Why acute otitis media is dangerous in adults? could it be a sign of cancer or weak immunity? thanks

??Dangerous ??: I would consider it unusual and a nuisance but not dangerous. If it led to a perforated ear drum, those do take much longer to heal and may require surgery. Adults who get acute otitis generally did so as kids, and many have allergic and or sinus issues that predispose to the problem. I can't buy a cancer or immune defect as a significant factor.