Analysis of Clinicopathological Factors Predicting Response to Neoadjuvant Chemoradiotherapy in Oesophageal Cancer

Multimodality therapy comprising neoadjuvant chemotherapy and radiation therapy prior to radical resection is increasingly utilised in oesophageal cancer. The achievement of a complete pathological response (pCR) or a major response is associated with an improved survival. Between 50 and 70% of patients, however, show no response to the neoadjuvant regimen and accordingly the identification of factors which predict a response to chemoradiotherapy would be of considerable clinical benefit. We investigated the following clinicopathological factors: demographics, social history, clinical history, tumour type, site, size, morphology and differentiation.

158 patients were identified who had undergone neo-adjuvant chemo-radiotherapy at this institution between January 1990 and August 2003. A complete pathological response was seen in 36 cases (23%). Statistical Analysis was performed using Chi-squares with Pearson's test, or Kruskal-Wallis test.

There was a significant relationship between response to chemoradiotherapy and pre-treatment tumour length. The median tumour length in the pCR group was 2cm (1–2.8cm) compared with 3cm (2–7cm) in the non-responders (p<0.05). A pCR response also occurred significantly more frequently amongst squamous cell carcinomas (41%) compared to adenocarcinomas (21%) (p<0.05). Other factors were not predictive of response.

The important observation in this study is that smaller tumours are predictive of a greater response to chemotherapy and radiation therapy. This may reflect different tumour biology, perhaps with acquired resistance to treatment-induced apoptosis in the larger tumours. A simpler explanation is that the existing dose and treatment schedule for combination chemoradiotherapy is sub-optimal in patients with larger tumours. Both these hypotheses require further evaluation.