Radiation Therapy May Give Patients With Kidney Cancer Subtype a ‘Level of Comfort’

Radiation therapy may be a viable option for patients with renal cell carcinoma in place of systemic therapy, which can often affect a patient’s quality of life, according to study results.

Dr. Chad Tang, lead author on this study and a professor in radiation oncology at The University of Texas MD Anderson Cancer Center in Houston, told CURE® that the topic of radiation therapy for renal cell carcinoma has been controversial. Prior to this study, others demonstrated that renal cell carcinoma was resistant towards radiation therapy and caused serious toxicities.

“(The study) suggests that for some patients with renal cell carcinoma, we can potentially get some duration of high quality of life before they get systemic therapy through a strategy of basically sequential, non-invasive, local therapy that’s achieved through (stereotactic body radiation therapy) or other high-dose radiation strategies,” Tang said.

The study, which was published in Lancet Oncology, included 30 patients with renal cell carcinoma, five or fewer metastatic lesions and who were previously treated with no more than one systemic therapy. Patients were treated with radiotherapy to all lesions and were not on systematic therapy. Once lesion locations were considered safe, patients were treated with further radiotherapy.

The primary goal of feasibility was met, meaning that all patients went through at least one round radiotherapy with less than seven days of unplanned breaks. Tang explained that feasibility is important because before this study, many did not think radiation for patients with renal cell carcinoma and multiple spots was feasible.

Additionally, at median follow up of 17.5 months, progression-free survival (time during and after treatment when the patient lives without disease progression) was 22.7 months. Tang added that their overall survival rate continued to be 100% as of six months after treatment.

“Those two endpoints are good benchmark comparisons to the available literature. … That’s why its important to have (progression-free survival) and (overall survival) to at least show we’re not doing worse, I would say, than what’s published in the prospective systemic therapy trials for (the) firstline (setting),” Tang said.

Tang explained that an added benefit of this treatment is the impact it has on a patient’s quality of life. He said that universally, patients who are off systemic treatments have improved quality of life. Systemic therapies are excellent and efficient in renal cell carcinoma, but they do involve side effects that can cause pain for patients. Additionally, the cost associated with radiation therapy is lower than systemic therapies, he said.

“The patients who have gone off systemic therapy facilitated by the strategy have universally told me that they feel a lot better and they’re able to do more things in their life,” Tang noted. “Also, they’re telling me when they get their insurance bill, insurance pays for all this regardless. It’s actually a lot less because the current drug prices for immunotherapy doublet combinations are quite substantial. So on a societal level, (it is) potentially also less impactful in terms of the pocketbook for health care costs.”

Two patients had severe side effects that included back pain and muscle weakness, and one patient had life-threatening high blood sugar; there were not treatment-related deaths. “Generally speaking, I would say (radiation therapy) is more favorable than systemic therapy,” Tang added.

Tang noted that this trial only had 30 patients and will continue to expand to further develop this strategy for appropriately selected patients. He said it is important to bring awareness to this treatment option. At his institution, they have started to shift towards this radiation therapy strategy for certain patients.

“I think it’s very easy to tell the patients ‘Hey, look, we can treat you with this and we can watch that little ditzel that may or may not be a spot also in your lung. And if it becomes a disease later on, we can treat that too a year or two later,’” Tang concluded. “(Radiation therapy) gives, I think, people some level of comfort for this type of approach that (they) won’t, at the next follow-up, explode with a bunch of spots because (they’re) off systemic therapy.”

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