Cover made for Boom! comics. The series title is Malignant Man.
Quick Description from Boom!:"MALIGNANT MAN tells the story of Alan Gates, a cancer patient with a terminal diagnosis, who’s resigned to his fate…until he discovers that his tumor is actually a mysterious parasite! Granted a second lease on life and incredible, otherworldly powers, Alan must fight against an evil army buried beneath society’s skin, all the while unlocking the secrets of his forgotten past."