Kaplan-Meier estimates of observed survival in 185 patients presenting with HNSCC, based on cell line formation. Failure is defined as death, and for patients with multiple HNSCC, the date of the first tumor is used to estimate survival time. The median observed survival time, defined as the length of time from the patient's presentation in the clinic with an HNSCC until they either die or otherwise exit the study (censored, lost to follow-up), is 22 months if the tumor yields a cell line and 60 months if it does not (log-rank test for equality of survivor functions; p<0.05).