Obese Smokers at higher risk of dying from prostate cancer: Study

Sweden: The reduced prostate cancer (PCa) risk for smokers throughout the PSA era, especially for low-risk PCa, is most likely due to smokers' low prostate-specific antigen (PSA) testing uptake, says an article published in European Urology. By contrast, smokers had a higher risk of prostate cancer death, which is further aggravated when smoking status was combined with overweight and obesity. 

"There is a need for further studies to clarify the causes for the poorer diagnosis of PCa observed for smokers and the putative effect of smoking cessation after diagnosis," the researchers wrote in their study. 

Prospective and thorough studies evaluating the relationship between smoking and prostate cancer risk and mortality are limited. As a result, Sylvia H.J. Jochems and colleagues undertook this study to explore pre-diagnosis smoking habits (status, duration, intensity, and quit) as a risk factor for PCa incidence and mortality, both alone and in combination with body mass index (BMI).

Five Swedish cohorts were pooled, collecting data from health tests done in the Construction Workers Cohort between 1974 and 2016. A total of 351 448 males having smoking information from the five Swedish cohorts were included in the study. The hazard ratios (HRs) and confidence intervals (CIs) for PCa incidence (n = 24 731) and mortality (n = 4322) were calculated using Cox regression.

The key findings of this study were as follows:

1. Smoking was linked to a decreased chance of any PCa, with the effect being most obvious in low-risk PCa patients identified during the prostate-specific antigen period.

2. In both the complete cohort and the case-only analysis adjusted for clinical features, smoking was linked with a greater risk of PCa mortality, which was a consistent finding across case groups.

3. The connections for smoking status were reinforced by relationships between smoking intensity and, to a lesser extent, smoking duration and quitting.

4. Smoking combined with obesity (BMI 30 kg/m2) reduced the chance of low-risk PCa incidence while increasing the risk of PCa mortality.

5. The study's weakness is that only a subset of males received information on their smoking habits at the time of their PCa diagnosis.

In conclusion, this big, prospective study found that smokers had a decreased PCa risk, which is likely due to these men's poor PSA testing uptake. Smokers, on the other hand, had a greater risk of PCa mortality, which increased when smoking status was paired with being overweight or obese. More research is needed to determine the reasons for smokers' worse PCa prognosis and the potential benefit of smoking cessation after diagnosis.

Reference:

Jochems, S. H. J., Fritz, J., Häggström, C., Järvholm, B., Stattin, P., & Stocks, T. (2022). Smoking and Risk of Prostate Cancer and Prostate Cancer Death: A Pooled Study. In European Urology. Elsevier BV. https://doi.org/10.1016/j.eururo.2022.03.033