Neuroendokrine Tumoren des Abdomens

[Gastroenteropancreatic neuroendocrine neoplasms-Heterogeneity, management and perspectives of treatment and research]

The term neuroendocrine neoplasms (NEN) encompasses a molecularly and biologically very heterogeneous group of tumors, which have in common their origin in neuroendocrine cells. The also very heterogeneous subgroup of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) is the best classified and investigated group. This article provides a systematic review of the current classification, diagnostics and treatment options of GEP-NEN. In order to achieve a better overview, it was consciously decided not to use an approach based on the primary localization. Instead, a thematic organization according to classification, clinical phenotype, diagnostics and treatment was chosen.

Survival comparison between primary hepatic neuroendocrine neoplasms and primary pancreatic neuroendocrine neoplasms and the analysis on prognosis-related factors

BACKGROUND

Primary hepatic neuroendocrine neoplasms (PHNENs) are extremely rare and few articles have compared the prognosis of PHNENs with other neuroendocrine neoplasms (NENs). This study aimed to investigate the different prognosis between PHNENs and pancreatic NEN (PanNENs) and evaluate the relevant prognosis-related factors.

METHODS

From January 2012 to October 2016, a total of 44 NENs patients were enrolled and divided into two groups according to the primary tumor location which were named group PHNENs (liver; n = 12) and group PanNENs (pancreas; n = 32). Demographic, clinical characteristics and survival data were compared between the two groups with Kaplan-Meier method and log-rank tests. Prognostic factors were analyzed using the Cox regression model.

RESULTS

The overall survival of group PHNENs and group PanNENs were 25.4 ± 6.7 months and 39.8 ± 3.7 months, respectively (P = 0.037). The cumulative survival of group PanNENs was significantly higher than that of group PHNENs (P = 0.029). Univariate analysis revealed that sex, albumin, total bilirubin, total bile acid, aspartate aminotransferase, alkaline phosphatase, α-fetoprotein and carbohydrate antigen 19-9, histological types, treatments and primary tumor site were the prognostic factors. Further multivariate analysis indicated that albumin (P = 0.008), histological types NEC (P = 0.035) and treatments (P = 0.005) were the independent prognostic factors. Based on the histological types, the cumulative survival of patients with well-differentiated neuroendocrine tumor was significant higher than that of patients with poorly differentiated neuroendocrine carcinoma in group PHNENs (P = 0.022), but not in group PanNENs (P > 0.05). According to the different treatments, patients who received surgery had significantly higher cumulative survival than those with conservative treatment in both groups (P < 0.05).

CONCLUSIONS

PHNENs have lower survival compared to PanNENs. Histological types and treatments affect the prognosis. Surgical resection still remains the first line of treatment for resectable lesions and can significantly improve the survival.

Diagnostic fficiency of 68Ga-DOTATATE PET/CT as ompared to 99mTc-Octreotide SPECT/CT andonventional orphologic odalities in euroendocrine umors

OBJECTIVES

In view of somatostatin receptor (SSR) expression on cell membranes of the majority of neuroendocrine tumors (NETs), functional imaging exploiting analogs of SSR alongside the anatomical imaging is the mainstay of this diagnostic modality. In this prospective study, we assessed and directly compared the diagnostic parameters of 68Ga-DOTATATE PET/CT and 99mTc-Octreotide SPECT/CT, as well as CT/MRI.

METHODS

Twenty-five NET patients, either histologically proven or highly suspicious for NET, who were referred for Octreotide Scan were enrolled in this prospective study. They all underwent 99mTc-Octreotide SPECT/CT and then 68Ga-DOTATATE PET/CT. A blind interpretation was conducted for each imaging as well as for the previously obtained conventional imaging (CT or MRI). The patient-based and lesion-based analysis were conducted and the results of the three modalities were compared. The histopathologic confirmation or follow-up data were considered as the gold standard. Also, the impact of 68Ga-DOTATATE PET/CT on the patient's management was assessed.

RESULTS

Overall, 77 lesions in 14 patients, 135 in 19 and 86 in 16 were detected on 99mTc-Octreotide SPECT/CT, 68Ga-DOTATATE PET/CT and CT/MRI, respectively. On patient-based analysis, the sensitivity was 65%, 90% and 71% for 99mTc-Octreotide SPECT/CT, 68Ga-DOTATATE PET/CT and CT/MRI, respectively. Also, the specificity was 80%, 80% and 75% for 99mTc-Octreotide SPECT/CT, 68Ga-DOTATATE PET/CT and CT/MRI, respectively. The correlation between 68Ga-DOTATATE PET/CT and 99mTc-Octreotide SPECT/CT results was significant (=0.02; kappa value=0.57), no correlation, however, was depicted with CI (=0.07; kappa value=0.35). On lesion-based analysis, 68Ga-DOTATATE PET/CT found more organs (=0.02) and lesions (=0.001) in comparison with 99mTc-Octreotide SPECT/CT and also more lesions in comparison with CT/MRI (=0.003). In addition, comparing with 99mTc-Octreotide SPECT/CT and CT/MRI, 68Ga-DOTATATE PET/CT revealed more data in 44% and 36% of the patients, resulting in management modification in 24% and 20%, respectively.

CONCLUSION

Comparing with 99mTc-Octreotide SPECT/CT and CT/MRI, 68Ga-DOTATATE PET/CT provided more sensitivity and specificity in patients with NETs showing more involved organs as well as tumoral lesions. Also, 68Ga-DOTATATE PET/CT led to change of management in up to one-fourth of the patients, especially in a sub-group re-evaluated for recurrence.