FACTORS AFFECTING VARIOUS BIOMARKERS IN UNTREATED LUNG-CANCER PATIENTS AND HEALTHY DONORS

The purpose of the present communication was to determine in lung canc er patients and healthy donors if there was a possible association bet ween cancer and biomarkers of cytogenetic damage and ras p21 oncoprote in levels, and if various exogenous confounding factors (such as smoki ng habit) and endogenous ones (age, sex, etc.) could affect these biom arkers. Peripheral blood and plasma were collected from 31 lung cancer patients prior to treatment and 35 healthy donors of a similar socioe conomic status and from the same region in Poland. Chromosomal aberrat ions (CA), sister chromatid exchanges (SCE), high frequency cells (HFC ), and proliferative rate index (PRI) were examined from the blood and ras p21 oncoproteins from the plasma. These parameters were used as b iomarkers of genotoxic anomalies. All the biomarkers were examined for their relationship to confounding factors of age, sex, smoking habit, and immediate family cancer history. Results were analyzed by a t-tes t, analysis of variance (ANOVA), and stepwise multivariate regression analysis. All types of CA (including and excluding gaps), percent aber rant cells, SCE, and ras p21 oncoproteins were statistically significa ntly higher in cancer patients than in the healthy donors. Although th ere were smaller numbers of females in the cancer patients group who w ere older than the males, there was a difference due to sex (gender) w ith statistically significant increases in females for CA, SCE, and HF C, but there was no increase For ras p21 oncoproteins. Cytogenetic dam age was not related to other cancers in the immediate families of the groups. All major CA parameters differed significantly between smokers and non-smokers in the cancer patients group, and SCE and HFC differe d in the healthy donors group. Such parameters also showed a significa nt variability with the number of cigarettes smoked and the years of s moking habit. Multivariate regression analyses showed a significant as sociation between cytogenetic damage, ras p21 oncoproteins, and cancer . In conclusion, cytogenetic damage and ras p21 oncoproteins in this s tudy appear to be biomarkers associated with cancer, but have not been proved causally, and confounding factors such as age, sex (gender), a nd smoking can have an impact on them. (C) 1997 Wiley-Liss, Inc.