Epidermal growth factor receptor as a predictor of tumor response to preoperative chemoradiation in locally advanced gastric carcinoma.
OBJECTIVE
The purpose of our study was a retrospective evaluation whether the intensity of epidermal growth factor receptor (EGFR) expression predicts tumor response to preoperative chemoradiotherapy in patients with locally advanced gastric carcinoma.


METHODS
Thirty-six patients with gastric adenocarcinoma (cT2-4 or N+) were studied. Preoperative treatment consisted of 30-45 Gy of gastric irradiation with continuous 5-fluorouracil and weekly cisplatin. Surgical resection was performed 4-6 weeks later. EGFR expression in pretreatment tumor biopsies was assessed by immunohistochemistry. Level of EGFR expression was determined from the intensity and extent of staining. Tumor response was defined as a reduction of at least one T-stage level and/or finding of intense tumor regression in histopathologic examination.


RESULTS
Seventeen patients responded to preoperative chemoradiation -- 8 patients (22%) had pathologic complete response, 9 patients (25%) were downstaged. Positive EGFR expression was found in 8 tumors (22%), and represented a significant predictive marker of poor tumor response in multivariate logistic regression analysis (p = 0.015). Response to chemoradiotherapy was found in 60% (16/28) of EGFR negative patients and in 13% (1/8) of EGFR positive patients (p = 0.044). None of the eight EGFR positive patients achieved pathologic complete response in comparison with 8/28 (29%) of patients with EGFR negative staining (p = 0.16).


CONCLUSIONS
EGFR may represent a molecular marker predictive for poor response to preoperative chemoradiotherapy in locally advanced gastric carcinoma.
Sirak
Igor
I
Department of Oncology & Radiotherapy, Charles University Medical School & University Hospital, Hradec Kralove, Czech Republic. sirak@fnhk.cz
Petera
Jiri
J
Hatlova
Jana
J
Vosmik
Milan
M
Melichar
Bohuslav
B
Dvorak
Josef
J
Zoul
Zdenek
Z
Tycova
Vera
V
Lesko
Michal
M
Hajduch
Marian
M
D000230:Adenocarcinoma / Q000532:radiotherapy* / Q000601:surgery; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002945:Cisplatin / Q000627:therapeutic use; D003131:Combined Modality Therapy; D066246:ErbB Receptors / Q000378:metabolism*; D005472:Fluorouracil / Q000627:therapeutic use; D005743:Gastrectomy; D006801:Humans; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011879:Radiotherapy Dosage; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D016896:Treatment Outcome
D066246:ErbB Receptors; D002945:Cisplatin; D005472:Fluorouracil