He became chief of practical work in the department of urology at UBA, then between 1912 and 1915 he was assigned professor of Anatomical Pathology. Between 1915 and 1931 he worked as attached professor in Anatomical Pathology.
In 1912 Daniel Cranwell presented a paper called Cáncer experimental to the Argentine National Academy of Medicine which detailed the results of his experiments on laboratory animals. This work influenced the creation of an institute for the study and treatment of cancer. In 1922 it was succeeded by the Instituto de Medicina Experimental directed by Roffo. He had become the leading cancer specialist in Latin America.
Roffo was one of the first scientists to demonstrate the link between tobacco tars and the production of tumours ". By the end of the 1920s he was certain that there was a link between smoking and cancer, he went on to produce a number of papers on the subject of tobacco carcinogenesis in the 1930s. Robert N Proctor of Stanford University claimed that Roffo arguably represented the single greatest scientific threat to the tobacco industry prior to the 1950s.
Ángel Roffo died on July 23, 1947 and the Institute of Oncology (Instituto de Oncología) at UBA was renamed in his honour.
- "Tobacco Carcinogenesis". World Health Organisation. Retrieved 2007-02-09.