title: Paradoxical Reductions in Serum Anti-p53 Autoantibody Levels by Chemotherapy in Unresectable Colorectal Cancer: An Observational Study.
abstract: OBJECTIVE
  The anti-p53 autoantibody is an emerging tumor marker that is commonly produced in response to p53 mutations. The usefulness of this antibody has been suggested in screening for and the monitoring of recurrence in colorectal cancer; however, its significance as a marker during chemotherapy remains largely unknown.
  
  
  METHODS
  We measured serum anti-p53 antibody levels in patients with unresectable colorectal cancer who underwent first-line systemic chemotherapy. Tumor responses were evaluated by computed tomography. We determined whether temporal changes in this antibody during therapy are associated with radiological responses.
  
  
  RESULTS
  Of the 83 patients in our study, 29 (35%) had elevated serum anti-p53 antibody levels before chemotherapy. Among these, antibody levels decreased in all 14 responders. In contrast, among those patients with elevated pretherapeutic serum anti-p53 antibody levels, 89% showed a paradoxical decrease in antibody levels and exhibited disease progression after chemotherapy. Moreover, serum anti-p53 antibody levels before and after chemotherapy were not associated with survival.
  
  
  CONCLUSIONS
  These results suggest that serum anti-p53 antibody levels are of limited value in the evaluation of responses to palliative chemotherapy in patients with colorectal cancer.
authors.affiliation: Department of Surgical Oncology, The University of Tokyo, Tokyo, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nozawa
authors.forename: Soichiro
authors.initials: S
authors.lastname: Ishihara
authors.forename: Kazushige
authors.initials: K
authors.lastname: Kawai
authors.forename: Koji
authors.initials: K
authors.lastname: Murono
authors.forename: Koji
authors.initials: K
authors.lastname: Yasuda
authors.forename: Kensuke
authors.initials: K
authors.lastname: Otani
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishikawa
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Tomomichi
authors.initials: T
authors.lastname: Kiyomatsu
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hata
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000276:immunology*; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001323:Autoantibodies / Q000097:blood*; D000068258:Bevacizumab / Q000008:administration & dosage; D002166:Camptothecin / Q000031:analogs & derivatives / Q000627:therapeutic use; D000069287:Capecitabine / Q000008:administration & dosage; D002272:Carcinoembryonic Antigen / Q000097:blood; D000068818:Cetuximab / Q000008:administration & dosage; D015179:Colorectal Neoplasms / Q000097:blood / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000276:immunology*; D018450:Disease Progression; D004338:Drug Combinations; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D002955:Leucovorin / Q000627:therapeutic use; D008875:Middle Aged; D009944:Organoplatinum Compounds / Q000627:therapeutic use; D010094:Oxonic Acid / Q000008:administration & dosage; D010166:Palliative Care; D011247:Pregnancy; D015996:Survival Rate; D005641:Tegafur / Q000008:administration & dosage; D016159:Tumor Suppressor Protein p53 / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D002272:Carcinoembryonic Antigen; D004338:Drug Combinations; D009944:Organoplatinum Compounds; D016159:Tumor Suppressor Protein p53; C079198:S 1 (combination); D005641:Tegafur; D000068258:Bevacizumab; D010094:Oxonic Acid; D000069287:Capecitabine; D000068818:Cetuximab; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin