Prediction of disease recurrence in patients after complete pancreatic NET (PanNET) G2 resection.

INTRODUCTION: The number of detected pancreatic neuroendocrine tumours (PanNETs) has been increasing over the last decades. Surgical resection remains the only potentially curative treatment, but the management is still controversial. This study aimed to compare patients after radical PanNET G2 resection to determine the most important predictive factors for relapse. MATERIAL AND METHODS: All patients with histologically confirmed PanNET G2 who underwent successful surgery between 2006 and 2020 with the intention of radical treatment were enrolled. RESULTS: In total, 44 patients were eligible for the analysis. The average follow-up was 8.39 ± 4.5 years. Disease recurrence was observed in 16 (36.36%) patients. The dominant location of the primary tumour was the tail of the pancreas (43.18%), especially in the subgroup with disease recurrence (56.25%). The smallest tumour diameter associated with the PanNET G2 recurrence was 22 mm. The relationship between the largest dimension of the tumour with a division of < 4 cm vs. > 4 cm and the relapse was close to statistical significance. Recurrence was associated with a larger tumour size (p = 0.018). There was a statistically significant relationship and a weak correlation between Ki-67 (p = 0.036, V Cramer = 0.371) and disease relapse. CONCLUSION: For the group of PanNET G2 patients after radical surgery, the overall risk of recurrence was 36.36%, with the highest rate in the first 5 years after surgery, but in individual cases it occurred significantly later, even 10 years after surgery. The most important predictive factors of the PanNET G2 recurrence was Ki-67 over 5.75% and size of tumour > 4 cm.

Value of Peptide Receptor Radionuclide Therapy as Neoadjuvant Treatment in the Management of Primary Inoperable Neuroendocrine Tumors.

INTRODUCTION: Neuroendocrine neoplasms including neuroendocrine tumors (NETs) are often diagnosed as primary disseminated or inoperable. In those cases, systemic extensive therapy is necessary, but radical treatment is unlikely. As described in the literature, in some selected cases, peptide receptor radionuclide therapy (PRRT) may be used as a first-line/neoadjuvant therapy that allows further successful surgery. Such treatment may enable a reduction of total tumor burden or allow a radical treatment which improves the final outcomes. AIM: This study aims to assess whether neoadjuvant PRRT could be a treatment option for patients with initially unresectable NETs. METHODS: Among the group of 114 patients treated with PRRT between the years 2005 and 2020, in 32 cases, it was the first-line therapy, mainly due to massive disease burden at the time of diagnosis. Among them, nine patients received PRRT as the first-line treatment due to the primary inoperable tumors with the intention of preoperative reduction of the tumor size in order to allow for a surgical treatment. RESULTS: Neoadjuvant PRRT enabled surgery in four out of nine (45%) patients. Finally, in two out of four cases, the goal (radical surgery) has been achieved. CONCLUSION: PRRT may be considered not only as a palliative but also as a neoadjuvant therapy in advanced, somatostatin-positive NETs that were initially inoperable.

Clinical Approach to Neuroendocrine Neoplasm Associated With Ovarian Teratoma.

Background: Neuroendocrine neoplasms are a heterogeneous group of cancers that develop from enterochromaffin cells of the diffuse endocrine system, with an increase in incidents over the last years. Ovarian neuroendocrine tumors (NET) are rare neoplasms, comprising 0.1% of all ovarian neoplasms and less than 5% of all neuroendocrine tumors. They may arise alone (as monodermal, specialized teratoma - ovarian carcinoid) or as a part of other ovarian lesion: cystic mature or immature teratomas. Due to the rarity and limited amount of such cases reported in the literature, there is no consensus on diagnostic and therapeutic procedures in this group of patients. Materials and Methods: The group of 10 patients at the age of 19 to 77 years (mean 42.8 ± 17.9), diagnosed with unilateral NET within ovarian teratoma were analyzed. The histopathological type of tumor, progression free survival after surgical treatment and presence of hormonally active syndrome were assessed. Results: 70% (n=7) of patients was diagnosed with mature cystic teratomas containing NET component and 30% (n=3) with monodermal teratoma (strumal carcinoid). All cases of monodermal teratomas were found in women at premenopausal age. Determined Ki67 ranged from 2% to 9%. Ninety percent of lesions (n=9) stained positive for synaptophysin and chromogranin, while markers: CK20, CK7, TTF-1 and CDX2 were negative in all cases, which ruled out their metastatic nature. None of the patients presented with carcinoid syndrome. All followed-up patients remain progression-free, which confirms surgical intervention being a crucial and sufficient method of treatment. Conclusions: The prognosis and clinical behavior of NETs associated with ovarian teratomas are good with long progression-free survival.

Self-Administration of Long-Acting Somatostatin Analogues in NET Patients-Does It Affect the Clinical Outcome?

Background and Objectives: Long-acting somatostatin analogues (SSA) (octreotide LAR and lanreotide Autogel) are recommended as first line treatment of locally advanced or metastatic well-differentiated neuroendocrine tumors (NETs) with a good expression of somatostatin receptor (SSTR). Both of these SSAs are usually administered via injections repeated every 4 weeks. The purpose of the study was to compare the route of SSA administration (injection performed by professional medical staff and self-administration of the drug) with progression-free survival. Materials and methods: 88 patients in 2019 and 96 patients in 2020 with locally advanced or metastatic well-differentiated NETs were included in the study. All patients had a good expression of SSTR type 2 and had been treated for at least 3 months with a stable dose of long-acting somatostatin analogue every 4 weeks. All of them had received training on drug self-injections from professional NET nurses at the beginning of the COVID-19 epidemic. Results: The rate of NET progression in the study group in 2020 was higher than in 2019 29.1% vs. 18.1% (28 vs. 16 cases), p = 0.081. Conclusions: The method of administration of long-acting SSA injection performed by professional medical staff vs. self-injection of the drug may significantly affect the risk of NET progression. The unequivocal confirmation of such a relationship requires further observation.