[Staging of thyroid cancer--comparison of cases diagnosed preoperatively versus incidentally after surgery for benign goiter]. / Porównanie stopnia zaawansowania raka tarczycy rozpoznanego przedoperacyjnie i przypadkowo po operacji wola nienowotworowego.

ABSTRACT

INTRODUCTION: The aim of this study was to compare staging of incidentally diagnosed thyroid cancer (TC) to staging of preoperatively suspected TC. METHODS: This was a retrospective study of 224 patients who underwent surgery for primary TC between 2009 and 2011. Clinical and pathological data included in the TNM and AJCC staging system (7th edition, 2010) were analysed. Staging of incidentally diagnosed TC was compared to staging of preoperatively suspected TC. RESULTS: Suspicion of TC was made before surgery in 57.6% patients, and in 42.4% patients TC was diagnosed postoperatively. Papillary TC was predominant and followed by follicular TC, which were suspected in 88.4% and 4.7% of patients before surgery, and were diagnosed in 77.9% and 16.8% of patients postoperatively (p=0.035 and p<0.001, respectively). Preoperatively diagnosed TC was predominant in patients below 45 years of age (64.3% vs. 25.3%; p<0.001), was at lower stage at the diagnosis (according to AJCC in stage I 42.6% vs. 67.4%; p<0.001; in stage II 6.2% vs. 12.6%; p=0.095; in stage III 38.0% vs. 16.8%; p<0.001; in stage IV 13.2% vs. 3.2%; p=0.009, respectively), and it was more common multicentric (29.5% vs. 9.5%; p<0.001) than incidental TC. CONCLUSIONS: Approximately 40% of cases of TC is diagnosed incidentally based on postoperative pathology report. Incidental TC is predominant below age 45 years, is revealed with early-stage more common than TC diagnosed preoperatively, and occurs multicentric less frequently.