Iwata Takashi, Shimada Mitsuo, Kurita Nobuhiro, Nishioka Masanori, Morimoto Shinya, Yoshikawa Kozo, Higashijima Jun, Nakao Toshihiro, Komatsu Masato
Department of Surgery, University of Tokushima, Tokushima, Japan.
Hepatogastroenterology. 2012 Jun;59(116):990-3. doi: 10.5754/hge10068.
BACKGROUND/AIMS: Chemo-radiation therapy (CRT) has been used to improve local control and survival in patients with advanced rectal carcinoma. However, a significant proportion of patients shows poor response to adjuvant CRT. We thus investigated the usefulness of RAD51 expressions as a predictive maker of the CRT response.
Forty two patients who suffered from lower rectal cancer were investigated. All patients received preoperative CRT consisting of TS-1, concurrent with 40Gy of pelvic irradiation before having curative radical resection. The relationship between pathological responses of the tumors after therapy and expression of RAD51 was evaluated by immunostaining of resected specimen.
Positive expression of RAD51 was observed in 24 of 42 patients (57.1%). RAD51 positively expressed in 68.2% (15 of 22 cases) of SD and 42.2% (9 of 20 cases) of PR and CR. There is a tendency of reverse correlation between clinical response and expression of RAD51. Regarding the correlation between pathological response and RAD51 expression, positive expression of RAD51 was recognized in 75.0% (15 of 20 cases) of Grade 1, 47.1% (8 of 17 cases) of Grade 2 and 20.0% (1 of 5 cases) of Grade 3. A significant reverse correlation was recognized between RAD51 expression and pathological responses.
RAD51 expression could be one of the most important predictive factors of preoperative CRT for advanced lower rectal cancer.
背景/目的：化疗放疗（CRT）已被用于改善晚期直肠癌患者的局部控制和生存率。然而，相当一部分患者对辅助性CRT反应不佳。因此，我们研究了RAD51表达作为CRT反应预测指标的有用性。
对42例低位直肠癌患者进行了研究。所有患者在进行根治性切除术前均接受了由替吉奥组成的术前CRT，并同时进行40Gy的盆腔照射。通过对切除标本进行免疫染色，评估治疗后肿瘤的病理反应与RAD51表达之间的关系。
42例患者中有24例（57.1%）观察到RAD51阳性表达。RAD51在疾病稳定（SD）的患者中阳性表达率为68.2%（22例中的15例），在部分缓解（PR）和完全缓解（CR）的患者中阳性表达率为42.2%（20例中的9例）。临床反应与RAD51表达之间存在负相关趋势。关于病理反应与RAD51表达之间的相关性，RAD51阳性表达在1级患者中占75.0%（20例中的15例），在2级患者中占47.1%（17例中的8例），在3级患者中占20.0%（5例中的1例）。RAD51表达与病理反应之间存在显著的负相关。
RAD51表达可能是晚期低位直肠癌术前CRT最重要的预测因素之一。
