Use of an endoscope-compatible probe to detect colonic dysplasia with Fourier transform infrared spectroscopy

Abstract

Colorectal cancer is the third most common form of malignancy in the United States, and approximately 149,900 new cases and 50,000 deaths occur each year, resulting in a major cause of morbidity and mortality.¹ Screening for this disease is commonly done with endoscopy, in which the mucosal surface of the colon is examined with reflected white light, to look for raised lesions called polyps. Such polyps can be either benign (hyperplastic) or premalignant (dysplastic, termed adenomas), but definitive pathological diagnosis cannot be made unless a biopsy is performed. Hyperplastic polyps have no risk of evolving into malignancy, while dysplastic lesions have a predictable risk that increases with the size of the lesion.² Dysplastic mucosa can persist in a latent phase for approximately $10\text{to}20\text{years}$ before transforming; thus, a window of opportunity exists to prevent cancer if adequate techniques for early detection can be developed. In addition, numerous benign inflammatory polyps can be found in patients with inflammatory bowel disease that cannot be distinguished endoscopically from dysplastic polyps.³ Polyp removal during endoscopy incurs an increased risk of bleeding or perforation. In addition, it takes time to excise these lesions, thus prolonging the duration of sedation, and additional cost is incurred for histopathological examination of tissue. Thus, a technique that can identify dysplasia during endoscopy could have tremendous diagnostic value in medical care.