Endoscopic Ultrasonography role in the multimodality treatment of stage II-III rectal cancer: preliminary results

Background and aims: standard treatment for stage II-III rectal cancer is a multimodality approach with primary combined chemioradiotherapy and radical surgery. It is very important, for a better planning of chemioradiotherapy, an accurate evaluation of the depth of the tumor infiltration (T-status) and of the presence of loco-regional lymph node metastasis (N-status). Endoscopic ultrasonography (EUS) is now the technique of choice for locoregional staging of rectal cancer. The purpose of this ongoing study is to present preliminary data regarding restaging using EUS in patients who underwent preoperative chemioradiotherapy.

Method: from January 2003 to June 2005, 38 patients with rectal cancer were investigated using flexible sigmoidoscopy and multiple biopsies for histological and molecular analysis. EUS was performed before chemioradiotherapy. Four weeks after the preoperative treatment (radiotherapy at the dosage of 46 Gy in 23 fractions of 2 Gy/day/week combined with chemotherapy with 5fluorouracil at the dosage of200–225mg/mq/day in continuous infusion) all patients underwent restaging by EUS. After six weeks tumor resection was performed. EUS examination was performed using an echo-endoscope with radial scanner. The EUS staging was compared to the pathology findings.

Results: overall, the pre-chemioradiotherapy EUS staging was: 6 uT2N1, 14 uT3N0, 17 uT3N1, 1 uT4N0; EUS restaging after preoperative therapy shown: 3 uT1N0, 1 uT1N1, 13 uT2N0, 15 uT3N0, 6 uT3N1. Tumor resection has been performed in 93.7% of patients (36/38), with a pathological staging as follow: 3 complete response have been, 3 pT1N0, 10 pT2N0, 1 pT2N2, 7 pT3N0, 12 pT3N1.

Conclusion: our data show that EUS is an effective preoperative staging technique for treatment of stage II- III rectal cancer but is not accurate for determining tumor response after neoadjuvant chemioradiotherapy.