Department of Obstetrics and Gynecology, Mayo Clinic, Rochester, Minnesota, USA.
Department of Gynecology, IEO, European Institute of Oncology IRCCS, Milan, Italy.
Int J Gynecol Cancer. 2024 May 6;34(5):689-696. doi: 10.1136/ijgc-2023-005173.
Ultrastaging is accurate in detecting nodal metastases, but increases costs and may not be necessary in certain low-risk subgroups. In this study we examined the risk of nodal involvement detected by sentinel lymph node (SLN) biopsy in a large population of apparent early-stage endometrial cancer and stratified by histopathologic characteristics. Furthermore, we aimed to identify a subgroup in which ultrastaging may be omitted.
We retrospectively included patients who underwent SLN (with bilateral mapping and no empty nodal packets on final pathology) ± systematic lymphadenectomy for apparent early-stage endometrial cancer at two referral cancer centers. Lymph node status was determined by SLN only, regardless of non-SLN findings. The incidence of macrometastasis, micrometastasis, and isolated tumor cells (ITC) was measured in the overall population and after stratification by histotype (endometrioid vs serous), myometrial invasion (none, <50%, ≥50%), and grade (G1, G2, G3).
Bilateral SLN mapping was accomplished in 1570 patients: 1359 endometrioid and 211 non-endometrioid, of which 117 were serous. The incidence of macrometastasis, micrometastasis, and ITC was 3.8%, 3.4%, and 4.8%, respectively. In patients with endometrioid histology (n=1359) there were 2.9% macrometastases, 3.2% micrometastases, and 5.3% ITC. No macro/micrometastases and only one ITC were found in a subset of 274 patients with low-grade (G1-G2) endometrioid endometrial cancer without myometrial invasion (all <1%). The incidence of micro/macrometastasis was higher, 2.8%, in 708 patients with low-grade endometrioid endometrial cancer invading <50% of the myometrium. In patients with serous histology (n=117), the incidence of macrometastases, micrometastasis, and ITC was 11.1%, 6.0%, and 1.7%, respectively. For serous carcinoma without myometrial invasion (n=36), two patients had micrometastases for an incidence of 5.6%.
Ultrastaging may be safely omitted in patients with low-grade endometrioid endometrial cancer without myometrial invasion. No other subgroups with a risk of nodal metastasis of less than 1% have been identified.
超分期在检测淋巴结转移方面非常准确，但会增加成本，并且在某些低风险亚组中可能不是必需的。在这项研究中，我们在两个转诊癌症中心检查了大量表现为早期子宫内膜癌患者中通过前哨淋巴结 (SLN) 活检检测到的淋巴结受累风险，并按组织病理学特征进行分层。此外，我们旨在确定一个可以省略超分期的亚组。
我们回顾性纳入了在两个转诊癌症中心接受 SLN（双侧定位和最终病理无空淋巴结包）±系统淋巴结切除术治疗的疑似早期子宫内膜癌患者。淋巴结状态仅通过 SLN 确定，而不考虑非 SLN 发现。在整个人群中以及按组织类型（子宫内膜样 vs 浆液性）、肌层浸润（无、<50%、≥50%）和分级（G1、G2、G3）分层后，测量了巨转移、微转移和孤立肿瘤细胞 (ITC) 的发生率。
共完成了 1570 例双侧 SLN 定位：1359 例子宫内膜样癌和 211 例非子宫内膜样癌，其中 117 例为浆液性癌。巨转移、微转移和 ITC 的发生率分别为 3.8%、3.4%和 4.8%。在子宫内膜样组织学患者（n=1359）中，有 2.9%的患者有巨转移，3.2%的患者有微转移，5.3%的患者有 ITC。在 274 例无肌层浸润（均<1%）且低分级（G1-G2）子宫内膜样癌的患者中，发现了一个亚组，其中无巨/微转移，仅有一个 ITC。在 708 例低分级子宫内膜样癌侵犯肌层<50%的患者中，微/巨转移的发生率更高，为 2.8%。在浆液性组织学患者（n=117）中，巨转移、微转移和 ITC 的发生率分别为 11.1%、6.0%和 1.7%。对于无肌层浸润的浆液性癌（n=36），两名患者有微转移，发生率为 5.6%。
在无肌层浸润的低分级子宫内膜样癌患者中，可以安全地省略超分期。尚未确定其他转移风险低于 1%的亚组。
