375P - Survival and prognostic factors of head and neck squamous cell carcinoma patients treated with either definitive CCRT or post operative CCRT with platinum-based chemotherapy in Rajavithi hospital, Thailand

Background

To determined survival and prognostic factors for non-nasopharyngeal head and neck squamous cell carcinoma (HNSCC) patients treated with surgery followed by concurrent chemoradiotherapy (CCRT) or definitive CCRT (dCCRT), aiming to identify optimal chemotherapy doses.

Methods

This retrospective cohort study reviewed 277 non-NPC HNSCC patients treated with platinum-based CCRT at Rajavithi Hospital between January 1^st, 2016 and April 30^th, 2021. Clinical features, staging, treatment, and outcomes were collected and analyzed.

Results

Overall, 277 patients were diagnosed as HNSCC; median age: 55.9 years; male: 81.2%; ECOG 0-1: 98.9%. The clinical stage was I-III, IVa, and IVb in 23.8%, 53.4%, and 22.8%, respectively. Cisplatin was used in 39.0%, while carboplatin was used in 61.0%. 53.4% underwent surgery followed by CCRT while 46.6% underwent definitive CCRT. Patients treated with adjuvant CCRT led to significantly longer overall survival (OS) and disease-free survival (DFS) than definitive CCRT (HR: 0.54, p<0.001 for OS; HR: 0.61, p<0.001 for DFS). Higher stage and the presence of pathological risk factors were poor prognostic factors for OS in the adjuvant CCRT group, while higher stage and oral cavity and hypopharynx were associated with poorer OS in the definitive CCRT group. Among the interquartile range of cumulative doses (CDs), the study also found a statistically significant difference in OS and DFS for the dCCRT group with carboplatin at the 2^nd Quartile compared to the others (6.75-8.58 AUC) (HR 0.38, 95%CI; 0.17-0.86, p=0.02 and HR 0.41, 95%CI; 0.18-0.91, p=0.03, respectively). There was no significant difference in OS/DFS between patients who received CDs of cisplatin of either less or more than 200 mg/m2 or carboplatin in adjuvant CCRT in all population.

Conclusions

This study showed comparable survival outcomes to historical data. Surgery followed by adjuvant CCRT remains the recommended approach. The CDs of cisplatin or carboplatin did not significantly impact outcomes. A trend towards improved survival with CDs within a specific range requires confirmation in further prospective studies.

Clinical trial identification

6518.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.