Alice Durand

PURPOSE: Alkylating agents (ALKY) are the main chemotherapies used for advanced neuroendocrine tumors (NETs). O ⁶ -Methylguanine-DNA methyltransferase (MGMT) status, as proficient (p) or deficient (d), may predict the response to ALKY. PATIENTS AND METHODS: MGMT-NET (ClinicalTrials.gov identifier: NCT03217097 ) was a phase II trial randomly assigning 1:1 for pMGMT or 2:1 for dMGMT-NETs to either ALKY or oxaliplatin (Ox). Inclusion criteria were a confirmed advanced pancreatic, thoracic, or unknown primary NETs with an indication for chemotherapy and tissue available. The primary aim was to detect a difference of 35% between the 3-month objective response rate (ORR) in pMGMT-NETs versus in dMGMT-NETs when treated with ALKY. A biomarker-stratified design was performed to compare ALKY and Ox in the dMGMT and pMGMT strata for the secondary end points. dMGMT was defined using pyrosequencing (PSQ; methylated MGMT ≥9%) and using immunochemistry ( H -score of MGMT P = .172. However, best ORR (18 [52.9%] v 3 [11.5%]) and median progression-free survival (14.6 [95% CI, 7.2 to 22.1] v 11.3 [9.4 to 13.2] months) were higher for dMGMT-NETs versus pMGMT-NETs. MGMT status does not seem to affect the Ox efficacy. CONCLUSION: Despite the fact that the primary end point was not reached, ALKY has clinical activity in patients with dMGMT-NETs.

Extra-pulmonary neuroendocrine carcinomas (EP-NECs) are lethal cancers with limited treatment options. Identification of contributing factors to the observed heterogeneity of clinical outcomes within the EP-NEC family is warranted, to enable identification of effective treatments. A multicentre retrospective study investigated potential differences in “real-world” treatment/survival outcomes between small-cell (SC) versus (vs.) non-SC EP-NECs. One-hundred and seventy patients were included: 77 (45.3%) had SC EP-NECs and 93 (54.7%) had non-SC EP-NECs. Compared to the SC subgroup, the non-SC subgroup had the following features: (1) a lower mean Ki-67 index (69.3% vs. 78.7%; p = 0.002); (2) a lower proportion of cases with a Ki-67 index of ≥55% (73.9% vs. 88.7%; p = 0.025); (3) reduced sensitivity to first-line platinum/etoposide (objective response rate: 31.6% vs. 55.1%, p = 0.015; and disease control rate; 59.7% vs. 79.6%, p = 0.027); (4) worse progression-free survival (PFS) (adjusted-HR = 1.615, p = 0.016) and overall survival (OS) (adjusted-HR = 1.640, p = 0.015) in the advanced setting. Within the advanced EP-NEC cohort, subgroups according to morphological subtype and Ki-67 index (p = 0.021) and OS (adjusted-p = 0.051), with the non-SC subgroup with a Ki-67 index of <55% and non-SC subgroup with a Ki-67 index of ≥55% showing the best and worst outcomes, respectively. To conclude, the morphological subtype of EP-NEC provides complementary information to the Ki-67 index and may aid identification of patients who could benefit from alternative first-line treatment strategies to platinum/etoposide.