Exploratory Diagnostic Utility of a Modified Feng-Derived Preoperative Risk Score for Predicting Occult Contralateral Carcinoma in Filipino Patients With Clinically Solitary Papillary Thyroid Carcinoma.

introductionThe optimal surgical extent for clinically solitary papillary thyroid carcinoma remains debated. Total thyroidectomy addresses possible occult contralateral carcinoma but increases morbidity and requires lifelong hormone replacement, while thyroid lobectomy may avoid overtreatment but risks leaving occult disease. This study evaluated a modified preoperative risk score using clinical and ultrasonographic findings to predict occult contralateral carcinoma in Filipino patients. MATERIALS AND

methodsThis single-center retrospective diagnostic accuracy study included 135 adult patients who underwent total thyroidectomy for clinically solitary papillary thyroid carcinoma at Chong Hua Hospital, Cebu, from 2019 to 2023. Preoperative variables included a primary tumor measuring more than 1 cm, presence of benign-appearing additional nodules, suspected extrathyroidal extension, suspected central lymph node involvement, and suspected lateral lymph node involvement. The modified preoperative score was calculated for each patient using preoperative neck ultrasonography and physical examination findings. The primary outcome was occult contralateral carcinoma on final histopathology. Model discrimination was examined by plotting a receiver operating characteristic curve and calculating the area under the curve.

resultsOccult contralateral carcinoma was identified in 19 of 135 patients. The adapted preoperative scoring system demonstrated strong discriminative ability in this cohort, yielding an area under the receiver operating characteristic curve of 0.91 (95% CI, 0.845 to 0.976). Using a threshold of at least four points, the score showed apparent sensitivity of 94.7%, specificity of 87.1%, positive predictive value of 54.6%, negative predictive value of 99.0%, and overall accuracy of 88.2%.

conclusionsThe modified preoperative risk score showed promising apparent diagnostic performance for predicting occult contralateral carcinoma among Filipino patients with clinically solitary papillary thyroid carcinoma. Its high negative predictive value suggests potential usefulness as an adjunctive rule-out tool during preoperative counseling, but only when interpreted together with established guideline-based risk stratification, tumor characteristics, nodal assessment, patient preferences, and surgeon judgment. The score should not be used as an independent determinant of surgical extent, particularly given its modest positive predictive value. Prospective multicenter validation is needed before routine clinical use.