Impact of adjuvant therapy on outcomes of cancer of the stomach and gastroesophageal junction in the real-world.

BACKGROUND

Since the FLOT4 gastric cancer (GC) trial, the use of adjuvant chemotherapy has been perceived as limited and its added value questioned. We wanted to objectify this perception and reassess the value of adjuvant chemotherapy in a real-world setting.

METHODS

In our retrospective cohort study we analyzed real-world data from 147 patients with GC or cancer of the gastroesophageal junction (AEG) who received perioperative FLOT. Data originated from clinical care at the university hospital, local hospitals and medical practices. Clinicopathologic data, survival outcomes, and targetable biomarkers were analyzed.

RESULTS

Median overall survival (OS) and tumor specific survival (TSS) were 19.4 ± 2.9 and 19.9 ± 3.1 months, respectively. 84.4% completed all cycles of neoadjuvant chemotherapy. The pathological complete response rate was 11.8%. Adjuvant chemotherapy was initiated in only 42.9%. Survival rates of patients with marked tumor regression (TRG1) were not improved by adjuvant chemotherapy. Conversely, patients with partial histopathologic response (TRG2) showed a marked trend and those with minimal histopathologic response (TRG3) showed a significantly longer survival with any number of adjuvant chemotherapy cycles (OS: 22.3 ± 2.6 months versus 8.7 ± 2.4 months, p = 0.005; TSS: 22.3 ± 4.5 months versus 8.7 ± 2.4 months, p = 0.016). Targetable biomarkers PD-L1, Claudin 18.2, HER2 and microsatellite instability were detected in 53.4%, 26.2%, 7.8%, and 3.9% of the TRG2/3 patient subset, respectively.

CONCLUSIONS

In the real-world setting, adjuvant chemotherapy proved to be a critical turning point of the FLOT regimen. It should be sought-even in a reduced form-in patients with TRG2/3.