Biological markers and DNA flow cytometric analysis in radically resected patients with non-small cell lung cancer. A study of the perugia multidisciplinary team for thoracic tumors

Aims and background. The aim of this study was to evaluate the relationship between a panel of biological markers (p53, Bcl-2, HER-2, Ki67, DNA ploidy and S-phase fraction) and clinical-pathological parameters and its impact on outcome in non-small cell lung cancer (NSCLC). Methods and study design. Tumor tissue specimens obtained after surgical resection were collected from consecutive patients with NSCLC. We used an immunocyto-chemical technique for p53, Bcl-2, HER-2 and Ki67 analysis in fine-needle aspirates obtained from surgical samples that were also evaluated by flow cytometric DNA analysis using a FACScan flow cytometer. Results. From April 2000 to December 2005, 136 patients with radically resected NSCLC were recruited. Median age was 66 years (range, 31-84 years), male/female ratio 117/19, ECOG performance status 0/1 127/4, stage I/II/III 76/25/35, squamous/adenocarcinoma/large-cell/mixed histology 62/49/17/8, smokers yes/no 121/11. Positivity of p53, Bcl-2, HER-2 and Ki67 was detected in 51.4%, 27.9%, 25.0% and 55.8% of the samples, respectively; 82.9% of the cases revealed aneuploid DNA histograms and 56.7% presented an S-phase fraction of more than 12%. Statistically significant associations between high Ki67 and poorly differentiated tumors (P = 0.016) and a smoking history (P = 0.053); p53 positivity and high Ki67 (P = 0.002); HER-2 positivity and adenocarcinoma subtype (P = 0.015) and presence of lymph node involvement (P = 0.006); and Bcl-2 positivity and squamous cell carcinoma subtype (P= 0.058) were observed. At univariate analysis, high Ki67 proved to be the only marker associated with disease-free survival (P = 0.047). After adjusting for stage, none of the examined immunocytochemical markers emerged as an independent factor for disease-free and overall survival; only pathological stage was identified as an independent prognostic factor for disease-free survival (P = 0.0001) and overall survival (P = 0.0001). In the group of 76 patients classified as TNM stage I, high Ki67 was the only marker associated with recurrence of disease (P= 0.05). Conclusions. Our data do not support a relevant prognostic role of immunocyto-chemical markers in NSCLC, even if the Ki67 index might have particular relevance to identify patients with more aggressive tumors who are at high risk for disease relapse.