Impact of historic histopathologic sample review on the risk of recurrence in patients with differentiated thyroid cancer

ABSTRACT Objective To compare the historic risk of recurrence (RR) and response to therapy to risk stratification estimated with historical pathology reports (HPRs) and contemporary re-review of the pathological slides in patients with differentiated thyroid cancer (DTC). Subjects and methods Out of 210 DTC patients with low and intermediate RR who underwent total thyroidectomy and remnant ablation in our hospital, 63 available historic pathologic samples (HPS) were reviewed. The RR and the response to therapy were evaluated considering historical histological features (histological type, tumor size, capsular invasion, number of lymph node metastases) and then, reassessed after observing additional histological features (vascular invasion, extrathyroidal extension, size of lymph node metastases, presence of extranodal extension, and/or status of the resection margins). Results A change in the RR category was observed in 16 of 63 cases (25.4%). Out of 46 patients initially classified as low RR, 2 patients were reclassified as intermediate RR, 4 as high RR, and 1 as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Out of 17 patients initially classified as intermediate RR, 3 were reassigned to the low RR group, 5 as high RR, and 1 as NIFTP. The percentages of structural incomplete response at final follow-up changed from 2.2 to 0% (p = 1) in patients with low RR and from 6.3 to 20% (p = 0.53) in patients with intermediate RR. Conclusion A detailed report of specific features in the HPR of patients with DTC might give a more accurate RR classification and a better estimation of the response to treatment.

摘要
目的 比较分化型甲状腺癌（differentiated thyroid cancer, DTC）患者的既往复发风险（recurrence risk, RR）与治疗应答，和通过历史病理报告（historical pathology reports, HPRs）及当代病理玻片复阅评估的风险分层结果之间的差异。
对象与方法 本研究纳入我院210例接受甲状腺全切除术及残余灶消融的低、中复发风险分化型甲状腺癌患者，其中63例可获取的历史病理样本（historic pathologic samples, HPS）得以复阅。研究先基于既往组织学特征（组织学类型、肿瘤大小、包膜侵犯、淋巴结转移数目）评估复发风险及治疗应答，随后结合新增组织学特征（血管侵犯、甲状腺外侵犯、淋巴结转移灶大小、结外侵犯情况及/或手术切缘状态）进行重新评估。
结果 63例患者中有16例（25.4%）出现复发风险分类变更。最初归类为低复发风险的46例患者中，2例被重新归类为中复发风险，4例归类为高复发风险，1例归类为非浸润性滤泡性甲状腺肿瘤伴乳头状核特征（noninvasive follicular thyroid neoplasm with papillary-like nuclear features, NIFTP）。最初归类为中复发风险的17例患者中，3例被重新分配至低复发风险组，5例归类为高复发风险，1例归类为NIFTP。低复发风险患者的结构性不完全应答率在最终随访时从2.2%变更为0%（p = 1），中复发风险患者则从6.3%变更为20%（p = 0.53）。
结论 对分化型甲状腺癌患者历史病理报告中的特定特征进行详细记录，可实现更精准的复发风险分类，并能更准确地预估治疗应答效果。