Safety and efficacy of HER2 blockade by trastuzumab-based chemotherapy-containing combination strategies in HER2+ gastroesophageal adenocarcinoma

Since completion of the Trastuzumab for Gastric Cancer study, trastuzumab with doublet chemotherapy (a fluoropyrimidine and a platinum) has been the gold-standard first-line therapy for patients with locally advanced unresectable or metastatic human epidermal growth factor receptor 2-positive (HER2+) gastroesophageal adenocarcinoma (GEA). The safety and efficacy of 23 studies of first-line trastuzumab plus doublet chemotherapy, without checkpoint inhibitors (n = 19) or with checkpoint inhibitors (n = 4), conducted in patients with locally advanced unresectable or metastatic HER2+ GEA, including phase II/III, prospective, and retrospective observational studies, were summarized. In studies without checkpoint inhibitors, the median duration of trastuzumab treatment ranged from 19.5 to 39.0 weeks and from 15.3 to 30.0 weeks for chemotherapy. In studies with checkpoint inhibitors, the median duration of pembrolizumab/trastuzumab/chemotherapy was 30 weeks, and 18 weeks for chemotherapy. In studies without checkpoint inhibitors, treatment-emergent adverse events (TEAEs) of grade ≥3 ranged from 32% to 84%. Serious adverse events (SAEs) ranged from 15% to 39%. Adverse events resulting in discontinuation ranged from 0% to 30%. Treatment-related deaths occurred in 0%-9% of patients. In studies with checkpoint inhibitors, TEAEs of grade ≥3 were 57%. SAEs ranged from 31% to 38%. Adverse events resulting in discontinuation ranged from 5% to 24%. Treatment-related deaths occurred in 0%-3% of patients. In studies without checkpoint inhibitors, objective response rate (ORR) ranged from 39% to 82%, median progression-free survival (PFS) from 5.7 to 11.6 months, and median overall survival (OS) from 11.2 to 27.6 months. In studies with checkpoint inhibitors, ORR ranged from 39% to 86%, median PFS from 8.0 to 13.0 months, and median OS from 19.3 to 27.3 months. This review provides a historical benchmark on safety and efficacy of available first-line chemotherapy-based standard of care for patients with locally advanced unresectable or metastatic HER2+ GEA.

Efficacy of trastuzumab and potential risk factors on survival in patients with HER2-positive metastatic gastric cancer

Aim: To evaluate the efficacy of trastuzumab and potential risk factors on survival in patients with HER2-positive metastatic gastric cancer. Methods: We retrospectively included 138 patients who were given trastuzumab-based chemotherapy as first-line treatment and analyzed the relationship between clinical response rates and maintenance treatment status and survival outcomes. Results: In the whole group, the median progression-free survival and overall survival were 10.2 and 16 months, respectively. Clinical response was obtained in 79% of patients. The median overall survival was 16.9 months in follow-up group and 19.0 months in the maintenance group in patients with clinical response. Continuation of maintenance trastuzumab created a significant survival advantage (p = 0.021). Eastern Cooperative Oncology Group performance status 2 (hazard ratio [HR]: 2.02), grade 3 (HR: 1.78) and more than four metastatic lesions (HR: 1.67) were determined as risk factors for death. Conclusion: We recommend the continuation of maintenance trastuzumab in patients with clinical response, but those with identified risk factors may not benefit from treatment because life expectancy may be low.

Review of Survival, Safety, and Clinical Outcomes in HER2+ Metastatic Gastric Cancer Following the Administration of Trastuzumab

BACKGROUND

Therapies targeting human epidermal growth factor receptor 2 (HER2) have become a focus for improving treatment outcomes in patients with gastric cancer. This literature review sought to assesses clinical outcomes, including safety, survival, and treatment outcomes, of patients who received trastuzumab for the treatment of HER2+ metastatic gastric cancer.

METHODS

Searches were conducted in PubMed and Embase to identify observational research studies investigating the clinical outcomes of trastuzumab and combination therapies for the treatment of HER2+ metastatic gastric cancer, published January 1, 2014-August 22, 2019. Article screening was a two-phase process, and the results of each screening level were documented in accordance with PRISMA.

