|LETTER TO EDITOR
|Year : 2019 | Volume
| Issue : 2 | Page : 254-255
Depth of infiltration cut-off and the need to do an elective neck dissection in early oral cancer- Do we have the final verdict?
Department of Head and Neck Surgical Oncology, Tata Memorial Hospital, Homi Bhabha National Institute (HBNI), Mumbai, Maharashtra, India
|Date of Web Publication||20-Dec-2019|
1209, 12th Floor, HBB, Tata Memorial Hospital, Parel, Mumbai - 400 012, Maharashtra; Homi Bhabha National Institute (HBNI), Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Thiagarajan S. Depth of infiltration cut-off and the need to do an elective neck dissection in early oral cancer- Do we have the final verdict?. Cancer Res Stat Treat 2019;2:254-5
|How to cite this URL:|
Thiagarajan S. Depth of infiltration cut-off and the need to do an elective neck dissection in early oral cancer- Do we have the final verdict?. Cancer Res Stat Treat [serial online] 2019 [cited 2020 Feb 28];2:254-5. Available from: http://www.crstonline.com/text.asp?2019/2/2/254/273680
The authors quest to find a magic number, in terms of depth of infiltration (DOI), predicting the neck nodal metastasis in oral squamous cell carcinoma (OSCC) is understandable but questionable. One has to understand that the terms tumor thickness (TT) and DOI are different terminologies, which in the past have been used interchangeably. However, there is a consensus now that the DOI is a much better predictor of nodal metastasis and has found its long-overdue place in the latest edition of the tumor-node-metastasis (TNM) staging system., The question that was debated and discussed for many years was whether to do an elective neck dissection (END) or a therapeutic neck dissection (TND). The next question was, at what DOI should the neck dissection be performed. The randomized controlled trial (RCT) by D'Cruz et al. established a clear survival benefit, both in terms of overall survival and disease-free survival, of performing an END over a TND. The trial reported that the survival benefit of performing an END was observed in patients with TT of >3 mm. The authors in the present study have concluded that at least an END should be considered for a TT of >4.5 mm, ignoring the available evidence. This conclusion is a bit hard to accept in light of the results from the D'Cruz RCT. It is not clear if the authors have excluded studies that have reported TT in the time period mentioned in the eligibility criteria and have only included studies that have reported the DOI. Furthermore, it would be of interest to know which oral cavity subsites were included in the studies in the systematic review. I also wonder how the authors used the receiver operating characteristic curve in the meta-analysis since there is no clarity as to whether independent patients' data were used.
Although we have the results of D'Cruz et al. addressing the question of whether to do an END or not, as well as the TT at which it should be done, the Japanese group too do not seem to be convinced. Hanai et al.(RESPOND: JCOG1601) are conducting a similar RCT with a noninferiority trial design addressing the same question. In this study, the patients are to be selected based on the DOI between 3 and 10 mm with a sample size of 440. The study started accrual in November 2017. The study is to be completed in 10 years (5 + 5 years). In this study, however, the patients are to be followed up with a computed tomography scan at different time intervals. In contrast, D'Cruz et al. in their trial randomized patients between physical examination alone or ultrasound of the neck on follow-up. They reported that follow-up with an ultrasound of the neck did not confer any survival advantage over physical examination in the postoperative follow-up.
We, at present, have evidence that clearly mentions that END in T1 and T2 OSCC offers a survival advantage. This advantage is seen for tumors with thickness >3 mm. However, it would be interesting to see the results of the Japanese trial.
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Conflicts of interest
There are no conflicts of interest.
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