First of all, our cameras have a sensor and a lens. (A lance is a weapon of medieval ages and censors are something in countries with limited freedom of press.)
Fungus infections on camera sensors can be cleaned, they usually only appear on the surface. Fungus in lenses are more difficult to clean since it usually appears between the lens elements. In order to clean these areas, the lens has to be dismantled, cleaned and reassembled. Newer lenses also tend to have lens groups held together by glue or other means, which makes cleaning more difficult.
Best to avoid fungus right from the beginning: if not used, keep your equipment in a dry cabinet within the recommended relative humidity (usually ~50%). Best of course: use your equipment. The exposure to sunlight keeps fungus away.
If a previous fungus infection was properly cleaned and the equipment is kept in good condition then there is nothing to worry.