# Long-term outcomes of platinum-based chemotherapy for T4 stage sinonasal adenoid cystic carcinoma

## TL;DR

This study found that platinum-based chemotherapy did not improve long-term survival for T4 sinonasal adenoid cystic carcinoma patients and might even worsen outcomes after five years.

## Contribution

The study is the first to report a potential negative long-term impact of platinum-based chemotherapy in T4 SNACC patients.

## Key findings

- Platinum-based chemotherapy was not associated with improved overall survival, progression-free survival, or metastasis-free survival.
- Chemotherapy was linked to worse 10-year overall survival compared to no chemotherapy.
- Multivariate analyses confirmed no significant benefit of chemotherapy on survival or metastasis risk.

## Abstract

To investigate the impact of platinum-based chemotherapy on long-term outcomes of T4 sinonasal adenoid cystic carcinoma (SNACC).

We retrospectively analyzed clinical data from 87 consecutive patients with T4 SNACC who underwent surgery plus radiotherapy with or without platinum-based chemotherapy in our institution between 1993 and 2019.

Of the 87 cases of T4 SNACC, 57.5% (50/87) of patients underwent platinum-based chemotherapy. Overall, chemotherapy was not associated with overall survival (OS) (P = 0.814), PFS (progression-free survival) (P = 0.508), local recurrence-free survival (LRFS) (P = 0.500) or distant metastasis-free survival (DMFS) (P = 0.202) improvement. Besides, chemotherapy significantly decreased 10-year OS (27.9% vs. 58.8%, P = 0.034) compared with the no-chemotherapy group. Univariate (P = 0.383) and multivariate logistic analyses (P = 0.213) suggested that chemotherapy did not reduce the risk of distant metastasis. Furthermore, multivariate Cox regression analysis indicated that chemotherapy did not improve OS (P = 0.789) or PFS (P = 0.556).

Platinum-based chemotherapy did not seem to provide a long-term survival advantage for patients with T4 SNACC and might be associated with worse outcomes after 5 years, although these findings need confirmation through prospective studies.