Neck Dissection May Be Warranted For All Primary Parotid Cancers

NEW YORK MAR 25, 2005 (Reuters Health) - Routine neck dissection appears to be indicated for all patients with primary parotid cancers, even if there is no clinical evidence of disease in the neck (cN0), according to Swiss researchers.  However, the team stress that prospective studies are needed to confirm this strategy.

In the March issue of Otolaryngology: Head & Neck Surgery, Dr. P. Zbaren and colleagues, from the University Hospital in Berne note that treatment of oral cavity, pharyngeal, and laryngeal cancers with cN0 is well established. By contrast, the best approach for cN0 parotid cancers in unclear.

To investigate further, the researchers assessed regional recurrence rates and survival in 83 patients who underwent parotidectomy for cN0 parotid cancers.  About half of the patients were also treated with elective neck dissection and half were simply observed.

In 59 of the cases (71%), the cancer diagnosis was known before surgery, the authors point out.  The exact tumor histology was known in 36 cases (43%) and the grade was known in 37 (44%).

In the neck dissection group, occult metastases were identified in eight patients.   Five of these cases occurred in the presence of a high-grade cancer, but three were seen with low-grade malignancy.

Recurrent disease developed in five patients (12%) in the neck dissection group, less than half of the 11 (26%) seen in the observation group, the researchers point out.  Moreover, all seven recurrences involving the neck were confined to the observation group.

The 5-year actuarial survival rates for the two groups were similar, hovering around 82%.  In contrast, the disease-free survival rate for the neck dissection group was 86%, much higher than the 69% rate seen in the observation group.

Given that the exact tumor type or grade is often not known at the time of surgery, "we suggest routine elective neck dissection in all primary carcinoma of the parotid glands," the investigators conclude.

SOURCE;

• Otolaryngology: Head & Neck Surgery 2005;132:387-391.