NECK DISSECTION AFTER RT BENEFICIAL FOR N2b AND GREATER STAGE

NEW YORK (Reuters Health) Nov 25 - When patients with head and neck cancer and advanced nodal disease have a clinical complete response (cCR) to chemoradiation, subsequent neck dissection may improve local and distant disease control, new research hints.

"Nevertheless, any potential benefit from postradiotherapy neck dissection (PRND) should be balanced with the increased morbidity after the procedure," the researchers say.

"Currently, we would still recommend observation for patients who have a complete radiographic response in the cervical lymph nodes after chemoradiation, especially for HPV-positive oropharyngeal patients who have a higher rate of local control," Dr. Michael Spiotto from The University of Chicago Knapp Center for Biological Discovery, Chicago, Illinois, told Reuters Health by email.

"Our observations remain hypothesis generating at this point and we urge further retrospective evaluation of existing patient data and potentially prospective evaluation of this hypothesis," he wrote.

After chemoradiation for head and neck cancer, the vast majority of patients who achieve cCR on imaging have their disease regionally controlled without PRND. But the extent to which PRND affects nonregional sites of disease remains unclear, Dr. Spiotto and colleagues explain in JAMA Otolaryngology Head and Neck Surgery online November 21.

To investigate, they took a look back at 287 patients treated for stage III/IV head and neck squamous cell carcinoma (HNSCC) with definitive chemoradiation - including 74 who underwent PRND.

Patients with advanced nodal disease (N2b or higher, 176 patients) had improved progression-free survival (PFS) with PRND (74.6% vs 39.1%; p=<0 .001="" 68.2="" a="" advanced="" but="" did="" disease="" less="" nodal="" not="" or="" p="0.98).</p" those="" vs="" with="">

Patients with N2b or higher nodal disease undergoing PRND had better two-year local control (85.5% vs 53.5%; p<0 --="" .001="" 45.7="" 61.7="" 67.5="" and="" control="" didn="" distant="" freedom="" from="" have="" locoregional="" metastasis="" overall="" p="" peers="" prnd.="" regional="" relative="" similar="" survival="" t="" their="" to="" vs="" who="">

The researchers note that even in patients with HNSCC and advanced nodal disease (stage N2b or greater) and a cCR on imaging, PRND improved control at nonregional disease sites. On multivariable analysis, PRND was the only significant predictor of improved local control and PFS. In addition, advanced nodal stage correlated with decreased PFS in the absence of PRND.

"Our data and others suggest that clearance of involved lymphatics may affect disease control at nonregional sites," they write.

It is important to note, however, that PRND may increase morbidity and thereby negate any therapeutic benefit. Therefore, patients who might benefit from PRND need to be carefully selected to derive meaningful therapeutic benefit, the researchers say.

The relatively short follow-up time is a limitation of the study, the researchers say. Also, due to a limited number of HPV-positive patients, their results suggesting a benefit of PRND on nonregional control "likely apply to HPV-negative HNSCCs."

For now, they say, it remains unclear which patient, tumor, and molecular characteristics may predict improved local control with a PRND after a cCR. "We propose that PRND should be reevaluated for patients with HPV-negative cancers and extensive nodal disease."

"At most, there have only been hints in the literature to confirm our finding," Dr. Spiotto told Reuters Health. "Some groups (Leemans et al. Cancer 1994, among others) have reported that cervical lymph node involvement predicts for recurrence at the primary tumor site. Currently, this question has not been directly addressed in clinical trials. The majority of trials looking at post-radiotherapy lymph node dissection have only used pathological correlates or looked primarily at regional failure rates. Furthermore, many of these trials were biased towards oropharyngeal cancers that have a high incidence of HPV-positive disease and would not likely have benefitted from a post-radiotherapy neck dissection. Therefore, we need a trial in carefully selected patients to determine if there is a benefit."

SOURCE: http://bit.ly/1dvXXNN

JAMA Otolaryngol Head Neck Surg 2013.