1395P - Impact of delay in adjuvant chemotherapy on survival in resected gastric cancer: Real world data from India

Background

Adjuvant chemo(radio)therapy is known to improve survival in resected gastric cancer. However, there is scant data on the effect of delay in start of adjuvant treatment (AT) after surgery, and guidelines regarding optimal timing are mostly empirical.

Methods

In this ambispective observational study, we evaluated the survival outcome of patients who underwent upfront curative intent radical gastrectomy followed by AT at our center from 2002 through 2019. Patients who received neoadjuvant chemotherapy were excluded. Cox proportional hazards model was used to identify the predictors of progression-free survival (PFS) and overall survival (OS).

Results

Table: 1395P

Prognostic factors for disease progression and death

Variable	n	5-year PFS	p-value	5-year OS	p-value
ECOG performance status 0 or 1 2	12023	49.1 ± 5.2%30.7 ± 10.1%	0.05	69.0 ± 5.1%42.8 ± 12.7%	0.027
AJCC-8 Stage group I II III	965160	80.0 ± 17.9%56.3 ± 7.7%32.4 ± 4.9%	0.007	80.0 ± 17.9%75.6 ± 7.3%54.6 ± 5.8%	0.058
Time to initiation of adjuvant treatment Up to 8 weeks More than 8 weeks	16165	45.5 ± 5.0%34.3 ± 7.6%	0.005	65.6 ± 5.3%52.9 ± 8.7%	0.01

Two hundred forty-three patients (median age 53 years) with stage I-III stomach cancer were included in the analysis. Most (73%) patients underwent D2 or D3 lymphadenectomy; 17% received adjuvant chemotherapy alone while 83% received chemoradiotherapy. AT was initiated at median 42 days after surgery; 17% started within 4 weeks, 55% between 4–8 weeks, and 28% after 8 weeks. 76% patients completed all planned chemotherapy and 94% completed full course radiation, with 20% and 7% respectively requiring interruptions for toxicity. With median follow-up of 28 months, 5-year PFS and OS for the full cohort were 42.2 ± 4.1% and 63.7 ± 4.4%, respectively. On multivariate analysis, disease stage, ECOG performance status and time to AT emerged as significant predictors of PFS and OS (Table) while type of lymphadenectomy (D1/D2/D3), number of resected lymph nodes and margin positivity did not. Delay in initiation of AT beyond 8 weeks was associated with significantly worse 5-year PFS (HR 2.28; 95% CI 1.29 – 4.04; p = 0.005) and OS (HR 2.65; 95% CI, 1.27 – 5.52; p = 0.01).

Conclusions

Our findings suggest that delaying AT beyond 8 weeks after radical gastrectomy may be detrimental to disease progression and survival in patients with gastric cancer. If patients have adequately recovered, AT should preferably be initiated within 8 weeks of surgery.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.