Firefighter Cancer Registry Act of 2018 (Sec. 2) This bill requires the Centers for Disease Control and Prevention (CDC) to develop and maintain a voluntary registry of firefighters in order to collect history and occupational information that can be used to determine the incidence of cancer among firefighters. The registry must be used to improve monitoring of cancer among firefighters and to collect and publish epidemiological information. The CDC should seek to include specified information in the registry, including the number and type of fire incidents attended by an individual. To collect information for the registry, the CDC must enable the registry to connect to state-based cancer registries. The CDC must also: (1) develop a strategy to encourage participation in the registry, (2) develop guidance for states and firefighting agencies regarding the registry, and (3) seek feedback on the registry from nonfederal experts. The CDC must make registry data available to the public and in accordance with privacy laws.