Pneumatosis intestinalis in cancer patients who received immune checkpoint inhibitors

PURPOSE

Immune checkpoint inhibitor (ICI) therapy may give rise to immune-related adverse events (irAEs). Pneumatosis intestinalis (PI), or gas within the bowel wall, has very rarely been observed following ICI therapy, and its clinical significance is unclear. We described the clinical characteristics and outcomes of PI as a possible irAE in cancer patients.

METHODS

We retrospectively identified 12 adult cancer patients with radiologic evidence of PI within 1 year after ICI exposure during January 2010-January 2023. Clinical characteristics, treatment, and outcomes were evaluated.

RESULTS

The median age of our sample was 64 years. The most common cancer types were thoracic/head & neck and gastrointestinal. Eleven patients (92%) received anti-PD-1/L1 monotherapy, while 1 patient (8%) received a combination of anti-PD-1/L1 and anti-CTLA-4. PI occurred a median of 7 months after the first ICI dose. Half the patients (50%) were asymptomatic on diagnosis, and the most common presenting symptom was abdominal pain (42%). Six patients experienced complications, namely pneumoperitoneum (n = 6, 50%) and microperforation (n = 1, 8%), identified on imaging. Nine patients were treated with antibiotics and 3 patients were monitored conservatively. Nine patients (75%) resumed cancer treatment after PI.

CONCLUSION

PI may develop as an irAE. While half of cases were incidental radiologic findings, management with antibiotics as well as hospitalization for observation may still be appropriate. The decision to restart cancer therapy and possibly resume ICI therapy remains to be elucidated. Further large-scale studies may be warranted to clarify the association between PI and ICI therapy.

Sclerosing mesenteritis following immune checkpoint inhibitor therapy

PURPOSE

Sclerosing mesenteritis (SM), a fibroinflammatory process of the mesentery, can rarely occur after immune checkpoint inhibitor (ICI) therapy; however, its clinical significance and optimal management are unclear. We aimed to assess the characteristics and disease course of patients who developed SM following ICI therapy at a single tertiary cancer center.

METHODS

We retrospectively identified 12 eligible adult cancer patients between 05/2011 and 05/2022. Patients' clinical data were evaluated and summarized.

RESULTS

The median patient age was 71.5 years. The most common cancer types were gastrointestinal, hematologic, and skin. Eight patients (67%) received anti-PD-1/L1 monotherapy, 2 (17%) received anti-CTLA-4 monotherapy, and 2 (17%) received combination therapy. SM occurred after a median duration of 8.6 months from the first ICI dose. Most patients (75%) were asymptomatic on diagnosis. Three patients (25%) reported abdominal pain, nausea, and fever and received inpatient care and corticosteroid treatment with symptom resolution. No patients experienced SM recurrence after the completion of corticosteroids. Seven patients (58%) experienced resolution of SM on imaging. Seven patients (58%) resumed ICI therapy after the diagnosis of SM.

CONCLUSIONS

SM represents an immune-related adverse event that may occur after initiation of ICI therapy. The clinical significance and optimal management of SM following ICI therapy remains uncertain. While most cases were asymptomatic and did not require active management or ICI termination, medical intervention was needed in select symptomatic cases. Further large-scale studies are needed to clarify the association of SM with ICI therapy.

[Combination strategies for checkpoint inhibition: Current practices and perspectives]

T-cell checkpoint blockade therapies have revolutionized treatment protocols and prognosis in patients with cancer. Pointed out by the success of PD-1 (programmed cell death-1) plus CTLA-4 (cytotoxic-T-lymphocyte associated antigen 4) blockade in patients with melanoma, the perspective of new synergistic immunotherapy combinations seems to be an important opportunity to improve outcomes for patients. In this article, we first focus on immunotherapy combinations that have shown their efficiency and that are currently approved in solid tumors. Then, we present a summary of emerging targets with reported pre-clinical efficacy and currently evaluated through ongoing clinical trials and other immunomodulatory molecules in the tumor microenvironment.