Detailed Abstract
[Oral Presentation 1 - Biliary & Pancreas (Biliary Disease/Surgery)]
[OP 1-7] Prognostic significance of HER2 expression in advanced gallbladder cancer
Seung Eun LEE*1 , Hee-Sung KIM2 , Yoo Shin CHOI1 , Sun-Whe KIM1 , Hee-Joo SON1 , Jin-Seok HUH3 , In-Woong HAN3 , Kee-Taek JANG4 , Keun- Soo AHN5 , Hyung-Il SEO6
1 Department Of Surgery, Chung-Ang University College Of Medicine, REPUBLIC OF KOREA
2 Department Of Pathology, Chung-Ang University College Of Medicine, REPUBLIC OF KOREA
3 Department Of Surgery, Sungkyunkwan University College Of Medicine, REPUBLIC OF KOREA
4 Department Of Pathology, Sungkyunkwan University College Of Medicine, REPUBLIC OF KOREA
5 Department Of Surgery, Keimyung University College Of Medicine, REPUBLIC OF KOREA
6 Department Of Surgery, Pusan National University College Of Medicine, REPUBLIC OF KOREA
Background : Gallbladder carcinoma (GBC) is an aggressive malignancy with high mortality and poor prognosis and new targeted therapeutic options are needed. The aim of this study is to evaluate the clinicopahological significance of human epidermal growth factor receptor 2 (HER2) overexpression and amplification in advanced GBC and to provide evidence for targeted therapy in the future.
Methods : Tissue microarrays were constructed with 137 advanced GBC cases who underwent surgery and were pathologically confirmed as T3 or T4 between 2010 and 2017. Immunohistochemistry (IHC) and silver-enhanced in situ hybridization (SISH) for HER2 were performed using scoring criteria for gastric cancer. Only cases with an IHC score of 3+ or an IHC score of 2+ and proven gene amplification (HER2/CEN17 ratio ≥ 2.0) were considered HER2 positive.
Results : IHC for HER2 was negative (0 & +1) in 83.0% (122/137), equivocal (+2) in 8.2% (12/137) and positive (+3) in 8.8% (13/137) of cases. HER2 gene amplification by SISH was observed in 40.9% (56/137) of cases, 28.9% (22/76), 50.0% (18/36), 33.3% (4/12), and 92.3% (12/13) of IHC 0, 1+, 2+, and 3+, respectively and HER2 positive was observed in 11.7% (16/137) of cases. The overall survival rates of the patients with HER2 gene amplification and adjuvant chemotherapy were significantly worse than the patients without HER2 gene amplification (29.9 vs. 44.6, p=0.027) and adjuvant chemotherapy (17.5 vs. 41.8, p=0.004).
Conclusions : Although there was no significant independent prognostic factor in multivariate analysis, HER2 gene amplification showed the possibility as a prognostic factor in advanced GBC. Prospective standardized HER2 testing and randomized control studies are needed to prove clinical efficacy of targeted HER2 inhibition in advanced GBC.
Methods : Tissue microarrays were constructed with 137 advanced GBC cases who underwent surgery and were pathologically confirmed as T3 or T4 between 2010 and 2017. Immunohistochemistry (IHC) and silver-enhanced in situ hybridization (SISH) for HER2 were performed using scoring criteria for gastric cancer. Only cases with an IHC score of 3+ or an IHC score of 2+ and proven gene amplification (HER2/CEN17 ratio ≥ 2.0) were considered HER2 positive.
Results : IHC for HER2 was negative (0 & +1) in 83.0% (122/137), equivocal (+2) in 8.2% (12/137) and positive (+3) in 8.8% (13/137) of cases. HER2 gene amplification by SISH was observed in 40.9% (56/137) of cases, 28.9% (22/76), 50.0% (18/36), 33.3% (4/12), and 92.3% (12/13) of IHC 0, 1+, 2+, and 3+, respectively and HER2 positive was observed in 11.7% (16/137) of cases. The overall survival rates of the patients with HER2 gene amplification and adjuvant chemotherapy were significantly worse than the patients without HER2 gene amplification (29.9 vs. 44.6, p=0.027) and adjuvant chemotherapy (17.5 vs. 41.8, p=0.004).
Conclusions : Although there was no significant independent prognostic factor in multivariate analysis, HER2 gene amplification showed the possibility as a prognostic factor in advanced GBC. Prospective standardized HER2 testing and randomized control studies are needed to prove clinical efficacy of targeted HER2 inhibition in advanced GBC.
SESSION
Oral Presentation 1
Room A 3/23/2023 1:50 PM - 2:50 PM