Local Excision for organ preservation in early REctal cancer with No Adjuvant treatment (LORENA Trial): prospective observational study protocol - Perez, Rodrigo Tovar; Cerdan-Santacruz, Carlos; Cano-Valderrama, Oscar; Escovar, Fernando Jimenez; Lorente, Blas Flor; Perez, Rodrigo; Garcia-Septiem, Javier (Cirugía Española, 2024)