QoL not diminished by tumor-treating fields therapy for glioblastoma
medwireNews: Adding tumor-treating fields (TTFields) to standard treatment with temozolomide does not negatively affect health-related quality of life (HRQoL) in patients with newly diagnosed glioblastoma, an analysis of EF-14 data shows.
The only exception was more itchy skin which is “an expected consequence from the transducer arrays,” Martin Taphoorn (Haaglanden Medical Center, The Hague, the Netherlands) and co-investigators remark.
As previously reported by medwireNews, the phase III EF-14 randomized clinical trial compared TTFields and temozolomide with temozolomide alone in 695 patients who had undergone surgery and radiotherapy for glioblastoma. It showed that TTFields therapy significantly improves both progression-free and overall survival in these patients.
However, the nature of the treatment, in which patients are required to have four transducer arrays attached to their shaved scalp and be connected to a portable medical device for at least 18 hours per day for 5 days during each 28-day cycle, means it is important to also assess HRQoL.
In this secondary analysis of EF-14 data, Taphoorn and team found that eight of nine predefined HRQoL scales remained stable (<10-point change from baseline) in both treatment arms throughout the 12-month assessment period.
However, for itchy skin there was a significant and clinically relevant deterioration (10.4-point decrease from baseline), indicating increased itchiness, at 3 months in the TTFields plus temozolomide arm, compared with a small improvement (2.3 points) in the temozolomide arm. The difference between the arms remained significant at 6 and 9 months, but not at 12 months.
The researchers report in JAMA Oncology that deterioration-free survival was significantly longer with TTFields for global health status (4.8 vs 3.3 months), physical (5.1 vs 3.7 months) and emotional functioning (5.3 vs 3.9 months), pain (5.6 vs 3.6 months), and leg weakness (5.6 vs 3.9 months).
“The prolonged deterioration-free survival for these scales is explained by the extended progression-free survival for patients in the combined TTFields plus temozolomide arm, as progressive disease is included as an event in this analysis,” Taphoorn et al write.
When disease progression was removed as a deterioration event, to reflect the influence of treatment, the investigators found that the only negative influence TTFields plus temozolomide had on HRQoL was for itchy skin, whereby the time to deterioration (TTD) was 8.2 months versus a significantly longer 14.4 months with temozolomide alone.
By contrast, adding TTFields to temozolomide significantly prolonged the TTD for pain compared with temozolomide alone, at 13.4 versus 12.1 months. There were no significant TTD differences between the groups for global health, physical, cognitive, role, social, and emotional functioning, or for weakness of legs.
“Combining the results of the survival and HRQoL analyses suggests that the addition of TTFields to adjuvant temozolomide is of value to patients with glioblastoma,” Taphoorn and colleagues conclude.
In an accompanying commentary, Lia Halasz (University of Washington, Seattle, USA) and Timur Mitin (Oregon Health and Sciences University, Portland, USA) say that although it is “comforting” to know that TTFields did not negatively affect HRQoL, it is important to remember that participants chose to take part in the trial, and were therefore already open to wearing a device on their scalp every day.
“In our experience, there are many social and cultural reasons that patients have for declining TTFields despite the data of improved survival,” they write.
Halasz and Mitin conclude: “Overall, these new data on HRQoL, coupled with the overall survival results of EF-14, strengthen the inclusion of TTFields as an important treatment for our patients with [glioblastoma] if they are willing to wear the device.”
By Laura Cowen
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