Aberrant expression of cyclin D1 is associated with poor prognosis in early stage cervical cancer of the uterus

Objective. Many investigators have studied the expression of G1 phase regul atory protein in uterine cervical cancer. However, it is unclear which step of the genetic expression participates in cyclin D1 expression and what it s prognostic meaning is. The aims of this study were to evaluate the regula tory level of cyclin D1 expression and the relationship between the express ion of cyclin D1 and its inhibitor, p21(WAF1/CIP1),and to evaluate their im pact on the prognosis of early stage cervical cancer. Methods. The presence of cyclin D1 mRNA was studied using Northern blot in 6 normal cervices and 7 invasive cervical cancer specimens. Western blot wa s used to detect the cyclin D1 protein in 8 normal cervices and 8 invasive cancer specimens. Thirty-two cases of FIGO stage Ib-IIa cervical cancers (2 8 squamous cell carcinomas, 3 adenocarcinomas, 1 adenosquamous cell carcino ma), 31 cases of cervical intraepithelial neoplasia 3 (CIN 3), and 28 norma l cervices were stained for cyclin D1 and p21(WAF1/CIP1) using monoclonal a ntibody. Statistical analysis was performed to assess the differences in ex pression and their prognostic significance. Results. Cyclin D1 mRNA was found to be underexpressed in cervical cancer. Western blot also revealed underexpression of cyclin D1 protein in cervical cancer compared to normal controls. Positive immunohistochemical staining of cyclin D1 was noted in 28/28 (100%) of the normal controls, 1/31 (3%) ca ses of CIN 3, and 9/32 (28%) cases of invasive cancer. The number of positi vely stained specimens was lower than that of normal controls in CIN 3 and cervical cancer specimens (P = 0.005). Fifteen of 28 (54%) normal controls, 15/31 cases (48%) of CIN 3, and 27/32 cases (84%) of invasive cancer were proved positive for p21(WAF1/CIP1) immunohistochemistry. p21(WAF1/CIP1) was more highly expressed in cervical cancer than in that of either normal con trols or CIN specimens (P = 0.001). Positive immunostaining of cyclin D1 an d p21(WAF1/CIP1) was not related to high-risk factors (pelvic lymph node me tastasis, deep cervical stromal invasion, parametrial invasion, large tumor size, and unusual histologic type) and human papilloma virus infection. Po sitive cyclin D1 immunostaining was associated with decreased disease-free survival and a lower overall survival (P = 0.0175 and 0.0189, respectively) . On multivariate analysis, positive cyclin D1 expression was a significant prognostic variable for recurrence (P = 0.0004). Conclusion. Underexpressi on of cyclin D1 was regulated at the level of transcription in cervical can cer. Although cyclin D1 was underexpressed in cervical neoplasias, it was m ore frequently expressed in malignant lesions, p21(WAF1/CIP1) was more high ly expressed in cervical cancers than in either normal cervices or CIN 3 sp ecimens. Unfavorable prognoses were associated with cyclin D1 expression, a nd not with the expression of its inhibitor, p21(WAF1/CIP1). We conclude th at immunohistochemical assessment of cyclin D1 can be a useful molecular ma rker for predicting prognosis in early stage cervical cancer of the uterus. (C) 2001 Academic Press.