title: Expression of hypoxia-inducible factor 1α predicts clinical outcome after preoperative hyperthermo-chemoradiotherapy for locally advanced rectal cancer.
abstract: Hypoxia-inducible factor 1α (HIF-1α) is an intrinsic marker of tumor hypoxia. It has been considered that hypoxic conditions reduce radiosensitivity, but the role of HIF-1α in patients treated with preoperative therapy for rectal cancer is still unclear. The aim of this study was to evaluate the predictive value of tumor response to preoperative hyperthermo-chemoradiotherapy (HCRT) and the prognostic significance of HIF-1α expression in patients with locally advanced rectal cancer. Between 2003 and 2006, 50 patients with histologically proven rectal adenocarcinoma who underwent HCRT followed by surgery were investigated. HIF-1α expression was immunohistochemically evaluated using pre-treatment biopsies. The total radiation dose was 40-50 Gy and chemotherapy consisted of 5-FU and LV administered by continuous infusion on Day 1-5, Day 15-19, and Day 29-33 during radiotherapy. Hyperthermia treatment was performed for once a week for 2-5 sessions. The surgical operation was performed 8 weeks after HCRT and each resected specimen was graded by histological criteria of the Japanese Classification of Colorectal Carcinoma. The effects of HIF-1α on clinical outcomes were analyzed by univariate and multivariate analysis. Positive HIF-1α expression was recognized in 42.0% of samples (21/50). Resected specimens that showed pathological grades 1, 2, and 3 numbered 17, 24, and 9 cases, respectively. There were no significant differences between the HIF-1α-positive group and HIF-1α-negative group for pathological grading and pCR. Overall survival (OS) rate at 3 years in the HIF-1α-negative group was 85.2%, which was significantly better than the 60.6% in the HIF-1α-positive group. Recurrence-free survival (RFS) rate at 3 years in the HIF-1α-negative group was 82.8%, being significantly better than 47.6% in the HIF-1α-positive group. In addition, elevated HIF-1α expression was significantly correlated with recurrence-free survival and metastasis-free survival rate in multivariate analysis. HIF-1α expression might be predictive of recurrence-free survival and metastasis-free survival rate for rectal cancer patients treated with HCRT.
authors: Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan.
authors: Mariko
authors: M
authors: Shioya
authors: Takeo
authors: T
authors: Takahashi
authors: Hitoshi
authors: H
authors: Ishikawa
authors: Hideyuki
authors: H
authors: Sakurai
authors: Takeshi
authors: T
authors: Ebara
authors: Yoshiyuki
authors: Y
authors: Suzuki
authors: Jun-ichi
authors: J
authors: Saitoh
authors: Tatsuya
authors: T
authors: Ohno
authors: Takayuki
authors: T
authors: Asao
authors: Hiroyuki
authors: H
authors: Kuwano
authors: Takashi
authors: T
authors: Nakano
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D059248:Chemoradiotherapy; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy*
chemical_list: D014408:Biomarkers, Tumor; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit