Treatment Outcomes in Patients with Metastatic Neuroendocrine Tumors: a Retrospective Analysis of a Community Oncology Database

Morbidity and Outcomes of Primary Tumor Management in Patients with Widely Metastatic Well-Differentiated Small Bowel Neuroendocrine Tumors

BACKGROUND

The benefit of primary tumor resection in distant metastatic small bowel neuroendocrine tumors (SBNETs) is controversial, with treatment-based morbidity not well-defined. We aimed to determine the impact of primary tumor resection on development of disease-specific complications in patients with metastatic well-differentiated SBNETs.

PATIENTS AND METHODS

A retrospective analysis was performed of patients diagnosed with metastatic well-differentiated jejunal/ileal SBNETs at a single tertiary care cancer center from 1980 to 2016. Outcomes were compared on the basis of treatment selected at diagnosis between patients who underwent initial medical treatment or primary tumor resection.

RESULTS

Among 180 patients, 71 underwent medical management and 109 primary tumor resection. Median follow-up was 116 months. Median event-free survival did not differ between treatment approaches (log-rank p = 0.2). In patients medically managed first, 16/71 (23%) required surgery due to obstruction, perforation, or bleeding. These same complications led to resection at presentation in 31/109 (28%) surgically treated patients. Development of an obstruction from the primary tumor was not associated with disease progression/recurrence (HR 1.14, 95% CI 0.75-1.75) with all patients recovering postoperatively. Ongoing tumor progression requiring secondary laparotomy was associated with worse mortality (HR 7.51, 95% CI 3.3-16.9; p < 0.001) and occurred in 20/109 (18%) primary tumor resection and 7/16 (44%) initially medically treated patients.

CONCLUSIONS

Rates of event-free survival among patients with metastatic SBNETs do not differ on the basis of primary tumor management. The development of an obstruction from the primary tumor was not associated with worse outcomes with all patients salvaged. Regardless of initial treatment selected, patients with metastatic SBNET should be closely followed for early signs of primary tumor complications.

Identification of a new prognostic score for patients with high-grade metastatic GEP-NEN treated with palliative chemotherapy

PURPOSE

High-grade gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN G3) are rare and heterogeneous malignancies with poor prognosis. Aim of this study was to develop prognosticators identifying those patients that derive the most benefit from currently available systemic therapies.

METHODS

This retrospective analysis included 78 patients with metastatic GEP-NEN G3. For patients with imaging data available (n = 52), the overall response rate (ORR) and disease control rate (DCR) were evaluated according to the Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1). A Cox proportional hazard model was used to analyze the prognostic value of selected clinical and blood-based biomarkers. The impact of palliative chemotherapy regimens on time-to-treatment-failure (TTF) and overall survival (OS) was assessed.

RESULTS

Median OS of the study cohort was 9.0 months (95% CI 7.0-11.1). The majority of patients received first-line treatment with platinum plus etoposide (83.3%). The ORR and DCR of the RECIST-evaluable subgroup were 34.6% and 76.9%. Median TTF upon first-line treatment was 4.9 months (95% CI 3.4-6.4). Multivariate analysis identified the Eastern Cooperative Oncology Group performance status (ECOG PS), lactate dehydrogenase (LDH) and absolute lymphocyte count as independent prognostic factors. A prognostic score based on these parameters discriminated patients with favorable and unfavorable outcomes.

CONCLUSION

Outcomes of patients with GEP-NEN G3 are still limited. A new prognostic score identifying those patients benefitting from current platinum/etoposide-based chemotherapy protocols may help as stratification factor in future trial design.

Treatment patterns and oncological outcome of patients with advanced small intestinal neuroendocrine tumors: real-world data from the Medical University of Vienna

Background:

Different oncological therapies have been approved for small intestinal neuroendocrine tumors (SI-NETs), but relatively little is known about efficacy and long-term outcome outside of phase III trials.

Methods:

This retrospective analysis assessed patients with well-differentiated, metastatic SI-NETs treated at the Medical University of Vienna, an approved European Neuroendocrine Tumor Society (ENETS) Center of Excellence for neuroendocrine tumors. The primary objective was to assess progression-free survival (PFS) following approved therapies, that is, octreotide, lanreotide, peptide receptor radionuclide therapy (PRRT), and everolimus, in a representative real-world collective.

