Role of radiotherapy in the multidisciplinary treatment of lacrimal gland adenoid cystic carcinoma.

BACKGROUND

The optimal treatment approach for lacrimal gland adenoid cystic carcinoma (LGACC) remains controversial.

OBJECTIVES

We aim to demonstrate the value of radiotherapy (RT) in the multidisciplinary treatment of LGACC.

DESIGN

This was a retrospective cohort study.

METHODS

This study was conducted on 90 patients with LGACC treated from 2002 to 2023. We compared the overall survival (OS), progression-free survival (PFS), recurrence-free survival (RFS), and distant metastasis-free survival (DMFS) between those treated with surgery alone versus surgery plus postoperative radiotherapy (PORT). In addition, the ipsilateral visual outcome and ocular complications were evaluated.

RESULTS

The addition of radiotherapy significantly improved the 5-year RFS (63.4% vs 31.1%, p = 0.014) and PFS (56.8% vs 31.1%, p = 0.036) while showing no improvement in OS (79.7% vs 85.6%, p = 0.98) and DMFS (67.3% vs 70.1%, p = 0.70) compared to surgery alone. Further analysis indicated that, compared to the photon-RT group, the proton/carbon-ion group showed no significant differences in 5-year OS (p = 0.7), RFS (p = 0.37), PFS (p = 0.45), and DMFS (p = 0.57). Univariate (odds ratio (OR) = 0.14, 95% confidence interval (CI): 0.04-0.49, p = 0.002) and multivariate (OR = 0.16, 95% CI: 0.04-0.62, p = 0.008) logistic regression indicated that radiotherapy was a protective factor for local recurrence. Furthermore, among the long follow-up of 35 patients accepting eye-sparing surgery plus PORT, 13 patients (37.1%) had best-corrected visual acuity (⩾20/40) and 14 (40.0%) had severe vision loss (<20/200); furthermore, dry eye disease (100%, 35/35) and cataract progression (45.7%,16/35) are the most common ocular complications.

CONCLUSION

Surgery plus radiotherapy is a safe and effective multidisciplinary treatment in improving local control with tolerable long-term ocular toxicity, but of limited impact on OS for LGACC.