RESULTS

Twenty articles met the selection criteria for data extraction. Studies focused on treatment patterns or survival, safety, and clinical outcomes, as well as the natural history of disease. In the combined HER2+ patient populations included in this review, tumors were located in the stomach (33.7%), gastroesophageal junction (GEJ, 14.2%), unspecific GEJ or stomach (50.3%), or esophagus (1.9%). Studies observed increases in both overall survival and progression-free survival with the use of trastuzumab-based chemotherapy compared with chemotherapy treatment alone. Additionally, trastuzumab-based chemotherapy appeared to improve survival and clinical outcomes regardless of the presence of multi-organ metastases or tumor location.

CONCLUSIONS

Trastuzumab-treated patients have longer survival times than those not treated with trastuzumab and tolerate treatment well, with few serious adverse events. New treatments for second- and subsequent-line therapies would increase regimen options.

MINI-ABSTRACT

The treatment patterns and clinical outcomes observed in this literature review suggest patients treated with trastuzumab have longer survival times compared with chemotherapy treatment alone and tolerate treatment.

Contrast-Enhanced CT Parameters of Gastric Adenocarcinoma: Can Radiomic Features Be Surrogate Biomarkers for HER2 Over-Expression Status?

Objective

The aim of this study was to determine the role of contrast-enhanced computed tomography (CE-CT) parameters in predicting the expression status of HER2 in gastric adenocarcinoma (GAC) patients before radical gastrectomy.

Materials and Methods

A total of 460 GAC patients who underwent non-contrast CT (NC-CT) and CE-CT examinations before radical resection were enrolled in this retrospective study. The radiologists reviewed their CT scans and recorded parameters, including CT attenuate value (CAV) and corrected CAV (cCAV). The pathologist identified the postoperative HER2 expression status, and HER2 expression status was evaluated by immunohistochemical staining (IHC). The association between CE-CT parameters and HER2 expression status was analyzed.

Results

Among the 460 patients, 84 patients had HER2 over-expression status, at a prevalence of 18.3%. The CAVs were significantly different between the 2 different HER2 expression groups in the non-contrast and arterial phases (non-contrast phase: p = 0.005; arterial phase: p < 0.001). Besides, there was a significant difference in the cCAVs between the 2 groups in the arterial phase (arterial phase: p = 0.003). Univariate and multivariate logistic regression analyses identified that the maximum diameter of tumor, differentiation degree, CAV in non-contrast, arterial, and portal phases, and cCAV in the arterial phase were predictive factors of HER2 expression status.

Conclusion

Our analyses showed that the CE-CT parameters were significantly different between different HER2 expression groups. CE-CT parameters could serve as simple, objective predictive factors of HER2 expression status of GAC patients.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the management of patients with metastatic oesophageal cancer: a JSMO-ESMO initiative endorsed by CSCO, KSMO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of oesophageal cancer was published in 2016, and covered the management and treatment of local/locoregional disease, limited disease, locally advanced disease and the management of advanced/metastatic disease. At the ESMO Asia Meeting in November 2017 it was decided by both ESMO and the Japanese Society of Medical Oncology (JSMO) to convene a special guidelines meeting immediately after the JSMO Annual Meeting in 2018. The aim was to adapt the ESMO 2016 guidelines to take into account the ethnic differences associated with the treatment of metastatic oesophageal cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with metastatic oesophageal cancer representing the oncological societies of Japan (JSMO), China (CSCO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence, and was independent of both the current treatment practices and the drug availability and reimbursement situations in the individual participating Asian countries.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the management of patients with metastatic gastric cancer: a JSMO-ESMO initiative endorsed by CSCO, KSMO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of gastric cancer (GC) was published in 2016, and covered the management and treatment of local, locoregional, locally advanced and metastatic disease. At the ESMO Asia Meeting in November 2017 it was decided by both ESMO and The Japanese Society of Medical Oncology (JSMO) to convene a special guidelines meeting immediately after the JSMO Annual Meeting in 2018. The aim was to adapt the ESMO 2016 guidelines to take into account the ethnic differences associated with the treatment of metastatic GC in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with metastatic GC representing the oncological societies of Japan (JSMO), China (CSCO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of both the current treatment practices and the drug availability and reimbursement situations in the individual participating Asian countries.