Many drugs are being tested to fight Covid-19, but now researchers report that blocking testosterone might help prevent the infection in men.
Italian men with prostate cancer on androgen-deprivation therapy (ADT) were less likely to get infected with Covid-19 and had less severe cases if they were infected, the researchers found.
Lead researcher Dr Andrea Alimonti, an oncologist at the Università della Svizzera Italiana in Bellinzona, Switzerland, thinks it might be worth trying this therapy on men with severe cases of Covid-19.
"This could give us a therapeutic window to treat patients that have been infected and haven't gotten better, to see whether this therapy would lead them to recover faster or to decrease the severity of their symptoms," he said.
Alimonti's interest was piqued when he saw data that men were more likely to develop Covid-19 than women and suffer more severe bouts of the disease.
Putting two and two together, he realised that an enzyme (TMPRSS2), which Covid-19 needs to infect cells, was blocked by androgen-deprivation therapy.
"For many years, we have known that androgen-deprivation therapy can block the level of this enzyme. My speculation was this could explain that androgen levels control this enzyme and why men can be infected and develop more severe symptoms, compared to women," Alimonti said.
Based on this retrospective study, Alimonti doesn't think this therapy should be used to treat men, in general, to possibly prevent Covid-19.
"We cannot say that the non-prostate cancer patient will benefit, because this needs to be validated in a prospective clinical study," he explained.
For the study, Alimonti and his colleagues collected data on more than 4 500 men in the Veneto region of Italy.
The investigators found that men who had cancer had nearly two times the risk for Covid-19, but only four men getting ADT became infected, and none died.
Very interesting biology
When the researchers looked at more than 37 000 men with prostate cancer who were not taking ADT, 114 developed Covid-19 and 18 died. But among more than 79 000 men with other cancers, 312 developed Covid-19 and 57 died.
Dr Anthony D'Amico, a professor of radiation oncology at Harvard Medical School in Boston, thinks other factors might explain why men with prostate cancer are less likely to get Covid-19.
For one, men with prostate cancer receiving ADT aren't immunosuppressed like other cancer patients, he said. Second, these men get one shot of ADT and can stay home, unlike other cancer patients who need frequent trips to the hospital for chemotherapy, which puts them at greater risk for infection.
"I don't want to put a big damper on this. The biology is very interesting. There very well may be something there, but I think that there are confounders here," D'Amico said.
Men shouldn't be asking their doctors to start them on ADT in hopes of avoiding getting infected, he said.
"If you're on ADT, there may be some protective benefit, but I still would advise you to pay attention to the national guidelines on physical distancing, as well as frequent hand-washing, because it's not proven that, in fact, ADT will protect you from getting the infection and if you get it it'll be less severe, so I'm cautious," D'Amico said.
Dr Manish Vira, system chief of urology at Northwell Cancer Institute in Lake Success, New York, agreed that men shouldn't be seeking ADT.
"This study is very preliminary, and by no means is a definitive study to recommend changing treatment or treating patients with ADT," he said. "ADT has its own set of side effects, and I agree it's way too early to recommend this type of treatment."
ADT can cause hot flashes, fatigue, loss of lean muscle mass, and in the long term, can cause a decrease in bone mineral density and metabolic and cardiovascular issues that affect patients who have diabetes. "So, this is certainly not something that's easy as, say, taking a baby aspirin," Vira explained.
The report was published on 6 May in the Annals of Oncology.