Risk of recurrence after endoscopic resection of nonpedunculated T1 colorectal cancer

Is tumour location a dominant risk factor of recurrence in early rectal cancer?

BACKGROUND

Impact of rectal tumour location on risk of lymph node metastases (LNM) and recurrence in early RC is poorly studied and elusive. Tumour location as a prognostic factor may contribute to optimise management of early RC in the future. The aim of this study was to investigate rectal tumour location as an independent predictor of oncologic outcome in early rectal cancer (RC).

METHODS

Retrospective multicentre national cohort study on prospectively collected data on all patients with T1-T2 RC, undergoing surgical resection between 2009 and 2021. Tumour location was categorised as distal (0-5 cm), mid (5-10 cm), and proximal (10-16 cm), measured from the anal verge.

RESULTS

Incidence of LNM in the 2424 included T1-T2 RC patients was 18.2%, 17.3% and 21.6% for distal, mid and proximal tumours, respectively. Recurrence was detected in 130 (7.6%) out of 1705 patients available for recurrence analyses (60-month median follow-up). Incidence of recurrence was twice as high in distal (11.4%) compared to proximal (5.6%) tumours and was 8.3% in mid located tumours. Distal (HR 2.051, CI 1.248-3.371, P < 0.05) and mid (HR 1.592, CI 1.061-2.388, P < 0.05) tumour location were significant risk factors of recurrence in uni- and multivariate Cox regression analyses.

CONCLUSIONS

This study shows that tumour location significantly affects incidence of recurrence in early RC, with an increasing risk for mid and especially distal location, found to be a predominant risk factor of recurrence. Our findings stress the need for an increased awareness on differences in oncologic outcome related to tumour location in early RC.

Risk Factors Associated With Lymph Node Metastasis and Recurrence in Surgical Cases of pT1 Colorectal Cancer

Objective This study aims to investigate the risk factors for lymph node metastasis (LNM) and postoperative recurrence in patients undergoing surgery for pT1 colorectal cancer (pT1-CRC). Materials and methods We retrospectively analyzed 150 patients who underwent bowel resection with lymph node dissection for pT1-CRC at our department between September 2011 and December 2021. Univariate and multivariate analyses were performed to examine the effects of sex, depth of tumor invasion, venous invasion, lymphatic invasion, tumor budding (BD), and histological type on LNM and recurrence. We analyzed recurrence-free survival (RFS) curves. Results LNM was observed in 21 (14.0%) patients. Univariate analysis identified female sex, undifferentiated histological type, positive lymphatic invasion, and tumor budding grade 2/3 (BD2/3) as significant risk factors for LNM, whereas multivariate analysis identified female sex, undifferentiated histological type, and BD2/3 as independent risk factors. No cancer-related deaths were observed during the median observation period of 60.7 months. The five-year RFS rate differed significantly between LNM- and LNM+ patients, at 97.3% and 66.4%, respectively (p=0.0005). BD2/3 was also the significant risk factor for recurrence in the univariate analysis (p<0.0001). In LNM- patients, the five-year RFS was 98.7% for BD1 and 88.2% for BD2/3 (p=0.0014), while in LNM+ patients, it was 100% for BD1 and 37.0% for BD2/3 (p=0.036), with significant differences observed. Conclusion In pT1-CRC patients, female sex, undifferentiated histological type, and BD2/3 were the risk factors for LNM. The recurrence rate was higher in patients with LNM than in those without LNM. Regardless of LNM, BD2/3 was the risk factor for the postoperative recurrence of pT1-CRC.

Risk of recurrence in high-risk T1 colon cancer following endoscopic and surgical resection: registry-based cohort study

BACKGROUND

Endoscopic resection of T1 colon cancer (CC) is currently limited by guidelines related to risk of lymph node metastases. However, clinical outcome following endoscopic and surgical resection is poorly investigated.

METHOD

A retrospective multicentre national cohort study was conducted on prospectively collected data from the Swedish colorectal cancer registry on all non-pedunculated T1 CC patients undergoing surgical and endoscopic resection between 2009 and 2021. Patients were categorized on the basis of deep submucosal invasion (Sm2-3), lymphovascular invasion (LVI), poor tumour differentiation, and R1/Rx into low- and high-risk cases. The primary outcomes of interest were recurrence rates and disease-free interval (DFI, defined as time from treatment to date of recurrence) according to resection methods and risk factors (sex, age at diagnosis, histologic grade, LVI, perineural invasion, mucinous subtype, submucosal invasion, tumour location, resection margin and nodal positivity in the surgical group).

