The evaluation of proliferative activity in CIN III and microinvasive cervical cancer and its role in recurrence.

Objective: To evaluate the proliferation activity in CIN III lesions and Ia1 carcinoma according to the risk of recurrence.

Study Design: The proliferation markers PCNA (proliferating cell nuclear antigen) and mitotic index were studied in 75 patients with CIN III and in 20 patients with an Ia1 squamous carcinoma of the cervix by staining representative tissue sections for the PCNA and assessing the mitotic index. Associations between the studied proliferation markers and various histopathologic characteristics as well as recurrence were assessed.

Results: Three groups of PCNA were constituted: <20, 20--40, > OR =40% positive tumour nuclei, which contained, respectively, 45 (47%), 29 (31%), and 21 (22%) patients. Microinvasive carcinomas have a higher proliferation activity than CIN III (PCNA P=0.005; mitotic index P=0.094). For CIN III, there was a significantly lower risk for recurrence in the group with lower mitotic activity, compared to the group with higher mitotic activity (Kaplan-Meier: log-rank testing P=0.044). Significance was, however, not reached for the different PCNA categories (Kaplan-Meier, log-rank test P=0.068). Multiple regression analysis showed that in our population of CIN III lesions, only age of diagnosis and treatment modality were relevant (independent) prognostic indicators for recurrence.

Conclusions: In CIN III lesions there is evidence for an association between proliferation activity and the risk of recurrence. The observed crude association weakens when adjusting for age at diagnosis and treatment modality. Apparently this feature is associated with more aggressive biological behaviour and could be used to identify women who are at higher risk of recurrence.