Results:

A total of 77 patients receiving systemic treatment for advanced SI-NETs between 2010 and 2021 were included, with a median follow-up time of 82.3 months [95% confidence interval (CI), 57.8–106.8 months]. In the entire collective, the estimated median PFS following first-line therapy was 32.0 months (95% CI, 23.5–40.5 months). Peritoneal carcinomatosis was significantly associated with worse PFS ( p = 0.016). Regarding therapeutic strategies and outcome, 59 patients received somatostatin analogs first line and no significant difference in PFS was observed between lanreotide and octreotide (29.3 versus 35.5 months, p = 0.768). Across all treatment lines, 42 patients underwent PRRT (estimated median PFS: 32.0 months; 95% CI, 25.6–38.3 months) and a small subgroup of 7 patients received everolimus (estimated median PFS: 9.2 months; 95% CI, 1.6–17.0 months). For the total cohort, the estimated median OS following first-line therapy was 100.6 months (95% CI, 82.3–118.8 months), but the high proportion of deaths attributed to NET (77.8%) underlines the lethal nature of the disease. No unexpected toxicities were observed.

Conclusions:

While peritoneal carcinomatosis emerged as an adverse prognostic factor for PFS in this collective, the long-term outcome of patients treated at a specialized NET center using approved therapies appeared comparable to pivotal studies in SI-NET.

Real-world treatment patterns and outcomes in PD-L1-positive non-small cell lung cancer

Aim: We report real-world treatment patterns and outcomes in patients with PD-L1+ non-small cell lung cancer (NSCLC). Methods: This retrospective, observational study using the ConcertAI Oncology Dataset (Symphony AI, CA, USA), included patients with PD-L1+ (≥1% expression) metastatic NSCLC who began first-line (1L) treatment between 2016 and 2019. Treatment outcomes were assessed by treatment class (immune checkpoint inhibitor [ICI] monotherapy, ICI combinations or chemotherapy). Results: In total, 128 (25.5%), 237 (47.3%) and 136 patients (27.1%) received 1L chemotherapy, 1L ICI monotherapy and 1L ICI combinations, respectively. ICI combinations and monotherapy had improved clinical outcomes versus chemotherapy. Adjusted analyses showed no significant difference in outcome between ICI monotherapy and ICI combinations. Conclusion: ICI-based treatments are being increasingly adopted into clinical practice and were associated with better outcomes versus chemotherapy.

Somatostatin Analogs for Pancreatic Neuroendocrine Tumors: Any Benefit When Ki-67 Is ≥10%?

BACKGROUND

Long-acting somatostatin analogs (SSAs) are the primary first-line treatment of well-differentiated advanced gastroenteropancreatic neuroendocrine tumors (NETs), but data about their efficacy in pancreatic NETs (panNETs) with Ki-67 ≥10% are still limited.

MATERIALS AND METHODS

To assess the clinical outcomes of advanced, nonfunctioning, well-differentiated panNETs with Ki-67 ≥10% receiving first-line long-acting SSAs in a real-world setting, we carried out a retrospective, multicenter study including patients treated between 2014-2018 across 10 centers of the NET CONNECT Network. The primary endpoints were time to next treatment (TNT) and progression-free survival (PFS), whereas overall survival (OS) and treatment safety were secondary endpoints.

RESULTS

A total of 73 patients were included (68 grade [G]2, 5 G3), with liver metastases in 61 cases (84%). After a median follow-up of 36.4 months (range, 6-173), the median TNT and PFS were 14.2 months (95% confidence interval [CI], 11.6-16.2) and 11.9 months (95% CI, 8.6-14.1) respectively. No statistically significant difference was observed according to the somatostatin analog used (octreotide vs. lanreotide), whereas increased tumor grade (hazard ratio [HR], 4.4; 95% CI, 1.2-16.6; p = .04) and hepatic tumor load (HR, 2; 95% CI, 1-4; p = .03) were independently associated with shortened PFS. The median OS recorded was 86 months (95% CI, 56.8-86 months), with poor outcomes observed when the hepatic tumor burden was >25% (HR, 3.4; 95% CI, 1.2-10; p = .01). Treatment-related adverse events were reported in 14 patients, most frequently diarrhea.

