Immunoprofile of adenosquamous carcinoma in gastric cancer.

BACKGROUND: Gastric adenosquamous carcinoma (GASC) is a rare subtype of gastric cancer. Research on GASC treatment is limited, and its outcome is usually poor. We investigated the clinical features, immunoprofile of GASC, and determined the optimal treatment modality for these patients. METHODS: Patients with GASC from Taipei Veterans General Hospital were retrospectively reviewed. Clinical features and treatment outcomes were evaluated. Adequate samples were examined for surrogate biomarkers for immunotherapy by IHC staining. RESULTS: Total 14 (0.35%) GASC patients were found among 4034 gastric cancer patients. The median tumor size was 6.8 cm in 10 patients with stage III GASC, and all these patients underwent radical gastrectomy followed by adjuvant therapy. The median progression-free survival (PFS) and overall survival (OS) were 6.0 and 11.5 months, respectively. Two patients with stage IV GASC received frontline immunotherapy. Their median PFS and OS were 9.0 and 12.5 months. In immunoprofiling, 25.0% (n = 3), 75.0% (n = 9), and 33.3% (n = 4) of the samples had deficient mismatch repair (dMMR) protein, combined positive score (CPS) of ≥1, and CPS of ≥10, respectively. The univariate analysis revealed that programmed death-ligand 1 ≥5% (HR: 0.12; 95% CI: 0.01-0.97; p = 0.047) was significant associated with superior OS. One stage IV patient with CPS ≥10 and dMMR proteins received nivolumab monotherapy as frontline treatment that resulted 14-month PFS. CONCLUSION: Patients with GASC are more likely to yield positive results for CPS and dMMR. Biomarkers should be examined, and immunotherapy can be considered as frontline systemic treatment.

Elevated PD-L1 Expression and Microsatellite Instability in Elderly Patients With Gastric Cancer.

Immunotherapy in combination with chemotherapy is the current treatment of choice for frontline programmed cell death ligand 1 (PD-L1)-positive gastric cancer. However, the best treatment strategy remains an unmet medical need for elderly or fragile patients with gastric cancer. Previous studies have revealed that PD-L1 expression, Epstein-Barr virus association, and microsatellite instability-high (MSI-H) are the potential predictive biomarkers for immunotherapy use in gastric cancer. In this study, we showed that PD-L1 expression, tumor mutation burden, and the proportion of MSI-H were significantly elevated in elderly patients with gastric cancer who were older than 70 years compared with patients younger than 70 years from analysis of The Cancer Genome Atlas gastric adenocarcinoma cohort [≥70/<70: MSI-H: 26.8%/15.0%, P =0.003; tumor mutation burden: 6.7/5.1 Mut/Mb, P =0.0004; PD-L1 mRNA: 5.6/3.9 counts per million mapped reads, P =0.005]. In our real-world study, 416 gastric cancer patients were analyzed and showed similar results (≥70/<70: MSI-H: 12.5%/6.6%, P =0.041; combined positive score ≥1: 38.1%/21.5%, P <0.001). We also evaluated 16 elderly patients with gastric cancer treated with immunotherapy and revealed an objective response of 43.8%, a median overall survival of 14.8 months, and a median progression-free survival of 7.0 months. Our research showed that a durable clinical response could be expected when treating elderly patients with gastric cancer with immunotherapy, and this approach is worth further study.

Microsatellite Instability, Epstein-Barr Virus, and Programmed Cell Death Ligand 1 as Predictive Markers for Immunotherapy in Gastric Cancer.

Immunotherapy benefits selected cases of gastric cancer (GC), but the correlation between biomarkers and prognosis is still unclear. Fifty-two patients with GC who underwent immunotherapy were enrolled from June 2016 to December 2020. Their clinical features and biomarkers-microsatellite instability-high (MSI-H), programmed cell death ligand 1 (PD-L1) combined positive score (CPS), and Epstein-Barr encoding region (EBER)-were analyzed. Eight patients had MSI-H, five patients had EBER, 29 patients had CPS ≥ 1, and 20 patients had no biomarker. The overall response rates (ORRs) of the MSI-H, EBER, PD-L1 CPS ≥ 1, and all-negative group were 75%, 60%, 44.8%, and 15%, respectively. Compared with that of the all-negative group, progression-free survival (PFS) was better in the MSI-H (p = 0.018), CPS ≥ 5 (p = 0.012), and CPS ≥ 10 (p = 0.006) groups, but not in the EBER (p = 0.2) and CPS ≥ 1 groups (p = 0.35). Ten patients had combined biomarkers, CPS ≥ 1 with either MSI-H or EBER. The ORRs were 66.7% for CPS ≥ 1 and MSI-H and 75% for CPS ≥ 1 and EBER. PFS was better in patients with combined biomarkers (p = 0.01). MSI-H, EBER, and CPS are useful biomarkers for predicting the efficacy of immunotherapy.

Nanoliposomal irinotecan with 5-fluorouracil and folinic acid in metastatic pancreatic cancer after previous gemcitabine-based therapy: A real-world experience.

BACKGROUND: Nanoliposomal irinotecan (nal-IRI), accompanied by 5-fluorouracil (5-FU) and leucovorin (LV), is an effective and safe therapy for patients in whom metastatic pancreatic ductal adenocarcinoma has progressed after gemcitabine-based chemotherapy. Our aim was to evaluate the effectiveness and safety of a nal-IRI + 5-FU/LV regimen for patients with metastatic pancreatic cancer and gemcitabine-based treatment failure in the real world. METHODS: We retrospectively collected the baseline characteristics, treatment courses and dosage, treatment response, overall survival (OS), progression-free survival (PFS), and adverse effects of patients treated with the nal-IRI-based regimen at Taipei Veterans General Hospital. RESULTS: Sixty-seven patients who received the nal-IRI + 5-FU/LV regimen from August 2018 to June 2019 were identified. Their median age was 65 years and 52% were male. Most patients had an Eastern Cooperative Oncology Group performance status of 0 to 1, but patients with an Eastern Cooperative Oncology Group performance status of 2 to 4 before initiation of the nal-IRI regimen were also enrolled (31%). The median dose intensity was 40.4 mg/m2 and the median treatment duration was 8.3 weeks (range: 5 days-75.7 weeks). Objective response and disease control rates were 10.4% and 38.8%, respectively. The median OS)was 7.9 months (95% confidence interval [CI]: 5.6-10.1 months) and the median PFS was 2.9 months (95% CI: 1.6-4.1 months). Elevated total bilirubin (hazard ratio [HR]: 4.31, 95% CI: 1.21-15.30, p = 0.024), carcinomatosis (HR: 3.75, 95% CI: 1.46-9.66, p = 0.006), and previous treatment with irinotecan (HR: 4.86, 95% CI: 1.67-14.10, p = 0.004) were associated with a worse OS. Previous treatment with irinotecan (HR: 3.03, 95% CI: 1.22-7.49, p = 0.02) was associated with a worse PFS. The most common all-grade adverse effects were anemia (73.9%), nausea (66.2%), and fatigue (61.5%). The most common grade 3-4 adverse effects were neutropenia (21.5%), anemia (18.5%), and diarrhea (15.4%). CONCLUSION: Clinically, nal-IRI + 5-FU/LV is effective and tolerable at reduced doses in patients with metastatic pancreatic adenocarcinoma that has progressed after gemcitabine-based therapy.