High prevalence of olfactory dysfunction detected in treatment-naive patients with head and neck cancer.

Background: Previous studies demonstrated the difficulty of patients with Head and Neck Cancer (HNC) in sensing food taste, a function in which olfaction has a significant role. However, neither study employed psychophysical tests or control groups to establish the veracity of such complaints.

Aims/objectives: In this study, we quantitatively tested the olfactory function of HNC individuals and compared their function to that of healthy controls.

Methods: Thirty-one HNC naïve treatment patients and thirty-one controls, matched for sex, age, schooling, and smoking, were tested with the University of Pennsylvania Smell Identification Test (UPSIT).

Results: The olfactory function was significantly worse among the patients diagnosed with head and neck cancer [UPSIT cancer = 22.9(CI 95%: 20.5-25.4) vs. UPSIT controls = 29.1(CI 95%: 26.9-31.3);  < .001]. Most patients with HNC had olfactory disorders ( = 29, 93.5%). The risk of olfactory loss was higher in the cancer group [OR: 10.5(CI 95%: 2.1-51.9;  = .001)].

Conclusion And Significance: Olfactory disorders can be detected in more than 90% of patients with head and neck cancer when evaluated using a well-validated olfactory test. Smell disorders may be a potential marker for early diagnosis of HNC.