Vironen J, Juhola M, Kairaluoma M, Jantunen I, Kellokumpu I
Helsinki University Central Hospital, Jorvi Hospital, Espoo, Finland.
Int J Colorectal Dis. 2005 Sep;20(5):440-5. doi: 10.1007/s00384-004-0733-y. Epub 2005 Apr 23.
Preoperative radiotherapy (PRT) for rectal carcinoma has been shown to cause tumour regression and increase local control and patient survival. The aim of this study was to examine the usefulness of tumour regression grading (TRG) in quantifying the effect of PRT.
Depending on the tumour stage (uT), as defined by preoperative endorectal ultrasound (ERUS), fixity and distance from the anal verge, 126 patients with rectal cancer underwent either surgery alone, or received short-course 25-Gy radiotherapy or long-course 50-Gy radiotherapy combined with 5-fluorouracil (5-FU) before surgery. TRG in each group was assessed and compared with the downstaging, defined as a change in preoperative uT stage and pathologic stage (pT).
Complete response (no residual tumour, TRG 1) was seen in 7% of the patients (3/44) and total or major regression (TRG 1-3) in 73% of the patients (32/44) treated with 50-Gy chemoradiation. Of those treated with 25-Gy PRT, 21% (9/42) showed major tumour regression. Of the patients who underwent ERUS and PRT, 32% (26/83) were downstaged when comparing uT with pT, but 53% (14/26) of the downstaged tumours showed no response by TRG. In comparison, 50% (28/57) of the tumours with no downstaging showed a marked response by TRG (p=0.05).
Tumour regression grading offers detailed information of the effect of PRT and shows that tumour regression is more marked after long-term chemoradiation than after short-course radiotherapy (p=0.02). In contrast, T-stage downstaging was similar in both groups and did not correlate with the TRG results (p=0.05).
已证实直肠癌术前放疗（PRT）可导致肿瘤消退，提高局部控制率及患者生存率。本研究旨在探讨肿瘤消退分级（TRG）在量化PRT效果方面的实用性。
根据术前直肠内超声（ERUS）所定义的肿瘤分期（uT）、固定情况及距肛缘距离，126例直肠癌患者要么单纯接受手术，要么在术前接受短程25 Gy放疗或长程50 Gy放疗联合5-氟尿嘧啶（5-FU）。评估每组的TRG，并与降期情况进行比较，降期定义为术前uT分期和病理分期（pT）的变化。
接受50 Gy放化疗的患者中，7%（3/44）出现完全缓解（无残留肿瘤，TRG 1），73%（32/44）出现完全或主要消退（TRG 1-3）。接受25 Gy PRT的患者中，21%（9/42）出现主要肿瘤消退。在接受ERUS和PRT的患者中，比较uT和pT时，32%（26/83）出现降期，但降期肿瘤中有53%（14/26）经TRG评估无反应。相比之下，未降期的肿瘤中有50%（28/57）经TRG评估有明显反应（p = 0.05）。
肿瘤消退分级提供了PRT效果的详细信息，表明长期放化疗后的肿瘤消退比短程放疗后更明显（p = 0.02）。相比之下，两组的T分期降期情况相似，且与TRG结果无关（p = 0.05）。
