Ly Catherine L, Blaha Ondrej, Wei Wei, Galan Anjela, Kluger Harriet, Ariyan Stephan, Olino Kelly, Clune James E
Division of Plastic and Reconstructive Surgery, Department of Surgery, Yale School of Medicine, New Haven, CT, United States.
Department of Biostatistics, Yale School of Public Health, New Haven, CT, United States.
Front Oncol. 2023 Jan 6;12:1077226. doi: 10.3389/fonc.2022.1077226. eCollection 2022.
Mitotic rate (MR) is considered an important prognostic factor for melanoma but is not currently used for staging because its nuanced effect is not yet well-delineated. We sought to determine if T category-specific MR is predictive of sentinel lymph node (SLN) positivity, recurrence, and melanoma-specific mortality (MSM).
A retrospective review of patients with primary cutaneous melanoma from 1994 to 2020 at a single academic center was performed. Patient demographics and tumor characteristics were recorded. MR was considered elevated for each AJCC8-defined T category if it was ≥2 mitoses/mm for T1, ≥4 mitoses/mm for T2, ≥6 mitoses/mm for T3, or ≥7 mitoses/mm for T4. Statistical analysis was performed to assess the predictive accuracy of MR on selected outcomes while controlling for ulceration.
Data from 2,984 patients with complete records were analyzed. Along with Breslow thickness and ulceration, elevated MR was associated with higher risk of MSM (HR 1.816, =0.0001). There was no difference among patients with ulcerated T1 or T2 tumors regardless of MR, but those with non-ulcerated T1 or T2 tumors and elevated MR were more likely to have positive SLNs (P<0.0001 and =0.0043, respectively) and recurrence (=0.0007 and =0.0004, respectively) compared to counterparts with low MR. There were no notable differences for T3 or T4 tumors based on MR.
Elevated MR is associated with SLN positivity and recurrence in thin melanomas, independent of ulceration. SLN biopsy should therefore be strongly considered for patients with non-ulcerated lesions <0.8 mm thick if the MR is ≥2 mitoses/mm.
有丝分裂率（MR）被认为是黑色素瘤的一个重要预后因素，但目前尚未用于分期，因为其细微影响尚未得到充分阐明。我们试图确定特定T分类的MR是否可预测前哨淋巴结（SLN）阳性、复发和黑色素瘤特异性死亡率（MSM）。
对1994年至2020年在单一学术中心的原发性皮肤黑色素瘤患者进行回顾性研究。记录患者的人口统计学和肿瘤特征。如果根据美国癌症联合委员会第8版（AJCC8）定义的每个T分类中，T1的MR≥2个有丝分裂/毫米、T2的MR≥4个有丝分裂/毫米、T3的MR≥6个有丝分裂/毫米或T4的MR≥7个有丝分裂/毫米，则认为MR升高。在控制溃疡因素的同时，进行统计分析以评估MR对选定结局的预测准确性。
分析了2984例有完整记录患者的数据。除了Breslow厚度和溃疡外，MR升高与MSM风险较高相关（风险比1.816，P = 0.0001）。无论MR如何，溃疡型T1或T2肿瘤患者之间没有差异，但与低MR的患者相比，非溃疡型T1或T2肿瘤且MR升高的患者更有可能出现SLN阳性（分别为P<0.0001和P = 0.0043）和复发（分别为P = 0.0007和P = 0.0004）。基于MR，T3或T4肿瘤没有显著差异。
MR升高与薄黑色素瘤的SLN阳性和复发相关且独立于溃疡。因此，如果MR≥2个有丝分裂/毫米，对于厚度<0.8毫米的非溃疡病变患者，应强烈考虑进行SLN活检。
