Adjuvant intraoperative post-dissectional tumor bed chemotherapy-A novel approach in treating midgut neuroendocrine tumors

Adjuvant therapy following resection of gastroenteropancreatic neuroendocrine tumors provides no recurrence or survival benefit

BACKGROUND AND OBJECTIVES

Lack of high-level evidence supporting adjuvant therapy for patients with resected gastroenteropancreatic neuroendocrine tumors (GEP NETs) warrants an evaluation of its non-standard of care use.

METHODS

Patients with primary GEP NETs who underwent curative-intent resection at eight institutions between 2000 and 2016 were identified; 91 patients received adjuvant therapy. Recurrence-free survival (RFS) and overall survival (OS) were compared between adjuvant cytotoxic chemotherapy and somatostatin analog cohorts.

RESULTS

In resected patients, 33 received cytotoxic chemotherapy, and 58 received somatostatin analogs. Five-year RFS/OS was 49% and 83%, respectively. Cytotoxic chemotherapy RFS/OS was 36% and 61%, respectively, lower than the no therapy cohort (P < .01). RFS with somatostatin analog therapy (compared to none) was lower (P < .01), as was OS (P = .01). On multivariable analysis, adjuvant cytotoxic therapy was negatively associated with RFS but not OS controlling for patient/tumor-specific characteristics (RFS P < .01).

CONCLUSIONS

Our data, reflecting the largest reported experience to date, demonstrate that adjuvant therapy for resected GEP NETs is negatively associated with RFS and confers no OS benefit. Selection bias enriching our treatment cohort for individuals with unmeasured high-risk characteristics likely explains some of these results; future studies should focus on patient subsets who may benefit from adjuvant therapy.

Does the addition of adjuvant intraoperative tumor bed chemotherapy during midgut neuroendocrine tumor debulking procedures benefit patients?

Background

Midgut neuroendocrine tumor (NET) patients are often diagnosed at advanced stages with extensive mesenteric nodal and hepatic metastasis. The only potentially curative treatment is surgical tumor eradication. Despite an aggressive resection, macro and microscopic residual disease still may remain in the resection bed. We hypothesize that the application of 5-fluorouracil (5-FU) within the tumor bed will help eliminate microscopic residual disease.

Methods

Records of 189 patients who underwent extensive cytoreductive surgeries during 2003-2012 for advanced, midgut NETs with extensive mesenteric lymphadenopathy were reviewed. Eighty-six patients (46%) who had 5-FU saturated gel foam strips secured into their mesenteric resection sites served as the study group and a matching 103 patients (54%) who did not have such an intra-operative chemotherapy served as controls. Survival from the time of diagnosis and post-operative complications between the two groups were compared.

Results

Mortality rates at 30, 60 and 90 days post-operatively were 4%, 0%, 0% versus 2%, 0%, 2% for study and control groups, respectively. Major complications (Grades III & IV) at the same intervals were 0, 0, 1 versus 2, 3, 2 for study and control groups, respectively. Median survival was 236 months versus 148 months for the study and control groups, respectively 24 (P=0.15).

Conclusions

Intraoperative tumor resection bed chemotherapy is a safe adjuvant without discernible toxicity. This procedure may provide survival benefits to midgut NET patients with extensive mesenteric lymphadenopathy undergoing extensive cytoreductive surgery. Further study in prospective trials must be conducted to determine definitive benefit to the NET patient.

Analysis of the factors affecting lymph node metastasis and the prognosis of rectal neuroendocrine tumors

OBJECTIVE

To analyze the factors affecting lymph node metastasis and the prognosis of rectal neuroendocrine tumors after surgical treatment.

METHODS

A retrospective analysis was conducted using the clinical data from 156 cases of rectal neuroendocrine tumors during the period of January 1999 to December 2013. The Kaplan-Meier method was used to calculate the survival time, Cox regression analysis was performed for statistical analysis of clinicopathological factors that may be associated with lymph node metastasis and prognosis, and correlation analysis was carried out using binary logistic regression.

RESULTS

The overall 5-year survival rate of the entire group was 95.7%. Multivariate analysis showed that the depth of invasion was an independent prognostic factor (P < 0.001). The incidence of lymph node metastasis was 7.7% (12/156), and logistic regression analysis showed that lymph node metastasis was related to the depth of invasion (P = 0.003) and tumor diameter (P = 0.006).

CONCLUSION

The surgical approach of rectal neuroendocrine tumors should be selected based on a comprehensive consideration of factors such as tumor size, depth of invasion and lymph node metastasis.