Elective management of cervical and parotid lymph nodes in stage N0 cutaneous squamous cell carcinoma of the head and neck: a decision analysis

There is uncertainty regarding the threshold for recommending elective regional nodal treatment in the management of stage N0 cutaneous squamous cell carcinoma of the head and neck (cSCCHN). Elective treatment in the form of nodal surgery or irradiation is associated with morbidity. However, patients managed with careful observation sometimes present with advanced disease which often require more extensive therapy or may be unsalvageable altogether. We used decision analysis to examine the tradeoffs and benefits of different management approaches in the stage N0 patient. A decision tree comprising the three different treatment strategies was built: surveillance, elective nodal dissection (END) and elective nodal irradiation (ENI). Probabilities of nodal recurrence and likelihood of successful salvage were obtained from the literature. A convenience sample of patients previously treated for metastatic and non-metastatic cSCCHN was interviewed using the standard gamble technique to determine utility for post-treatment health states. Sensitivity analysis was performed and the effect on the expected utility was examined. When the probability of occult metastasis was >19 %, ENI resulted in a higher expected utility than observation. When the probability of occult metastasis exceeds 25 %, END has a higher expected utility compared to observation. Given the current available evidence, a wait-and-see approach is justified in patients with a probability of occult metastases <19 %.