Multi-Institutional Patterns of Use of Tumor-Treating Fields for Patients with Malignant Pleural Mesothelioma

Our plain-English summary of Multi-Institutional Patterns of Use of Tumor-Treating Fields for Patients with Malignant Pleural Mesothelioma, by T. Kutuk, J.M. Walker, M.T. Ballo, et al (Current Oncology, 2023).

The study

• Authors: T. Kutuk, J.M. Walker, M.T. Ballo, R.B. Cameron, J.B. Alvarez, S. Chawla, E. Luk, D. Behl, A. Dal Pra, N. Morganstein, T. Refaat, A. Sheybani, C. Squillante, J. Zhang, R. Kotecha
• Journal: Current Oncology
• Published: 2023;30(6):5195-5200
• Read it: PubMed · Publisher · Free full text

Abstract

(1) Background: The objective of this analysis was to evaluate the device usage rates and patterns of use regarding Tumor-Treating Fields (TTFields) for patients with malignant pleural mesothelioma (MPM) throughout the US. (2) Methods: We evaluated de-identified data from 33 patients with MPM enrolled in FDA-required HDE protocols at 14 institutions across the US from September 2019 to March 2022. (3) Results: The median number of total TTFields usage days was 72 (range: 6-649 days), and the total treatment duration was 160 months for all patients. A low usage rate (defined as less than 6 h per day, 25%) was observed in 34 (21.2%) months. The median TTFields usage in the first 3 months was 12 h per day (range: 1.9-21.6 h), representing 50% (range: 8-90%) of the potential daily duration. The median TTFields usage after 3 months decreased to 9.1 h per day (range: 3.1-17 h), representing 38% (range: 13-71%) of the daily duration, and was lower than usage in the first 3 months (p = 0.01). (4) Conclusions: This study represents the first multicenter analysis of real-world TTFields usage based on usage patterns for MPM patients in clinical practice. The real-world usage level was lower than the suggested daily usage. Further initiatives and guidelines should be developed to evaluate the impact of this finding on tumor control.

In plain English

This short report, called a Communication, examined how much patients with malignant pleural mesothelioma actually used Tumor-Treating Fields (TTFields), a device whose arrays are applied to the chest. The authors looked back at device-log data from 33 patients with unresectable disease treated at 14 US institutions between September 2019 and March 2022. Patients were advised to wear the device at least 18 hours a day. Median use was 12 hours a day (50% of the day) in the first three months and 9.1 hours a day (38%) after three months. The authors reported this drop as statistically significant (p = 0.01). Over all treatment, median use was 10.3 hours a day (43%). Three patients (9.1%) used the device more than 75% of the time, the level the manufacturer suggests. Twenty-three patients (69.7%) stopped treatment, most often in the first three months. The authors concluded that real-world use was lower than the suggested daily use and that the decline needs further study. Because the data were de-identified, they could not evaluate clinical outcomes.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective multi-institutional analysis of de-identified device usage data (published as a Communication)
• Who was studied: 33 patients with histologically confirmed unresectable malignant pleural mesothelioma (MPM) enrolled in FDA-required Humanitarian Device Exemption (HDE) protocols at 14 US institutions, September 2019 to March 2022
• Exposure: Treatment with continuous Tumor-Treating Fields at 150 kHz delivered through arrays on the chest. Patients were advised to wear the device at least 18 hours a day. The article does not study asbestos exposure.
• Main results:
  • Across all patients, the median number of total TTFields usage days was 72 (range: 6 to 649 days). Total treatment duration for all patients was 160 months.
  • Low usage, defined as less than 6 hours a day (25%), was seen in 34 (21.2%) of the treatment months.
  • In the first three months, median use was 12 hours a day (range: 1.9 to 21.6 h), or 50% (range: 8 to 90%) of the potential daily duration.
  • After three months, median use fell to 9.1 hours a day (range: 3.1 to 17.0 h), or 38% (range: 13 to 71%) of the day. This was lower than in the first three months (p = 0.01).
  • Over all treatment courses, median use was 10.3 hours a day (range: 1.9 to 21.4 h), or 43% (range: 8 to 89%) of the day.
  • Three (9.1%) patients used the device more than 75% of the time, the manufacturer-suggested usage. Four (12.1%) used it more than 68%, the median usage rate in the earlier STELLAR study.
  • Six (18.2%) patients had usage below the low usage rate.
  • Use differed significantly across months: highest in the first treatment month at 56% (range: 8 to 90%) and lowest in the last treatment month at 32% (range: 1 to 74%) (p less than 0.05).
  • Twenty-three (69.7%) patients discontinued treatment, most commonly in the first three months. Four (12.1%) discontinued by the first month.
  • Median time on treatment was 2 months (range: 1 to 7) for physicians who treated one to four patients and 5 months (range: 1 to 23) for physicians who treated five or more (p = 0.037). Median monthly usage rate did not differ by physician experience (44.5% vs 42%, p = 0.57).
• The authors' conclusion: The authors concluded that TTFields is a feasible treatment for appropriately selected MPM patients. They found real-world use lower than the suggested daily use and said the decline after the first 3 months calls for further evaluation and optimization of treatment strategies.
• Limitations the authors state:
  • The study was retrospective, so prior treatments such as chemotherapy and radiotherapy regimens were not standardized across participants.
  • The number of patients was limited because MPM is rare and TTFields has specific indications.
  • Because the data were de-identified, clinical outcomes and patterns of failure could not be evaluated.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma.

Related studies

• Integration of Tumor-Treating Fields into the Multidisciplinary Management of Patients with Solid Malignancies — Y. Wang, M. Pandey, et al. (2019)
• Feasibility of Tumor Treating Fields with Pemetrexed and Platinum-Based Chemotherapy for Unresectable Malignant Pleural Mesothelioma: Single-Center, Real-World Data — T. Kutuk, H. Appel, et al. (2022)
• Prevention and Management of Dermatologic Adverse Events Associated With Tumor Treating Fields in Patients With Glioblastoma — M.E. Lacouture, M.J. Anadkat, et al. (2020)
• Expert guidance on prophylaxis and treatment of dermatologic adverse events with Tumor Treating Fields (TTFields) therapy in the thoracic region — M.J. Anadkat, M. Lacouture, et al. (2022)
• Advancements and current trends in tumor treating fields: a scientometric analysis — Y. Xing, F. Yasinjan, et al. (2024)
• Tumor Treating Fields dually activate STING and AIM2 inflammasomes to induce adjuvant immunity in glioblastoma — D. Chen, S.B. Le, et al. (2022)

Browse more research in Current Oncology, or return to medical research.