• Is the Morphological Subtype of Extra-Pulmonary Neuroendocrine Carcinoma Clinically Relevant?

      Frizziero, Melissa; email: melissa.frizziero@cruk.manchester.ac.uk; Durand, Alice; orcid: 0000-0002-0193-9058; email: alice.durand@chu-lyon.fr; Taboada, Rodrigo G.; orcid: 0000-0001-5674-2669; email: gomes.taboada@gmail.com; Zaninotto, Elisa; email: elisa.zaninotto@gmail.com; Luchini, Claudio; orcid: 0000-0003-4901-4908; email: claudio.luchini@univr.it; Chakrabarty, Bipasha; email: bipasha.chakrabarty@nhs.net; Hervieu, Valérie; email: valerie.hervieu@chu-lyon.fr; Claro, Laura C. L.; email: laura.claro@accamargo.org.br; Zhou, Cong; orcid: 0000-0002-6938-4685; email: cong.zhou@cruk.manchester.ac.uk; Cingarlini, Sara; email: cingarlini@icloud.com; et al. (MDPI, 2021-08-18)
      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 (55% vs. ≥55%) had significantly different PFS (adjusted-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.