J. M. Low1,2, M. Skwarski3,4, R. Macpherson5, G. S. Higgins1,3, and D. R. McGowan1,6; 1Department of Oncology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom, 2Postgraduate Centre, Buckinghamshire Heathcare NHS Trust, Aylesbury, United Kingdom, 3Department of Oncology, University of Oxford, Oxford, United Kingdom, 4Department of Clinical Oncology, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom, 5Department of Radiology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom, 6Department of Medical Physics and Clinical Engineering, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
Purpose/Objective(s): Hypoxia is a common characteristic of solid tumors, including non-small cell lung cancer (NSCLC). Hypoxia is associated with increased resistance to cell death, thus rendering it resistant to standard cancer treatment such as radiotherapy and chemotherapy. Surgical intervention is the primary approach of treatment for NSCLC patients in whom tumor is resectable. However, whether baseline tumor hypoxia affects overall survival and disease progression of patients with NSCLC following surgical management remains unclear. The hypothesis of this retrospective study is that surgical outcomes are worse with the presence of baseline hypoxia, as measured by radiotracer fluoromisonidazole (F-MISO) uptake detected by hypoxia-positron emission tomography/computed tomography (PET-CT), in NSCLC patients who underwent surgical resection during the ATOM trial (NCT02628080) at a single institution. Materials/
Methods: We only selected participants from the ATOM trial who did not receive atovaquone prior to surgical intervention. We then extracted data such as patient demographics, stage of cancer at time of surgery, presence of baseline hypoxia (defined as tumor-to-blood ratio (TBR) 1.4 greater than 1.5 mL), overall survival (OS) at 1 and 3 years, and 1-year progression free survival (PFS). Kaplan-Meier survival analysis for time from surgery to death was compared between patients with or without baseline hypoxia and the p-value was calculated with log-rank test. Results: A total of 26 trial participants from the ATOM study were included in this analysis. The majority were male (n=19, 73.1%), with a mean age of 69.3 years. Fourteen patients had baseline hypoxia whilst 12 patients did not. The 1- and 3-year OS for patients with baseline hypoxia were 86% and 71%, respectively. For those without baseline hypoxia, OS at 1 and 3 years were 92% and 83%, respectively. One-year PFS for patients with baseline hypoxia was 55%; those without hypoxia had 1-year PFS of 80%. Using Kaplan-Meier analysis, there was no statistically significant difference when comparing both groups (p = 0.63). Conclusion: Patients with baseline hypoxia tend to have worse surgical outcomes compared to those without baseline hypoxia. However, the Kaplan Meier survival analysis demonstrated that the difference in survival is not statistically significant. A larger sample size from multi-center studies in the future is warranted to investigate this further.
