Ord R A
Department of Oral and Maxillofacial Surgery, University of Maryland, Baltimore, MD, USA.
Oral Maxillofac Surg. 2012 Jun;16(2):181-8. doi: 10.1007/s10006-012-0325-x. Epub 2012 May 13.
The management of the N0 neck in early stage oral cancer remains controversial. The evidence in the literature for elective neck dissection, which is reviewed in this paper, is conflicting. My personal view is that most papers mistakenly assume that the N0 equates to an "early stage" neck whereas a neck with palpable nodes represents disease at a "late" stage.
I believe that this is the same mindset that prevented us from realizing that depth rather than size was the important prognostic determinant for the primary tumor; because the T stage was based on tumor size. The N stage is also based on size and number of nodes and by these criteria N0 would be the earliest stage. However, although an N0 neck with impalpable intra-nodal disease may be regarded as early impalpable disease an N0 neck with microscopic extra-capsular spread (ECS) would be "late/advanced" impalpable disease. Likewise, a clinically positive neck with intra-nodal disease still represents early disease compared to a clinically positive neck with ECS.
The lack of trials and studies stratifying NO and N +ve necks into early and late disease and comparing outcomes between these cohorts may explain the lack of clear-cut evidence regarding the role for elective neck dissection.
早期口腔癌N0颈部的处理仍存在争议。本文所综述的文献中关于选择性颈清扫术的证据相互矛盾。我个人的观点是,大多数论文错误地认为N0等同于“早期”颈部,而可触及淋巴结的颈部代表“晚期”疾病。
我认为正是这种思维模式使我们未能认识到深度而非大小才是原发肿瘤的重要预后决定因素;因为T分期是基于肿瘤大小。N分期同样基于淋巴结的大小和数量,按照这些标准N0将是最早阶段。然而,尽管一个无可触及淋巴结内疾病的N0颈部可被视为早期不可触及疾病,但一个有微小包膜外扩散(ECS)的N0颈部则属于“晚期/进展期”不可触及疾病。同样,与有ECS的临床阳性颈部相比,如果一个有淋巴结内疾病的临床阳性颈部仍代表早期疾病。
缺乏将N0和N阳性颈部分为早期和晚期疾病并比较这些队列之间结果的试验和研究,这可能解释了关于选择性颈清扫术作用缺乏明确证据的原因。