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Yan M, Toh TS, Lindsay PE, Weiss J, Hueniken K, Yeung C, Sugumar V, Pinto D, Tadic T, Sun A, Bezjak A, Cho J, Raman S, Giuliani M, Moraes FY, Liu G, Hope AJ, Lok BH. Limited-stage small cell lung cancer: Outcomes associated with prophylactic cranial irradiation over a 20-year period at the Princess Margaret Cancer Centre. Clin Transl Radiat Oncol 2021; 30:43-49. [PMID: 34296000 PMCID: PMC8282904 DOI: 10.1016/j.ctro.2021.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 06/27/2021] [Indexed: 11/25/2022] Open
Abstract
Prophylactic cranial irradiation (PCI) was more commonly used in younger patients. PCI utilization rates did not change throughout our 20-year institutional experience. PCI was associated with improved OS and lower brain metastasis risk, independent of MRI follow-up or era of treatment. For LS-SCLC patients with good thoracic response, PCI remains the standard-of-care.
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.
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Affiliation(s)
- 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
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