Long-term oncological outcomes of endoscopic full-thickness resection after previous incomplete resection of low-risk T1 CRC (LOCAL-study): study protocol of a national prospective cohort study.

BACKGROUND: T1 colorectal cancer (CRC) without histological high-risk factors for lymph node metastasis (LNM) can potentially be cured by endoscopic resection, which is associated with significantly lower morbidity, mortality and costs compared to radical surgery. An important prerequisite for endoscopic resection as definite treatment is the histological confirmation of tumour-free resection margins. Incomplete resection with involved (R1) or indeterminate (Rx) margins is considered a strong risk factor for residual disease and local recurrence. Therefore, international guidelines recommend additional surgery in case of R1/Rx resection, even in absence of high-risk factors for LNM. Endoscopic full-thickness resection (eFTR) is a relatively new technique that allows transmural resection of colorectal lesions. Local scar excision after prior R1/Rx resection of low-risk T1 CRC could offer an attractive minimal invasive strategy to achieve confirmation about radicality of the previous resection or a second attempt for radical resection of residual luminal cancer. However, oncologic safety has not been established and long-term data are lacking. Besides, surveillance varies widely and requires standardization. METHODS/DESIGN: In this nationwide, multicenter, prospective cohort study we aim to assess feasibility and oncological safety of completion eFTR following incomplete resection of low-risk T1 CRC. The primary endpoint is to assess the 2 and 5 year luminal local tumor recurrence rate. Secondary study endpoints are to assess feasibility, percentage of curative eFTR-resections, presence of scar tissue and/or complete scar excision at histopathology, safety of eFTR compared to surgery, 2 and 5 year nodal and/or distant tumor recurrence rate and 5-year disease-specific and overall-survival rate. DISCUSSION: Since the implementation of CRC screening programs, the diagnostic rate of T1 CRC is steadily increasing. A significant proportion is not recognized as cancer before endoscopic resection and is therefore resected through conventional techniques primarily reserved for benign polyps. As such, precise histological assessment is often hampered due to cauterization and fragmentation and frequently leads to treatment dilemmas. This first prospective trial will potentially demonstrate the effectiveness and oncological safety of completion eFTR for patients who have undergone a previous incomplete T1 CRC resection. Hereby, substantial surgical overtreatment may be avoided, leading to treatment optimization and organ preservation. Trial registration Nederlands Trial Register, NL 7879, 16 July 2019 ( https://trialregister.nl/trial/7879 ).

Review article: Non-alcoholic fatty liver disease in morbidly obese patients and the effect of bariatric surgery.

BACKGROUND: Morbid obesity is strongly associated with non-alcoholic fatty liver disease. The effects of bariatric surgery on liver tests an histological abnormalities after weight loss are controversial. AIM: To review the literature on the prevalence of non-alcoholic fatty liver disease in patients with morbid obesity with respect to laboratory and histopathological parameters and the effect of weight loss on these parameters after bariatric surgery. RESULTS: Standard liver tests do not seem to be a sensitive tool for the assessment and follow-up of non-alcoholic fatty liver disease in obesity. In nearly all patients with morbid obesity, histological abnormalities reflecting non-alcoholic fatty liver disease are present. Bariatric surgery in these patients will decrease the grade of steatosis. However, there are some concerns about the effect of bariatric surgery on hepatic inflammation and fibrosis. In particular, older follow-up studies reported negative results as opposed to more recent studies, which also showed improvement in hepatic inflammation and fibrosis. Unfortunately, most studies had limitations because of the selection of patients. CONCLUSION: Despite limitations in many studies, bariatric surgery seems to be a promising treatment in patients with obesity presenting with non-alcoholic fatty liver disease.