講演情報
[INTS3-2]Post-Immunotherapy Bowel Obstruction in MSI-H Colorectal Cancer: A Case Report and Scoping Review of Predictive Factors
*Kevin Fenghua Zhang1, Kabbyto Chen1, Amanda Hii1, Samwel Makanyengo1, Richard Simpson1 (1. Colorectal Unit, Gosford Hospital, Australia)
Immune checkpoint inhibitors (ICIs) are increasingly used in the management of microsatellite instability-high (MSI-H) or mismatch repair-deficient colorectal cancer with high response rates. Rarely, bowel obstruction may occur despite effective tumour response, complicating clinical decision-making and mimicking disease progression. We report a case study and scoping review of the literature to identify patient and tumour factors associated with post-immunotherapy obstruction.
A literature search was performed in MEDLINE and SCOPUS to identify studies that reported bowel obstruction as a primary or secondary outcome in patients treated with immune checkpoint inhibitors for colorectal cancers. Two reviewers screened the articles for eligibility. Given the nature of the studies, a narrative synthesis was undertaken.
A total of 63 articles were screened, of which 14 reviews met the inclusion criteria and reported bowel obstruction as a primary or secondary outcome. Patient factors such as age and sex, and histopathological features, were not consistently associated with obstruction risk. Tumour-specific factors, including high tumour grade, metastatic disease and significant luminal compromise, were more frequently associated with obstruction. Management was predominantly surgical, most commonly segmental resection. Conservative approaches were less frequently successful. The reported case involved a 66-year-old man with MSI-H descending colon adenocarcinoma who developed acute large bowel obstruction two weeks after completing pembrolizumab therapy, requiring emergency Hartmann’s procedure. Histopathology demonstrated complete pathological response with treatment-related changes only.
Immune checkpoint mediators have been reported to paradoxically precipitate or cause bowel obstructions. Recognition of tumour-related risk factors may allow earlier identification and proactive management. Awareness of this phenomenon is essential to avoid misinterpretation as disease progression and to guide timely surgical intervention.
A literature search was performed in MEDLINE and SCOPUS to identify studies that reported bowel obstruction as a primary or secondary outcome in patients treated with immune checkpoint inhibitors for colorectal cancers. Two reviewers screened the articles for eligibility. Given the nature of the studies, a narrative synthesis was undertaken.
A total of 63 articles were screened, of which 14 reviews met the inclusion criteria and reported bowel obstruction as a primary or secondary outcome. Patient factors such as age and sex, and histopathological features, were not consistently associated with obstruction risk. Tumour-specific factors, including high tumour grade, metastatic disease and significant luminal compromise, were more frequently associated with obstruction. Management was predominantly surgical, most commonly segmental resection. Conservative approaches were less frequently successful. The reported case involved a 66-year-old man with MSI-H descending colon adenocarcinoma who developed acute large bowel obstruction two weeks after completing pembrolizumab therapy, requiring emergency Hartmann’s procedure. Histopathology demonstrated complete pathological response with treatment-related changes only.
Immune checkpoint mediators have been reported to paradoxically precipitate or cause bowel obstructions. Recognition of tumour-related risk factors may allow earlier identification and proactive management. Awareness of this phenomenon is essential to avoid misinterpretation as disease progression and to guide timely surgical intervention.