Core-Needle Biopsy May be Associated With Superior Diagnostic Utility and Improved Outcomes Compared to Fine-Needle Aspiration Cytology in Major Salivary Gland Cancer.

BACKGROUND

Preoperative identification of major salivary gland (MSG) cancers is crucial for determining appropriate treatment strategies. However, whether fine-needle aspiration cytology (FNAC) or core-needle biopsy (CNB) should be the preferred first-line diagnostic modality remains controversial.

PURPOSE: This study compared the diagnostic utility of FNAC and CNB and assessed their associations with treatment strategies and survival outcomes in patients with primary MSG cancer.

STUDY DESIGN, SETTING, SAMPLES: This retrospective cohort study was conducted at Kyungpook National University Hospital. Patients diagnosed with primary MSG cancer after surgery were included. Exclusion criteria were metastatic cancers, nonsalivary epithelial malignancies, absence of preoperative FNAC or CNB, or procedures performed over 1 year before surgery.

PREDICTOR VARIABLE: The predictor variable was the biopsy technique: FNAC or CNB.

MAIN OUTCOME VARIABLES: The primary outcomes were (1) diagnostic utility (sensitivity and nondiagnostic rates); (2) treatment strategies, defined as surgical extent (partial vs subtotal/total gland excision; no vs elective vs therapeutic neck dissections); and (3) 5-year disease-free survival.

COVARIATES: Covariates included age, sex, smoking, alcohol, comorbidity, primary clinical presentation, and tumor characteristics based on imaging and pathological findings.

ANALYSES: Data were analyzed using t-tests, χ2 or Fisher's exact tests, Kaplan-Meier method with log-rank tests, and Cox regression model. Diagnostic sensitivity was calculated using the final histopathological diagnosis from surgical resection as the reference standard.

RESULTS

A total of 129 subjects were included (mean age, 57.2 ± 15.3 years; 82 [63.6%] male). Of those, 97 (75.2%) underwent FNAC and 32 (24.8%) underwent CNB. CNB showed higher sensitivity for diagnosis of malignancy than FNAC (86.7 vs 45.9%, P < .001) and fewer nondiagnostic results (0.0 vs 10.3%, P < .001). CNB was associated with shorter time to surgery (43.1 ± 28.2 vs 125.1 ± 107.6 days, P < .001), more frequent subtotal/total gland excision (90.6 vs 43.3%, P < .001), and elective neck dissection (53.1 vs 18.6%, P < .001). In advanced disease, CNB was associated with better 5-year disease-free survival (77.6 vs 53.4%, P = .041). FNAC was an independent prognostic factor for treatment failure (hazard ratio, 2.963; P = .040).

CONCLUSION AND RELEVANCE: CNB was associated with superior diagnostic utility compared to FNAC, more appropriate surgical management, and improved outcomes for patients with MSG cancer.