Annually, over 3,000 patients in the Netherlands are diagnosed with head and neck squamous cell carcinoma (HNSCC), with 21% occurring in the larynx (LSCC). Prognosis is strongly dependent on the TNM stage, with advanced tumors having a worse outcome. Treatment options include surgery and radiotherapy, with or without systemic therapy. Up to 50% of HNSCC patients develop a recurrence after primary treatment. Salvage surgery offers a chance for cure in a select group but is associated with significant complication risks.
This thesis of Karlijn van den Bovenkamp found that only 41% of patients who underwent salvage neck dissection (a surgery to remove cervical lymph nodes) had viable tumor cells, meaning more than half were unnecessarily exposed to the risks of salvage surgery. Factors linked to the presence of viable tumor cells included primary treatment with radiotherapy alone (without systemic therapy), HPV-negative tumors, and an increase in lymph node size after treatment. Complications, such as wound infection, occurred in 28% of patients, with more extensive neck dissections linked to a higher complication risk. This emphasizes the importance of selective neck dissections where possible.
Reliable markers for radiosensitivity are lacking, and treatment decisions for locally advanced LSCC are mostly based on clinical features. Research into more accurate markers is crucial to avoid (unnecessary) salvage surgery and improve outcomes. In this thesis, tumor markers HIF-1α, pFADD, and DNMT3A were associated with outcomes after radiotherapy (locoregional recurrence or disease-specific mortality). CA-IX, Ki-67, DNMT1, and DNMT3B were not associated with recurrence risk or disease-specific mortality in this patient group.
