This paper focuses on the scientific and political context that where in the origin of the institutionalization of the fight against cancer in Portugal over the first quarter of the 20th century. From the growing impact of an intense medical discourse about the disease to the first statistical studies, as well as the need to increase local scientific work on cancer science, all these elements saw the unfolding of the first projects that were at the origin of the Portuguese Institute for the Study of Cancer in 1923. It was not without tensions and moments of political disinterest that the project materialized. Under the newly implemented Republican political guidelines since 1910, there was a desire to prompt a greater state intervention in matters concerning public health, although the fight against cancer was perceived more as a matter of mere medical research and medical training than a serious public health problem demanding specific hospital structures.