Incidence, Stage, Treatment, and Survival of Noncardia Gastric Cancer

Importance

Gastric cancer is the fifth most common cancer worldwide, and investigating its incidence, characteristics, treatment, and outcomes over the past decades can help in selecting clinical strategies and future research directions.

Objective

To analyze the trends in incidence, staging, and treatment of gastric cancer.

Design, Setting, and Participants

This nationwide, population-based cohort study included patients diagnosed with noncardia gastric cancer (NCGC) between 1989 and 2021 in the Netherlands.

Main Outcomes and Measures

Differences in tumor characteristics, treatment, and survival were analyzed per fixed time periods (1989-1993, 1994-1998, 1999-2003, 2004-2008, 2009-2013, 2014-2018, and 2019-2021).

Results

In total, 47 014 patients (median [IQR] age, 73 [64-80] years; 28 032 [60%] male patients) were identified with mostly adenocarcinomas of the antrum region (when location was known). Age-standardized incidence decreased from 20.3 to 6.1 per 100 000 person-years between 1989 and 2021. During the study period, unknown T and N stages were recorded less frequently, and metastatic disease was diagnosed more frequently (1989-1993: 2633 of 9493 patients [28%]; 2019-2021: 1503 of 3200 patients [47%] in 2019-2021). Over time, fewer patients with metastatic disease underwent surgery with or without other treatment modalities (68% in 1989-1993 vs 64% in 2019-2021), and palliative chemotherapy in metastatic NCGC increased from 9% to 40%. For patients with nonmetastatic disease, 5-year relative survival improved from 28% (95% CI, 26.5%-29.2%) to 36% (95% CI, 33.5%-37.6%) between 1989 and 2021. For patients with nonmetastatic disease undergoing a resection, 5-year survival increased from 40% (95% CI, 38.3%-41.8%) to 51% (95% CI, 47.9%-53.3%). For patients with metastatic disease, 1-year relative survival increased from 10% (95% CI, 8.7%-11.1%) to 19% (95% CI, 17.2%-21.6%), but 3-year relative survival remained poor at 5% (95% CI, 3.6%-7.5%).

Conclusions and Relevance

In this nationwide cohort study involving 47 014 patients diagnosed with NCGC (1989-2021), the results showed a decrease in incidence, more accurate staging, a shift in treatment modalities, and improved patient survival.

Circulating tumor DNA predicts outcome in metastatic gastroesophageal cancer

BACKGROUND

Circulating tumor DNA (ctDNA) has predictive and prognostic value in localized and metastatic cancer. This study analyzed the prognostic value of baseline and on-treatment ctDNA in metastatic gastroesophageal cancer (mGEC) using a region-specific next generation sequencing (NGS) panel.

METHODS

Cell free DNA was isolated from plasma of patients before start of first-line palliative systemic treatment and after 9 and 18 weeks. Two NGS panels were designed comprising the most frequently mutated genes and targetable mutations in GEC. Tumor-derived mutations in matched metastatic biopsies were used to validate that the sequencing panels assessed true tumor-derived variants. Tumor volumes were calculated from baseline CT scans and correlated to variant allele frequency (VAF). Survival analyses were performed using univariable and multivariable Cox-regression analyses.

RESULTS

ctDNA was detected in pretreatment plasma in 75% of 72 patients and correlated well with mutations in metastatic biopsies (86% accordance). The VAF correlated with baseline tumor volume (Pearson's R 0.53, p < 0.0001). Detection of multiple gene mutations at baseline in plasma was associated with worse overall survival (OS, HR 2.16, 95% CI 1.10-4.28; p = 0.027) and progression free survival (PFS, HR 2.71, 95% CI 1.28-5.73; p = 0.009). OS and PFS were inferior in patients with residual detectable ctDNA after 9 weeks of treatment (OS: HR 4.95, 95% CI 1.53-16.04; p = 0.008; PFS: HR 4.08, 95% CI 1.31-12.75; p = 0.016).

CONCLUSION

Based on our NGS panel, the number of ctDNA mutations before start of first-line chemotherapy has prognostic value. Moreover, residual ctDNA after three cycles of systemic treatment is associated with inferior survival.

The association between effectiveness of first-line treatment and second-line treatment in gastro-oesophageal cancer

BACKGROUND

Population-based predictive factors for the effectiveness of second-line palliative systemic therapy in gastro-oesophageal cancer are not available. This study investigates the predictive value of effectiveness of first-line treatment for second-line treatment outcomes in gastro-oesophageal cancer in a real-world setting.

METHODS

Patients with metastatic gastro-oesophageal cancer diagnosed in 2010-2017 who were treated with second-line therapy after disease progression on first-line therapy were identified from the Netherlands Cancer Registry. Patients were divided into four groups as per duration of time to treatment failure (TTF) of the first line (0-3, 3-6, 6-9 and >9 months), and the association with overall survival (OS) and second-line TTF was assessed using Kaplan-Meier curves and two-sided multivariable regression models.

RESULTS

Median OS since the start of the second line of patients (n = 611) with first-line TTF of 0-3, 3-6, 6-9 and >9 months was 4.0, 4.1, 5.5 and 7.1 months, respectively (P < 0.001). Median second-line TTF of patients with first-line TTF of 0-3, 3-6, 6-9 and >9 months was 2.8, 2.4, 3.0 and 4.5 months, respectively (P < 0.001). Patients with first-line TTF of >9 months showed a longer OS than patients with first-line TTF of 0-3 months (adjusted hazard ratio (HR) 1.90; 95% confidence interval (CI) 1.46-2.47), 3-6 months (adjusted HR 1.88; 95% CI 1.47-2.39) and 6-9 months (adjusted HR 1.31; 95% CI 1.04-1.65). Results for second-line TTF were similar.

CONCLUSIONS

This study shows a positive correlation between effectiveness of first-line therapy and outcomes of second-line therapy in gastro-oesophageal cancer. Physicians should take duration of the first line into account when considering second-line palliative systemic therapy.