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2019 Thoracic Cancers Symposium: Trends in Use of Prophylactic Cranial Irradiation for Extensive-Stage SCLC

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Key Points

  • All 49 radiation oncologists who specialized in treating thoracic cancers were aware of the Takahashi et al trial, and two-thirds (67%) had altered their practice in response to its findings.
  • Fewer than half of those who offered prophylactic cranial irradiation for extensive-stage SCLC prior to 2017 continued to do so after it was published.
  • Researchers confirmed the trend of shifting away from prophylactic cranial irradiation in a subsequent nationwide survey of radiation oncologists (n = 431).

A new survey of radiation oncologists points to a sharp decline in the use of prophylactic cranial irradiation for patients with extensive-stage small cell lung cancer (SCLC), indicating a rapid change in standard practice for the disease following the 2017 publication of a major clinical trial by Takahashi et al in The Lancet Oncology. Survey results were presented in a presscast in advance of the 2019 Multidisciplinary Thoracic Cancers Symposium (Abstract 3).

“SCLC has a tendency to spread past the lungs to the brain, and brain metastases substantially diminish a patient’s quality of life. Prophylactic cranial irradiation is preventative radiation therapy given after first-line treatment to eliminate cancerous cells before they become symptomatic metastases,” said Olsi Gjyshi, MD, PhD, first author of the study and a radiation oncology resident at The University of Texas MD Anderson Cancer Center.

“Radiation oncologists largely adopted prophylactic cranial irradiation for extensive-stage SCLC following the 2007 publication of a randomized EORTC trial [in The New England Journal of Medicine] that linked its use to extended overall survival. However, with the recent publication [by Takahashi et al in The Lancet Oncology] of a Japanese trial showing no survival benefit from prophylactic cranial irradiation compared to magnetic resonance imaging surveillance, it is important to come to a consensus on how best to treat these patients. Our survey indicates that most providers no longer routinely use prophylactic cranial irradiation for patients with extensive-stage disease that responds to chemotherapy.”

Radiation Oncologist Survey Results

To determine the extent of practice changes, researchers surveyed attending radiation oncologists at academic cancer centers across the United States (24% survey response rate). Anonymous email surveys were collected in September 2018, more than a year after the Takahashi et al trial was published, and the same year National Comprehensive Cancer Network (NCCN®) Guidelines were updated to reflect its findings.

All 49 radiation oncologists who specialized in treating thoracic cancers were aware of the Takahashi et al trial, and two-thirds (67%) had altered their practice in response to its findings. Specifically, fewer than half of those who offered prophylactic cranial irradiation for extensive-stage SCLC prior to 2017 continued to do so after it was published (78% vs 38%, P < .001).

Researchers confirmed the trend of shifting away from prophylactic cranial irradiation in a subsequent nationwide survey of radiation oncologists (n = 431). The trend was consistent across private practices and academic centers. One-fourth of these physicians reported a decline in prophylactic cranial irradiation referrals by medical oncology for patients with extensive-stage SCLC, and 12% also reported fewer referrals for limited-stage SCLC.

“With extensive-stage disease, prophylactic cranial irradiation may best be reserved for patients who are likely to benefit from it, such as those with excellent performance status, younger age (< 70 years), and excellent cognitive functions at baseline,” said Dr. Gjyshi. “Caution should be used in extrapolating the Takahashi et al data to patients with limited-stage disease, and further trials may be necessary to address this question.”

“Declining prophylactic cranial irradiation use could impact enrollment in future clinical trials, however, so careful consideration should be given to future studies and trials that plan to investigate the role of prophylactic cranial irradiation in this patient population,” he concluded.

Disclosure: The study presenter’s full disclosures can be found at thoracicsymposium.org.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.


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