%0 Journal Article %T Prognostic Value of Mandard and Dworak Tumor Regression Grading in Rectal Cancer: Study of a Single Tertiary Center %A Marisa D. Santos %A Cristina Silva %A Anabela Rocha %A Eduarda Matos %A Carlos Nogueira %A Carlos Lopes %J ISRN Surgery %D 2014 %R 10.1155/2014/310542 %X Goal. To evaluate the prognostic value of Mandard and Dworak grading systems regarding neoadjuvant chemoradiotherapy (CRT) response on rectal cancer. Materials and Methods. We queried our centerĄ¯s database for patients with colo rectal cancer with locally advanced rectal cancer (LARC) who received neoadjuvant CRT followed by total mesorectum excision (TME) between 2003 and 2011. After excluding 18 patients from the initial query the remaining 139 were reassessed for disease recurrence and survival; the specimensĄ¯ slides were reviewed and classified according to two tumor regression grading (TRG) systems: Mandard and Dworak. Based on these TRG scores, two patient groups were created: patients with good response versus patients with bad response (Mandard TRG1+2 versus Mandard TRG3+4+5 and Dworak TRG4+3 versus Dworak TRG2+1+0). Overall survival (OS), disease-free survival (DFS), and disease recurrence were then evaluated. Results. Mean age was 64.2 years and median follow up was 56 months. No significant survival difference was found when comparing patients with Dworak TRG 4+3 versus Dworak TRG2+1+0 ( ). Mandard TRG1+2 presented with significantly better OS and DFS than Mandard TRG3+4+5 (OS ; DFS ). Conclusions. Mandard system provides higher accuracy over Dworak system in predicting rectal cancer prognosis when neoadjuvant CRT is applied for tumor regression. 1. Introduction Improved outcome in the treatment of locally advanced rectal cancer (LARC) is related to the introduction of total mesorectal excision (TME) and neoadjuvant treatment [1¨C3]. In locally advanced rectal cancer (LARC) the use of neoadjuvant chemoradiotherapy (CRT) reduces locoregional recurrence and can lead to better prognosis depending on the tumor regression grade. Rectal cancer prognosis appears to be related to neoadjuvant CRT response [4¨C6]. After curative surgery with TME, tumor extension through the rectal wall (pT), spreading to the regional lymph nodes (pN) and the circumferential resection margin (CRM) constitute the main criteria to estimate prognosis in rectal carcinoma patients [7]. In LARC, chemoradiotherapy applied before surgery may change the pathologic stage and CRM of the resected specimen. Several studies have demonstrated that clinical outcome depends not only on the initial stage of the tumor, but also on the CRT-induced tumor response which varies among individual patients [8]. Tumor response to neoadjuvant CRT can induce cytoreduction and downstaging of the lesion and can also cause histological changes which can be assessed by tumor regression systems, which in %U http://www.hindawi.com/journals/isrn.surgery/2014/310542/