Blood type may influence response to immune checkpoint inhibitor (ICI) therapy among patients with metastatic cancer, according to a study published in The Oncologist

The study suggests that type O blood is associated with longer time to treatment failure (TTF). Researchers also found an association between longer TTF and the presence of immune-related adverse events (irAEs).

The researchers retrospectively analyzed data from 107 patients with metastatic cancer receiving treatment with an ICI between 2014 and 2019. The mean age of the cohort was 58.5 (range, 28-91) years, 55.1% of patients were men, and 69.2% were Caucasian. 

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Cancer types included head and neck (n=25), lung (n=23), gastrointestinal (n=19), skin (n=15), gynecologic (n=7), breast (n=6), genitourinary (n=4), endocrine (n=3), hematologic (n=2), neurologic (n=1), and soft tissue (n=2) cancers.

Most patients had type O blood (n=44), followed by type A (n=41), type B (n=17), and type AB (n=5). 

In all, 41% of patients developed irAEs. Fifty percent of patients with type O blood developed an irAE, as did 34.9% of patients with type A, B, or AB blood. 

Patients who had irAEs had significantly longer TTF than patients without irAEs (adjusted hazard ratio [aHR], 0.52; 95% CI, 0.33-0.82). 

Likewise, patients with type O blood had significantly longer TTF than patients with other blood types (aHR, 0.50; 95% CI, 0.32-0.78). There was no significant difference in TTF between patients with type A, B, or AB blood.

Among patients with type O blood, the TTF was significantly longer for patients with irAEs than for those without irAEs (aHR, 0.41; 95% CI 0.18-0.96). There was no association between TTF and irAEs among patients with type A, B, or AB blood (aHR, 0.69; 95% CI, 0.39-1.21).

The median TTF was 13.4 months for patients who had type O blood and irAEs. For all other patients, the median TTF was less than 2.55 months. 

“The magnitude of benefit associated with type O blood and irAEs seen in our study was substantial,” the researchers wrote. “[I]rAEs may be a biomarker of improved response, but only for those with type O blood.” 

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Chen R, Hakimi K, Zhang X, Messer K, Patel SP. Patient blood type is associated with response to immune checkpoint blockade in metastatic cancer. Oncologist. Published online July 11, 2022. doi:10.1093/oncolo/oyac128