Limited-stage small cell lung cancer: Outcomes associated with prophylactic cranial irradiation over a 20-year period at the Princess Margaret Cancer Centre

Michael Yan; Tzen S. Toh; Patricia E. Lindsay; Jessica Weiss; Katrina Hueniken; Christy Yeung; Vijithan Sugumar; Dixon Pinto; Tony Tadic; Alexander Sun; Andrea Bezjak; John Cho; Srinivas Raman; Meredith Giuliani; Fabio Ynoe Moraes; Geoffrey Liu; Andrew J. Hope; Benjamin H. Lok

Clinical and Translational Radiation Oncology (Sep 2021)

Limited-stage small cell lung cancer: Outcomes associated with prophylactic cranial irradiation over a 20-year period at the Princess Margaret Cancer Centre

Michael Yan,
Tzen S. Toh,
Patricia E. Lindsay,
Jessica Weiss,
Katrina Hueniken,
Christy Yeung,
Vijithan Sugumar,
Dixon Pinto,
Tony Tadic,
Alexander Sun,
Andrea Bezjak,
John Cho,
Srinivas Raman,
Meredith Giuliani,
Fabio Ynoe Moraes,
Geoffrey Liu,
Andrew J. Hope,
Benjamin H. Lok

Affiliations

Michael Yan: Department of Oncology, Cancer Centre of Southeastern Ontario, Queen’s University, Kingston, ON, Canada
Tzen S. Toh: The Medical School, University of Sheffield, Sheffield, United Kingdom; Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, ON, Canada
Patricia E. Lindsay: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
Jessica Weiss: Department of Biostatistics, Princess Margaret Cancer Centre, Toronto, ON, Canada
Katrina Hueniken: Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Biostatistics, Princess Margaret Cancer Centre, Toronto, ON, Canada
Christy Yeung: Department of Laboratory Medicine and Pathology, University of Toronto, Toronto, ON, Canada
Vijithan Sugumar: Department of Physiology and Pharmacology, Western University, London, ON, Canada
Dixon Pinto: Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
Tony Tadic: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
Alexander Sun: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
Andrea Bezjak: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
John Cho: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
Srinivas Raman: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
Meredith Giuliani: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
Fabio Ynoe Moraes: Department of Oncology, Cancer Centre of Southeastern Ontario, Queen’s University, Kingston, ON, Canada
Geoffrey Liu: Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada
Andrew J. Hope: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
Benjamin H. Lok: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, ON, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada; Corresponding author at: Princess Margaret Cancer Centre, 610 University Ave, Toronto, ON M5G 2M9, Canada.

Journal volume & issue: Vol. 30
pp. 43 – 49

Abstract

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Background & purpose: Prophylactic cranial irradiation (PCI) is recommended for limited-stage small-cell lung cancer (LS-SCLC) patients with good response to concurrent chemoradiation. We report our institution’s 20-year experience with this patient population and associated clinical outcomes. Materials & methods: A retrospective cohort of consecutive LS-SCLC patients treated with curative intent chemoradiation at our institution (1997–2018) was reviewed. Overall survival (OS) was calculated using the Kaplan-Meier method, and significant covariates determined by the Cox proportional hazards model. Covariates predictive of PCI were determined using Fisher's exact test and the Mann-Whitney test. Brain failure risk (BFR) was calculated using the cumulative incidence method treating death as a competing event. Treatment cohorts (historic vs. contemporary) were stratified by the median year of diagnosis (2005). Results: A total of 369 patients with LS-SCLC were identified, of which 278 patients were notionally PCI eligible. PCI was given to 196 patients (71%). Younger age was associated with PCI utilization (p < 0.001). PCI utilization rates did not change between the historic and contemporary treatment era (p = 0.11), whereas magnetic resonance imaging (MRI) use at baseline and follow-up became more prevalent in the contemporary era (p = <0.001). On multivariable analysis, PCI utilization was associated with improved OS (HR 1.88, 95% CI 1.32–2.69) and decreased BFR (HR 4.66, 95% CI 2.58–8.40). Patients who had MRI follow-up had a higher incidence of BFR (HR 0.35, 95% CI 0.18–0.66) in multivariable analyses. Conclusions: For LS-SCLC patients at our institution, PCI is more frequently utilized in younger patients, and the utilization rate did not change significantly over the past 20 years. PCI was independently associated with improved OS and lower BFR. Omission of PCI in LS-SCLC patients should not be routinely practiced in the absence of further prospective data.

Published in Clinical and Translational Radiation Oncology

ISSN: 2405-6308 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Medicine: Medicine (General): Medical physics. Medical radiology. Nuclear medicine; Medicine: Internal medicine: Neoplasms. Tumors. Oncology. Including cancer and carcinogens
Website: https://www.journals.elsevier.com/clinical-and-translational-radiation-oncology

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