Significance of the Ki-67 proliferation index in the assessment of the therapeutic response to cisplatin-based chemotherapy in patients with advanced cervical cancer.

Objective: The purposes of this study were to examine the therapeutic response of advanced cervical cancer to Ki-67 proliferative index (Ki-67 PI) dependent cisplatin chemotherapy, and to determine Ki-67 PI referential value that is expected to provide a satisfactory therapeutic response of cervical cancer to cisplatin chemotherapy.

Patients And Methods: This prospective study enrolled 59 patients treated for cervical cancer at Clinic for Oncology, Clinical Center Nis, Serbia. According to the obtained Ki-67 PI values, patients were divided into three groups, and all the patients received the same cytostatic, cisplatin. Therapeutic response to chemotherapy was evaluated in relation to disease progression presence or absence and progression-free survival after a year follow-up since the first chemotherapy.

Results: Survival rate increases with an increase of Ki-67 PI by Kaplan-Meier survival analysis, meaning that survival rate is statistically significantly shorter in the group of patients with Ki-67 PI < 40% in comparison to patients from other two groups (p=0.010). Mann-Whitney test confirmed a statistically significant increase in survival rate among the groups of patients formed according to Ki-67 PI (p<0.05). Kaplan-Meier survival analysis confirmed that the mean survival rate in the group of patients with Ki-67 PI values over 60% is statistically significantly longer in comparison to patients with Ki-67 PI values below or equal 60% (p<0.001).

Conclusions: Advanced cervical cancer with a high Ki-67 PI expression responds better to cisplatin-based chemotherapy, thus resulting in a longer survival rate. The values of Ki-67 PI were determined: high Ki-67 PI (≥ 60%), moderate Ki-67 PI (40-60%), and low Ki-67 PI (≤ 40%).