Abstract Library

#4289 Temozolomide-associated hypermutation and response to immunotherapy in advanced pulmonary neuroendocrine tumours

Introduction: Temozolomide (TMZ) cytotoxicity depends on an intact DNA mismatch repair (MMR) pathway and low levels of O6-methylguanine DNA methyltransferase (MGMT). However, absence of MGMT-mediated repair coupled with defective MMR (dMMR) may lead to enrichment of C:G to A:T transitions throughout the genome, a marked increase in tumour mutational burden (TMB), and loss of TMZ-induced cytotoxicity. This resistance mechanism is called TMZ-associated hypermutation (TAH). Theoretically, this effect could lead to sensitivity to checkpoint inhibitor immunotherapy.

Conference:

Presenting Author: Buikhuisen W

Authors: Buikhuisen W, Badrising S, Moonen L, Derks J, Monkhorst K,

Keywords: Pulmonary NET, whole genome sequencing, temozolomide signature, immunotherapy,

#4177 Performance of a prognostic OTP, CD44, Ki-67 biomarker panel on paired biopsies and resections of lung carcinoids

Introduction: Previously OTP, CD44 and ki-67 have been identified as prognostic biomarkers for lung carcinoid (LC).

Conference:

Presenting Author: van Weert T

Authors: van Weert T, Moonen L, Hillen L, von der Thüsen J, Lap L,

Keywords: OTP, CD44, Ki-67, lung carcinoid, relapse prediction,

#4175 Immunohistochemical profiling of lung carcinoid subtypes and marker comparison of matched primary and metastatic tumors

Introduction: Multi-omic studies have identified three lung carcinoid (LC) subtypes (A1, A2, B) with unique gene expression for OTP, ASCL1 & HNF1a.

Conference:

Presenting Author: Leunissen D

Authors: Leunissen D, Moonen L, von der Thüsen J, den Bakker M, Hillen L,

Keywords: lung carcinoid, TTF1, S100, metastatic disease,

#3889 Patterns of recurrence in patients with resected pulmonary carcinoid – A Dutch nationwide study

Introduction: In patients (pts) with resected pulmonary carcinoids (PC), recurrence of disease may occur up to 10 years after surgery, but the exact incidence remains unknown.

Conference:

Presenting Author: Moonen L

Authors: Moonen L, Derks J, Hillen L, den Bakker M, von der Thüsen J,

Keywords: Pulmonary carcinoid, recurrence, surgery, screening, nationwide registry,

#3867 Radiological follow-up (FU) in resected pulmonary typical carcinoids (pTC) – Do the benefits outweigh the risks?

Introduction: Primary resection is treatment of choice of pulmonary carcinoids (PC) and recurrences occur ~7% of TC and ~35% of atypical carcinoid (AC). Because of a risk of late recurrence, even in TC, long-term radiological FU is generally advised. As PC are frequent in relatively young pts, there is a risk of late radiation-induced cancer.

Conference:

Presenting Author: Heijboer F

Authors: Heijboer F, Mulders T, van Straten M, Moonen L, Speel E,

Keywords: pulmonary carcinoid, typical carcinoid, atypical carcinoid, primary resection, follow-up, ct scan,