A Machens1, H Dralle2. 1. Department of General, Visceral and Vascular Surgery, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Straße 40, Halle (Saale) D-06097, Germany. Electronic address: AndreasMachens@aol.com. 2. Department of General, Visceral and Vascular Surgery, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Straße 40, Halle (Saale) D-06097, Germany.
Abstract
AIMS: The higher incidence of extranodal growth (breach of a lymph node capsule) in the presence of extrathyroidal extension (breach of the thyroid capsule) in papillary thyroid cancer prompted conclusions that the biology of thyroid cancer is conferred to the lymph nodes, causing invasion of perinodal tissues. This study aimed at quantifying the independent contributions of clinical-pathological factors to extranodal growth in thyroid cancer. METHODS: Multivariate analyses of 1250 patients operated on for node-positive papillary (PTC; 702 patients) or node-positive medullary thyroid cancer (MTC; 548 patients), 138 and 130 of whom harbored extranodal growth. RESULTS: After correction for multiple testing, extranodal growth correlated with number of lymph node metastases (means of 17.0 vs. 10.1 nodes for PTC, 20.6 vs. 13.4 nodes for MTC; each P < 0.001) and male gender (49 vs. 35% for PTC, P = 0.005; 62 vs. 46% for MTC; P = 0.002); and in MTC also with extrathyroidal extension (46 vs. 30%; P = 0.002). On multivariate analysis, independent determinants of extranodal growth were number of lymph node metastases (odds ratios of 2.1, 3.7 and 3.7 for PTC (P ≤ 0.01) and 2.7, 3.3, and 4.0 for MTC (P ≤ 0.004) looking at 6-10, 11-20 and >20 involved nodes against a 1-5 node baseline) and male gender (odds ratio 1.6 for PTC, 1.7 for MTC; each P = 0.02), but not extrathyroidal extension. CONCLUSIONS: In PTC and MTC, extranodal growth develops independently from extrathyroidal extension. This finding argues against mere transference of primary tumor characteristics to lymph nodes, pointing more to accrual of invasive properties by nodal tumor deposits.
AIMS: The higher incidence of extranodal growth (breach of a lymph node capsule) in the presence of extrathyroidal extension (breach of the thyroid capsule) in papillary thyroid cancer prompted conclusions that the biology of thyroid cancer is conferred to the lymph nodes, causing invasion of perinodal tissues. This study aimed at quantifying the independent contributions of clinical-pathological factors to extranodal growth in thyroid cancer. METHODS: Multivariate analyses of 1250 patients operated on for node-positive papillary (PTC; 702 patients) or node-positive medullary thyroid cancer (MTC; 548 patients), 138 and 130 of whom harbored extranodal growth. RESULTS: After correction for multiple testing, extranodal growth correlated with number of lymph node metastases (means of 17.0 vs. 10.1 nodes for PTC, 20.6 vs. 13.4 nodes for MTC; each P < 0.001) and male gender (49 vs. 35% for PTC, P = 0.005; 62 vs. 46% for MTC; P = 0.002); and in MTC also with extrathyroidal extension (46 vs. 30%; P = 0.002). On multivariate analysis, independent determinants of extranodal growth were number of lymph node metastases (odds ratios of 2.1, 3.7 and 3.7 for PTC (P ≤ 0.01) and 2.7, 3.3, and 4.0 for MTC (P ≤ 0.004) looking at 6-10, 11-20 and >20 involved nodes against a 1-5 node baseline) and male gender (odds ratio 1.6 for PTC, 1.7 for MTC; each P = 0.02), but not extrathyroidal extension. CONCLUSIONS: In PTC and MTC, extranodal growth develops independently from extrathyroidal extension. This finding argues against mere transference of primary tumor characteristics to lymph nodes, pointing more to accrual of invasive properties by nodal tumor deposits.
Authors: Else Marie Opsahl; Lars Andreas Akslen; Ellen Schlichting; Turid Aas; Katrin Brauckhoff; Anne Irene Hagen; Alf Frimann Rosenlund; Eva Sigstad; Krystyna K Grøholt; Lovise Mæhle; Lars Fredrik Engebretsen; Lars H Jørgensen; Jan Erik Varhaug; Trine Bjøro Journal: Eur Thyroid J Date: 2018-11-08