CONCLUSION

SSAs exert antiproliferative activity in panNETs with Ki-67 ≥10%, particularly in G2 tumors, as well as when hepatic tumor load is ≤25%.

IMPLICATIONS FOR PRACTICE

The results of the study call into question the antiproliferative activity of somatostatin analogs (SSAs) in pancreatic neuroendocrine tumors with Ki-67 ≥10%. Patients with grade 2 tumors and with hepatic tumor load ≤25% appear to derive higher benefit from SSAs. Prospective studies are needed to validate these results to optimize tailored therapeutic strategies for this specific patient population.

Synthetic Makaluvamine Analogs Decrease c-Kit Expression and Are Cytotoxic to Neuroendocrine Tumor Cells

In an effort to discover viable systemic chemotherapeutic agents for neuroendocrine tumors (NETs), we screened a small library of 18 drug-like compounds obtained from the Velu lab against pulmonary (H727) and thyroid (MZ-CRC-1 and TT) neuroendocrine tumor-derived cell lines. Two potent lead compounds (DHN-II-84 and DHN-III-14) identified from this screening were found to be analogs of the natural product makaluvamine. We further characterized the antitumor activities of these two compounds using pulmonary (H727), thyroid (MZ-CRC-1) and pancreatic (BON) neuroendocrine tumor cell lines. Flow cytometry showed a dose-dependent increase in apoptosis in all cell lines. Induction of apoptosis with these compounds was also supported by the decrease in myeloid cell leukemia-1 (MCL-1) and X-chromosome linked inhibitor of apoptosis (XIAP) detected by Western blot. Compound treatment decreased NET markers chromogranin A (CgA) and achaete-scute homolog 1 (ASCL1) in a dose-dependent manner. Moreover, the gene expression analysis showed that the compound treatment reduced c-Kit proto-oncogene expression in the NET cell lines. Induction of apoptosis could also have been caused by the inhibition of c-Kit expression, in addition to the known mechanisms such as damage of DNA by topoisomerase II inhibition for this class of compounds. In summary, makaluvamine analogs DHN-II-84 and DHN-III-14 induced apoptosis, decreased neuroendocrine tumor markers, and showed promising antitumor activity in pulmonary, thyroid, and pancreatic NET cell lines, and hold potential to be developed as an effective treatment to combat neuroendocrine tumors.

Treatment Patterns and Survival among Patients with Metastatic Gastroenteropancreatic Neuroendocrine Tumours in Sweden - a Population-based Register-linkage and Medical Chart Review Study

Background: Gastroenteropancreatic neuroendocrine tumours (GEP-NETs) are neoplasms derived from the endocrine system in the gastrointestinal tract and pancreas. Treatment options include surgery; pharmacological treatments like somatostatin analogues (SSA), interferon alpha, molecular targeted therapy and chemotherapy; and peptide receptor radionuclide therapy.

The objective of this study was to describe treatment patterns and survival among patients with metastatic GEP-NET grade 1 or 2 in Sweden.

Methods: Data was obtained via linkage of nationwide registers. Patients diagnosed with metastatic GEP-NET grade 1 or 2 in Sweden between 2005 and 2013 were included (n=811; National population). In addition, medical chart review was performed for the subpopulation diagnosed at Sahlgrenska University Hospital, Gothenburg (n=127; Regional population). Treatment patterns, including treatment sequences, and overall survival were assessed.

Results: Most patients had small intestinal NET (76%). In the regional population, 72% had grade 1 tumours; 50% had functioning tumours. The two most common first-line treatments were surgery (57%) and SSA (25%). After first-line surgery, 46% received SSA, while 40% had no further treatment. After first-line SSA, 52% received surgery, while 27% had no further treatment. Overall median survival time from date of diagnosis was 7.0 years (95% CI 6.2-not reached). Among patients with distant metastases, pancreatic NET (vs. small intestinal NET) was associated with poorer survival (HR 1.9; 95% CI 1.1-3.3), as were liver metastases (HR 3.2; 95% CI 1.5-7.0).

Conclusions: First-line surgery was typically followed by SSA or no further treatment. Among patients with distant metastases, pancreatic NET or liver metastases were associated with a poorer survival.