A 55-year-old woman undergoes a sigmoid colectomy for microsatellite-stable sigmoid colon cancer. The final pathology demonstrates a 4-cm moderately differentiated adenocarcinoma with 2 cm proximal and distal margins negative for residual disease. A total of 12 lymph nodes were identified in the specimen, none of which were positive for adenocarcinoma. Which of the following is true regarding the quality of her resection?