Background

The American Joint Commission on Cancer will remove mitotic rate from its staging guidelines in 2018.

Objective

Using a large nationally representative cohort, we examined the association between mitotic rate and lymph node positivity among thin melanomas.

Methods

A total of 149,273 thin melanomas in the National Cancer Database were examined for their association of high-risk features of mitotic rate, ulceration, and Breslow depth with lymph node status.

Results

Among 17,204 patients with thin melanomas with data on Breslow depth, ulceration, and mitotic rate who underwent a lymph node biopsy, there was a strong linear relationship between odds of having a positive lymph node and mitotic rate (R² = 0.96, P < .0001, β = 3.31). The odds of having a positive node increased by 19% with each 1-point increase in mitotic rate (odds ratio, 1.19; 95% confidence interval, 1.17-1.21). Cases with negative nodes had a mean mitotic rate of 1.54 plus or minus 2.07 mitoses/mm² compared with 3.30 plus or minus 3.54 mitoses/mm² for those with positive nodes (P < .0001).

Limitations

The data collected do not allow for survival analyses.

Conclusions

Mitotic rate was strongly associated with the odds of having a positive lymph node and should continue to be reported on pathology reports.

中文翻译：

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薄黑色素瘤患者的有丝分裂率与阳性淋巴结有关

背景

美国癌症联合委员会将从2018年的分期指南中删除有丝分裂率。

客观的

我们使用了具有全国代表性的大型队列，研究了薄黑色素瘤之间的有丝分裂率与淋巴结阳性之间的关联。

方法

在美国国家癌症数据库中，共检查了149,273例薄型黑色素瘤与有丝分裂率，溃疡和Breslow深度的高风险特征与淋巴结状态的相关性。

结果

在17204名行Breslow深度，溃疡形成和有丝分裂率数据的薄型黑色素瘤患者中，进行了淋巴结活检，淋巴结阳性的几率与有丝分裂率之间存在很强的线性关系（R ²  = 0.96，P  <。 0001，β= 3.31）。随着有丝分裂率每增加1点，拥有阳性结点的几率就会增加19％（赔率，1.19； 95％置信区间，1.17-1.21）。淋巴结阴性的患者的平均有丝分裂率为1.54 +/- 2.07 mitoses / mm ^2，而淋巴结阳性的患者的平均有丝分裂率为3.30 +/- 3.54 mitoses / mm ²（P  <.0001）。

局限性

收集的数据不允许进行生存分析。

结论

有丝分裂率与淋巴结阳性几率密切相关，病理报告应继续报道。