There are fewer adverse events with immune checkpoint inhibitors (ICPI) than with chemotherapy, however, some patients receiving ICPI may require intensive care treatment in case of severe immune-related adverse events (IRAE’s), which should be immediately recognized to permit an appropriate treatment. We present data of patients admitted to The Royal Marsden Cancer Critical Care Unit (CCU) with IRAE’s. Our objective was also to determine if baseline inflammatory biomarkers (IB), such as LDH, neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR) and systemic inflammatory response index (SIRI) at admission could correlate with patient outcomes.
17 patients were identified between January 2012 and July 2019. Survival analysis was performed using Kaplan-Meier curves and Cox regression, using SPSS v24. All ratios were calculated with absolute counts of neutrophils, lymphocytes and monocytes. Best cut-off ratios were obtained using ROC curves.
Most patients (88.2%; n = 15) had the diagnosis of metastatic melanoma. 6 patients were treated with ipilimumab, 3 with nivolumab, 7 with the combination of both and 1 patient with pembrolizumab. Median length of stay in the CCU was 4 days. The most common reason for admission was colitis in 47.1% (n = 8) of patients. Median overall survival (OS) from date of admission was 8.7 months. Outcome from CCU (stable discharge or long-term rehab) correlates with survival (R2=0.61). In the group of patients with LDH ≥ 189, OS was 1.4 months and in the group with LDH<189, OS was not yet reached (HR 0.28; p = 0.05). In the group with NLR ≥ 6.8, OS was 1.5 months and in the group of NLR<6.8, the median OS was 27.6 months (HR 0.34; p = 0.11).
It is likely that the number of critical care admissions may increase with more patients receiving ICPI. These events can be responsible for great morbidity which might be associated with increased mortality. IB such as high LDH, high NLR and high SIRI might correlate to poor outcome and worse survival and could be used to develop awareness of these events and a more effective approach. However, some of these results were not statistically significant and further studies are needed with a larger data to validate them.
The authors.
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All authors have declared no conflicts of interest.