New research has shown that experiencing menopause before the age of 45 is associated with a higher risk of bladder cancer; this higher risk was even more notable in smokers. The study, which looked at health outcomes in more than 220,000 patients, was presented by Abufaraj et al at the European Association of Urology (EAU) 2019 Congress (Abstract 175).
Bladder cancer is more common in men than in women, but women are more likely to suffer from advanced bladder cancer and are less likely to survive than men. Around 27,000 European women and 19,000 American women are diagnosed with bladder cancer each year.
About 1 woman in 20 undergoes early menopause—ie, before the age of 45 years. The average age at menopause is 51 in developed countries.
Researchers studied the medical history of nurses who had enrolled in the Nurses’ Health Study I and II. They found that women who started menopause before age 45 were 45% more likely to have bladder cancer than those who experienced menopause after age 50. If these women had smoked, the risk of bladder cancer was 53% greater than among women who had later menopause.
Lead researcher Mohammad Abufaraj, MD, of the Medical University of Vienna, commented, “We found that smoking women who experienced menopause before they were 45 years old had a greater risk of bladder cancer. Smoking remains the most important risk factor for bladder cancer. Our data also revealed that it is unlikely that female factors—such as [menarche], number of pregnancies, oral contraceptive use, or the use of hormone replacement therapy—are associated with bladder cancer risk. Smoking is associated with earlier age at menopause, thereby further increasing the risk of developing bladder cancer.”
Dr. Abufaraj added, “This study indicates that earlier age at menopause (that is, shorter reproductive life) seems to increase the risk of bladder cancer. Our primary interpretation is that a factor like smoking, which is known to correlate with earlier age at menopause, remains of grave concern as the main cause of bladder cancer. It reinforces the warning that smoking really is harmful in ways that we might not have easily imagined.”
Previous research published by Rink et al in European Urology found that smoking has a dose-response relationship with prognosis in both early and advanced bladder cancer. Moreover, 10 years after stopping smoking, this risk had returned to the same level as that of nonsmokers.
Disclosure: The study authors’ full disclosures can be found at scientific-programme.uroweb.org/eau19.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.