IMMUNE checkpoint inhibitor therapy rarely caused persistent taste and smell dysfunction in long term cancer survivors, according to a cross-sectional study comparing patients treated with ICIs with caregivers.
The study included 50 patients who had completed ICI therapy at least 2 years earlier and 51 caregivers. Patients had been treated for melanoma, non-small cell lung cancer, or urogenital cancer, with a median of 3.7 years since their last ICI cycle. The analysis assessed subjective taste and smell dysfunction, objective taste and smell performance, xerostomia, saliva flow rate, and saliva composition.
Objective Taste and Smell Findings Were Reassuring
Objective testing showed no significant difference in taste function between patients and caregivers. Median taste scores were 11 in both groups, and hypogeusia was observed in 31% of patients and 29% of caregivers.
Smell outcomes were similarly comparable. Hyposmia, based on smell identification or threshold testing, was seen in 29% and 29% of patients, respectively, compared with 20% and 27% of caregivers. No significant differences were found in smell identification or smell threshold scores.
These findings suggest that persistent objective taste and smell dysfunction after immune checkpoint inhibitor therapy may be uncommon, although sensory symptoms can still occur in a subgroup of patients.
Subjective Symptoms Still Matter in Clinical Care
Patient reported outcomes told a more nuanced story. Six patients reported mild subjective taste alterations and two reported moderate alterations, compared with two caregivers who reported mild taste alterations. Patients also had higher total scores on the Chemotherapy induced Taste Alteration Scale and lower appetite scores than caregivers.
However, subjective taste scores did not correlate significantly with objective taste testing. This mismatch may reflect the limitations of objective tests, which assess basic taste detection but may not capture symptoms such as phantom tastes, altered flavor perception, or dysgeusia.
Saliva Flow and Xerostomia After ICI Therapy
Unstimulated and stimulated saliva flow rates did not differ significantly between groups. Xerostomia severity was also similar, although patients reported greater dryness in the anterior palate and anterior tongue on regional oral dryness assessment.
Sodium output was significantly higher in patients after correction for salivary flow rate, while other salivary components were not significantly different. The clinical relevance of this finding remains uncertain.
Overall, the findings are broadly reassuring for patients receiving immune checkpoint inhibitor therapy. Clinicians should still ask directly about taste, smell, appetite, and oral dryness, as perceived sensory changes may affect quality of life even when objective testing appears normal.
Reference
van Elst JM et al. Prevalence and characteristics of persistent taste and smell dysfunction after immune checkpoint inhibitor therapy for cancer. Support Care Cancer. 2026;34(6):564.
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