The 65th Annual Meeting & Exhibition of the Southern Thoracic Surgical Association kicked off with several basic science presentations, including two focused on non-small cell lung cancer (NSCLC).
The first presentation discussed the findings of the study “High Inflammatory Markers in Peripheral Blood are Associated With Recurrence in Patients With pT1 Non-Small Cell Lung Cancer Undergoing Surgical Resection.” In this retrospective chart review, researchers sought to determine the role of inflammatory markers in stage I NSCLC patients’ peripheral blood. The study included only stage I NSCLC patients whose sole treatment between 2000 and 2015 was surgery, as well as patients who had available baseline complete blood counts (CBC). Patients lost to follow-up or who died within 30 days of surgery were excluded. The study’s primary end-point was recurrence.
Final analyses included 100 eligible patients. The cohort was almost evenly split between male and female, and median age was 67 years. The overall five-year recurrence rate in the group was 24.1%.
Study author Sainath Asokan, a second-year medical student at the Boston University School of Medicine, presented the study’s findings.
“Unlike in previous studies, […] we found that neutrophil-to-lymphocyte ratio, as well as platelet-tolymphocyte ratio, did not reach significant associations for recurrence,” he said.
Interestingly, the researchers observed an association between high lymphocyte count and higher recurrence (5-year RFS for low lymphocyte, 85% vs high lymphocyte, 51%; P = 0.003), as well as high platelet count and higher recurrence (5-year RFS for low platelet, 81% vs high platelet, 54%; P = 0.017).
“High lymphocytes and high platelets have a hazard ratio of more than 7 and almost 11, respectively,” Asokan said. “Interestingly, a patient of male gender was almost 16 times more likely to recur.”
Patients with pT1 lesions who had high neutrophil, lymphocyte, and platelet counts were at increased recurrence risk, Asokan reported.
“If we look at just pT1 patients now, the 5-year recurrence-free survival for the low-lymphocyte count group was 100%, whereas for the high-lymphocyte count group, it was only 70%,” Asokan noted.
Squamous cell cancer patients tended to have higher neutrophils and platelets counts, the study also found. The study’s retrospective, single-center design was cited as a limitation.
“Based on your review of the literature and the work that you’ve done, what’s the mechanism behind this?” asked discussant Matthew J. Bott, MD, of Memorial Sloan Kettering Cancer Center in New York City.
“One of our next steps is going to be looking into tumor-infiltrating lymphocyte counts in a similar database,” Asokan said. “We are postulating that perhaps the tumor being penetrated less by T-cells is leading to the higher counts of peripheral inflammatory markers that we’re seeing in this study.”
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The second presentation focused on NSCLC shared findings from a study entitled, “FDG-PET SUVm Does Not Correlate With Glucose Metabolism in Non-Small Cell Lung Cancer.” The goal of this prospective study was to determine whether a patient’s maximum standard uptake value (SUVm) is predictive of glycolytic tumor metabolism using metabolic flux analysis.
The trial included 41 NSCLC patients who had not yet been treated but were candidates for resection. Patients underwent fluorodeoxyglucose positron emission tomography (FDG-PET) computed tomography and dynamic contrast enhanced (DCE) magnetic resonance imaging. Patients were steadily infused with 13C-glucose on the index procedure date prior to resection. Metabolite mass spectrometry analysis was used to evaluate blood, tumor, and normal lung tissue samples, which were compared with clinical parameters including SUVm, DCE tissue perfusion, oncogenotype, tumor volume (TV), stage, and grade. The cohort (mean age, 67 years) included 14 males and 16 never smokers; mean TV was 15.44 cm3 and mean SUVm was 8.17. Researchers observed similar enrichment and abundance of glycolytic metabolites in low SUVm tumors and FDG avid tumors. FDG avid tumors had significantly more pentose phosphate pathway metabolites, which suggested to researchers a greater flow to biosynthesis and tumor growth.
“SUVm was negatively correlated with tumor glucose enrichment, in contrast to what we had previously believed. A higher SUVm does not represent high glucose absorption,” said study author Kemp Kernstine, MD, of the UT Southwestern Medical Center located in Dallas, Texas, who presented the findings. We concluded that FDG-PET SUVm does not correlate with tumor glucose absorption. It does not appear to correlate with TCA glycolysis. FDG avid tumors use glucose through alternative pathways, rather than glycolysis; possibly, the lactate is coming from the bloodstream. SUVm appears to correlate with proliferation and cellularity.”
During discussion, Dr. Kernstine added, “I think the point of this is that there’s something to metabolism and determining outcome in patients. FDG has some relationship to metabolism, that’s probably an important aspect, but it’s not a direct correlation. There’s something else that it’s telling us. We’re learning that if a tumor is capable of bypassing glycolysis and producing lactate, the patient has very poor outcomes, regardless of cell type and stage,” he added.