Feasibility analysis of using patient-derived tumour organoids for treatment decision guidance in locally advanced head and neck squamous cell carcinoma.

Background: Current treatment for head and neck squamous cell carcinoma (HNSCC) involves surgery, radiotherapy, and chemotherapy. Despite aggressive multimodal approaches, tumour recurrence occurs in 40-60 % of cases, leading to poor survival outcomes. HNSCC lacks common genetic drivers for tailored therapies, and reliable biomarkers for treatment selection are scarce. We investigated the procedural requirements for incorporating drug- and radiosensitivity screens in patient-derived organoids (PDOs) within a clinical trial framework.

Patients And Methods: Fresh tumour samples (N = 198) from 186 HNSCC patients were included. Success rates of organoid establishment were correlated with clinical and procedural parameters. Timelines for establishment of PDO cultures were determined, and their long-term growth potential assessed by serial passaging. Additionally, we conducted whole exome sequencing on matched tumour-organoid pairs. Three PDO models were employed to establish radiosensitivity assays.

Results: In total, PDO models displaying histomorphological features and genomic alterations of parental tumours were successfully established for 35 % of patient tumours. Success rates rose to 77 % for samples with a tumour cell content of 30 % or higher. Advanced patient age, prior radiotherapy, and delays in tissue processing were identified as negative predictors for engraftment. The estimated time interval needed for screens was compatible with PDO-guided selection of curative-intent radiotherapy regimens.

Conclusions: Our findings suggest that with high-quality samples and efficient tissue processing, PDO screens can be successfully performed in 77 % of HNSCC patients. Given the procedural challenges involved, future clinical trials aiming to the utility of PDOs for guiding treatment decisions should consider implementing centralised PDO screening.