**12. Management of high-grade dysplasia / intramucosal cancer**

Data from case series suggest that up to 10% of patients with Barrett's oesophagus develop HGD, and that HGD may be associated with a focus of adenocarcinoma in up to 30% of patients. Several studies also have described high rates of progression to malignancy – annual rates of progression of 2.2%, 4% and 11.8% have been described recently. (Schnell et al., 2001b; Buttar et al., 2001; Reid et al., 2000b) In addition, the average time to progression from HGD to cancer is known to be short, typically around 24 months, (ranging from 6-43 months), (although, in most cases, HGD remains stable without progression, or may even regress). (BSG Working Party, 2005)

In confirmed cases of IMC, clinicians must not only consider T-stage, but also other important prognostic indicators including the grade of cellular differentiation and the presence of lymphatic or vascular invasion, when formulating a management strategy.

It is now clear that ER has an important diagnostic role in the determining these important prognostic indicators. Endoscopic ultrasound (EUS) is also important in intramucosal cancer to assess for the presence of early nodal metastases. EUS has been shown to be substantially more accurate than CT for detecting nodal metastases and the role of CT in investigation of intramucosal tumours is probably limited. PET-CT is a more reliable means of assessing the presence of distant metastasis which would circumvent the need for surgery and necessitate palliative therapy.

EUS is known to be poor at distinguishing between T1a and T1b tumours (33-85% accuracy) and importantly, under-diagnosis of T1b lesions is common. (May et al., 2004; Zuccaro et al., 2005). ER assessment is much more reliable but may fail to completely excise the submucosa making exact distinction between T1sm1 and T1sm2 difficult. Frequently pathologists use the measured depth of invasion in micrometers to differentiate the two. However, there is a paucity of published data correlating measured depth of submucosal invasion with likelihood of lymph node metastasis. Currently the role of endoscopic submucosal dissection (ESD) in the oesophagus is unclear and further trials are awaited.

If endoscopic therapy is to be considered ahead of surgery for early oesophageal tumours and HGD, a number of important considerations should be satisfied (Box 3). Similarly, if surgery is to be considered in cases where there is no overt evidence of lymphatic spread, complication rates must be low. Many papers continue to quote historic rates of mortality following oesophagectomy. It is important when contemplating treatment options to compare up-to-date data which reflects recent improvements in operative outcomes (mortality and morbidity) since surgical centralisation took place.

#### **Box 3. Important considerations when considering the role of endoscopic therapy.**

