DNA‐adduct levels as a predictor of outcome for NSCLC patients receiving daily cisplatin and radiotherapy

We aimed to investigate whether biological factors related to radiosensitivity and chemosensitivity have prognostic significance in non-small-cell-lung-cancer (NSCLC) patients treated with daily low doses of cisplatin and radiotherapy. We treated 27 NSCLC patients with concomitant daily low-dose cisplatin and radiotherapy between 1993 and 1995. Tumour specimens were analyzed for p53 and bcl-2 expression, and for cell proliferation using antibodies against ki-67. In addition, apoptosis was measured by an end-labeling technique (TUNEL). Finally, cisplatin-induced DNA modification in buccal cells was assessed immunocytochemically using a specific anti-serum. Univariate and multivariate analyses were performed to assess the association between the different variables and survival. The median follow-up was 41 months, and 21 patients (78%) have died. In a univariate analysis, age, tumour stage and cisplatin-DNA-adduct staining were the only factors significantly associated with survival (p < 0.05, log-rank test). p53, bcl-2, Ki-67 and apoptosis showed no relationship with outcome. Multivariate analysis revealed that cisplatin-DNA-adduct staining remained an independent prognostic factor (hazard ratio, 0.10, 95% CI, 0.02–0.49), with shorter survival times for patients with low adduct staining. Int. J. Cancer (Pred. Oncol.) 89:160–166, 2000. © 2000 Wiley-Liss, Inc.