Abstract
Introduction: Cancer is a genetic disease that affects people worldwide, and breast cancer is the most common cancer in women. Studies have been conducted on molecular parameters to predict tumor behavior and develop therapeutic strategies. Telomeres, which are at the end of chromosomes, have been studied for their relationship with breast cancer, but more research is needed to understand their role in the disease. Circulating-free DNA (cfDNA) is DNA that is free in the bloodstream and is considered a promising target for early cancer detection, treatment response monitoring, and prognosis assessment. This study is aimed at comparing cfDNA telomere length of breast cancer patients and healthy individuals and analyzing the impact of neoadjuvant chemotherapy on telomere length in cfDNA. Materials and Methods: Blood samples were collected from 33 breast cancer patients undergoing neoadjuvant chemotherapy before and after treatment. The quantitative PCR method is used to measure the average telomere lengths. Results: This study found that the telomere length of cfDNA in breast cancer patients before and after treatment is significantly shorter than in the control group. Neoadjuvant chemotherapy is found to shorten the cfDNA telomere length, especially in the treatment-responsive group. Conclusion: Our study suggests that telomere length in cfDNA may be a useful biomarker for predicting therapy response and possible reoccurrence of the disease in breast cancer patients.