A Retrospective Analysis for Patients with HER2-Positive Gastric Cancer Who Were Treated with Trastuzumab-Based Chemotherapy: In the Perspectives of Ethnicity and Histology.
While the Trastuzumab for Gastric Cancer (ToGA) trial demonstrated the efficacy and safety of trastuzumab-based chemotherapy in HER2-positive metastatic gastric cancer, the overall survival (OS) benefit was not found in Asian and diffuse-type cancer patients. The aim of the study is to investigate predictive markers for trastuzumab-based chemotherapy.



Data of patients with HER2-positive gastric cancer treated with trastuzumab-based chemotherapy were analyzed retrospectively.



A total of 168 Asian patients were included. The median age was 60 years (range, 27 to 85 years) and the male:female ratio was 118 (70.2%):50 (29.8%). Fourteen (8.3%), 63 (37.5%), 75 (44.6%), and 11 (6.5%) patients had well, moderately, poorly-differentiated tubular adenocarcinoma and signet ring cell carcinoma, respectively. With 14 complete responses and 73 partial responses, the response rate was 50.6%. The median progression-free survival (PFS) was 10.2 months (95% confidence interval [CI], 8.7 to 11.7), and the median OS was 18.5 months (95% CI, 16.4 to 50.6). Next, we investigated the effect of poorly-differentiated histology (PDH, poorly-differentiated tubular adenocarcinoma+signet ring cell carcinoma) on clinical outcomes. The median PFS (8.9 months vs. 11.5 months, p=0.16) was slightly inferior in PDH patients, and the median OS was significantly shorter in PDH patients (14.6 months vs. 19.0 months, p=0.025).



While subset analysis of the ToGA trial demonstrated that trastuzumab-based chemotherapy may not be beneficial for Asians and patients with PDH, our data may suggest that even in Asian patients and patients with PDH, trastuzumab-based chemotherapy could be associated with improved clinical outcomes in patients with HER2-positive gastric cancer.
Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul, Korea.
Jun Ho
JH
Yi
Division of Hematology-Oncology, Department of Internal Medicine, Gyeongsang National University School of Medicine, Jinju, Korea.
Jung Hun
JH
Kang
Division of Hematology/Oncology, Department of Internal Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
In Gyu
IG
Hwang
Division of Hematology/Oncology, Department of Internal Medicine, Gachon University Gil Hospital, Incheon, Korea.
Hee Kyung
HK
Ahn
Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
Hyun Jin
HJ
Baek
Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
Soon Il
SI
Lee
Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
Do Hyoung
DH
Lim
Division of Hematology and Oncology, Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.
Young-Woong
YW
Won
Division of Hematology and Oncology, Department of Medicine, Samsung Changwon Hospital, Sungkyunkwan University, Changwon, Korea.
Jun Ho
JH
Ji
Division of Oncology, Department of Medicine, Yonsei University, Severance Hospital, Seoul, Korea.
Hyo Song
HS
Kim
Division of Oncology, Department of Medicine, Yonsei University, Severance Hospital, Seoul, Korea.
Sun Young
SY
Rha
Department of Internal Medicine, Dong-A University College of Medicine, Busan, Korea.
Sung Yong
SY
Oh
Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
Kyung Eun
KE
Lee
Division of Hematology-Oncology, Department of Internal Medicine, VHS Medical Center, Seoul, Korea.
Taekyu
T
Lim
Division of Hematology-Oncology, Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Korea.
Chi Hoon
CH
Maeng
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Moon Jin
MJ
Kim
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Seung Tae
ST
Kim
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Jeeyun
J
Lee
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Joon Oh
JO
Park
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Young Suk
YS
Park
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Ho Yeong
HY
Lim
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Won Ki
WK
Kang
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Se Hoon
SH
Park
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000074322:Antineoplastic Agents, Immunological / Q000627:therapeutic use; D044466:Asian People; D005260:Female; D006653:Histology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000208:ethnology* / Q000378:metabolism / Q000473:pathology; D000068878:Trastuzumab / Q000627:therapeutic use*
D000074322:Antineoplastic Agents, Immunological; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab
ErbB-2 receptor; Ethnic groups; Histology; Stomach neoplasms; Trastuzumab