Endocrine Abstracts

Background: Somatostatin receptor (SSTR) expression has been characterized in well-differentiated neuroendocrine tumors (NET). However, the understanding of receptor expression in various non-neuroendocrine solid tumors is limited. This study was performed to evaluate SSTR-2 in various cancers to provide a rational basis for SSTR-2 targeted anti-cancer therapies.Methods: Formalin-fixed paraffin, paraffin-embedded tissue was obtained from pathology archiv...

Background: Peptide receptor radionuclide therapy (PRRT) with Lutetium-177 DOTATATE (LUTATHERA) is an effective treatment option for somatostatin receptor (SSTR) positive metastatic gastroenteropancreatic neuroendocrine tumors (NETs) and has also demonstrated antitumor activity in SSTR positive NETs from other primary sites. While the median progression free survival (mPFS) is around 29 months, there is a subset of patients who are refractory to PRRT and demonstrate progressio...

Background: Chromogranin A (CGA) and 5-HIAA are meaningful biomarkers in managing neuroendocrine tumors (NETs). CGA, though nonspecific, can reflect disease bulk and typically decreases after debulking surgery. 5-HIAA is specific to NETs though its measurement may require a special diet, a 24-hour urine collection, or specialized blood collection tubes; but usually decreases after debulking procedures. Serotonin, though useful in diagnosing NETs, is not followed as a biomarker...

Background: Immune checkpoint inhibitor (ICI) maintenance therapy is the standard of care for frontline management of extensive-stage small cell lung cancer (ES SCLC). However, the overall survival benefit of the addition of ICI maintenance to frontline ES SCLC treatment is modest and further improvement is needed. We hypothesized that the addition of poly (ADP-ribose) polymerase inhibition to ICI maintenance therapy for patients with platinum-sensitive ES SCLC could improve t...

Background: Telotristat etiprate (TE), an oral tryptophan hydroxylase inhibitor, is intended to treat carcinoid syndrome (CS) by reducing serotonin production. TE was evaluated in TELESTAR, a phase 3 study; the primary endpoint showed significant reductions in bowel movement (BM) frequency for 2 TE dosages + standard of care (SOC) vs. SOC. TELESTAR patients had CS inadequately controlled on somatostatin analog therapy with ≥4 BMs per day. They were interviewed about base...

Background: Radiation is a potent inducer of DNA double-strand breaks, and ribonucleotide reductase (RNR) is the rate-limiting enzyme in the synthesis and repair of DNA, making RNR-targeted therapy a rationale therapeutic strategy for radiosensitization. ETCTN 10388 (NCT04234568) evaluated safety and efficacy of the combination of lutetium 177 DOTATATE, a beta-emitting radionuclide in combination with triapine, a ribonucleotide reductase (RNR) inhibitor. <p class="abstext"...

Background: Radiolabeled somatostatin analogs provide a means of delivering targeted radiation with a high therapeutic index to NETs that express somatostatin receptors (SSTRs). We hypothesize that the addition of an effective radiation sensitizer could help improve the antitumor activity of Lutathera. Radiation is a potent inducer of DNA damage. The primary repair mechanism of radiation-induced double-stranded breaks (DSBs) is the nonhomologous end-joining (NHEJ) pathway, in ...