[Lancet] Overweight/obesity affects risk of common cancers An epidemiological survey published in the Lancet recently showed that higher body mass index (BMI) was associated with an increased risk of developing 10 common cancers. This is the largest study of its kind, with data from more than 5 million UK adults included. Researchers from the London School of Hygiene and Tropical Medicine and the Farr Institute of Health Informatics estimate that more than 12,000 cases of these 10 cancers are associated with being overweight or obese in the UK each year, and that if the average BMI of the population continues to grow, there will be an additional 3,000 or so cancer cases each year. ”The number of people who are overweight and obese is growing rapidly in the UK and around the world. It is now well known that obesity induces more diabetes and cardiovascular disease. And our findings show that if this trend continues, we will also see more cases of cancer emerge.” Study leader Krishnan, from the London School of Hygiene and Tropical Medicine? Krishnan Bhaskaran, PhD, said. Using data from the UK Clinical Practice Research Datalink (CPRD), the researchers included 5.24 million subjects aged 16 years and older and followed them for an average of 7.5 years. The researchers recorded the subjects’ body mass index (BMI), corrected for age, sex, smoking status and other factors, to compare the differences in cancer risk among individuals with different BMIs. At the end of the study, a total of 166,955 subjects were detected with one of the 22 most common types of cancer. The results showed that for every 5 (in kg/m2) increase in body mass index from normal, there was a significant increase in the risk of cancer at each of the following sites: a 62% increase in the risk of uterine tumors, a 31% increase in gallbladder cancer, a 25% increase in kidney cancer, a 10% increase in cervical cancer, and an approximately 9% increase in the risk of thyroid cancer and leukemia. Higher body mass index also increased the overall risk of liver, colon, ovarian and breast tumors, but there was variation in the effects. In some cancer types, higher body mass index within the normal range also appears to be associated with increased risk. In addition, there are data suggesting that the risk of prostate and premenopausal breast cancers may be slightly reduced in people with higher body mass index. There is a lot of variation in the effect of body mass index on different cancers,” Baskaran explained. For example, at higher BMI, the risk of uterine tumors increases substantially; for other cancers, we observe a more modest increase in risk or no change in risk. For some cancers, such as breast cancer that appears before menopause, those with higher BMI appear to have an even lower risk. These differences tell us that weight affects cancer risk in several different ways, depending on the specific type of cancer.” Based on the results, the researchers estimate that excess weight in the UK may be responsible for 41 percent of uterine tumors, and 10 percent or more of gallbladder, kidney, liver and colon cancers. They also concluded that when the average BMI in the population as a whole rises by 1 kg/m2 (equivalent to about 3 to 4 kg of extra weight gain per person), it leads to about 3,790 additional cases of cancer in the UK each year. In a related commentary, Peter Campbell from the American Cancer Society (ACS) said that the increase in BMI would result in an additional 3,790 cancer cases per year in the UK. Campbell (Dr. Peter Campbell) said: “We have ample evidence that obesity is an important cause of much unnecessary cancer disease and death. Adjusting health policies to curb obesity is necessary and no more research is needed to prove this.” Body mass index in this study was calculated by dividing body weight by height squared (in kg/m2). A range of 18.5 to 24.9 was used as the ideal range, with 25 to 29.9 considered overweight and 30 or more considered obese.