TURKISH JOURNAL OF ONCOLOGY 2026 , Vol 41 , Num 3
Evaluation of Olfactory Functions in Cancer Patients Before Radiotherapy
Hatice ÖNDER1, Gül KANYILMAZ2, Mustafa AÇIKGÖZ3, Esra ACIMAN DEMİREL3
1Department of Radiation Oncology, Aydın City Hospital, Aydın-Türkiye
2Department of Radiation Oncology, Necmettin Erbakan University, Meram Faculty of Medicine, Konya-Türkiye
3Department of Neurology, Bülent Ecevit University Faculty of Medicine, Zonguldak-Türkiye
DOI : 10.5505/tjo.2026.4966 OBJECTIVE
In this study,we aimed to detect olfactory functions of patients with objective method and the factors which can affect these, who referred to our department for definitive radiation therapy.

METHODS
This study included the patients without head and neck cancer. All patients functions of odor threshold, discrimination and idenfication were assessed with ‘Sniffin Sticks’ test before radiation therapy. The overall score is called composite threshold-discrimination-idenfication score. As these scores, ≤16 was evaluted as anosmia, 16-30 as hyposmia and >30 normal smell function.

RESULTS
This study included 48 patients with a median age of 59 years (30-76 years). With patients who had chemotherapy before radiation therapy, statistically significant olfactory disfunction (hyposmia+anosmia) was determined. 26 of 29 patients (90%) who had chemotherapy, had olfactory disfunction (p=0.02) and 7 of 10 patients (70%) who had normal smell functions had no prior chemotherapy (p=0.04). As multivariant analysis, increased age (OR:1.33, 95% CI 1.08-1.64;p=0.007) and to be treated with chemotherapy (OR:32.95, 95% CI 1.35-801.45; p=0.032) were significant factors in terms of olfactory disfunction.

CONCLUSION
In this study, we established olfactory disfunction at 79% patients who were planned definitive radiotheraphy. As multivariant analysis; increasing age and to be treated with chemotherapy were statistically significant parameters as to olfactory disfunction .The patients with cancer , smell and taste disfunctions can occur frequently and to be aware of these pathologies is important for providing required treatment support. Keywords : Chemotherapy; olfactory disfunction; radiotheraphy