PREDICTION OF RADIOTHERAPY RESPONSE OF CERVICAL-CARCINOMA THROUGH MEASUREMENT OF PROLIFERATION RATE

Estimation of tumour proliferation may allow the design of individuali sed radiotherapy schedules to optimise response. This prospective stud y correlates the tumour proliferation rate of cervical carcinoma with response to conventional radiotherapy. The potential tumour cell doubl ing rate (T-pot) was estimated following Bash labelling of the tumours in vivo using the DNA precursor, bromodeoxyuridine (BrdUrd); samples were analysed by Bow cytometry. Tumour ploidy, DNA index and mitotic c ount were also assessed as was histological grade and type. Multiple b iopsies from each tumour were obtained from 121 women. The median T-po t was 4.0 days, median S-phase duration 12.8 h and median adjusted lab elling index 9.8%. Higher BrdUrd labelling was seen in patients who de veloped pelvic tumour recurrence following radiotherapy. This was the only biological/histological parameter with univariate and multivariat e significance in relation to locoregional recurrence (P = 0.006 and P = 0.034 respectively). This study represents the first assessment of T-pot in relation to long-term response of cervical tumours treated by radiotherapy treatment. The association of high BrdUrd labelling and poor pelvic disease-free survival indicates the need for further resea rch into the potential of radiotherapy schedule alteration to reflect tumour proliferation. The predictive value may be enhanced by combinat ion with other biological parameters.