Treatment Algorithm for Patients With Gastric Adenocarcinoma: An Austrian Consensus on Systemic Therapy

Significant effect of posterior line treatment of HER2 positive advanced gastric cancer: A case report

At present, there are few options for third line and above treatment of advanced gastric cancer and the single drug effect is poor. HER2 positive gastric cancer is an important subtype of gastric cancer and has certain immune characteristics. The combination of HER2 inhibitor and PD-1 inhibitor has a synergistic effect, and anti-tumor drugs targeting HER2 can play an anti-angiogenesis role by downregulating VEGF. We report a patient with HER2-positive gastric cancer who developed post-operative tumor recurrence and metastasis after adjuvant chemotherapy and radiotherapy. Trastuzumab combined with albumin paclitaxel was used as second-line treatment with progression-free survival for 9 months. In third line treatment, we retained trastuzumab and combined it with camrelizumab and apatinib. During the treatment period, although the patient stopped taking the drugs due to the side effects of camrelizumab and apatinib, he achieved a PFS of 10.4 months. Considering the good effect of the third line treatment, we added another PD-1 inhibitor and continued to combine trastuzumab treatment. We found that the patient still benefited from the treatment and continued to survive for another 4 months. At present, the patient is treated with DisitamabVedotin (HER2-ADC) combined with PD-1 inhibitor, and no overall survival outcome has been observed.

Checkpoint inhibitors in metastatic gastric and GEJ cancer: a multi-institutional retrospective analysis of real-world data in a Western cohort

Background

Safety and efficacy of immune checkpoint inhibitors in advanced gastric or gastroesophageal junction (GEJ) cancer could be demonstrated in predominantly Asian cohorts, whereas data in Western patients outside of clinical trials are vastly missing.

Methods

In this multi-institutional retrospective analysis conducted at nine oncologic centers in Austria, we tried to assess feasibility of checkpoint inhibitors in advanced gastric/GEJ cancer in a real-world Western cohort.

Results

In total, data from 50 patients with metastatic gastric/GEJ cancer who received nivolumab or pembrolizumab in a palliative setting between November 2015 and April 2020 have been evaluated. The median number of previous palliative therapy lines was two. The median progression-free survival (PFS) and overall survival (OS) were 2.1 (95% CI: 1.4–2.8) and 6.3 (95% CI: 3.3–9.3) months, respectively. There was no statistically significant difference in median OS according to microsatellite or PD-L1 status. However, a trend towards prolonged PFS and OS for the microsatellite instability high subgroup could be observed. Patients with an ECOG Performance Status (PS) ≥ 2 displayed a significantly worse outcome than those with an ECOG PS ≤ 1 (p = .03). Only one patient discontinued immunotherapy due to treatment-related toxicity.

Conclusions

Our results support feasibility of nivolumab and pembrolizumab in pre-treated patients with metastatic gastric and GEJ cancer in a Western real-world cohort. Further phase II/III studies are needed to confirm clinical efficacy.

Local and Central Evaluation of HER2 Positivity and Clinical Outcome in Advanced Gastric and Gastroesophageal Cancer-Results from the AGMT GASTRIC-5 Registry

Trastuzumab in combination with a platinum and fluorouracil is the treatment of choice for patients with advanced human epidermal growth factor receptor 2 (HER2) positive gastric cancer and gastroesophageal junction (GEJ) cancer. Pathological assessment of the HER2 status in gastric/GEJ cancer, however, still remains difficult. However, it is a crucial prerequisite for optimal treatment. The GASTRIC-5 registry was designed as an observational, multi-center research initiative comparing local and central HER2 testing. HER2 status was assessed by immunohistochemistry (IHC) and in equivocal cases (IHC score 2+) by additional in-situ hybridization. Between May 2011 and August 2018, tumor samples of 183 patients were tested in local and central pathology laboratories, respectively. Central testing revealed HER2 positivity in 38 samples (21%). Discordant HER2 results were found in 12% (22 out of 183) with locally HER2 positive/centrally HER2 negative results (9%, 17 out of 183), exceeding locally HER2 negative/centrally HER2 positive results (3%, 5 out of 183). Centrally confirmed HER2 positive patients receiving trastuzumab-based palliative first-line therapy showed a longer median overall survival compared to centrally HER2 positive patients not receiving trastuzumab (17.7 months (95% CI: 10,870–24,530) vs. 6.9 months (95% CI: 3.980–9.820), p = 0.016). The findings of the GASTRIC-5 registry corroborate the challenge of HER2 testing in gastric/GEJ cancer and highlight the necessity for central quality control to optimize individual treatment options. Centrally HER2 positive patients not receiving trastuzumab had the worst outcome in a Western real-world gastric/GEJ cancer cohort.