Comparison of survival with somatostatin analog and chemotherapy and prognostic factors for treatment in 165 advanced neuroendocrine tumor patients with Ki-67 20% or less

Abstract

The objectives of this study were to compare progression-free survival (PFS) with somatostatin analog (SSA) versus chemotherapy (CTx) in first-line therapy and to determine the patient group in which these treatments were more effective in neuroendocrine tumors (NETs) with a Ki-67 index of 20% or less. Patients who received SSA or CTx and had unresectable locally advanced and metastatic NETs with a Ki-67 index of 20% or less were retrospectively selected from 13 centers in the Turkish database between 2000 and 2015. One hundred and sixty-five patients were enrolled. The median age was 56 years and the male-to-female ratio was 1.09. Seventy-four (45%) patients were of grade 1 NET and 91 (55%) were of grade 2. SSA was given to 104 patients, whereas 61 were treated with CTx. The objective response rate after SSA was 15.4%; another 73.1% had stable disease. The objective response rate after CTx was 36.1%, and 40.9% had stable disease (P=0.008). The median PFS in SSA patients was 21 months (95% confidence interval: 12.4-29.6), and 8 months for CTx (95% confidence interval: 5.5-10.6) (P<0.001). There was no significant difference between PFS of receiving SSA and CTx in pancreatic neuroendocrine tumor (PNET) patients; however, the PFS of receiving SSA was longer in non-PNET patients (P<0.001). SSA was better treatment in advanced NET patients with a Ki-67 index of less than 5%, having a primary resected and a performance status of 0 (P<0.05). SSA may be preferred over CTx in advanced NET patients with low-to-intermediate grade.

Predictors of antiproliferative effect of lanreotide autogel in advanced gastroenteropancreatic neuroendocrine neoplasms

“…Other studies that evaluated the median PFS in patients on LAN treatment for the management of GEP or bronchial NETs are summarised in Supplementary File 1 (Table 1a, b) [4,5,[11][12][13][14][15][16][17][18][19][20][21]. The PFS reported in our study is in agreement with other publications [4,5,13,14,16,20,21].…”

Predictive Factors for Resistant Disease with Medical/Radiologic/Liver-Directed Anti-Tumor Treatments in Patients with Advanced Pancreatic Neuroendocrine Neoplasms: Recent Advances and Controversies

“…Like the findings observed with PRRT, poorer performance status [ 172 ], symptomatic tumors [ 173 ] and the prior lack of primary tumor resection [ 172 ] are associated with decreased PFS with SSA treatment ( Table 2 , Right Panel). Two different studies report significant decreases in PFS in patients with baseline (pre-SSA) documentation of disease progression [ 173 , 174 ], suggesting a significant but mild anti-tumor activity of SSAs in patients with panNENs, as well as with GI-NENs.…”

“…Several studies report a worse clinical outcome in patients with elevated baseline levels of CgA [ 172 , 175 ], whereas the decrease in CgA levels after SSA treatment is predictive of an improved PFS [ 176 , 177 ]. A recent post hoc analysis of the Phase 3 CLARINET study demonstrated that 5-HIAA responders had significantly improved PFS with lanreotide treatment ( p = 0.007), while no significant difference in PFS was observed between CgA responders and no-responders.…”

“…An increased tumor grade [ 42 , 172 , 179 , 223 ], presence of a poorly-differentiated tumor [ 175 ] and an increasing Ki-67 index [ 173 ] are reported to correlate with worse outcomes with SSA treatment ( Table 2 , Right Panel). Some studies reported that a Ki-67 threshold of 5% was more predictive of PFS with SSA treatment than the cut-off value proposed by 2010 WHO classification to separate G1 and G2 (i.e., <3%) [ 172 , 224 ].…”

Challenges in treatment of a patient suffering from neuroendocrine tumor G1 of the hilar bile duct: a case report

“…Martyn et al [ 17 ] reported that compared with the placebo group, the SSA group could significantly prolong progression-free survival (PFS) in patients with metastatic enteropancreatic neuroendocrine tumors (Ki-67 < 10%). Ersin et al [ 18 ] found that PFS in the SSA group was 21 months, which was better than the chemotherapy group as their first-line treatment for NET (Ki-67 ≤ 20%). PRRT has become an effective treatment for the NETs which express sufficient SSR.…”