RESULTS

In total, 1805 patients undergoing endoscopic (488) and surgical (1317) resection with 60.0 months median follow-up were included. Recurrence occurred in 18 (3.7%) endoscopically and 48 (3.6%) surgically resected patients. Adjuvant treatment was administered in 7.4% and 0.2% of the cases respectively in the surgical and endoscopically treated patients. Five-year DFI was 95.6% after endoscopic and 96.2% after surgical resection, with no significant difference when adjusting for confounding factors (HR 1.03, 95% c.i. 0.56 to 1.91, P = 0.920). There were no statistically significant differences in recurrence comparing endoscopic (1.7%) versus surgical (3.6%) low-risk and endoscopic (5.4%) versus surgical (3.8%) high-risk cases. LVI was the only significant risk factor for recurrence in multivariate Cox regression (HR 3.73, 95% c.i. 1.76 to 7.92, P < 0.001).

CONCLUSIONS

This study shows no difference in recurrence after endoscopic and surgical resection in high-risk T1 CC. Although it was not possible to match groups according to treatment, the multivariate analysis showed that lymphovascular invasion was the only independent risk factor for recurrence.

Impact of surgery after endoscopically resected high-risk T1 colorectal cancer: results of an emulated target trial

BACKGROUND AND AIMS

We aimed to compare the long-term outcomes of patients with high-risk T1 colorectal cancer (CRC) resected endoscopically who received either additional surgery or surveillance.

METHODS

We used data from routine care to emulate a target trial aimed at comparing 2 strategies after endoscopic resection of high-risk T1 CRC: surgery with lymph node dissection (treatment group) versus surveillance alone (control group). All patients from 14 tertiary centers who underwent an endoscopic resection for high-risk T1 CRC between March 2012 and August 2019 were included. The primary outcome was a composite outcome of cancer recurrence or death at 48 months.

RESULTS

Of 197 patients included in the analysis, 107 were categorized in the treatment group and 90 were categorized in the control group. From baseline to 48 months, 4 of 107 patients (3.7%) died in the treatment group and 6 of 90 patients (6.7%) died in the control group. Four of 107 patients (3.7%) in the treatment group experienced a cancer recurrence and 4 of 90 patients (4.4%) in the control group experienced a cancer recurrence. After balancing the baseline covariates by inverse probability of treatment weighting, we found no significant difference in the rate of death and cancer recurrence between patients in the 2 groups (weighted hazard ratio, .95; 95% confidence interval, .52-1.75).

CONCLUSIONS

Our study suggests that patients with high-risk T1 CRC initially treated with endoscopic resection may not benefit from additional surgery.

Long-term outcomes of endoscopic or surgical resection in T1 colorectal cancer patients: a retrospective cohort study

BACKGROUND

The personalized treatments of T1 colorectal cancer (CRC) remains controversial. We compared the long-term outcomes of T1 CRC patients after endoscopic resection (ER) and surgery, and evaluated the risk factors for the long-term prognosis.

METHODS

T1 CRCs after resection at the Cancer Hospital, Chines Academy of Medical Sciences from June 2011 to November 2021 were reviewed. High-risk factors included positive resection margin, poor differentiation, deep submucosal invasion (DSI ≥ 1000 μm), lymphovascular invasion and intermediate/high tumor budding. Comparative analyses were conducted based on three treatment methods: follow-up after ER (Group A), additional surgery after ER (Group B) and initial surgery (Group C). The primary endpoints included recurrence-free survival (RFS) and overall survival (OS). Cox proportional hazard regression models were constructed to identify risk factors for RFS and OS.

RESULTS

A total of 528 patients were enrolled (173 patients in Group A, 102 patients in Group B, 253 patients in Group C). The 3-year RFS, 5-year RFS, 3-year OS, and 5-year OS rates were 96.7%, 94.7%, 99.1%, and 97.8%, respectively. In the absence of other high-risk factors, RFS (P = 0.321) and OS (P = 0.155) of patients with DSI after ER were not inferior to those after surgery. Multivariate analyses identified sex (HR 0.379; 95% CI 0.160-0.894), Charlson comorbidities index (CCI) (HR 3.330; 95% CI 1.571-7.062), margin (HR 8.212; 95% CI 2.325-29.006), and budding (HR 3.794; 95% CI 1.686-8.541) as independent predictive factors of RFS, and identified CCI (HR 10.266; 95% CI 2.856-36.899) as an independent predictive factor of OS.

CONCLUSION

The long-term outcomes of ER are comparable to those of surgery in T1 CRC patients with DSI when other high-risk factors are negative. Resection margin, tumor budding, sex, and CCI may be the most important long-term prognostic factors for T1 CRC patients.

