Association of obesity and preoperative inflammatory biomarkers with aggressive clinicopathological features in papillary thyroid carcinoma: A retrospective cohort study

Objective: The rising incidence of papillary thyroid carcinoma (PTC) parallels the global obesity epidemic. Chronic low-grade inflammation, a hallmark of obesity, has been hypothesized to promote tumor aggressiveness. This study aimed to determine whether elevated body mass index (BMI) and preoperative inflammatory indices are associated with aggressive clinicopathological features in PTC.
Material and methods: We conducted a retrospective study including 486 patients who underwent total thyroidectomy for histologically confirmed PTC at Hassan II University Hospital, Fez, between 2022 and 2026. Preoperative complete blood counts were used to calculate NLR, PLR, and MLR. BMI was classified according to WHO criteria. Pathological reports were reviewed for tumor size, lymph node (LN) metastasis, extrathyroidal extension (ETE), multifocality, BRAF V600E mutation, and ATA risk stratification. Statistical analyses included Chi-square, Mann-Whitney U, multivariate logistic regression, and ROC curve analysis.
Results: Among 486 patients (67.9% female, mean age 43 years), 52% had BMI ≥ 25 kg/m². Overall, lymph node metastasis was present in 214 patients (44%) and extrathyroidal extension (ETE) in 155 patients (32%). Overweight/obese patients (BMI ≥ 25) had significantly higher rates of tumor size >20 mm (51% vs. 28%, p=0.018), LN metastasis (55% vs. 32%, p=0.024), ETE (41% vs. 22%, p=0.031), multifocality (57% vs. 38%, p=0.042), and high ATA risk (29% vs. 12%, p=0.038). On multivariate analysis, BMI ≥ 25 independently predicted LN metastasis (OR 2.3, p=0.024) and ETE (OR 2.8, p=0.031). Regarding inflammatory indices, NLR >2.5 (AUC 0.74) predicted LN metastasis and ETE, while PLR >120 (AUC 0.68) predicted multifocality and larger tumor size. BRAF V600E status was available for 30.9% of patients, where an MLR >0.28 (AUC 0.65) was significantly associated with BRAF V600E positivity and disease recurrence
Conclusion: Elevated BMI and preoperative NLR, PLR, and MLR are independently associated with aggressive pathological features in PTC. These low-cost, routine biomarkers may improve preoperative risk stratification after external validation.