Sister chromatid exchanges in breast cancer patients who underwent chemotherapy

Abstract

-The study aimed to determine the effects of cytostatic and genotoxic drugs used to treat breast cancer on sister chromatid exchange (SCE). SCE values were examined in 25 female patients with breast cancer in pre-treatment, treatment process and remission period as well as in 22 nonsmoker women via peripheral blood culture technique. The SCE values of patient and control group were analyzed via "Mann-Whitney U test". Whilst SCE values of patient group were 8.25 ± 3.67, 10.19 ± 2.95 and 11.52 ± 3.33 in pre-treatment, treatment process and remission periods respectively, it was 7.01 ± 1.24 in control group. When overall SCE values of patients group in pre-treatment period were compared with those of control group, no significant difference was observed (p > 0.05), whereas highly significant differences were observed between treatment process and remission period of patient groups and control group in terms of SCE values (p < 0.01). If patients are exposed to any cytostatic and clastogenic drugs, the increase in the exchange values was considered remarkable. These findings reinforced the availability of sister chromatid exchange technique in directing of treatment and monitoring the genetic abnormalities caused by genomic instability which may occur due to the drugs used for treatment.

Cytogenetic findings in patients diagnosed with breast cancer having undergone adjuvant chemotherapy regimens

“…Moreover, in comparison to pre-treatment specimens, post-treatment blood samples showed significantly reduced PRI values (P < 0.0001; Table 3). Similar results have been obtained by others (Kopjar et al, 2007;Tekcan et al, 2012).…”

“…The FAC protocol was shown to be the most genotoxic of those studied (Kopjar et al, 2007). Tekcan et al (2012) also recorded a significantly augmented SCE rate in post-chemotherapy peripheral blood lymphocytes. In their investigation, patient groups were treated with AC, 5-fluorouracil + epirubicin + cyclophosphamide, or epirubicin + cyclophosphamide.…”

“…Due to their divergent modes of action, the various classes of antineoplastic drugs are expected to cause different types of DNA lesions, and to varying extents. Other authors have also investigated the levels of DNA damage in peripheral blood lymphocytes of BC patients after chemotherapy (Kopjar et al, 2007;Tekcan et al, 2012). For instance, Kopjar et al (2007) recorded a significantly elevated SCE frequency and lowered PRI in peripheral blood samples collected following treatment.…”

Sister chromatid exchange: A possible approach to characterize familial breast cancer patients

“…Since age and genomic instability are associated with failure of DNA repair and accumulation of DNA damage in the genome, many authors have evaluated the association between SCE frequency and age, but data in the literature are controversial (4,14,19,(22)(23)(24). In accordance with other studies, we found no correlation between age and SCE frequency, either in familial or in sporadic patients (4,14).…”

“…Increased genetic susceptibility could be associated with genomic instability, which could lead to chromosomal breakage. Sister chromatid exchange (SCE) is an error-free recombination mechanism, defined as a symmetrical exchange between portions of apparently homologous sister chromatids (4). Although little is known about its molecular basis, these exchanges presumably involve DNA breakage and subsequent reunion of newly synthesized DNA chains during replication (5,6).…”