Treatment Outcomes of Total Versus Superficial Parotidectomy With Postoperative Radiotherapy for High-Grade Parotid Carcinoma Confined to the Superficial Lobe: A Propensity Score-Adjusted Analysis.

BACKGROUND

The optimal surgical management of high-grade parotid carcinoma confined to the superficial lobe remains controversial, with limited evidence comparing total and superficial parotidectomy in this setting.

OBJECTIVE

To compare oncologic outcomes and complications between total parotidectomy with postoperative radiotherapy (TP + PORT) and superficial parotidectomy with postoperative radiotherapy (SP + PORT).

STUDY

DESIGN

Multicentre retrospective cohort study.

METHODS

Adult patients (> 18 years) with high-grade parotid carcinoma confined to the superficial lobe treated between 2011 and 2023 were identified at tertiary centres. Exclusion criteria included preoperative facial nerve palsy, metastatic disease to the parotid gland, prior head and neck radiotherapy, receipt of concurrent chemoradiation and follow-up < 12 months.

RESULTS

A total of 108 patients were included (TP + PORT, n = 63; SP + PORT, n = 45) with a median follow-up of 53 months. Baseline characteristics were comparable except for older age and a higher proportion of Milan category VI cytology in the TP + PORT group (p < 0.05). Local, regional and distant recurrence rates and mortality did not differ significantly between groups (p = 0.55, 0.26, 1.00 and 0.36, respectively). All local recurrences occurred within 24 months (mean: 7.2 months). Age and positive resection margins were independent predictors of mortality (p < 0.01). Five-year overall survival was 73.0% in the TP + PORT group and 81.5% in the SP + PORT group. IPTW-adjusted analyses confirmed no significant differences in recurrence or mortality between groups (hazard ratio for mortality, 0.78; 95% CI: 0.32-1.90; p = 0.59). Permanent facial nerve palsy was significantly more common after TP + PORT (14.3% vs. 2.2%, p < 0.001), while other complications were similar.

CONCLUSION

Superficial parotidectomy with adequate margins followed by PORT achieves comparable oncologic outcomes with significantly fewer complications and may be preferred for high-grade parotid carcinoma confined to the superficial lobe.

LEVEL OF EVIDENCE: 2d (JBI).