Capsule Endoscopy in Lynch Syndrome for Small Intestinal Tumor Screening

Lynch syndrome (LS), or hereditary nonpolyposis colorectal cancer (HNPCC), is an autosomal dominantly inherited disorder characterized by a very high risk of early-onset colorectal and endometrial cancer and an increased risk of other cancers, including cancers of the stomach, ovary, urinary tract, hepatobiliary tract, pancreas and small bowel. LS is caused by germline mutations in one of the mismatch repair (MMR) genes, mostly hMLH1, hMSH2 and hMSH6. Recently, several studies, including one from the Netherlands, have evaluated the life-time risk of small bowel cancer (SBC) in LS patients. From these studies the life-time risk of SBC is estimated around 4%. This is similar to the life-time risk of colorectal cancer in the general population, for which screening is generally advised. The risk of SBC increases with age, with an estimated prevalence of 1:500 at the age of 40, rising to an estimated prevalence of around 1:70 at the age of 60. Compared with the general population, LS patients with SBC generally present 10-20 years earlier as most patients with sporadic SBC are in their sixth or seventh decade of life. The localisation of SBC in LS is almost equal in the duodenum and jejunum, with localisation in the ileum generally occurring at a lower frequency.Until now, screening for small bowel neoplasia in Lynch syndrome patients is generally not recommended. However, the development of two new techniques to visualize the small intestine has raised the question whether screening might be useful and advisable. Small bowel capsule endoscopy (CE) has been developed as a safe, patient-friendly, minimally invasive modality for visualization of the small bowel. In addition, double-balloon enteroscopy (DBE) has been developed, a technique which allows endotherapeutic interventions. The diagnostic yields of both techniques are markedly higher than the conventional methods, such as push-enteroscopy and enteroclysis. To date, no study has been performed on screening for small bowel neoplasia in Lynch syndrome patients by means of these techniques.

The primary aim of the study is to determine the prevalence and incidence of small bowel neoplasia in Lynch syndrome patients using small bowel CE and DBE.

Secondary objectives:

The secondary aim is to identify risk factors for small bowel pathology useful in clinical practice to identify patients that might benefit from screening and to determine the additional interventional risk associated with the endoscopic procedures.

This is a national multi-centre study evaluating the yield of small bowel screening using capsule endoscopy and double balloon enteroscopy in Lynch syndrome subjects. The intervention consists of performing a capsule endoscopy procedure at baseline and at 2-year follow-up. In patients with polyps or malignant appearing abnormalities on capsule endoscopy, double balloon enteroscopy will be performed with subsequent endoscopic or surgical removal of neoplastic lesions.