Changes of Ki-67 index in squamous cell carcinoma of the cervix during the early course of radiotherapy and prediction of prognosis.

PURPOSE

To determine whether changes in the Ki-67 index during the early course of radiotherapy could predict the prognosis in squamous cell carcinoma of the uterine cervix and be of value in clinical practice.

MATERIALS AND METHODS

Biopsy specimens from 23 cases of histologically confirmed squamous cell carcinoma of the cervix were stained with anti-Ki-67 monoclonal antibody prior to radiotherapy and after 9 Gy. The correlation between the Ki-67 index, local control and distant metastasis was determined by Spearman's correlation test.

RESULTS

Median age of the patients was 49. According to the FIGO staging system four patients had Stage IIA, 16 had Stage IIB, one had Stage IIIA and two had Stage IIIB disease. Among the whole group brachytherapy was applied to 17 patients (17/23) and weekly cisplatin (40 mg/m2) was applied to 15 patients (15/23). The mean Ki-67 index prior to radiotherapy and after 9 Gy for the entire group were 58.5% and 46.0%, respectively. The Ki-67 index after 9 Gy decreased in most of the patients (74%). During a median follow-up of 23 months four patients developed local recurrence and four patients developed distant metastasis. No significant correlation was detected among the local control and changes in Ki-67 index after 9 Gy, whereas there was a moderate correlation between distant metastasis and changes in Ki-67 index after 9 Gy (r = 0.51, p = 0.01).

CONCLUSION

The Ki-67 index can be used safely as a proliferation marker in cervical carcinomas, and changes in the Ki-67 index during the early course of radiotherapy may predict the metastatic potential. However prospective studies including a large number of patients with long-term follow-up are necessary to confirm the clinical utility of this marker in cervical cancer.