Aim: The value of grading tumor regression after neoadjuvant therapy of rectal carcinoma was evaluated.
Patients and methods: Analysis was carried out using prospective data of 225 patients with rectal carcinoma treated by neoadjuvant radiochemotherapy followed by radical resection with curative intent. For the histological regression grading, the method of Dworak et al. (1997) was used with a slight modification.
Results: After neoadjuvant radiochemotherapy, the most important prognostic factors are pathologically assessed circumferential resection margin, quality of surgery (plane of surgery), and the ypT and ypN classification. In addition, the histological regression grade of primary tumor and regional lymph nodes influence outcome, especially the local recurrence rate.
Conclusion: After neoadjuvant therapy, the histological tumor regression grading should be assessed. A regression grading system based on the proposals of Dworak et al. (1997) is recommended.