K-ras Oncogene Activation as a Prognostic Marker in Adenocarcinoma of the Lung

N Engl J Med. 1990 Aug 30;323(9):561-5. doi: 10.1056/NEJM199008303230902.

Abstract

Background: The capability of activated oncogenes to induce malignant transformation of immortalized cells in vitro has suggested that they have a similar role in the pathogenesis of human tumors. We previously found that activation of the K-ras oncogene by a point mutation in codon 12 occurs in about one third of human lung adenocarcinomas.

Methods: We studied the clinical importance of this oncogene-activation in 69 patients with lung adenocarcinoma in whom complete resection of the tumor was possible. The polymerase chain reaction was used to amplify ras-specific sequences of DNA isolated from frozen or paraffin-embedded tumor samples. Ras point mutations were subsequently detected and classified with the use of mutation-specific oligonucleotide probes.

Results: Nineteen of the tumors harbored a point mutation in codon 12 of the K-ras oncogene. There was no association between the K-ras point mutation and the age at diagnosis, sex, or presence of previous or concurrent neoplasms. Tumors positive for K-ras point mutations tended to be smaller and less differentiated than those without mutations. The K-ras codon-12 point mutation was a strong (and unfavorable) prognostic factor: 12 of the 19 patients with K-ras point-mutation-positive tumors died during the follow-up period, as compared with 16 of the 50 patients with no mutation in the K-ras oncogene (P = 0.002). This difference in prognosis was also reflected in the duration of disease-free survival (P = 0.038) and in the number of deaths due to cancer (P less than 0.001).

Conclusions: The presence of K-ras point mutations defines a subgroup of patients with lung adenocarcinoma in whom the prognosis is very poor and disease-free survival is not usually long despite radical resection and a small tumor load.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / genetics
  • Adenocarcinoma / mortality*
  • Adult
  • Aged
  • Aged, 80 and over
  • DNA, Neoplasm / analysis
  • Female
  • Gene Expression Regulation, Neoplastic
  • Genes, ras*
  • Humans
  • Lung Neoplasms / genetics
  • Lung Neoplasms / mortality*
  • Male
  • Middle Aged
  • Prognosis
  • Survival Rate

Substances

  • DNA, Neoplasm