Status of chromosome breaks and gaps in breast cancer: a follow-up study

Genetic susceptibility and environmental factors are believed to be respons ible for chromosomal instabilities and higher incidence of breast cancer. W e conducted a follow-up study to find the levels of chromosome breaks and g aps in 20 premenopausal women with breast cancer before surgery, I month af ter surgery, and 3 years after surgery with respect to 20 age- and gender-m atched controls. The mean level of chromosome breaks and gaps was found to be significantly higher (P <0.001) in breast cancer patients (before surger y) as compared with the controls. The chromosome breaks and gaps after 1 mo nth of surgery were observed significantly decreased (P <0.005) when compar ed with that of patients before the surgery. Further significant increase i n chromosome breaks and gaps was found after 3 years of surgery as compared with both the patients after 1 month of surgery (P <0.05) and controls (P <0.005). The significant increase in chromosome breaks and gaps in breast c ancer patients (before surgery) may be due to the effects of genetic suscep tibility to environmental carcinogens and endogenous factors. However, the decrease in this level after 1 month of surgery may be due to the removal o f cancerous tissues, which in turn removes the effect of mutagens and clast ogenic factors. Further increase in chromosome breaks and gaps after 3 year s of surgery may be due to the long-term effects of therapeutic agents and genetic susceptibility to environmental carcinogens in the patients. The st udy furthermore suggests that the high level of chromosome breaks and gaps after 3 years of surgery may be a risk factor for the development of second ary tumor in patients. (C) 2001 Elsevier Science Inc. All rights reserved.