AgNORs as an early marker of sensitivity to radiotherapy in gynecologic cancer.

OBJECTIVE To evaluate the changes induced in silver-stained nucleolar organizer regions (AgNORs) by the first fraction of a radiotherapy protocol for gynecologic cancer on exfoliated cytologic samples to predict the therapeutic success of the full protocol. STUDY DESIGN Thirteen gynecologic cancer patients who were scheduled for radiotherapy were included in the study. Cell smears were taken from the affected area before and after the first fraction of a radiotherapy protocol and silver stained for AgNORs. AgNORs per nucleus were counted under a light microscope. Local disease control by the full radiotherapy protocol was assessed at one year by the Papanicolaou technique. RESULTS Local success of radiotherapy was greater for lesions with higher pretreatment AgNOR counts and for lesions that underwent a greater percentage reduction in AgNOR counts after the first fraction. We correlated local success of the full radiotherapy protocol with a predictive index based on AgNOR counts obtained before and after the first fraction. CONCLUSION A predictive index based on AgNOR counts can predict, as early as after the first fraction, the local control of disease by a full radiotherapy protocol. Knowledge of the probability of success long before the protocol is completed would allow reevaluation of therapeutic options.