Castration ‘An Unfortunate Term’ for Key Part of Prostate Cancer Treatment

When treating patients with prostate cancer, controlling testosterone levels in the body is key, as one expert explained.

“Testosterone is the fuel for prostate cancer cells – it's what gives the cancer the signals to grow and spread and do the things that cancers do,” explained Dr. Atish Choudhury, a genitourinary medical oncologist and the chair of the Gelb Center for Translational Research at Dana-Farber Cancer Institute in Boston. “So, lowering the level of testosterone in the body is the primary way that we treat prostate cancer because that then deprives the cancer of its fuel, and starts the process of killing cancer and putting some of the cancer cells to sleep as well.”

Doctors, Choudhury explained, give patients drugs to lower testosterone in conjunction with radiation treatments.

“There have been multiple clinical trials that have shown that it basically makes the radiation more effective at killing the cancer more completely than if the testosterone stays at its normal levels,” he said.

However, Choudhury acknowledged that “castration,” is a loaded term, used in this context to refer to the chemical lowering of a patient’s testosterone.

“Castration is a very unfortunate term that is used to describe the process of lowering levels of testosterone in the body, and it's been associated with actual surgical castration, which was a treatment that we used for prostate cancer previously, where you actually remove a man's testes and decrease the level of testosterone in that way. That was actually a very effective way to treat advanced prostate cancers,” Choudhury said. “Here, we're using hormone mimics or hormone blockers to lower the level of testosterone in the body.

“And so, it can certainly have many of the same sorts of side effects as what a surgical castration might in terms of the hormonal changes, but here those side effects are intended to be quite temporary, to make the radiation work as well as possible. And then we would then allow the testosterone to recover back to normal levels, and then the side effects should eventually then wear off.”

Those side effects, Choudhury said, include an expected reduction in both sexual interest and sexual function as the testosterone is lowered — although, as he noted, occasional patients still retain some libido and are able to achieve erections while their testosterone levels are low.

“The other side effects are very similar to what women might go through during menopause, which is a sudden hormonal change in them – so can certainly lead to things like fatigue, hot flashes, moodiness and achiness.

“But some of the concerning symptoms with long-term low testosterone is it can lead to weight gain, it can lead to metabolic changes, like increasing blood sugar and blood cholesterol, decreasing muscle mass and decreasing bone mass. That's why it's very important that after the treatment is done, we want the testosterone to recover back to the normal range, so people are not having to deal with those sorts of long-term side effects.”

These treatments and their accompanying unfortunate side effects, Choudhury explained, are in the interest of patients’ long-term quality of life.

“There is a trade-off when we use hormonal treatments with radiation to make it work as well as possible and lead to side effects that are going to worsen short-term quality of life,” he said. “It's all with the intention of decreasing the risk of a recurrence that can lead to bigger quality of life issues down the line. So, we have to think about quality of life in the short term, but also over the course of the patient's remaining life expectancy.”

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