Schee, L. van der (2019) T1 colorectal carcinoma in a screening population: do we underestimate its metastatic potential? thesis, Medicine.
Full text available on request.Abstract
Background and aims: Implementation of the FIT-based colorectal cancer (CRC) screening program in 2014 has led to an increased detection of early invasive CRC, with invasion limited to the submucosal layer (T1 CRC). Current risk stratification is based on non-screen-detected T1 CRCs, and it is unknown whether screen-detected and non-screen-detected T1 CRCs are similar concerning the risk of adverse outcome such as lymph node metastasis (LNM). In this study we compared LNM in screen-detected and non-screen detected T1 CRCs and aimed to find out whether the currently used Dutch criteria could successfully detect T1 CRCs at low risk of lymph node metastasis. Methods: A multicenter retrospective observational cohort-study was performed, identifying all consecutive T1 CRCs diagnosed between 2014 and 2017 from 7 hospitals in the Netherlands. It was recorded whether it was a screen-detected or non-screen-detected T1 CRC, together with polyp characteristics, histologic parameters and clinical variables such age, gender and comorbidities. The differences in LNM were evaluated by using multivariate logistic regression analysis, adjusting for clinical variables, polyp characteristics and histological factors. Risk classification was performed according to the current Dutch guideline which includes lymphovascular invasion, poor differentiation and a resection margin of ≤ 1 mm. Results: A total of 924 patients with T1 CRC were included in the study, of which 572 (61.9%) were screen-detected and 352 (38.1%) were non-screen-detected. Screen-detected patients were younger (67 vs. 70 yrs, p < 0.01), more often male (64.9% vs. 56.5%, p < 0.05) and had fewer comorbidities (94.7% ASA I-II vs. 82.6% ASA I-II, p < 0.001) than non-screen-detected patients. T1 CRCs from screen-detected patients were smaller (22 mm vs. 25 mm, p < 0.05) and more often located in the left-sided colon (60.6% vs. 52.1%, p < 0.05). There were no differences concerning morphology, histological features or surgical referral rate (51.2% vs. 55.2%). Within the group of patients treated with surgical resection, screen-detected T1 CRC was associated with a higher risk of LNM compared to non-screen-detected T1 CRC (15.9% vs. 9.4%; OR 1.97, 95% CI 0.97-4.00; p = .062). This difference was almost completely attributable to a higher risk for LNM in non-pedunculated screen-detected T1 CRCs, as the risk for LNM in pedunculated polyps was 9.7% in the screen-detected group, comparable to 7.3% in the non-screen-detected group. Using the Dutch risk criteria, still 19 cases (7.6%) within the group classified as low-risk were found to have LNM. Conclusion: There are strong indications that the non-pedunculated T1 CRCs detected within the FIT-based screening program differ from the non-screen detected T1 CRCs, with screen-detected patients being at higher risk for LNM. And worrisome, the Dutch risk criteria seem to miss a significant proportion of patients with LNM.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Faculty supervisor: and Vos tot Nederveen Cappel, W.H. de and gastroenterologist |
| Supervisor name: | Second supervisor: and Moons, L.M.G. and gastroenterologist and Institution: University Medical Center Utrecht, department |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 10:44 |
| Last Modified: | 25 Jun 2020 10:44 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/521 |
Actions (login required)
 |
View Item |