Curative criteria for endoscopic treatment of colorectal cancer

As endoscopic treatment enables en bloc resection of T1 colorectal cancers, the risk of recurrence, often assimilated to the risk of lymph node metastases, must be assessed in order to offer patients an additional treatment if this risk is deemed significant. The curative criteria currently used by most guidelines are depth of invasion <1 mm, well or moderately differentiated tumour, absence of lympho-vascular invasion, absence of significant budding and tumour-free resection margins. However, these factors must be assessed by qualified pathologists, as they are difficult to evaluate. Moreover, the combination of these factors leads to unnecessary surgery in over 80 % of patients whose tumours are classified as high risk. Refinement of current criteria and research into new tumour and immunological markers are needed to better predict the actual risk of our patients.

Management after non-curative endoscopic resection of T1 rectal cancer

Since the introduction of population-based screening, increasing numbers of T1 rectal cancers are detected and removed by local endoscopic resection. Patients can be cured with endoscopic resection alone, but there is a possibility of residual tumor cells remaining after the initial resection. These can be located intraluminally at the resection site or extraluminally in the form of (lymph node) metastases. To decrease the risk of residual cells progressing towards more advanced disease, additional treatment is usually needed. However, with the currently available risk stratification models, it remains challenging to determine who should and should not be further treated after non-curative endoscopic resection. In this review, the different management strategies for patients with non-curatively treated T1 rectal cancers are discussed, along with the available evidence for each strategy and relevant considerations for clinical decision making. Furthermore, we provide practical guidance on the management and surveillance following non-curative endoscopic resection of T1 rectal cancer.

Prediction of disease recurrence or residual disease after primary endoscopic resection of pT1 colorectal cancer-results from a large nationwide Danish study

PURPOSE

Risk assessment of disease recurrence in pT1 colorectal cancer is crucial in order to select the appropriate treatment strategy. The study aimed to develop a prediction model, based on histopathological data, for the probability of disease recurrence and residual disease in patients with pT1 colorectal cancer.

METHODS

The model dataset consisted of 558 patients with pT1 CRC who had undergone endoscopic resection only (n = 339) or endoscopic resection followed by subsequent bowel resection (n = 219). Tissue blocks and slides were retrieved from Pathology Departments from all regions in Denmark. All original slides were evaluated by one experienced gastrointestinal pathologist (TPK). New sections were cut and stained for haematoxylin and eosin (HE) and immunohistochemical markers. Missing values were multiple imputed. A logistic regression model with backward elimination was used to construct the prediction model.

RESULTS

The final prediction model for disease recurrence demonstrated good performance with AUC of 0.75 [95% CI 0.72-0.78], HL chi-squared test of 0.59 and scaled Brier score of 10%. The final prediction model for residual disease demonstrated medium performance with an AUC of 0.68 [0.63-0.72].

CONCLUSION

We developed a prediction model for the probability of disease recurrence in pT1 CRC with good performance and calibration based on histopathological data. Together with lymphatic and venous invasion, an involved resection margin (0 mm) as opposed to a margin of ≤ 1 mm was an independent risk factor for both disease recurrence and residual disease.

pT1 colorectal cancer: A treatment dilemma

The implementation of population screening programs for colorectal cancer (CRC) has led to a considerable increase in the prevalence pT1-CRC originating on polyps amenable by local treatments. However, a high proportion of patients are referred for unnecessary oncological surgeries without a clear benefit in terms of survival. Selecting the appropriate endoscopic resection technique in the moment of diagnosis becomes crucial to provide the best treatment alternative to each individual polyp and patient. For this, it is imperative to increase the optical diagnostic skill for differentiating pT1-CRCs and decide the appropriate initial therapy. En bloc resection is crucial to obtain an adequate histological specimen that might allow organ preserving therapeutic management. In this review, we address key challenges in T1 CRC management, explore the efficacy and safety of the available diagnostic and therapeutic approaches, and shed light on upcoming advances in the field.

Endoscopic Treatment of T1 Colorectal Cancer

Commonly accepted criteria for curative resection of T1 colorectal cancer include R0 resection with horizontal and vertical clear margins (R0), absence of lympho-vascular or vessel infiltration (L0, V0), a low to moderate histological grading (G1/2), low tumor cell budding, and limited (<1000 µm) infiltration into the submucosa. However, submucosal infiltration depth in the absence of other high-risk features has recently been questioned as a high-risk situation for lymph-node metastasis. Consequently, endoscopic resection techniques should focus on the acquisition of qualitatively and quantitively sufficient submucosal tissue. Here, we summarize the current literature on lymph-node metastasis risk after endoscopic resection of T1 colorectal cancer. Moreover, we discuss different endoscopic resection techniques with respect to the quality of the resected specimen.