Squamous cell carcinoma of unknown primary tumor metastatic to neck nodes: role of elective irradiation

Abstract

In patients with squamous cell carcinoma (SCC) metastases to neck lymph nodes and unknown primary tumor, the role of elective irradiation of uninvolved neck and potential mucosal primary sites is yet to be determined. The aim of this study was to review the experience treating SCC of unknown primary metastatic to neck nodes with surgery and postoperative radiotherapy (PORT) in Slovenia between 1995 and 2010 and to determine the importance of the extent of irradiated volume. For this purpose, the nationwide Cancer Registry of Slovenia database was used for identifying patients. 126 patients were identified. Involved-field PORT and extended-field PORT was used in 50 and 76 patients, respectively. At 5 years, locoregional control was 86 %, disease-specific survival 77 %, and overall survival 57 %. In multivariate analysis, the extent of irradiated volume has not been predictive for any outcome under study. Grade ≥3 acute and late radiotherapy-induced toxicities were more frequent in the extended-field PORT group. In conclusion, although not superior, involved-field PORT seems to be a preferred treatment option in SCC of unknown primary metastatic to neck nodes due to significantly reduced toxicity and better prospects for successful salvage.

Retrospective analysis of definitive radiotherapy for neck node metastasis from unknown primary tumor: Japanese Radiation Oncology Study Group study

“…This difference was anticipated to the fact that the mucosal region was contained in irradiated fields in the bilateral group. Strojan et al reported the comparison between involved-field and extended-field in postoperative setting (27). In multivariate analysis, the only factor that influenced locoregional control was the patients' age with older patients and the extent of RT field did not influence on any outcome.…”

Metastatic Squamous Cell Carcinoma to the Cervical Lymph Nodes From an Unknown Primary Cancer: Management in the HPV Era

“…Others have reported similar results in HPV negative populations in recent years (114). Strojan et al found no significant difference when they compared the risk of metachronous second primary tumors in patients with known primaries, and the risk of appearance of a mucosal primary in NCUP patients who were diagnosed during the same time span and were postoperatively irradiated either with involved-field or extended-field technique (116). Certainly, with HPV-related cancer that has undergone tonsillectomies and partial lingual tonsillectomy, it appears even less likely for a primary to emerge in a delayed fashion (117).…”

Treatment for retropharyngeal metastatic undifferentiated squamous cell carcinoma from an unknown primary site: results of a prospective study with irradiation to nasopharyngeal mucosa plus bilateral neck

“…However, conflicting data were reported by authors who favored treatment of the ipsilateral neck only, stating that a thorough workup to discover the primary tumor was more worthwhile than prophylactic extensive irradiation because of the high morbidity such as xerostomia [28, 29]. As far as we known, the current prospective study was the largest study evaluating the treatment efficacy of retropharyngeal metastatic undifferentiated squamous cell carcinoma.…”