProScion, in Herlev, Denmark.
“When assessing cancer risk, body mass index (BMI) and fat percentage may not be adequate measures as they fail to assess the distribution of fat mass,” she explained. “Avoiding central obesity may confer the best protection.”
The findings come from the Prospective Epidemiologic Risk Factor study, an observational, prospective cohort study designed to get a better understanding of age-related diseases in Danish postmenopausal women.
It included 5,855 women (mean age 71 years) who underwent baseline dual-energy X-ray absorptiometry (DXA) scans to assess body fat and body fat composition and have been followed for 12 years.
Using information from national cancer registries, the study recorded 811 solid cancers in the women and showed that the ratio of abdominal fat to peripheral fat was a significant independent predictor of cancer diagnosis up to 12 years after baseline (hazard ratio [HR] 1.30; 95%, CI: 1.11 to 1.52; p < 0.001). Neither BMI nor fat percentage showed significance.
Specifially, there were 293 breast and ovarian cancers, 345 lung and gastrointestinal (GI) cancers, and 173 other cancers. Looking in detail at specific cancers and risk factors the investigators determined that only lung and GI cancers were associated with high abdominal to peripheral fat ratios (HR: 1.68; 95%, CI: 1.12 to 2.53; p < 0.05 and HR: 1.34; 95%, CI: 1 to 1.8; p < 0.05, respectively).
Additional cancer risk factors were older age, receipt of hormone replacement therapy and smoking, but after controlling for these risk factors, fat ratio remained an independent risk factor.
“The average elderly women can very much use this information, as it is known that the menopause transition initiates a shift in body fat towards the central trunk area. Therefore elderly women should be especially aware of their lifestyle when they approach the pre-menopause age,” said Mærsk Staunstrup. “Clinicians can additionally use the information for a preventive conversation with women who are in higher risk of cancer. While clinicians have access to whole body DXA scanners at most hospitals, portable DXA scanners have become available on the commercial market and this may allow regional bone and fat scanning, however it may not be the most reliable for measuring central obesity,” she concluded.
Commenting on the study, Andrea De Censi, MD from Galliera Hospital, in Genova, Italy said the study provides important confirmation of the role of obesity and particularly insulin resistance in the etiology of several cancers.
“While obesity has previously been linked to cancer risk, the link to lung cancer is new and intriguing,” he commented.
“Increases in insulin, resulting from over-consumption of simple carbohydrates such as potatoes, wheat, rice and corn, result in fat accumulation that is specifically visceral and abdominal,” De Censi explained. Insulin also has detrimental effects on hormone production, and adipose cells in fat tissue increase chonic inflammation throughout the body, another risk factor for several cancers.
“These data open the door for clinicans to intiate a number of interventions in obese patients. In addition to fat loss with diet and exercise, there may be a potential role for a diabetes drug, such as metformin, which can lower insulin effects and contribute to cancer prevention.”
Notes to Editors
Please make sure to use the official name of the meeting in your reports: ESMO 2017 Congress
- Abstract 1408P_PR ‘A study of body fat composition, derived from DXA-scans, in association with cancer incidence in postmenopausal women’ will be presented by Ms. Staunstrup during Poster Display Session on Sunday, 10 September 2017, 13:15 to 14:15 (CEST) in Hall 8.
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A study of body fat composition, derived from DXA-scans, in association with cancer incidence in postmenopausal women
L.M. Staunstrup1, J.F. Christensen2, J. Blair1, H.B. Nielsen1, C. Christiansen3, C.L. Bager1
1Proscion, ProScion, Herlev/DENMARK, 2Centre For Physical Activity Reasearch, Rigshospitalet, København/DENMARK, 3Nordic Bioscience, Nordic Bioscience, Herlev/DENMARK
Background: Obesity is a known cancer risk factor, but epidemiological studies have mainly evaluated the link between obesity and cancer by non-specific assessment, e.g. weight, body mass index (BMI) and/or waist circumference. In women, it is known that menopause initiates a shift of body fat toward higher level of abdominal adiposity, which may mediate obesity-related cancer risk. Dual-energy X-ray absorptiometry (DXA) scan can determine whole-body and regional composition of lean and fat mass, but few studies have reported DXA scan-based body composition as predictors of cancer incidence. Accordingly, the aim of this study was to explore the association between obesity, evaluated by DXA scans, and cancer incidence in a cohort of postmenopausal women.
Methods: From 1999-2001, 5,858 women (age 71±6.5) were included in the Prospective Epidemiologic Risk Factor study which involved collection of medical and demographic background information. DXA-scans were collected at time of enrolment. Cancer diagnoses and information on death causes were obtained from different Danish registries ultimo 2012. DXA-scan values were transformed into z-scores and divided into high/low categories. Cox proportional hazard regression models were used to examine the association between body fat distribution and the risk of cancer incidence, adjusted for standard risk factors including BMI.
Results: There were 801 cancer events. In multivariable analysis, trunk fat, but not BMI nor fat percentage, was an independent predictor of cancer incidence (HR: 1.34; 95%, CI: 1.15 to 1.57; p < 0.001). When splitting the cancer-events into different cancer types (breast and ovarian (n=289), lung and gastrointestinal (GI) (n=342) and other cancers (n=170)), women with high abdominal fat ratio had more than 50% increased risk of developing lung and GI cancers compared to those with a low ratio (HR: 1.52; 95%, CI: 1.2 to 2; p < 0.001).
Conclusions: Trunk fat is associated with cancer incidence after adjustment for standard risk factors. These results support previous findings and show that information on fat distribution is important when determining cancer risk, whereas BMI and whole-body fat percentage may not be adequate.
Keywords: abdominal adiposity, geriatric oncology, women, risk prediction
Funding: The Danish Research Foundation
Disclosure: All authors have declared no conflicts of interest.