title: Molecular Predictors of Response to Neoadjuvant Chemoradiation for Rectal Cancer.
abstract: To determine whether the expression of specific molecular markers in the rectal cancer biopsies prior to treatment, can correlate with complete tumor response to chemoradiotherapy (CRT) as determined by the pathology of the surgical specimen.
  
  
  
  We retrospectively examined pretreatment rectal biopsies of patients aged 18 years or older with locally advanced rectal cancer who had been treated with neoadjuvant CRT and surgical resection in our tertiary-care, university-affiliated medical center, between January 2001 and December 2011. Samples were analyzed for expression of B-cell lymphoma 2, P53, Ki67, epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor, and the tumor regression grade after CRT and radical surgery.
  
  
  
  Forty-seven patients were included in the final analysis. Main outcome measures were the correlation between the expression of the molecular markers tested in the pretreatment biopsy, and complete tumor response. Complete pathologic response after CRT was attained in 27% of the patients. Percentage of cells expressing EGFR in the pretreated biopsies of patients having complete pathologic response after CRT and surgery was 33.08±7.87% compared to 19±15.36% (P=0.38), 6.66±2.83% (P<0.003), and 12.5±4.93% (P=0.033) in patients with partial response and tumor regression grades of 2, 3, and 4, respectively. The other molecular markers tested in the pretreatment biopsy did not corresponded with complete pathologic response.
  
  
  
  EGFR expression pattern in the pretreatment biopsies of rectal tumors can assist in identifying patients who will benefit from neoadjuvant CRT.
authors.affiliation: Institute of Oncology, Davidoff Cancer Center, Beilinson Hospital.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Kundel
authors.affiliation: Oncology Institute, Ziv Medical Center, Safed.|Faculty of Medicine in the Galilee, Bar-Ilan University.
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Nasser
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv.|Department of Pathology, Rabin Medical Center, Hasharon Hospital, Petach Tikva.
authors.forename: Lea
authors.initials: L
authors.lastname: Rath-Wolfson
authors.affiliation: Institute of Oncology, Davidoff Cancer Center, Beilinson Hospital.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv.
authors.forename: Ofer
authors.initials: O
authors.lastname: Purim
authors.affiliation: Department of Pathology, Rabin Medical Center, Hasharon Hospital, Petach Tikva.
authors.forename: Natalia
authors.initials: N
authors.lastname: Yanichkin
authors.affiliation: Institute of Oncology, Wolfson Medical Center, Holon.
authors.forename: Ronen
authors.initials: R
authors.lastname: Brenner
authors.affiliation: Meir Medical Center, Kfar Saba.
authors.forename: Tanya
authors.initials: T
authors.lastname: Zehavi
authors.affiliation: Faculty of Industrial Engineering and Management, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Yuval
authors.initials: Y
authors.lastname: Nardi
authors.affiliation: Institute of Oncology, Davidoff Cancer Center, Beilinson Hospital.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv.
authors.forename: Eyal
authors.initials: E
authors.lastname: Fenig
authors.affiliation: Institute of Oncology, Davidoff Cancer Center, Beilinson Hospital.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv.
authors.forename: Aaron
authors.initials: A
authors.lastname: Sulkes
authors.affiliation: Institute of Oncology, Davidoff Cancer Center, Beilinson Hospital.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv.
authors.forename: Baruch
authors.initials: B
authors.lastname: Brenner
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis*; D059186:Chemoradiotherapy, Adjuvant; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011379:Prognosis; D012004:Rectal Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor