Applying a neoscore in locally advanced rectal cancer is beneficial in predicting local recurrences after surgery

by Amal Rayan, Ahmed Soliman

Background and aim

The current study was undertaken to provide more detailed prognostic models for early prediction of local recurrences and local recurrence free survival (RFS) using different radiologic and pathologic features of locally advanced rectal carcinomas treated with neoadjuvant chemoradiation (CRT).

Methods

One hundred patients with locally advanced rectal carcinomas decided to receive neoadjuvant CRT were retrospectively recruited, Hazard ratios (HR) were determined in the two cox regression models and only significant ratios were considered for pointing, Models were built to determine their important effects of different predictors including: pathologic T (T), pathologic N (N), grade (G), clinical stage (cTNM), site (S), perineural invasion (PNI), and response to CRT (R) on 3-year RFS, goodness of performance of each model was measured by Harrell’s C index.

Results

HR of 1^st group of models: T+N, T+N+G, T+N+G+S, T+N+G+S+PNI, and T+N+G+S+PNI+R were summated and categorized into scores, these scores were significantly correlated with the risk of recurrence (Somer’s D = 0.5, p<0.0001) & Harrell’s C index = 0.751, (Somer’s D = 0.6, p<0.0001) & its Harrell’s C index = 0.794, (Somer’s D = 0.7, p<0.0001) & C index = 0.826, Somer’s D = 0.7, p<0.0001) & C index = 0.827, and (Somer’s D = 0.7, p<0.0001) & C index = 0.843 respectively. The 2^nd group of models including: cTNM stage, cTNM+G, cTNM+G+S, cTNM+G+S+PNI, cTNM+G+S+PNI+R scores which were significantly correlated with the HR of LRR (Somer’s D = 0.2, 0.5, 0.6, 0.6, & 0.6 respectively), (p = 0.006, <0.0001, <0.0001, <0.0001, <0.0001 respectively), the corresponding Harrell’s C indices were 0.595, 0.743, 0.782, 0.795, & 0.813 respectively.

Conclusion

We propose that the addition of biologic factors to staging of rectal cancer provide precise stratification and association with local recurrences in patients received preoperative CRT.