Weight gain in middle age linked to poorer prostate cancer prognosis
Gaining weight in adulthood is common. But how much does weight gain actually affect our lives? More specifically, how does it affect men’s chances of surviving a prostate cancer diagnosis? Researchers at Halmstad University have investigated these questions.
”A strength of the study is that it is based on repeated weight measurements over several decades. This provides a more detailed picture of how weight changes throughout life compared with studies that use only a single measurement.”
Marisa da Silva, Research Coordinator
Every year, around 10,000 people in Sweden are diagnosed with prostate cancer, and nearly 2,500 die from the disease. This makes prostate cancer the most common form of cancer among men in Sweden and the one that causes the most deaths.
Researchers from Halmstad University and other institutions have followed more than 250,000 Swedish men over a period of 25 years, studying changes in their weight between the ages of 17 and 60. By combining data from research cohorts and national registers, the researchers were able to analyse the associations between weight changes, prostate cancer and survival.
The results show that weight gain during adulthood does not appear to be associated with an increased risk of developing aggressive prostate cancer. Instead, the study shows that men who gained more weight before diagnosis had a higher risk of subsequently dying from the disease. In other words, weight gain did not appear to increase the risk of developing aggressive prostate cancer. But among men who were diagnosed with the disease, weight gain before diagnosis was associated with a higher risk of dying from it.
Weight gain between the ages of 45 and 60 in particular was associated with poorer survival. The association remained even after the researchers took into account how far the disease had progressed at the time of diagnosis.
PSA testing affects research
The study also highlights the methodological challenges involved in prostate cancer research. Since blood tests measuring the level of prostate-specific antigen (PSA) in the blood were introduced in Swedish healthcare, more cases of less aggressive prostate cancer have been detected, which may affect the results of epidemiological studies. In addition, men who undergo PSA testing tend to be more health-conscious and have a lower risk of being overweight than those who do not. The researchers therefore analysed the results separately for the periods before and after PSA testing became common in Sweden.
“A strength of the study is that it is based on repeated weight measurements over several decades. This provides a more detailed picture of how weight changes throughout life compared with studies that use only a single measurement”, says Marisa da Silva, Research Coordinator at Halmstad University and one of the researchers behind the study.
Marisa da Silva and her research colleagues hope that the findings can contribute to a better understanding of how changes in body weight associated with cancer development and survival, as well as inspire further studies that take a life-course perspective on health and disease.
Text: Vilma Olofsson
Photo: iStock
