3767 - Evaluation of the ESMO-Magnitude of Clinical Benefit Scale Version 1.1 (ESMO-MCBS v.1.1) for the Treatment of Extracranial Oligometastatic Non-Small Cell Lung Cancer with Radiosurgery

J. B. Yu¹, S. Qureshi², V. Jairam³, L. M. Yu⁴, P. Pendyala⁵, A. Riaz⁶, B. W. Corn⁷, E. Sapir⁸, and R. D. Ennis⁹; ¹Saint Francis Radiation Oncology, Hartford, CT, ²Columbia University Irving School of Medicine, New York, NY, ³Yale School of Medicine, New Haven, CT, ⁴Connecticut Radiation Oncology, Hartford, CT, ⁵Department of Radiation Oncology, Cleveland Clinic Akron General, Akron, OH, ⁶CINJ, New Brunswick, NJ, ⁷Shaare Zedek Hospital, Jerusalem, Israel, ⁸University of Michigan, Ann Arbor, MI, ⁹Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ

Purpose/Objective(s): The European Society of Medical Oncology (ESMO) magnitude of clinical benefit (MCBS) version 1.1 is an evaluation scale that is intended to measure the clinical benefit of a cancer-directed treatment. The MCBS scores treatments from 1 through 5 for non-curative therapy, with 1 being lowest clinical benefit vs. 5 being highest. In 2023, ASTRO and ESTRO published joint guidelines for the use of local radiotherapy in the management of extracranial Oligometastatic Non-Small Cell Lung Cancer (OM-NSCLC). We applied the ESMO-MCBS v.1.1 to studies used to inform the guideline. Materials/

Methods: The ASTRO/ESTRO guidelines were informed by 24 studies. These 24 studies were graded by the consensus of at least 3 authors according to ESMO-MCBS v1.1. When a score could not be assigned, the study was noted to be “unscorable” and the reason for the inability to score was recorded.
Results: Five studies were deemed scoreable. Nineteen single-arm and retrospective studies could not be scored. One study (Gomez) was published twice (initial report and update with longer follow up). Scores are shown in the table below. The highest scores given were 4, for randomized comparative studies that showed improvement in overall survival.
Conclusion: The use of local radiation in the treatment of extracranial OM-NSCLC is associated with a strong but not the highest clinical benefit, according to the ESMO MCBS v1.1. Radiotherapy associated scores of 4 were comparable to scores assigned to more expensive therapies such as pembrolizumab in combination with pemetrexed for EGFR and ALK negative metastatic NSCLC. Therefore, we hypothesize that that the “value” of radiotherapy is even greater than high-cost systemic therapies that have equivalent high clinical benefit. Future studies evaluating the benefit of local radiotherapy for OM-NSCLC should be randomized studies that also include evaluations of quality of life to raise scores above 4. Abstract 3767 – Table 1

Study First Author, Year, Journal	Study type	Intervention	Control (Control OS)	Rational for score	Score (Form)
Wang, JNCI 2023	Phase III RCT	Up-front SBRT to all sites of OMD as well as primary tumor prior to TKI therapy	TKI Therapy alone	Median OS for control 7.6 months OS HR 0.44 (95% CI 0.28-0.68)	4 (2a)
Gomez, Lancet Oncol 2016	Randomized Phase II (Initial)	LCT (surgery, RT, or both)	Standard maintenance tx or obs (Not reported)	Median PFS for intervention 11.9 months PFS HR 0.22 (95% CI 0.17-0.46)	3 (2b)
Gomez, JCO 2019	Randomized Phase II (Update)	LCT followed by standard maintenance therapy or obs	Standard maintenance therapy or obs only (17.0 months)	Median OS for control 24.2 months OS HR 0.30 (95% CI 0.12-0.75)	4 (2a)
Iyengar, JAMA Oncol 2018	Randomized Phase II	maintenance chemo + EBRT to primary sites of dz and identified mets	Maintenance chemo only (17 months)	Median PFS for intervention 9.7 months PFS HR 0.304 (95% CI 0.113-0.815)	3 (2b)
Palma, JCO 2020	Randomized Phase II	SOC chemo + SBRT	Standard of care chemo (28 months)	Median OS for control 50 months OS HR 0.48 (95% CI 0.31-0.76)	4 (2a)