Main Session
Sep
29
PQA 07 - Head and Neck Cancer, Lung Cancer/Thoracic Malignancies, and Nursing and Supportive Care
3621 - Time to Change of Systemic Therapy Following Local Consolidative Therapy in Oligoprogressive Non-Small Cell Lung Cancer
Presenter(s)
Yuhao Shi, MD, PhD - NYU Langone Health- Radiation Oncology, New York, NY
Y. Shi1, N. Mohamed1, J. Xiao1, J. K. Sabari2, E. Shum2, A. Chachoua3, M. Zervos3, P. B. Schiff1, J. T. Yang1, D. R. Gomez1, and B. T. Cooper1; 1Department of Radiation Oncology, NYU Grossman School of Medicine, New York, NY, 2Perlmutter Cancer Center, NYU Grossman School of Medicine, New York, NY, 3NYU Langone Health, New York, NY
Purpose/Objective(s):
Disease progression often requires a change to systemic therapy for metastatic non-small cell lung cancer patients, which can result in new adverse effects and reduced quality of life. This change may be avoided by comprehensive local consolidative therapy (LCT) to progressive sites of disease. Currently, disease trajectory after LCT remains unclear, particularly regarding time to change systemic therapy (TTCS). We evaluate patients treated with LCT for oligoprogression, to evaluate TTCS differences based on systemic therapy regimen, LCT sites and courses.Materials/Methods:
We assessed 447 patients diagnosed with lung cancer receiving LCT in the form of stereotactic body radiation therapy (SBRT) from 1/1/2017-12/22/2025. Eligible patients had oligoprogressive disease (=5 progressive lesions) and received comprehensive LCT. TTCS was defined as time from the last fraction of LCT to a change in systemic therapy or death. Clinical characteristics were compared using Fischer’s exact test. TTCS was compared using Kaplan Meier method and log rank test.Results:
Forty-four patients had oligoprogressive disease and trajectory data >3 months after initial course of LCT. At the time of LCT, 52.2% (n=23) were receiving tyrosine kinase inhibitor (TKI)-based therapy, 29.5% (n=13) received immune oncology (IO)-based therapy, 6.8% (n=3) received only chemotherapy, and 11.4% (n=5) were off systemic therapy. Eighty four percent of patients received only one course of treatment, and 98% received LCT to a single site of oligoprogression. The most common sites of LCT were lung (51%), bone (23%), and adrenal gland (13%). Forty-two percent of patients had EGFR alterations, 7% had ALK mutations, and 51% had other oncologic mutations. LCT of bone oligoprogression trended towards a lower TTCS than treatment of lung/adrenal gland sites (5.7 vs. 7.9/31.5 months, respectively, p=0.19). In addition, a higher proportion of patients receiving TKIs had treatment to bone sites (31.8% TKI vs 8.3% IO) and a lower proportion had treatment at adrenal sites (9.1% TKI vs 25% IO). Median TTCS was significantly lower for patients with EGFR-altered vs -wildtype tumors (5.7 vs 17.3 months, P=0.006) and for patients receiving TKI vs IO therapies (5.4 vs 10.2 months, P=0.040). Median TTCS was 31.5 vs 7.1 months for those receiving multiple vs single course LCT (P=0.20). Median TTCS after the first LCT course was similar to that after the second course and beyond, 9.9 vs 11.7 months.Conclusion:
In summary, we found that a significant percentage of patients were able to remain on initial systemic therapy for prolonged periods. Importantly, the benefit of LCT in prolonging TTCS does not appear to be attenuated with multiple courses, suggesting that repeat LCT may continue to be leveraged to further delay systemic therapy change. Differences in TTCS amongst EGFR-altered vs wildtype tumors may be explained by differences in LCT site. Prospective assessments of multiple SBRT courses in the setting of oligoprogression are needed.