The percentage of aneuploid cells is significantly correlated with survival in accurately staged patients with stage 1 resected squamous cell lung cancer and long‐term follow up

Previous studies have shown that ploidy is an important prognostic determinant in lung cancer, but in those studies followup was restricted to three years, while patients with Stage 1, 2 and 3 disease and with different histological subtypes were included. Theoretically, these factors could have influenced the findings, especially since aneuploidy strongly correlated with the stage of disease. Because of this, tumor ploidy was studied in surgically resected stage 1 (T1/2, N0M0) squamous cell lung cancer patients with a minimal followup of 6 years. All patients were accurately staged by mediastinal lymph node mapping. Fifty‐two from a group of 1539 patients with lung cancer diagnosed between 1980 and 1986 inclusive, fulfilled these criteria. Of these tumors, 23 (44%) were diploid with a 6‐year survival of 53% and 29 (56%) were aneuploid with a 6‐year survival of 48%. Although diploidy tended to be associated with local relapse of the tumor and ancuploidy with distant metastases, the difference was not significant and neither showed a survival advantage. However, within the aneuploid tumors, there was a significant correlation between the percentage of aneuploid cells and survival, defined as event‐free or time to death. Seventeen patients with a percentage of more than 10 had a worse outcome (12 died, 6 years survival 35%), than to the other 12 patients with less than 10% aneuploid cells (2 died, 6‐year survival 78%) (Mantel‐Cox = 6.04, P = 0.01). This implies that in patients with accurately staged and histologically proven Stage 1 squamous cell lung cancer and long‐term follow up, DNA content classified as diploid and aneuploid is not a prognostic factor for survival, but the percentage of aneuploid tumor cells is correlated with the prognosis.