Abstract
Purpose
To determine whether patients with clinically node negative (cNo) high grade salivary gland carcinomas benefit from an elective neck dissection prior to postoperative radiotherapy (RT).
Material/Methods
Between October 1964 and October 2009, 59 previously untreated patients with cNo high-grade salivary gland carcinomas (squamous cell carcinomas were excluded) were treated with curative intent using elective neck dissection (END; n = 41), or elective neck irradiation (ENI; n = 18) at the University of Florida College of Medicine (Gainesville, FL). All patients underwent resection of the primary cancer followed by postoperative RT. The median follow-up period was 5.2 years (range, 0.3–34 years).
Results
Occult metastases were found in 18 (44%) of the 41 patients in the END group. There were 4 recurrences (10%) in the END group and 0 recurrence in the ENI group. Neck control rates at 5 years were: END, 90%; ENI, 100%; and overall, 93% (p = 0.1879). Cause-specific survival was 94% in the ENI group, 84% in the END group, and 86% for all patients (p = 0.6998). There were 3 reported grade 3 or 4 toxicities. Two patients had a postoperative fistula and one patient had a grade 4 osteoradionecrosis that required a partial mandibulectomy.
Conclusions
Patients with cNo high grade salivary gland carcinomas who are planned to undergo surgery and postoperative RT likely do not benefit from a planned neck dissection.
1
Introduction
Major and minor salivary gland carcinomas are relatively uncommon, comprising approximately 1% to 3% of all head and neck malignancies . There are myriad histologies and biologic behaviors that contribute to this disease category. Elective neck management in this population remains undefined, and the indications for elective neck irradiation (ENI) versus observation versus elective neck dissection (END) vary between institutions. In general, the risk of occult nodal metastases in patients with high grade salivary gland carcinoma with a clinically negative node (cNo) probably is 20% or higher and these patients would likely benefit from elective node treatment. The purpose of this retrospective review is to determine the need for END in patients with cNo high grade salivary gland carcinomas who are planned to undergo resection of the primary cancer followed by postoperative radiotherapy (RT).
2
Materials and methods
Under an institutional review board-approved protocol, we reviewed the medical records of 59 consecutive cNo patients with previously untreated high grade salivary gland carcinomas who were treated with surgery and postoperative RT with curative intent at the University of Florida (Gainesville, FL) between October 1964 and October 2009. Patient characteristics including histology and site of the primary tumor can be found in Table 1 . Patients with tumors arising from the lacrimal gland, trachea, cervical esophagus, or from an unknown primary were excluded. Patients with squamous cell carcinomas were not included in the current study because the majority of these patients were likely to have had skin cancers that metastasized to the parotid lymph nodes compared with patients with primary salivary gland carcinoma.
| Characteristic | No. of patients (%) |
|---|---|
| Age, median (range) | 58 (14 to 81) years |
| Sex | |
| Male | 33 (56%) |
| Female | 26 (44%) |
| Race | |
| White | 52 (88%) |
| African American | 4 (7%) |
| Others | 3 (5%) |
| Clinical T classification | |
| T1 | 15 (25%) |
| T2 | 19(32%) |
| T3 | 7 (12%) |
| T4 | 18 (31%) |
| Median (range) radiotherapy (RT) dose | |
| All patients | 72.0 Gy (43.66–75.2 Gy) |
| Preoperative RT | 59.3 Gy (43.66–60.0 Gy) |
| Postoperative RT | 72.0 Gy (60.0–75.2 Gy) |
The median follow-up for patients was 5.1 years (range, 0.3 to 34.0 years). The median follow-up for living patients was 5.3 years (range, 1.0 to 34.0 years). Patients were clinically staged according to the 2009 American Joint Committee on Cancer (AJCC) staging system . Preoperative staging of the neck was based on physical examination and computed tomography.
Patients were grouped into 2 categories according to if and how the neck was electively managed: END (n = 41) and ENI (n = 18). Characteristics of the 2 groups can be found in Table 2 .
| Characteristic | Elective Neck Dissection | Elective Neck Irradiation |
|---|---|---|
| No. of patients | 41 | 18 |
| Histology | ||
| Adenocarcinoma | 9 (22%) | 4 (22%) |
| Adenoid cystic | 10 (24%) | 4 (22%) |
| Carcinoma ex-pleomorphic | 2 (5%) | 4 (22%) |
| High-grade oncocytic | 1 (3%) | 0 |
| High-grade myoepithelial | 0 | 1 (6%) |
| High-grade mucoepidermoid | 19 (46%) | 5 (28%) |
| T Stage | ||
| T1 | 9 (22%) | 6 (33%) |
| T2 | 11 (27%) | 8 (44%) |
| T3 | 6 (14%) | 1 (6%) |
| T4 | 15 (37%) | 3 (17%) |
The elective neck dissection included a bilateral modified radical neck dissection in 1 patient, a unilateral modified radical neck dissection in 28 patients, and a unilateral selective neck dissection in 12 patients.
Complications were graded according to Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) Radiation Morbidity criteria .
2.1
Statistical analysis
Statistical analysis was achieved with SAS and JMP software (SAS Institute, Cary, NC). The Kaplan–Meier product limit method provided estimates of various outcomes . The log-rank test statistic was utilized to assess statistical significance for these endpoints between the ENI and END groups.
2
Materials and methods
Under an institutional review board-approved protocol, we reviewed the medical records of 59 consecutive cNo patients with previously untreated high grade salivary gland carcinomas who were treated with surgery and postoperative RT with curative intent at the University of Florida (Gainesville, FL) between October 1964 and October 2009. Patient characteristics including histology and site of the primary tumor can be found in Table 1 . Patients with tumors arising from the lacrimal gland, trachea, cervical esophagus, or from an unknown primary were excluded. Patients with squamous cell carcinomas were not included in the current study because the majority of these patients were likely to have had skin cancers that metastasized to the parotid lymph nodes compared with patients with primary salivary gland carcinoma.
