Can cellphones cause brain tumors? A court in Italy determined that excessive cellphone use caused one man to develop a brain tumor, the first case to ever recognize the link between phone use and tumors. Roberto Romeo used a cellphone for three hours a day over the course of 15 years while working for cellphone company Telecom Italia. He sued the state social security agency for unsafe work practices after he developed a non-cancerous brain tumor and hearing loss. As scientists still debate over whether cellphones are linked to tumors, the American Cancer Society states that there is no good evidence behind the claims.