ESTRO 2024 - Abstract Book

S2197

Clinical - Upper GI

ESTRO 2024

1523

Digital Poster

Gallbladder cancer with RPLN have outcomes similar to locally advanced disease if treated radically.

Sushma Agrawal, Parul Priyanka

Sanjay Gandhi Postgraduate Institute of Medical Sciences, Radiotherapy, Lucknow, India

Purpose/Objective:

Retroperitoneal lymphadenopathy in GBC is considered as metastatic disease, however some surgical series of radical surgery with RPLN dissection have shown results marginally inferior to those with non-RPLN lymph-node dissection. Our population of advanced non-metastatic GBC comprises of 40% patients with RPLN (on radiology). Excluding them from neoadjuvant studies causes considerable difficulty in accrual of patients for neoadjuvant studies. Hence inclusion of RPLN in neoadjuvant studies and their outcomes as compared to non-RPLN are being reported.

Material/Methods:

Non-metastatic advanced GBC with good performance status (KPS.80) were initiated on first line chemotherapy (CT, cisplatin-gemcitabine) and thereafter responders were evaluated by CT-angiography and PET-CT scan for resectability. If found unresectable, they were offered chemo-radiotherapy (CTRT) to a dose of 45 Gy by conventional fractionation (3D-CRT technique) along with concurrent capecitabine @1250mg/m2 to GBC and regional lymphatics including RPLN. Thereafter boost dose of 9Gy/5# was given to GBC. Response assessment was done using CT scan abdomen by RECIST criteria. Outcomes (overall survival) between the 2 groups (RPLN vs Non RPLN) were computed with kaplan meier survival curves and chi-square tests spss v 20.

Results:

Amongst 189 patients of advanced non-metastatic GBC recruited from 2011-2022, 80 had RPLN. The demographic features of both groups were comparable. 68% patients were women, 30% underwent upfront stenting for obstructive jaundice, 90% had T3 and T4 disease and 45%, 30% and 25% had N0, N1, N2 in non-RPLN arm. Only 10% had undergone upfront laparoscopic staging and pathological proven RPLN. 40% patients received 4 cycles CT only and 50% patients received 6 cycles or more, and 33% received CTRT. By RECIST criteria, 10% vs 16% achieved CR, 39% vs 41% achieved PR, 16% vs 15% achieved SD, 2.7% vs 6% had disease progression and 14.5% vs 3.7% were non-evaluable respectively in Non-RPLN vs RPLN group. 12% vs 4% could undergo radical surgery in Non-RPLN vs RPLN group (p=0.03). The median overall survival was 9 months (95% CI 7.6-10.3 months) vs 10 months (95% CI 8 9.8 months) (p=NS) Fig 1. In those who received CT only, the median OS was 7 months vs 8 months, while in those who received CT followed by CTRT, the median OS was 14 months vs 13 months (p=0.65) in non-RPLN vs RPLN group respectively.