Cell Cycle Protein Expression in Neuroendocrine Tumors: Association of CDK4/CDK6, CCND1, and Phosphorylated Retinoblastoma Protein With Proliferative Index.

OBJECTIVES: Dysregulation of the cell cycle has been observed and implicated as an etiologic factor in a range of human malignancies, but remains relatively unstudied in neuroendocrine tumors (NETs). We evaluated expression of key proteins involved in cell cycle regulation in a large cohort of NETs. METHODS: We evaluated immunohistochemical expression of CDKN1B, CDKN1A, CDKN2A, CDK2, CDK4, CDK6, cyclin D1, cyclin E1, and phosphorylated retinoblastoma protein (phospho-RB1) in a cohort of 267 patients with NETs. We then explored associations between cell cycle protein expression, mutational status, histologic features, and overall survival. RESULTS: We found that high expression of CDK4, CDK6, CCND1, and phospho-RB1 was associated with higher proliferative index, as defined by MKI67. We additionally observed a trend toward shorter overall survival associated with low expression of CDKN1B. This association seemed strongest in SINETs (multivariate hazards ratio, 2.04; 95% confidence interval, 1.06-3.93; P = 0.03). We found no clear association between CDKN1B mutation and protein expression. CONCLUSIONS: Our results suggest that dysregulation and activation of the CDK4/CDK6-CCND1-phospho-RB1 axis is associated with higher proliferative index in NETs. Investigation of the therapeutic potential of CDK4/CDK6 inhibitors in higher grade NETs is warranted.

Retrospective review of serotonergic medication tolerability in patients with neuroendocrine tumors with biochemically proven carcinoid syndrome.

BACKGROUND: Patients with carcinoid tumors frequently could benefit from the pharmacologic treatment of depression and anxiety. However, many prescribers avoid serotonergic medications due to the theoretical risk of exacerbating carcinoid syndrome. METHODS: The authors conducted a retrospective chart review of patients with carcinoid tumors and elevated serotonin levels (as measured by 24-hour urine 5-hydroxyindoleacetic acid [5-HIAA]) at Dana-Farber/Brigham and Women's Cancer Center who initiated treatment with serotonergic antidepressants after a carcinoid diagnosis from 2003 to 2016. Each medication regimen was categorized based on the presence of adverse interactions as defined by clinical worsening of symptoms of carcinoid syndrome in the absence of progressive disease that temporally correlated with a serotonergic medication trial. RESULTS: A total of 73 serotonergic regimens received by 52 patients were included in the primary analysis. Among these medication trials, 8.2% of the regimens (6 regimens) were categorized as being associated with a likely adverse interaction, 61.6% of the regimens (45 regimens) were categorized as having no adverse reaction, 9.6% of the regimens (7 regimens) were categorized as an unlikely adverse reaction, and 20.6% of the regimens (15 regimens) were categorized as unknown. It is interesting to note that none of the 73 trials resulted in a carcinoid crisis requiring emergency care or hospitalization. Only 3 patients discontinued serotonergic medications due to worsening carcinoid syndrome. CONCLUSIONS: Serotonergic medications appear to be a safe option for the treatment of depressive and anxiety symptoms in the majority of patients with neuroendocrine tumors and carcinoid syndrome. In the current study, <10% of patients developed a combination of flushing, diarrhea, and bloating after the initiation of serotonergic medications. Clinicians can begin with low doses, monitor these symptoms, and reduce the dose or discontinue the medication if necessary. Cancer 2017;123:2735-42. © 2017 American Cancer Society.

Management of Neuroendocrine Tumor Liver Metastases: Long-Term Outcomes and Prognostic Factors from a Large Prospective Database.

BACKGROUND: Liver-directed therapies have been used to treat neuroendocrine liver metastases (NELM) for both symptomatic improvement and tumor growth control. We reviewed our experience with NELM to investigate the outcomes of available treatment modalities and to identify prognostic factors for survival. METHODS: We identified all patients with NELM, who were managed at our institution, from a prospectively collected institutional database. Overall survival (OS) was determined for each treatment modality. RESULTS: Between 2003 and 2010, we identified 939 patients with neuroendocrine tumors, of whom 649 patients had NELM. The primary tumor site was the small intestine in 245 patients (38%) and pancreas in 194 patients (30%). With a median follow-up of 44 months, the median, 5 and 10 year OS for each treatment group was as follows: hepatic resection (n = 58, 9%), 160 months, 90%, 70%; radiofrequency ablation (n = 28, 4%), 123 months, 84%, 55%; chemoembolization (n = 130, 20%), 66 months, 55%, 28%; systemic therapy (n = 316, 49%), 70 months, 58%, 31%; and observation (n = 117, 18%), 38 months, 38%, 20%. Age [hazard ratio (HR) 1.0, p < 0.001), small bowel primary site (HR 0.5, p < 0.001), hepatic resection (HR 0.3, p = 0.001), well-differentiated tumors (HR 0.3, p < 0.001), alkaline phosphatase within normal limit (WNL) (HR 0.4, p < 0.001), and chromogranin A WNL (HR 0.5, p < 0.001) were significant independent prognosticators for OS. CONCLUSIONS: This series represents one of the largest single-institution studies of NELM reported. We found that hepatic resection was associated with highly favorable OS. Our observations support hepatic resection in appropriately selected patients.