404P - Real-world analysis on molecular targeted therapy recommendations and attainment rates in cancer gene panel testing for metastatic breast cancer

Background

Comprehensive genomic profiles (CGP) have been covered by insurance in Japan since June 2019. Almost all patients were registered in the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) Registry. We examined the significance of CGP testing using real-world C-CAT data from patients with metastatic breast cancer (mBC).

Methods

A total of 1687 patients with an appropriate treatment history prior to the expert panel were included. This study examined factors that influence the rate of targeted therapy recommendations and their attainment.

Results

Alterations corresponding to ESCAT I-II and OncoKB level 1 recommendations were observed in 1035 (61%) patients. There was a trend towards a higher rate of recommendation in the group that underwent testing in ≥6 regimens (0-2 regimens: 52% (305/584), 3-5 regimens: 63% (394/628), ≥6 regimens: 71% (336/475)). The tissue and liquid panels were equally represented (61% and 61%). Luminal patients with PIK3CA-AKT1-PTEN alteration(s), a candidate for the AKT inhibitor capivasertib, were detected in 51% of cases (426/840). The proportion of patients who achieved the recommended targeted therapy was 7.6% (129/1687). Tissue panels tended to have higher rates of targeted treatment attainment than liquid panels (8.1% vs. 5.8%, p=0.15). Pembrolizumab was the most common (30 cases), followed by mTOR inhibitor (17 cases), and anti-HER2 therapy for non-HER2 subtype (10 cases). After metastatic treatment, there was a trend towards higher attainment rates in the group that underwent testing in 3-5 regimens (0-2 regimens: 3.3% (19/565), 3-5 regimens: 11.1% (70/558), and ≥6 regimens: 8.4% (40/435)).

Conclusions

This study clarified the real-world situation of cancer gene panel testing for mBC in Japan. Many targeted therapies are recommended, and it is important to appropriately utilize them. In addition, with the advent of new molecular targeting agents, the role of cancer gene panel testing in mBC will become increasingly important.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Tohoku University.

Funding

Has not received any funding.

Disclosure

H. Tada: Financial Interests, Personal, Invited Speaker: Chugai Pharma, Daiichi Sankyo, Pfizer, Lilly Japan, AstraZeneca, MSD, Kyowa Kirin International, Novartis, Takeda. M. Miyashita: Financial Interests, Personal, Invited Speaker: Astra Zenec a, Lilly, Pfizer, Chug ai Ph arm a, T aiho Oncology, Eisai, MSD. N.S. Harada: Financial Interests, Personal, Invited Speaker: Lilly, Chug ai Ph arm a, Kyow a Kirin, Astra Zenec a, Nov artis, Pfizer, Takeda, Eisai. A. Ebata: Financial Interests, Personal, Invited Speaker: Kyowa Kirin. M. Sato: Financial Interests, Personal, Invited Speaker: Lilly Japan, Chugai Pharma. T. Ishida: Financial Interests, Personal, Invited Speaker: Pfizer co., Roche co., Lilly. All other authors have declared no conflicts of interest.