Afterward, 19 patients, or 49 percent, had a positive pathology for malignancy. The other 20 had negative reports. “This was consistent with what was seen in the literature, of 40 to 46 percent,” Dr. Dooley said.
Explore This IssueFebruary 2011
Researchers analyzed the initial N stage of the malignancies to see whether there was any statistically significant link between N-stage level and a positive pathology report after dissection.
—Laura Dooley, MD
“The answer was no,” Dr. Dooley said. “We found that early N-stage patients were equally as likely to have positive pathology at neck dissection as those with more advanced N stage.”
N-stage 1 patients with positive pathology reports, a total of three out of the six, were comparable to the number of N-stage 3 patients with positive pathology, 5 out of 11.
Researchers also looked at the primary tumor site data to see whether that could be a significant predictor of a positive pathology after dissection. There was no link, except in the case of the oral cavity. But Dr. Dooley cautioned, “The oral cavity had the fewest number of patients overall and had very few patients (n=2) with residual neck disease…. We interpret this with some trepidation because of the small sample size.”
In terms of overall survival, those with progressive disease fared the worst, as expected. But the other groups—those who had a complete response right away, those who had a complete response after a delay and those who underwent a dissection for residual disease—all fared similarly, with five-year survival rates of 66 percent to 71 percent.
That trend held when survival was based on N stage: The stage was an important predictor regardless of the group the patient was in.
The HPV Factor
Because there has been a lot of discussion recently about the role of HPV in tonsil malignancies, researchers took a closer look at malignancies with the tonsil as the primary sub-site.
“Patients requiring neck dissection for residual palpable disease had survival greater than all other outcome groups,” Dr. Dooley said. “Interestingly, those patients with the worst survival were those who achieved a complete response immediately after treatment completion.”
At the time of the procedures, the James Graham Brown Center did not routinely assess tumors for HPV virus, but Dr. Dooley said that will be an area of continued work.