In patients with clinically node-negative oral cavity cancers, the rate of skip metastasis to neck level IV is extremely low, according to authors of a recent meta-analysis.
The rate of level IV involvement was about 2.5%, and the rate of skip metastasis was 0.5% in the analysis, which comprised 11 retrospective studies and 2 randomized clinical trials including a total of 1,359 patients with clinically node-negative oral cavity squamous cell carcinomas.
Encountering a suspected positive lymph node during neck dissection does not appear to be an indicator of high rates of level IV involvement, according to Anton Warshavsky, MD, and colleagues in the department of otolaryngology–head and neck surgery and maxillofacial surgery at Tel Aviv Sourasky Medical Center, Israel.
“Supraomohyoid neck dissection [SOHND] is adequate for this subset of patients,” Dr. Warshavsky and coauthors wrote in a report on the study that appears in JAMA Otolaryngology–Head & Neck Surgery.
SOHND, a type of selective neck dissection, refers to removal of lymph nodes in levels I-III. This approach is now frequently used in managing clinically node-negative oral cavity squamous cell carcinoma and provides control rates similar to those associated with more extensive neck dissections, Dr. Warshavsky and colleagues wrote.
However, concern regarding the risk of skip metastases, or involvement of neck level IV without involvement of lower levels, has stirred controversy. SOHND might not be adequate in these patients because of the possibility of occult metastasis to neck level IV.
Accordingly, Dr. Warshavsky and colleagues combed the available medical literature to find relevant articles for a meta-analysis to better characterize the rate of skip metastasis to level IV in patients who had undergone neck dissection.
Level IV involvement rates in clinically node-negative patients ranged from 0% to 11.4% in the 13 included studies. Based on fixed-effects modeling, the rate of involvement was 2.53% (95% CI, 1.64-3.55%), according to the published report.
The rate of skip metastasis was “extremely low,” wrote Dr. Warshavsky and coauthors. Rates ranged from 0% to 5.50%, with a fixed-effects model of 0.50% (95% CI, 0.09%-1.11%).
Cases involving higher levels of the neck did not impact the rate of level IV metastasis, results of a subgroup analysis found. Likewise, an analysis based on T stage showed that rates of level 4 involvement were comparable and low for T stages I-II and III-IV.
These findings are limited, however, not only by the retrospective nature of this study, but also by the fact that many studies reported limited data, hampering the investigators’ ability to run statistics and perform subgroup analyses.
“Unfortunately, data in almost all of the analyzed articles failed to report the relations between the primary tumor site and the neck levels involved by metastatic tumor,” they wrote. “Only primary lesions of the tongue could be accurately assessed.”
Dr. Warshavsky and coauthors reported no conflicts of interest related to the research.
SOURCE: Warshavsky A et al. JAMA Otolaryngol Head Neck Surg. 2019 May 9. doi: 10.1001/jamaoto.2019.0784.