BioPATH: A Biomarker Study in Asian Patients with HER2+ Advanced Breast Cancer Treated with Lapatinib and Other Anti-HER2 Therapy
- Author:
Sung Bae KIM
1
;
In Gu DO
;
Janice TSANG
;
Tae You KIM
;
Yoon Sim YAP
;
Gerardo CORNELIO
;
Gyungyub GONG
;
Soonmyung PAIK
;
Suee LEE
;
Ting Ying NG
;
Sarah PARK
;
Ho Suk OH
;
Joanne CHIU
;
Joohyuk SOHN
;
Moonhee LEE
;
Young Jin CHOI
;
Eun Mi LEE
;
Kyong Hwa PARK
;
Christos NATHANIEL
;
Jungsil RO
Author Information
- Publication Type:Original Article
- Keywords: Biomarkers; Breast neoplasms; HER2; Lapatinib; Trastuzumab
- MeSH: Asian Continental Ancestry Group; Biomarkers; Biopsy; Breast Neoplasms; Breast; Diagnosis; Disease-Free Survival; Female; Humans; Neoplasm Metastasis; Prevalence; RNA, Messenger; Trastuzumab
- From:Cancer Research and Treatment 2019;51(4):1527-1539
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: BioPATH is a non-interventional study evaluating the relationship of molecular biomarkers (PTEN deletion/downregulation, PIK3CA mutation, truncated HER2 receptor [p95HER2], and tumor HER2 mRNA levels) to treatment responses in Asian patients with HER2+ advanced breast cancer treated with lapatinib and other HER2-targeted agents. MATERIALS AND METHODS: Female Asian HER2+ breast cancer patients (n=154) who were candidates for lapatinib-based treatment following metastasis and having an available primary tumor biopsy specimen were included. The primary endpoint was progression-free survival (PFS). Secondary endpoints were response rate, overall survival on lapatinib, correlation between biomarker status and PFS for any previous trastuzumab-based treatment, and conversion/conservation rates of the biomarker status between tissue samples collected at primary diagnosis and at recurrence/metastasis. Potential relationships between tumor mRNA levels of HER2 and response to lapatinib-based therapy were also explored. RESULTS: p95HER2, PTEN deletion/downregulation, and PIK3CA mutation did not demonstrate any significant co-occurrence pattern and were not predictive of clinical outcomes on either lapatinib-based treatment or any previous trastuzumab-based therapy in the metastatic setting. Proportions of tumors positive for p95HER2 expression, PIK3CA mutation, and PTEN deletion/down-regulation at primary diagnosis were 32%, 31.2%, and 56.2%, respectively. Despite limited availability of paired samples, biomarker status patterns were conserved in most samples. HER2 mRNA levels were not predictive of PFS on lapatinib. CONCLUSION: The prevalence of p95HER2 expression, PIK3CA mutation, and PTEN deletion/downregulation at primary diagnosis were similar to previous reports. Importantly, no difference was observed in clinical outcome based on the status of these biomarkers, consistent with reports from other studies.
