Immune checkpoint inhibitors anti-PD-1 (Nivolumab and Pembrolizumab) represent a remarkable advance in non-small-cell lung cancer (NSCLC) treatment with impressive clinical activity and durable responses in some patients. However, immunotherapies generate new toxicity profiles called immune-related adverse events (irAEs) that require specific management. Gastrointestinal (GI) irAEs (diarrhea and colitis) are among the most common and if they are left unrecognised or untreated, they can become life threatening. Therefore, the identification of the risk factors for the development of diarrhea could be helpful for the prevention and management of GI irAEs. Among these, the presence of diverticulosis could affect the onset of diarrhea.
This retrospective analysis was conducted in 94 patients with metastatic NSCLC who received Nivolumab at the Papa Giovanni XXIII Hospital in Bergamo between 2015 and 2017. We evaluated the presence of diverticulosis before the start of immunotherapy, the degree and management of diarrhea during therapy and the correlation between the presence of diverticulosis and GI irAEs.
All patients had previously been treated with chemotherapy. 90 patients received Nivolumab at a dose of 3mg/kg while 4 patients received Nivolumab flat dose of 240mg. The RR was 14% and the DCR was 45%. The median PFS has not yet been reached. 19 of 94 patients had a radiological diagnosis of diverticulosis before the start of treatment and 11 of 94 patients developed diarrhea during the therapy. While of the 75 patients without diverticulosis only 7% developed diarrhea, 32% of patients with diverticulosis developed diarrhea. The chi-square test was used for statistical analysis. GI irAEs were in most cases of grade 2 and were treated with steroid therapy without having to resort to other types of immunosuppressive therapy. No patient discontinued treatment due to adverse event.
In our population, the presence of diverticulosis increases the risk of gastrointestinal irAEs. However, these patients can be treated with immunotherapy but they represent a risk class for the onset of diarrhea. Further studies are needed to confirm our findings.
The authors.
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All authors have declared no conflicts of interest.