Surgical treatment of extra-appendiceal colorectal neuroendocrine tumors

Endoscopic and surgical treatment of T1N0M0 colorectal neuroendocrine tumors: a population-based comparative study

BACKGROUND

With the rapid advances in endoscopic technology, endoscopic therapy (ET) is increasingly applied to the treatment of small (≤ 20 mm) colorectal neuroendocrine tumors (NETs). However, long-term data comparing ET and surgery for management of T1N0M0 colorectal NETs are lacking. The purpose of this work was to compare overall survival (OS) and cancer-specific survival (CSS) of such patients with ET or surgery.

METHODS

Patients with T1N0M0 colorectal NETs were identified within the Surveillance Epidemiology and End Results (SEER) database (2004-2016). Demographics, tumor characteristics, therapeutic methods, and survival were compared. Propensity score matching (PSM) was used 1:3 and among this cohort, Cox proportional hazards regression models were performed to evaluate correlation between treatment and outcomes.

RESULTS

Of 4487 patients with T1N0M0 colorectal NETs, 1125 were identified in the matched cohort, among whom 819 (72.8%) underwent ET and 306 (27.2%) underwent surgery. There was no difference in the 5-year and 10-year OS and CSS rates between the 2 treatment modalities. Likewise, analyses stratified by tumor size and site showed that patients did not benefit more from surgery compared with ET. Moreover, multivariate analyses found no significant differences in OS [Hazard Ratio (HR) = 0.857, 95% Confidence Interval (CI): 0.513-1.431, P = 0.555] and CSS (HR = 0.925, 95% CI: 0.282-3.040, P = 0.898) between the 2 groups. Similar results were observed when comparisons were limited to patients with different tumor size and site.

CONCLUSIONS

In this population-based study, patients with lesions < 10 mm treated endoscopically had comparable long-term survival compared with those treated surgically, which demonstrates ET as an alternative to surgery in T1N0M0 colorectal NETs of < 10 mm. Further high-quality prospective studies are warranted to comprehensively evaluate the role of ET in patients with tumors 10 to 20 mm.

Effects of tumor distance from anal verge on survival outcomes for rectal NENs and lymphatic metastasis risk score for colorectal NENs

OBJECTIVE

To explore whether the distance of rectal neuroendocrine neoplasms from the anal margin has an impact on the prognosis of patients and evaluate lymphatic metastases risk score for colorectal neuroendocrine neoplasms (NENs).

METHODS

Clinical pathological and follow-up data of 71 patients identified as colorectal neuroendocrine neoplasms by pathology from July 2011 to July 2019 were carefully collected.

RESULTS

Among 71 patients with colorectal NENs, most of the tumors were rectal NENs (62 cases). A total of 26 patients were in the presence of lymph node metastasis, and 44 patients had negative lymph nodes. Patients with lesions from the anal margin > 5 cm in rectum have a better prognosis (P = 0.022). Tumor stage (P = 0.034) and grade (P = 0.001) were independent risk predictors of lymphatic metastases. We developed a lymphatic metastasis risk score for rectal NENs, and patients with the score ≥ 7.5 were more likely to develop lymph node metastases (area 0.958, 95% CI 0.903-1.000, P = 0.000) with a sensitivity of 72.2% and a specificity of 97.3%.

CONCLUSION

Patients with lesions from the anal margin > 5 cm and lymphatic metastasis risk score ≥ 7.5 should be treated actively.