The prognostic value of lymph node yield in the earliest stage of colorectal cancer: a multicenter cohort study

Abstract

BackgroundIn patients with stage II colorectal cancer (CRC) the number of surgically retrieved lymph nodes (LNs) is associated with prognosis, resulting in a minimum of 10–12 retrieved LNs being recommended for this stage. Current guidelines do not provide a recommendation regarding LN yield in T1 CRC. Studies evaluating LN yield in T1 CRC suggest that such high LN yields are not feasible in this early stage, and a lower LN yield might be appropriate. We aimed to validate the cut-off of 10 retrieved LNs on risk for recurrent cancer and detection of LN metastasis (LNM) in T1 CRC, and explored whether this number is feasible in clinical practice.MethodsPatients diagnosed with T1 CRC and treated with surgical resection between 2000 and 2014 in thirteen participating hospitals were selected from the Netherlands Cancer Registry. Medical records were reviewed to collect additional information. The association between LN yield and recurrence and LNM respectively were analyzed using 10 LNs as cut-off. Propensity score analysis using inverse probability weighting (IPW) was performed to adjust for clinical and histological confounding factors (i.e., age, sex, tumor location, size and morphology, presence of LNM, lymphovascular invasion, depth of submucosal invasion, and grade of differentiation).ResultsIn total, 1017 patients with a median follow-up time of 49.0 months (IQR 19.6–81.5) were included. Four-hundred five patients (39.8%) had a LN yield ≥ 10. Forty-one patients (4.0%) developed recurrence. LN yield ≥ 10 was independently associated with a decreased risk for recurrence (IPW-adjusted HR 0.20; 95% CI 0.06–0.67; P = 0.009). LNM were detected in 84 patients (8.3%). LN yield ≥ 10 was independently associated with increased detection of LNM (IPW-adjusted OR 2.27; 95% CI 1.39–3.69; P = 0.001).ConclusionsIn this retrospective observational study, retrieving < 10 LNs was associated with an increased risk of CRC recurrence, advocating the importance to perform an appropriate oncologic resection of the draining LNs and diligent LN search when patients with T1 CRC at high-risk for LNM are referred for surgical resection. Given that both gastroenterologists, surgeons and pathologists will encounter T1 CRCs with increasing frequency due to the introduction of national screening programs, awareness on the consequences of an inadequate LN retrieval is of utmost importance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-017-0892-7) contains supplementary material, which is available to authorized users.

Introduction of a colorectal cancer screening programme: results from a single‐centre study

“…Because a formal oncological resection is the only way to excise the draining lymph nodes, local excision is only a valuable treatment alternative in the absence of LNM. In this study, 8.7% of patients undergoing surgery for a T1 carcinoma that was confirmed pathological prior to surgery had LNM, in accordance with previous literature as LNMs are reported in 8%–16% of patients . In T1 CRC with the deepest level of invasion, LNM risk of over 20% has been reported .…”

The Critical Role of Tumor Size in Predicting Prognosis for T1 Colon Cancer

“…Therefore, the predictive value of N stage should be reappraised according to T stage. Actually, in addition to N stage, many other predefined high‐risk clinical features, including poor differentiation, mucinous histology, and high CEA level, were infrequently found in T1 stage colon cancer . Hence, using these factors alone to predict survival of T1 stage colon cancer may not be reliable.…”

Pedunculated Morphology of T1 Colorectal Tumors Associates With Reduced Risk of Adverse Outcome

“…Clinical confounders included age, sex, tumor localization (right colon vs left colon vs rectum), and tumor size. 9,13,[21][22][23][24] The right colon was defined as the colon proximal to and including the splenic flexure and the left colon as the colon distal to the splenic flexure excluding the rectum. Histologic confounders included lymphovascular invasion (absent vs present), differentiation grade (good or moderate vs poor), and resection margins (negative [R0] vs not assessable [Rx] vs positive [R1]).…”

“…23,25,26 Treatment approach and LN yield were considered confounders because surgery decreases recurrence risk in high-risk T1CRC and a high LN yield has been associated with a decreased risk for recurrence. 21,22 Patients were categorized into 3 subgroups: endoscopic resection, surgical resection with fewer than 10 LNs retrieved, and surgical resection with 10 or more LNs retrieved. Transanal endoscopic microsurgery was considered an endoscopic treatment because no lymphadenectomy was performed.…”