RESUMO
Background: Predicting the roughly 50% of melanoma patients that will respond to immunotherapy is challenging. We tested if splenic volume could be a predictive biomarker. Methods: Splenic volume was measured by a semiautomated commercial software tool in pre- and post-treatment PET/CT, CT or MRI in 50 melanoma patients treated with immune checkpoint inhibitors. Results: Subjects with smaller spleens had better progression-free survival (median not achieved after 30.6 months of follow-up vs median 11.2 months; p = 0.0213) than their counterparts. A cut-off of <244 cm3 yielded a sensitivity of 83% and specificity of 54% to identify responders. Conclusion: Measuring splenic volume on imaging scans is feasible. Smaller pretreatment spleen volume is associated with better responses to immune checkpoint inhibitors.
For patients with relapsed or advanced melanoma, immunotherapy is the main treatment option. Not all patients respond to it and there are few ways of knowing the odds beforehand. Treatment can be costly and dangerous. We investigated if measuring the spleen using imaging scans already routinely done to monitor the disease could give doctors an idea of whether the patient had higher chances of responding to immunotherapy. Our main finding was that patients with smaller spleens before treatment initiation were more likely to respond to immunotherapy and live longer without the disease. This finding can potentially be used in day-to-day care to inform patients and their physicians of the patient's odds and help them make an informed joint decision.
