Immune checkpoint inhibitors (ICIs) have improved the survival of patients with different solid tumors and even resulted in cure of metastatic disease. Since the introduction of ICIs, an increasing number of patients is admitted to the ICU for severe and potentially life-threatening immune related adverse events (irAEs). The outcome of patients who are admitted to the ICU because of severe irAEs is still unknown. The aim of this systematic review is to collect evidence on the outcomes of patients with solid tumors who are admitted to the ICU because of irAEs.

Medline, Embase, Cochrane central register of controlled trials and Google Scholar were searched systematically from 1975 to 24 September 2024. Articles were only included when describing patients with solid tumors who were admitted to the ICU because of irAEs after treatment with ICIs. Two independent reviewers extracted the data and assessed the risk of bias.

A total of 183 articles were included: two prospective ICU population-based studies, four retrospective ICU population-based studies, 25 retrospective studies describing irAEs with incidental ICU admissions, one review of case reports, and 153 articles with a total of 177 case reports. The six ICU population-based studies contained a total of 169 patients who were admitted to the ICU due to irAEs. In these six studies, the most frequently reported irAEs were pneumonitis and neurological irAEs. Of these 169 patients, 26% of the patients died on the ICU and an additional 8% of patients in the three to six months thereafter due to irAEs or disease progression. In all 183 included articles, various irAEs were described and the reported mortality rate varied from 0 to 53%.

The potential favorable outcomes of both the solid tumors and irAEs will probably result in more need for ICU admissions. Prospective clinical trials are needed to optimize the treatment strategy of severe irAEs at the ICU. Based on the favourable outcomes after life-threatening irAEs, ICU admission should definitely be considered for patients with solid tumors who have life-threatening irAEs.

As cancer continues to be the leading cause of death worldwide, additional therapeutic options other than traditional platinum-based chemotherapy have become available that target tumor cells in innovative ways. Immunotherapies (e.g., immune checkpoint inhibitors (ICI)) ramp up the immune system to target cancer cells, providing patients with more personalized and tumor cell-specific treatment options. This new age oncological treatment option has been found to provide a more meaningful and stronger alternative to traditional chemotherapy, resulting in longer periods of remission and milder side effects. However, because ICI heightens the immune system, resultant autoimmune conditions can occur. One of the most recently shown adverse effects of ICI are extreme hyperglycemia (i.e., type 1 diabetes) and diabetic ketoacidosis (DKA). To determine the incidence of immunotherapy-induced diabetes, a systematic literature review was performed using CINHAL, EBSCO, MEDLINE, and Web of Science. A total of 403 articles were initially screened, with a final 28 case reports included. The results show that checkpoint inhibitors were found to be most commonly associated with new-onset diabetes as opposed to traditional chemotherapy. Additionally, 41% of patients developed autoimmune diabetes and DKA after being placed on a single therapy of pembrolizumab (targets PD-1: programmed cell death protein 1). However, the pathological process underlying the development of endocrinopathies after treatment with ICI continues to be under investigation.

Immunotherapy, specifically the use of checkpoint inhibitors such as pembrolizumab, has become an important tool in personalized cancer therapy. These inhibitors target proteins on T-cells that regulate the immune response against tumor cells. Pembrolizumab, which targets the programmed cell death 1 receptor on T-cells, has been approved for the treatment of metastatic melanoma and non-small cell lung cancer. However, it can also lead to immune-related side effects, including pneumonitis, colitis, thyroid abnormalities, and rare cases of type 1 diabetes.

The case presented involves an adult patient in 30s with breast cancer who developed hyperglycemia after receiving pembrolizumab treatment. The patient was diagnosed with diabetic ketoacidosis and further investigations were performed to evaluate for new-onset type 1 diabetes. The patient had a history of hypothyroidism and a family history of breast cancer. Treatment for diabetic ketoacidosis was initiated, and the patient was discharged for close follow-up with an endocrinologist.

This literature review highlights the occurrence of diabetic ketoacidosis and new-onset type 1 diabetes in patients receiving pembrolizumab treatment for different types of cancer. Overall, the article emphasizes the therapeutic benefits of immunotherapy in cancer treatment, particularly pembrolizumab, while also highlighting the potential side effect of immune-related diabetes that can occur in a small percentage of patients. Here we present a case where pembrolizumab lead to development of diabetes after a few cycles highlighting one of the rare yet a serious toxicity of the drug.