When patients are diagnosed with lung cancer, a simple test for serum biomarkers may be useful to determine a prognosis. Plasma proteins can indicate underlying tissue abnormalities, giving a clearer picture of how patients may respond to treatment. But first, scientists must understand which proteins are correlated to what disease and how an increase or decrease in these protein indicates a particular outcome.
“Prognostic implications in lung cancer of p53 antibodies are controversial,” stated Dr. Manlio Mattioni at Regina Elena National Cancer Institute in Italy in the journal article “Prognostic Role of Serum p53 Antibodies in Lung Cancer,” published in BMC Cancer. “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 tumor tissues.”
p53 is a tumor suppressor protein that can put a halt to cell replication. When the Tumor Protein 53 (TP53) gene is mutated in tumor cells, mutated p53 protein accumulates inside cells and increases the levels of circulating p53 antibodies. As indicated by Dr. Mattioni, the majority of cancer patients exhibit increased levels of p53 antibodies relative to healthy individuals or patients with benign tumors, suggesting implications for cancer diagnostics. The role of p53 antibodies in suggesting prognosis is less clear. Therefore, the team at Regina Elena National Cancer Institute wanted to test lung cancer patients for p53 antibodies and follow their clinical status over time.
Of the 255 individuals recruited for the study, 13 had small cell lung cancer (SCLC), 188 had non-small cell lung cancer (NSCLC), and 54 had benign tumors or were otherwise free of lung cancer. While control patients showed no serum p53 antibodies, 20.4% of cancer patients had a positive level of p53 antibody. Within the NSCLC patients, p53 antibodies were associated with the highest grade tumors.
At the close of the study, more NSCLC patients with no or lower levels of p53 antibodies were alive than those with high positive p53 antibody levels. “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,” stated Dr. Manlio.
From these results, it may be suggested that patients with NSCLC should be tested for p53 antibodies to give an indication of prognosis. While a negative read-out may not be very descriptive, a positive read-out may indicate the potential for a more aggressive disease.