ABSTRACT
In current literature few studies include prior tumors as a variable in survival analysis1, while it is obvious that prior tumors will have an effect on survival. Especially in head and neck squamous cell cancer (HNSCC), multiple primary tumors are a well-known phenomenon. This is of course related to the most important etiologic factors: nicotine and alcohol abuse. These agents exert their detrimental effect not only to the mucosal lining of the upper aerodigestive tract, but on many other organs as well.
