[The first mastectomy for breast cancer in America: Aguascalientes, México, 1777].

In this paper we present the first evidence of a mastectomy for breast cancer in America, performed in Aguascalientes, Mexico, in the eighteenth century. This intervention was recorded in an anonymous ex-voto in which Mrs. Josefa Peres Maldonado thanks the Black Christ of Encino and the Immaculate Conception or Virgin of the village for the good results obtained. The French physician and surgeon Peter Maille performed the operation with the help of friars of the convent-hospital San Juan de Dios. We review the history of the surgical treatment of breast cancer, the pictorial structure of the document, the surgical technique proposed by the Royal College of Surgeons (New Spain) at the time, and the association between this event and its time as an example of the impact that the Age of Enlightenment had in New Spain.