Abstract:

Objective

To evaluate whether S-phase fraction(SPF) can be used as a sensitive predictor for neoadjuvant chemotherapy in breast cancer patients.

Methods

The SPF change of breast cancer tissues from 66 breast cancer patients treated in Department of Breast Surgery, the First Affiliated Hospital of Guiyang Medical College, between January 2006 and November 2010 was detected by flow cytometry before and after neoadjuvant chemotherapy. Paired t test was used to analyze the change of SPF, and rank sum test was used to determine the relationship between SPF and clinical pathological characteristics.

Results

In all 66 cases, after neoadjuvant chemotherapy, there were 6 cases evaluated with complete pathologic response (pCR), 41 with partial response (PR),17 with stable disease (SD) and 2 with progressive disease (PD). In 41 patients with PR, SPF was (7.69±4.67)% before chemotherapy, (5.58±4.61)% after chemotherapy, respectively, and the difference was statistically significant (t=2.314, P=0.026). In 19 patients with PD plus SD, SPF was(4.52±3.30)% before chemotherapy, (4.19±3.01)% after chemotherapy, respectively, which indicated no statistically significant difference (t=2.314, P=0.026). SPF in the 47 patients with remission (including pCR, CR, PR) was (4.52±3.30)% before chemotherapy, which was statistically different from that in the 19 patients with PD plus SD before chemotherapy [(4.19±3.01)%] (t=2.314, P=0.026). SPF of breast cancer tissue before neoadjuvant chemotherapy was related with tumor diameter, clinical stage and lymph node metastasis (F = 8.258,11.920;Z = -2.194; P ＜0.05), but with no correlation with patients’ age and menstruation status(Z = -1.461,-1.097;P ＞0.05).

Conclusion

The neoadjuvant chemotherapy has a remarkable influence on S phase of breast cancer cells and it can decrease cell proliferation,implicating that the patients with higher SPF may be more sensitive to chemotherapy.

Key words: Breast neoplasms, Flow cytometry, Chemotherapy, adjuvant, Cell cycle