Two recent studies from the University of Virginia School of Medicine concluded that radiation treatment should be delayed for as long as possible after prostate removal in cancer patients to prevent unwanted side effects.
Timothy Showalter, a radiation oncologist from the UVA Cancer Center, said in a press release: “The common teaching has been, without clear evidence, that urinary incontinence and erectile function are worse when radiation is delivered earlier rather than later, but we didn’t see any protective effect of delayed radiation compared to earlier radiation. It contradicts the clinical principle of delaying radiation as long as possible for the sake of the patient’s side effects. It really speaks against that, and that ought not to be used for a reason to delay radiation.”
The outcomes raised discussion about the preferences on the use of adjuvant therapy — in which radiation is given soon after the prostate is removed to kill any of the remaining cancer cells — and salvage therapy, where radiation is given later. “Urologists tend to prefer to forgo adjuvant radiation therapy, because they fear the side effects, and radiation oncologists tend to prefer offering adjuvant radiation therapy because they fear the risk of metastasis [cancer spreading to other sites in the body],” Showalter explained.
He continued: “There’s this commonly held belief that the longer you delay radiation therapy, the more opportunity a patient has for recovery from prostatectomy, and therefore the better long-term function in terms of urinary and bowel function — the longer you delay it, the better they’ll function. A lot of clinicians believe that if you wait six months, 12 months, 18 months, that each additional step gets you some benefit in terms of toxicity. That didn’t make sense to me from a medical perspective, because I can’t think of any other surgery where we think recovery requires a year or more. We often, for other cancers, deliver post-operative radiation very soon.”
The findings are supported by the outcomes of almost 16,000 patients and show no evidence of adjuvant therapy increasing erectile dysfunction. “What we found is that the addition of radiation therapy after prostatectomy does lead to a noticeable increase in GI [gastrointestinal] and GU [genitourinary] side effects. However, delaying radiation therapy offers no protective benefit and in fact may increase the risk of GI complications,” Showalter stated.
Researchers suggest that patients should discuss the best strategy for their treatment with their physicians. “If someone’s at generally low risk of prostate cancer reoccurrence and they have low-grade disease, it’s probably still reasonable to take a delayed salvage radiation therapy approach. Once there’s a real, compelling reason to deliver radiation, there doesn’t seem to be a benefit to delaying their radiation in terms of avoiding complications. And we know from other studies, the earlier radiation is delivered, the more effective it is for these patients. The more likely it is to cure them,” Showalter concluded.