High growth fraction at 9 grays of radiotherapy is associated with a good prognosis for patients with cervical squamous cell carcinoma.
BACKGROUND
MIB-1, a murine monoclonal antibody, recognizes the Ki-67 antigen of routinely processed paraffin sections after microwave treatment. Cycling cells are positive for MIB-1 in their nucleus, and quiescent cells are negative for MIB-1. The MIB-1 labeling index represents the growth fraction of the cell population.


METHODS
A total of 150 cervical biopsy specimens were taken from 75 consecutive patients with cervical squamous cell carcinomas before radiotherapy (RT) and at 9 grays (Gy) of RT and were investigated to analyze the correlation between the MIB-1 labeling index or the deltaMIB-1 labeling index and patient prognosis or local disease control. The deltaMIB-1 index was calculated as the MIB-1 index at 9 Gy minus the MIB-1 index before RT.


RESULTS
The mean MIB-1 index was 38% (range, 11-67%) before RT and 54% (range, 15-85%) at 9 Gy. The MIB-1 index at 9 Gy was related to prognosis, including overall survival (P = 0.025), disease free survival (P = 0. 024), and metastasis free survival (P = 0.045). Patients who had a deltaMIB-1 index > 20% showed a trend toward a higher disease free survival rate compared with patients who had a deltaMIB-1 index < 20% (P = 0.093). Neither the MIB-1 index nor the deltaMIB-1 index was associated with local disease control.


CONCLUSIONS
The high growth fraction at 9 Gy is regarded as a predictive factor for a good prognosis in patients with cervical squamous cell carcinoma patients who undergo RT alone.
Oka
K
K
Division of Radiation Medicine, Research Center of Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan. oka-k@gb3.so-net.ne.jp
Suzuki
Y
Y
Nakano
T
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000911:Antibodies, Monoclonal; D002294:Carcinoma, Squamous Cell / Q000276:immunology / Q000473:pathology / Q000532:radiotherapy*; D002455:Cell Division; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D051379:Mice; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D002583:Uterine Cervical Neoplasms / Q000276:immunology / Q000473:pathology / Q000532:radiotherapy*
D000911:Antibodies, Monoclonal; D019394:Ki-67 Antigen