Evaluation of neoadjuvant chemo-radiotherapy with locally advanced rectal cancer by comparing tumour volume before and after treatment

Neoadjuvant chemotherapy is a standard preoperative therapeutical procedure with locally advanced rectal adenocarcinoma. The aim of the study was to compare the tumour volume reduction before and after the oncological therapy in relation to the change in the CEA value and to the outcome of the histopathological evaluation of response to the treatment. In the years 2004-2008, 274 rectal cancer patients were evaluated, of which 64 underwent neoadjuvant CRT with subsequent surgery and had also completed other inclusion criteria. The tumour volume before and after the CRT, percentage reduction in the tumour volume and the relation to the change in the CAE value and the histopathological evaluation were evaluated. The distance between the anus and the tumour was from 3 to 15 centimetres, the average value being 8.1 centimetres. In 5 cases the tumour was not histologically found in the resected specimen. Average value of the CEA value before the CRT was 18.12 ng/ml, range 0.7-98.1 ng/ml, after the CRT the average value was 7.00 ng/ml, range 0.5-18.7 ng/ml. The average tumour volume before CRT was 32.48, range 10.3-88.5, after the CRT the average volume was 20.13, range 4.7-55.1. A relation between the change in the T value and the volume reduction before and after the CRT of statistical significance has been proven in this group of patients. This relation however has not been proved in the N value change. Only in one-third of the evaluated patients was there a positive change in both T and N classification. No relation between the CEA value and the tumour volume change has been proven.