Lee-Saxton Yeon J, Egan Caitlin E, Bratton Brenden A, Thiesmeyer Jessica W, Greenberg Jacques A, Marshall Teagan E, Tumati Abhinay, Romero-Arenas Minerva, Beninato Toni, Zarnegar Rasa, Scognamiglio Theresa, Fahey Thomas J, Finnerty Brendan M
Department of Surgery, Weill Cornell Medicine, New York, NY 10065, USA.
Department of Surgery, Rutgers-Robert Wood Johnson Medical School, Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA.
J Clin Endocrinol Metab. 2025 Jan 21;110(2):e294-e300. doi: 10.1210/clinem/dgae203.
The significance of low mitotic activity in papillary thyroid cancer (PTC) is largely undefined.
We aimed to determine the behavioral landscape of PTC with low mitotic activity compared with that of no and high mitotic activity.
A single-institution consecutive series of patients with PTC from 2018 to 2022 was reviewed. Mitotic activity was defined as no mitoses, low (1-2 mitoses/2 mm2) or high (≥3 mitoses/2 mm2) per the World Health Organization. The 2015 American Thyroid Association risk stratification was applied to the cohort, and clinicopathologic features were compared between groups. For patients with ≥6 months of follow-up, Cox regression analyses for recurrence were performed.
A total of 640 PTCs were included-515 (80.5%) no mitotic activity, 110 (17.2%) low mitotic activity, and 15 (2.3%) high mitotic activity. Overall, low mitotic activity exhibited rates of clinicopathologic features including vascular invasion, gross extrathyroidal extension, and lymph node metastases in between those of no and high mitotic activity. PTCs with low mitotic activity had higher rates of intermediate- and high-risk American Thyroid Association (ATA) risk stratification compared with those with no mitotic activity (P < .001). Low mitotic activity PTCs also had higher recurrence rates (15.5% vs 4.5%, P < .001). Low mitotic activity was associated with recurrence, independent of the ATA risk stratification (HR 2.96; 95% CI 1.28-6.87, P = .01).
Low mitotic activity is relatively common in PTC and its behavior lies within a spectrum between no and high mitotic activity. Given its association with aggressive clinicopathologic features and recurrence, low mitotic activity should be considered when risk stratifying patients with PTC for recurrence.
甲状腺乳头状癌（PTC）中低有丝分裂活性的意义在很大程度上尚不明确。
我们旨在确定与无有丝分裂活性和高有丝分裂活性的PTC相比，低有丝分裂活性的PTC的行为特征。
回顾了2018年至2022年来自单一机构的连续PTC患者系列。根据世界卫生组织的标准，有丝分裂活性被定义为无有丝分裂、低（1 - 2个有丝分裂/2 mm²）或高（≥3个有丝分裂/2 mm²）。将2015年美国甲状腺协会风险分层应用于该队列，并比较各组之间的临床病理特征。对随访≥6个月的患者进行复发的Cox回归分析。
共纳入640例PTC，其中515例（80.5%）无有丝分裂活性，110例（17.2%）低有丝分裂活性，15例（2.3%）高有丝分裂活性。总体而言，低有丝分裂活性在血管侵犯、大体甲状腺外侵犯和淋巴结转移等临床病理特征的发生率介于无有丝分裂活性和高有丝分裂活性之间。与无有丝分裂活性的PTC相比，低有丝分裂活性的PTC具有更高的美国甲状腺协会（ATA）中、高风险分层率（P <.001）。低有丝分裂活性的PTC复发率也更高（15.5%对4.5%，P <.001）。低有丝分裂活性与复发相关，独立于ATA风险分层（HR 2.96；95% CI 1.28 - 6.87，P =.01）。
低有丝分裂活性在PTC中相对常见，其行为特征介于无有丝分裂活性和高有丝分裂活性之间。鉴于其与侵袭性临床病理特征和复发的关联，在对PTC患者进行复发风险分层时应考虑低有丝分裂活性。
