AB16. RECIST criteria in the response evaluation of gastric cancer to neoadjuvant chemotherapy: Achilles’ heel?

Objective: To explore the application of RECIST (Response Evaluation Criteria in Solid Tumors) criteria in the response evaluation of advanced gastric cancer to neoadjuvant chemotherapy.

Methods: A continuous cohort of fifty-eight advanced gastric cancer patients who were performed neoadjuvant chemotherapy enrolled in the study. CT examinations were performed during one week before and two cycles after chemotherapy. The gastric wall thickness and the short axis of lymph nodes on CT were measured. The evaluation standard was in accordance with RECIST criteria. Pearson correlation test was used to analysis the correlation of regression rate.

Results: There were 16 cases with targeted lesion of measurable lymph nodes defined by RECIST, and the availability of RECIST in this cohort was 27.6%. There were eight cases of partial response (PR), six of stable disease (SD), and two of progressive disease (PD), according to the evaluation by RECIST. The mean pre-therapy thickness of the gastric cancer was 16.38±11.50 mm, and post-therapy 12.38±9.00 mm. The mean pre-therapy short axis of lymph nodes was 25.25±16.25 mm, and post-therapy 20.25±7.50 mm. The retreat rate of the cancerous stomach wall thickness was 15.8%±7.8, and the lymph nodes was 25.0%±15.3. There was a good correlation between the regression of cancerous stomach wall and lymph nodes (r=0.925, P

Discussion: The RECIST criteria has limited value in the use of response evaluation of gastric cancer to neoadjuvant chemotherapy. The gastric wall thickness may be a substitution under the precondition of the stable distention of stomach wall.

Keywords: RECIST criteria; gastric cancer; neoadjuvant chemotherapy