1460P - Association between effectiveness of treatment with curative intent and outcomes of first-line systemic therapy in metachronous metastatic esophagogastric cancer

Background

Nearly half of patients (pts) with esophagogastric cancer (EGC) treated with curative intent experience disease recurrence. Survival is poor and palliative systemic therapy (ST) offers limited benefit. Thus far, it is unknown whether the effectiveness of treatment with curative intent is associated with the outcomes of first-line ST.

Methods

Pts with metachronous metastatic EGC initially treated for nonmetastatic disease (2015–2017) with i) neoadjuvant chemoradiotherapy and resection (nCRT), ii) perioperative chemotherapy (PC), iii) definitive chemoradiotherapy (dCRT), and subsequently with first-line ST, were identified from the Netherlands Cancer Registry. Effectiveness of curative treatment was assessed by the time to treatment failure (TTF, above or below the median), and, if applicable by pathological response (complete/subtotal or partial/no). Outcomes of first-line ST were assessed by TTF and overall survival (OS) from start of first-line ST. Associations were analyzed using Kaplan Meier curves and multivariable Cox proportional hazards models.

Results

We identified 468 pts. Pts in the nCRT (n=275) and PC group (n=81) with a TTF of the curative treatment longer than the median TTF, had a significantly longer first-line TTF, which also translated into a longer OS for pts in the nCRT group: 5.8 vs 8.6 months (HR 1.39 95% CI 1.08-1.80; Table). Outcomes of first-line ST were not significantly different between pts with good or poor pathological response in the nCRT and PC group. TTF of dCRT (n=112) was not associated with outcomes of first line ST. Table: 1460P

Multivariable cox regression analyses of time to treatment failure and overall survival since start of first-line systemic therapy

Conclusions

We demonstrated a positive correlation between the effectiveness of nCRT and PC and outcomes of first-line ST. When discussing the effectiveness of first-line ST with metachronous metastatic EGC pts, the time to recurrence after curative treatment may be an important consideration, while this may not be applicable for pathological response.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

UMC Utrecht.

Funding

Has not received any funding.

Disclosure

R.H.A. Verhoeven: Financial Interests, Institutional, Advisory Board, Consultancy: Daiichi Sankyo; Financial Interests, Institutional, Research Grant: Bristol Myers Squibb; Non-Financial Interests, Member of Board of Directors, The Dutch Upper-GI Cancer Group is the Dutch multidisciplinary research group regarding Upper-GI cancers: Dutch Upper-GI Cancer Group; Non-Financial Interests, Member of Board of Directors: International Association of Cancer Registries. H.W.M. van Laarhoven: Financial Interests, Institutional, Invited Speaker: Astellas, BeiGene, Benecke, BMS, Daiichi Sankyo, JAAP, Medtlaks, Novartis, Springer, Travel Congress Management BV; Financial Interests, Institutional, Advisory Board: Amphera, Anocca, Astellas, AstraZeneca, BeiGene, Boehringer Ingelheim, Daiichi Sankyo, Dragonfly, MSD, Servier; Financial Interests, Institutional, Other, Advices on protocol development: Myeloid; Financial Interests, Institutional, Other, Selection of articles for Framingham: Framingham; Financial Interests, Institutional, Research Grant, LyRICX study: Servier; Financial Interests, Institutional, Research Grant, TAPESTRY study: Merck; Financial Interests, Institutional, Research Grant, AUSPICIOUS study: Incyte; Financial Interests, Institutional, Research Grant, LOAD study: ORCA; Financial Interests, Institutional, Coordinating PI: Auristone; Financial Interests, Institutional, Local PI, DESTINY-GASTRIC03: AstraZeneca; Non-Financial Interests, Leadership Role, Chair upper GI Faculty: ESMO; Non-Financial Interests, Institutional, Product Samples, For all clinical study mentioned, study medication is provided: See 'research funding'. N. Haj Mohammad: Financial Interests, Institutional, Research Grant: Servier; Financial Interests, Institutional, Invited Speaker: Servier; Financial Interests, Institutional, Advisory Board: BMS, Merck, Lilly, AstraZeneca. All other authors have declared no conflicts of interest.