CHICAGO–Elective neck dissection in patients with clinically node-negative early oral squamous cell carcinoma results in a 37% reduction in mortality compared with therapeutic neck dissection and should be considered the standard of care, data presented at the 2015 American Society of Clinical Oncology (ASCO) annual meeting in Chicago, IL, have shown.
“Oral cancer is a problem of both the developed and developing world,” said Anil D’Cruz, MS, DNB, principal investigator and Director of Tata Memorial Hospital in Mumbai, India. For management of early oral cancers, there are two schools of thought: wait and watch/therapeutic neck dissection or early neck dissection, and differing results of previous studies have led to the use of both treatment options.
The prospective phase 3 trial enrolled 596 patients with lateralized T1 or T2 squamous carcinoma of the oral cavity who were amenable to peroral excision.
Participants were randomly assigned to undergo elective neck dissection at the time of primary surgery or therapeutic neck dissection at the time of nodal relapse. Surgery was extended to a modified neck dissection if patients were node-positive and all patients were eligible to receive adjuvant radiotherapy if necessary.
Results of an interim intent-to-treat analysis of the initial 500 patients with a minimum follow up of 9 months (243 in the elective arm vs. 253 in the therapeutic arm) showed that with a median follow-up of 39 months, there were 146 and 81 recurrences in the therapeutic and elective arms, respectively.
Researchers found that the 3 year overall survival rates were 80.0% in the elective neck dissection arm compared with 67.5% in the therapeutic arm (HR=0.64; 95% CI: 0.45,0.92; P=0.014).
Three-year disease-free survival was also significantly higher in the elective neck dissection arm versus the therapeutic neck dissection arm (69.5% vs. 45.9%; HR=0.45; 95% CI: 0.34-0.59; P<0.001).
Subgroup analyses showed that “the overall survival benefit with elective neck dissection was seen across all subgroups,” Dr. D’Cruz said.
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Elective neck dissection continued to be significantly better than therapeutic neck dissection with respect to both overall survival and disease-free survival after adjusting for confounding factors. “After adjusting for confounding factors in a multivariate analysis, elective neck dissection continues to improve overall survival,” Dr. Cruz said.
The study also demonstrated that in addition to treatment, tumor grade, lymphovascular embolization and/or perineural invasion, and depth of invasion of primary disease were prognostic factors for overall survivor.
Ultimately, “one death is prevented for every eight patients treated with elective neck dissection and one recurrence is prevented for every four patients treated with elective neck dissection,” Dr. Cruz concluded.
- D’Cruz A, Dandekar M, Vaish R, et al. Elective versus therapeutic neck dissection in the clinically node negative early oral cancer: A randomised control trial (RCT). J Clin Oncol. 2015;33:(suppl; abstr LBA3).