Is head and neck cancer hereditary?

Usually not. Head/neck cancers are typically environmentally driven- smoking, alcohol, tobacoo chewing, virus infections (hpv and ebv virus) are the causative factors. Some head/neck cancers such as thyroid cancers can be hereditary though.
No. Head and neck cancer typically refers to squamous cell cancer in the mouth/throat region and is not hereditary. More ofter associated with smoking, alcohol consumption, and hpv infection.
Uncommon. There can be a genetic predispostion for families to develop cancer but only a few head and neck cancers (thyroid, endorine neoplasms, neurofibromatosis and some others) are inherited.