Long-term outcomes after endoscopic removal of malignant colorectal polyps: Results from a 10-year cohort

BACKGROUND

Choosing an optimal post-polypectomy management strategy of malignant colorectal polyps is challenging, and evidence regarding a surveillance-only strategy is limited.

AIM

To evaluate long-term outcomes after endoscopic removal of malignant colorectal polyps.

METHODS

A single-center retrospective cohort study was conducted to evaluate outcomes after endoscopic removal of malignant colorectal polyps between 2010 and 2020. Residual disease rate and nodal metastases after secondary surgery and local and distant recurrence rate for those with at least 1 year of follow-up were investigated. Event rates for categorical variables and means for continuous variables with 95% confidence intervals were calculated, and Fisher's exact test and Mann-Whitney test were performed. Potential risk factors of adverse outcomes were determined with univariate and multivariate logistic regression models.

RESULTS

In total, 135 lesions (mean size: 22.1 mm; location: 42% rectal) from 129 patients (mean age: 67.7 years; 56% male) were enrolled. The proportion of pedunculated and non-pedunculated lesions was similar, with en bloc resection in 82% and 47% of lesions, respectively. Tumor differentiation, distance from resection margins, depth of submucosal invasion, lymphovascular invasion, and budding were reported at 89.6%, 45.2%, 58.5%, 31.9%, and 25.2%, respectively. Residual tumor was found in 10 patients, and nodal metastasis was found in 4 of 41 patients who underwent secondary surgical resection. Univariate analysis identified piecemeal resection as a risk factor for residual malignancy (odds ratio: 1.74; P = 0.042). At least 1 year of follow-up was available for 117 lesions from 111 patients (mean follow-up period: 5.59 years). Overall, 54%, 30%, 30%, 11%, and 16% of patients presented at the 1-year, 3-year, 5-year, 7-year, and 9-10-year surveillance examinations. Adverse outcomes occurred in 9.0% (local recurrence and dissemination in 4 patients and 9 patients, respectively), with no difference between patients undergoing secondary surgery and surveillance only.

CONCLUSION

Reporting of histological features and adherence to surveillance colonoscopy needs improvement. Long-term adverse outcome rates might be higher than previously reported, irrespective of whether secondary surgery was performed.

Is surgery alone sufficient for treating T1 gastric cancer with extensive lymph node metastases?

BACKGROUND

Whether or not surgery alone is sufficient for treating patients with pathological stage T1N2M0 (Stage IIA), T1N3a/bM0 (Stage IIB/IIIB), and T3N0M0 (Stage IIA) gastric cancer who were not indicated for adjuvant treatment according to the Japanese gastric cancer treatment guideline remains unclear.

METHODS

We retrospectively reviewed the clinical records of 236 patients who had been diagnosed with pT1N2-3b/pT3N0 gastric cancer and undergone R0 gastrectomy with lymph node dissection between January 2000 and December 2012 at the National Cancer Center Hospital, Japan.

RESULTS

The 5-year recurrence-free survival (RFS) rates (95% confidence interval [CI]) of the patients with pathological (p) T1N2-3b and T3N0 cancer were 73.9% (63.1-84.7) and 89.5% (84.0-95.0), respectively. The only significant prognostic factors for the survival identified by a multivariate Cox regression analysis in patients with pT1N2-3 cancer were the pN stage (N3a/N2: hazard ratio [HR] 2.940, 95% CI 1.314-5.577; N3b/N2: HR 8.688, 95% CI 3.096-24.382) and tumor diameter (<30/ ≥ 30 mm) (HR 2.919; 95% CI 1.351-6.304). We divided the patients with pT1N2-3 gastric cancer into 3 risk categories (high, moderate, low) using these 2 significant prognostic factors and found that the 5-year RFS rates were significantly different among the 3 risk groups (low risk, 93.0%; moderate risk, 66.7%; high risk, 25.0%; P < 0.001).

CONCLUSIONS

pT3N0 and large pT1N2 with a diameter ≥ 30 mm had an excellent prognosis, while pT1N2-3 with at least N3a/b or a tumor diameter < 30 mm showed a relatively poor prognosis. These patients may be candidates for adjuvant chemotherapy.

Analysis of lymphatic and blood vessel invasion biomarkers in T1 esophagogastric adenocarcinomas for improved patient prognostication

Lymphovascular invasion (LVI) in T1 esophagogastric adenocarcinoma may predict risk of recurrence despite definitive treatment with surgery or endoscopic resection. Podoplanin and CD34 are emerging biomarkers of lymphatic and blood vessel invasion, respectively, and could be adopted to refine LVI assessment. A consecutive series of 65 patients with T1 adenocarcinomas diagnosed at Nottingham University Hospitals were investigated. T1 tumors from 43/65 patients who received primary surgery only were suitable for LVI evaluation by hematoxylin and eosin (H&E) staining as well as by CD34 and Podoplanin immunohistochemistry. LVI was correlated to clinicopathological features and recurrence free survival. H&E staining detected LVI in 11.6% (5/43) of T1 tumors. CD34 and Podoplanin immunohistochemistry significantly improved LVI detection to 25.6% (11/43). Compared with LVI by H&E, immunohistochemical evaluation of blood vessel invasion (CD34) or lymphatic vessel invasion (Podoplanin) was significantly associated with higher grade (P = 0.005), submucosal invasion (T1b) (P = 0.018), lymph node positivity (N1) (P = 0.029) and poor recurrence free survival (P = 0.0003). Our study provides evidence that CD34 and Podoplanin immunohistochemistry could improve LVI detection and allow better prognostication of patients and optimum selection of definitive treatment. Larger multicenter studies are required for further validation that could have significant clinical implications.