is for hpv-related oropharynx. tumor extension extension of the tumor to the base of tongue reduces the chances of cure drastically. it also increases the chances of recurrence after treatment. metastasis spread of cancer cells to local structures like tissues, vessels, large nerves and lymphatics worsens a patient's prognosis. a study that analyzed the survival rate in hpv-related oropharynx carcinoma to that in hpv-unrelated oropharynx carcinoma. the study revealed that based on the hpv status of the patient, for stage iii and stage iv oropharynx carcinoma, there was a discrepancy in survival after three years. the survival was 82% in hpv positive and then also 57% in hpv negative cancers.