New tumor regression grade for rectal cancer after neoadjuvant therapy and radical surgery.

Jun Li,Bo Lv,Jiatian Yuan,Jie Yin,Junjie Hu,Hao Liu,Sai Liu,Feng Du

doi:10.18632/oncotarget.6008

Abstract

In this retrospective study, we defined a new tumor regression grade (NTRG), which we used to evaluate the prognosis of patients with locally advanced rectal cancer who received neoadjuvant therapy and then underwent radical surgery between June 2004 and October 2011. Calculated as the TRG plus a lymph node score, the NTRG was determined for 347 patients: NTRG 0, 46 patients (13.3%); NTRG 1, 63 (18.2%); NTRG 2, 183 (52.7%); NTRG 3, 30 (8.6%); NTRG 4, 25 (7.2%). Among this group, 45 (97.8%) NTRG 0, 56 (88.9%) NTRG 1, 148 (80.9%) NTRG 2, 24 (66.7%) NTRG 3, and 10 (40.0%) NTRG 4 patients experienced 5-year disease-free survival. We also found that NTRG is significantly associated with 5-year local recurrence, distant metastasis and disease-free survival (P = 0.004, 0.007 and 0.039, respectively). The NTRG may thus be an independent prognostic factor for oncologic outcomes in rectal cancer patients after neoadjuvant therapy and radical surgery, but this conclusion must be validated in randomized trials.

Highlights

Rectal cancer patients receiving neoadjuvant therapy may experience late local recurrence and distant metastasis [1]
A total of 347 patients with stage II or III rectal cancer who received radical surgery within 7.5 ± 0.2 weeks after neoadjuvant therapy were identified in this retrospective study
No significant association was found between the new tumor regression grade (NTRG) and the degree of tumor differentiation after radical surgery

Summary

Introduction

Rectal cancer patients receiving neoadjuvant therapy (preoperative chemoradiotherapy or radiotherapy only) may experience late local recurrence and distant metastasis [1]. Long-term follow-up of participants in the CAO/ ARO/AIO-94 Rectal Cancer Trial revealed a continuous increase in local recurrence for up to 10 years [2]. A large number of neoadjuvant chemoradiotherapy trials have explored the use of the pathologic complete response (pCR) and/or tumor regression grade (TRG) as primary end points, and various grading systems have been proposed. The TRG does not account for lymph node involvement, which is an important determinant of prognosis [1]. We attempted to develop a new method for evaluating oncological outcomes that takes into consideration both the TRG and lymph node status

Methods

Results

Conclusion