title: Prognostic role of serum p53 antibodies in lung cancer.
abstract: BACKGROUND
  Mutations in the TP53 (Tumour Protein 53) gene can lead to expression of mutant p53 proteins that accumulate in cancer cells and can induce circulating p53 antibodies in cancer patients. Our aim was to evaluate the presence and prognostic role of these antibodies in lung cancer patients and to investigate whether they were related to p53 expression or TP53 mutations in tumour tissues.
  
  
  METHODS
  A total of 201 lung cancer patients were evaluated for p53 antibodies by ELISA (Enzyme-Linked Immunosorbent Assay) and control was obtained from 54 patients with non-malignant disorders; p53 expression was evaluated in 131 of the lung cancer patients by immunohistochemistry and TP53 mutations were then investigated in 53 tumours positively staining for p53 and in 12 tumours without p53 overexpression, whose DNA was available for direct sequencing.
  
  
  RESULTS
  Our results show that 20.4% of cancer patients have positive levels of p53 antibodies, while none of the controls resulted positive. High levels of p53 expression are detected in 57.3% of cases and a significant correlation between serum p53 antibodies and high levels of p53 expression in the corresponding tumours is observed. In non-small cell lung cancer, p53 antibodies are significantly associated with poorly differentiated tumours; furthermore, high levels of p53 expression significantly correlated with squamous cell carcinoma and tumours with highest grade. Survival time of non-small cell lung cancer patients low/negative for serum p53 antibodies was significantly longer compared to patients with positive levels (p = 0.049); in particular, patients with squamous cell carcinoma, but not adenocarcinoma, low/negative for these antibodies show a significant better survival compared to serum-positive patients (p = 0.044).
  
  
  CONCLUSIONS
  In our study, detection of serum p53 antibodies in non-small cell lung cancer patients has been shown to be useful in identifying subsets of patients with poor prognosis. A significant correlation between the presence of serum p53 antibodies in lung cancer patients and p53 overexpression in the corresponding tumours was also observed. We did not find a significant correlation between levels of serum p53 antibodies and TP53 mutations in the corresponding tumours.
authors.affiliation: Department of Experimental Oncology, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144, Rome, Italy. mattioni@ifo.it.
authors.forename: Manlio
authors.initials: M
authors.lastname: Mattioni
authors.affiliation: Molecular Oncogenesis Laboratory, Department of Experimental Oncology, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144, Rome, Italy. soddu@ifo.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Soddu
authors.affiliation: Molecular Oncogenesis Laboratory, Department of Experimental Oncology, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144, Rome, Italy. prodosmo@ifo.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Prodosmo
authors.affiliation: Pathology Department, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144, Rome, Italy. visca@ifo.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Visca
authors.affiliation: Pathology Department, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144, Rome, Italy. contisalva1@libero.it.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Conti
authors.affiliation: Thoracic Surgery Unit, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144, Rome, Italy. gabrielealessandrini@yahoo.it.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Alessandrini
authors.affiliation: Thoracic Surgery Unit, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144, Rome, Italy. facciolo@ifo.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Facciolo
authors.affiliation: Laboratory of Medical Physic and Expert System, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144, Rome, Italy. strigari@ifo.it.
authors.forename: Lidia
authors.initials: L
authors.lastname: Strigari
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000912:Antibodies, Neoplasm / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate / Q000639:trends; D016159:Tumor Suppressor Protein p53 / Q000097:blood*
chemical_list: D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; D016159:Tumor Suppressor Protein p53