Mo1394 Endoscopic Ultrasound-Directed Core Biopsy of the Liver for Diffuse Hepatic Disease

Introduction: Advances in cross sectional imaging techniques have resulted in increased detection rates of indeterminate lung lesions (ILLs) during preoperative colorectal cancer staging. However detection of ILLs may result in diagnostic uncertainty, lead to unnecessary investigations with increased radiation exposure, or alter surgical or medical treatment plans. The aims of this study were to: (i.) identify the incidence of ILLs in a large cohort of patients diagnosed with colorectal adenocarcinoma; and, (ii.) evaluate the significance of these lesions. Method: A review was undertaken of consecutive patients with biopsy proven adenocarcinoma of the colon or rectum in one district general hospital over a five-year period (2002 2007; n=680). For all patients the following data were collected: number and size of lung lesions identified on preoperative thorax CT, findings of interval CT imaging, pathological staging, and disease status at final follow-up. Results: 102 (15%) of the 680 patients identified were found to have ILLs on initial preoperative CT thorax. In 44/102 cases, a solitary nodule was detected, while 35/102 had ≥ 5 nodules. 52/102 did not undergo interval evaluation of ILLs (35 had associated extra-colonic / pulmonary disease [stage 4 29; stage 3 6]). In contrast, 50/102 patients found to have ILLs on initial preoperative staging underwent interval assessment. For 20 patients, interval CT thorax (40%) demonstrated no change, in the remaining cases 17 (34%) patients were found to have decreased and 13 (26%) increased size/number of ILLs, respectively. 11/13 patients with increased ILL size / number developed pulmonary metastases (pathological stage 4 9; stage 3 1; stage 2 1). Of the 11 patients who developed lung metastases, 8 had 2 ≥ nodules at initial presentation, while bilateral ILLs were present in 6 cases. Conclusion. This study has demonstrated that ILLs can be detected by preoperative staging investigations for up to 15% of patients presenting with colorectal cancer. Progression of these lesions to recognized pulmonary metastasis was found to be associated with the presence of multiple / bilateral nodules and with the presence of nodal / distant metastases. We therefore recommend targeted surveillance in this highrisk group.