Session Item

A simple scoring system (T-score) for integrating diagnostic information from clinical examination and MRI has recently been shown to be a strong prognostic tool for local control (LC) and overall survival (OS) in patients with locally advanced cervical cancer (LACC) treated with chemoradiation and MRI guided brachytherapy (BT) in a single centre cohort¹. The aim of the present work was to investigate the performance of the T-score in the prospective multicentre EMBRACE I study and to use the T-score for evaluating the prognostic implications of regression obtained during initial chemoradiation.

The EMBRACE I study recruited 1416 patients of which 1318 were available for analysis of both local control and survival. All patients were treated with external beam radiotherapy followed by MRI guided adaptive BT. Concomitant chemotherapy was given to 95%. A ranked ordinal scale of 0-3 points (Table 1) was used to assess the primary tumour regarding local involvement of 8 anatomic locations typical for spread of cervical cancer: cervix, left parametrium, right parametrium, corpus uteri, vagina, bladder, ureter, rectum. The 8 locations and the ranking were aligned with already established definitions used in e.g. staging systems. A 1-point increase per step was used. The T-score was calculated twice for each patient by adding the points obtained from each of the 8 locations (possible range of 0-23) at diagnosis and at BT, respectively.

The median T-score at diagnosis was 5 with a mean value of 5.6. The cumulative frequency distribution of the T-score showed a left shift when re-scored at BT (Figure 1A) with a significant decrease of the mean to 4.2 (p≤0.001). Overall survival of 697 patients with a low initial T-score (≤5) or 351 patients with an initial high (>5) but low T-score at BT (≤5) was similar (Fig. 1B). In contrast, survival in the 270 patients with a T-score remaining high at BT (>5) was significantly reduced (p≤0.001). A similar pattern (Fig. 1C) was observed for local control (p=0.001). By dividing the patients into four groups according to T-score (0-3/4-5/6-8/>8) a significant and gradual decrease in survival with increasing T-score (p≤0.001) could be demonstrated both at diagnosis (not shown) and at BT (Fig. 1D), but with a better discrimination and a larger difference between the T-score groups using the latter. Cox regression showed that the T-score was a significant predictor of both OS and LC when analysed in the context of traditional prognostic parameters for LACC.

The T-score concept is applicable to the Embrace I study cohort and provides substantial information concerning impact of initial regression during chemoradiation on the probability for obtaining local control and survival. The T-score is a potential selection tool for treatment modifications.