Abstract 4842
Background
The incidence of pancreatic cancer (PAC) has continued to rise in recent years. PAC can be divided into head of PAC (HPAC) and body/tail of PAC (BTPAC) by the anatomical location. The patients (pts) with BTPAC are usually diagnosed at relatively advanced stage and had worse survival than those with HPAC. The comparative molecular signatures between different locations in Chinese PAC pts remain unclear.
Methods
154 tumor specimens (HPAC, N = 85; BTPAC, N = 69) and matched normal blood samples of Chinese PAC pts were detected and analyzed in a CAP&CLIA certified laboratory (OrigiMed company) with Yuansu panel including 450 genes. Total 100 males (65%) and 54 females (35%) with a mean age of 61 years old (yrs) were enrolled. We measured the somatic variations and calculated tumor mutational burden (TMB) after filtering known driver mutations (muts). Meanwhile, germline muts were analyzed among the tumor susceptibility genes. Fisher tests were used for comparative analyses.
Results
The median age in HPAC and BTPAC was 60 yrs and 62 yrs. Pts with stage 3&4 accounted for 40% and 60% in HPAC and BTPAC (P<0.05). Genomic alterations of KRAS and SMAD4 were significantly more prevalent in BTPAC (KRAS in BTPAC vs. HPAC= 97% vs. 82%, P=0.004; SMAD4 in BTPAC vs. HPAC= 42% vs. 21%, P=0.008). 2 NTRK3 fusions (3%) were found in BTPAC but 0 in HPAC. Additionally, muts frequency in Wnt pathway was 57% in BTPAC, whereas 37% in HPAC (P=0.02). No significant difference was found in TP53 (83% vs. 81%), CDKN2A (32% vs. 27%) and germline muts frequency (12% vs. 14%) between BTPAC and HPAC, nor in the mean TMB value (3.22 muts/Mb vs. 3.59 muts/Mb). For HPAC, there were more muts in HR pathway genes (24% vs. 19%), although the difference was not statistical significance. 2 BRCA2 germline muts were found in HPAC but neither BRCA1 nor BRCA2 was found in BTPAC.
Conclusions
Genomic pattern did not show apparent difference between the anatomic locations of PAC. However, we found more driver muts in KRAS and SMAD4 and more Wnt pathway muts related to proliferation and metastasis in BTPAC. Further research should be done to better understand the cancer biology among the locations and identify more therapy targets for precision medicine.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5203 - Novel fusion genes identified from matched primary and recurred breast cancers by RNA-sequencing
Presenter: Soojeong Choi
Session: Poster Display session 2
Resources:
Abstract
5873 - Association between PIK3CA mutation status and development of brain metastases in HR+/HER2- metastatic breast cancer
Presenter: Donna Fitzgerald
Session: Poster Display session 2
Resources:
Abstract
3588 - The role of AXL as mechanism of resistance to trastuzumab and a prognostic factor in breast cancer HER2 positive: a translational approach.
Presenter: Anna Adam-Artigues
Session: Poster Display session 2
Resources:
Abstract
5640 - Untargeted assessment of tumor fractions in plasma for monitoring and prognostication from metastatic breast cancer patients undergoing systemic treatment
Presenter: Marija Balic
Session: Poster Display session 2
Resources:
Abstract
2616 - Clinical application of mutational analysis in breast cancer patients: the relevance of PIK3CA analysis for precision medicine.
Presenter: Juan Miguel Cejalvo
Session: Poster Display session 2
Resources:
Abstract
3870 - A retrospective gene expression analysis of surgically-removed Breast Cancer Brain Metastasis (BCBM)
Presenter: Meritxell Mallafré-Larrosa
Session: Poster Display session 2
Resources:
Abstract
1240 - Endocrine therapy alone versus targeted combination strategy as first line treatment in elderly patients with hormone receptor-positive advanced breast cancer: meta-analysis of Phase II and III randomized clinical trials
Presenter: Claudia Omarini
Session: Poster Display session 2
Resources:
Abstract
5535 - Alpelisib (ALP) + fulvestrant (FUL) for patients with hormone receptor–positive (HR+), HER2− advanced breast cancer (ABC): management and time course of key adverse events of special interest (AESIs) in SOLAR-1
Presenter: Hope Rugo
Session: Poster Display session 2
Resources:
Abstract
3093 - Changes in Hormone-Receptor status in Luminal breast cancers between primary tumor and metastases: results of the observational cohort GIM-13 AMBRA Study
Presenter: Marina Cazzaniga
Session: Poster Display session 2
Resources:
Abstract
1378 - MONARCH 3: Updated time to chemotherapy and disease progression following abemaciclib plus aromatase inhibitor (AI) in HR+, HER2- advanced breast cancer (ABC)
Presenter: Miguel Martín
Session: Poster Display session 2
Resources:
Abstract