Value of endoscopic ultrasonography for assessment of patients presenting elevated tumor marker levels after surgery for colorectal cancers.

Background And Study Aims: This prospective study was undertaken to evaluate the role of endoscopic ultrasound (EUS) in patients presenting with elevated tumor marker levels (CEA, CA 19-9) after surgery for colorectal cancer.

Patients And Methods: During a 26-month period, colonic EUS was performed in 21 patients who had undergone surgical treatment for colorectal cancers. All patients presented with elevated tumor marker levels at the time of examination but all other diagnostic procedures (US, CT scan of the abdomen and thorax, bone scintigraphy and colonoscopy) did not demonstrate recurrence. Colonic EUS was performed using a linear convex probe (echoendoscopes Pentax: FG 32 UA, 36 U, 38 UX). In cases with normal findings on colonic EUS, upper gastrointestinal tract EUS was also performed.

Results: 21 colonic EUS and six upper gastrointestinal tract EUS examinations were performed. Of 21 colonic EUS examinations, 15 showed either local recurrence (n = 9) or peritoneal carcinomatosis (n = 6) and six EUS-guided biopsies were performed. Of these 15 patients, 13 were operated on and results were confirmed in 12 of 13 patients, namely in 8/9 cases with suspected anastomotic recurrence and in all four operated cases with presumed peritoneal carcinomatosis. EUS-guided biopsy had diagnosed three of the four cases before. Upper GI EUS was performed in the six cases with normal colonic EUS; two cases showed mediastinal lymph nodes and one showed celiac lymph nodes. EUS-guided biopsy confirmed the malignancy of these nodes. For the diagnosis of recurrence, sensitivity, specificity and accuracy of lower plus upper gastrointestinal EUS were 94.4%, 66.6% and 90.4% respectively.

Conclusion: EUS of the colon and--in selected cases--also of the upper gastrointestinal tract is quite useful in this clinical setting. Further studies are needed to evaluate the impact of EUS on outcome in larger patient numbers.