Survival rates for men with metastatic prostate cancer have increased by an average of six months, something which coincides with the gradual introduction of "dual treatment" since 2016. This is according to a register study of all Swedish men diagnosed between 2008 and 2020. The results are published in JAMA Network open.

Dual treatment means that patients receive both standard hormone therapy (GnRH therapy) and chemotherapy or androgen receptor blockers. Research has previously shown that men receiving this treatment live approximately one year longer than those receiving GnRH treatment alone.

"Dual treatment for men with newly diagnosed metastatic prostate cancer was gradually introduced in Sweden after the results of the randomized trials came in, and dual treatment is now recommended in the national care program for prostate cancer. We wanted to see if the change in treatment of these patients was followed by increased survival," explains Marcus Westerberg from the Department of Surgical Sciences at Uppsala University, one of the researchers behind the study.

Researchers from Uppsala University and San Raffaele Hospital in Milan, Italy, used the National Prostate Cancer Register (NPCR) to study all men diagnosed with metastatic prostate cancer in Sweden between 2008 and 2020.

The results showed that in 2016 only 1% of men at this stage received dual therapy, while 40% received it in 2020. The largest increase was among men aged under 65 and the smallest increase among men over 80.

The average survival rate among these men increased from 2.7 between 2008 and 2012 to 3.2 years in 2017–2020; equivalent to an increase of about six months. The biggest increase in survival was among men under 80. In the analysis, the researchers also took into account age and other diseases.

"Although care should be taken when interpreting our results, we found a clear temporal association between the introduction of dual treatment and improved survival rates. The study suggests that treatments that have been successful in randomized trials are also successful at the population level when introduced into routine care," Westerberg concludes.