Abstract: A first and a second identical or different mycobacterial immunogenic compositions, each comprising at least a Mycobacterium bovis bacillus Calmette-Guerin (BCG), an antigenically related non-pathogenic mycobacteria, or one or more immunogenic component(s) thereof, as therapeutic active ingredient(s) for use in the treatment of cancer by parenteral or oral administration of the first composition to a cancer patient before local administration of the second composition at tumor site. A method in vitro for monitoring cancer treatment by immunotherapy with BCG, antigenically related non-pathogenic mycobacteria, or immunogenic component(s) thereof, comprising assaying BCG-specific immune response in a patient.