Analysis of prognostic factors for the indication of central lymphadenectomy in papillary thyroid carcinomas

In this study we examined whether it was possible following preoperative parameters statistically significant correlation with the presence of metastatic lymph nodes in the papillary thyroid carcinoma. We conducted a retrospective study in a group of patients with a preoperative diagnosis of papillary carcinoma who underwent total thyroidectomy associated with routine lymphadenectomy of the central compartment (level VI).

The study group consisted of patients whose definitive histological lymph node examination was positive for metastasis (N1), and the control group comprised patients found negative for metastasis (N0).

Tumour diameter had a significance at 10% level [Pr(>|z|): 0.056], thus indicating that increased tumour size results in a higher probability of being in group N1. The logistic regression revealed that variables with a significance at 5% level for the presence of metastatic lymph nodes in the central compartment (N1) were: sex [Pr(>|z|): 0.019], overall patient age [Pr(>|z|): 0.012] and age >45 [Pr(>|z|): 0.022]. We performed a statistical analysis with the association of three preoperative variables (presence of ultrasound-revealed microcalcifications, presence of solid hypoechogenic nodule and type III vascularisation on echocolour-Doppler); this was found to result in a highly significant probability of entering into group N1.

We found variables statistically significant for the presence of metastatic central compartment lymph nodes, including female sex, age >45 yrs and tumour diameter >1.5 cm. The association of papillary carcinoma with microcalcifications, solid hypoechogenic nodule structure and type III vascularisation on echocolour-Doppler also resulted in a statistically significant increase in the probability of positive level VI lymph nodes.