ESTRO 2024 - Abstract Book

S2154

Clinical - Upper GI

ESTRO 2024

3. Kelly RJ, Ajani JA, Kuzdzal J, et al. Adjuvant Nivolumab in Resected Esophageal or Gastroesophageal Junction Cancer. N Engl J Med. 2021 Apr;384(13):1191-1203.

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Poster Discussion

Feasibility and outcomes of neoadjuvant strategies (NAT) in unresectable gallbladder cancer (GBC)

Sushma Agrawal 1 , Rahul Rahul 2 , Ashish Singh 2 , Rajan Saxena 2

1 Sanjay Gandhi Postgraduate Institute of Medical Sciences, Radiotherapy, Lucknow, India. 2 Sanjay Gandhi Postgraduate Institute of Medical Sciences, Surgical gastroenterology, Lucknow, India

Purpose/Objective:

GBC usually presents as unresectable disease and is the third commonest cancer in women in Northern belt of India. So we conducted a prospective observational feasibility study to evaluate the effect of neoadjuvant strategies (NAT) on radiologic downstaging and resectability.

Material/Methods:

Patients with locally advanced GBC were treated with standard neoadjuvant chemotherapy (NACT). Those who were unresectable after 4 cycles NACT were offered chemoradiotherapy [CTRT] (45Gy by 3DCRT technique along with weekly concurrent cisplatin, 5FU [prior to 2014] and thereafter concurrent capecitabine). Radiological downstaging and response assessment (RECIST criteria) by CT angiography after NACT or CTRT was done to evaluate downstaging of liver infiltration, adjacent structure involvement (CBD, hepatic artery, portal vein, duodenum, colon) and lymphadenopathy. Features affecting resectability and resectability rates after NACT or CTRT were evaluated. Those found suitable for resection underwent PET-CT scan to rule out distant disease.

Results:

217 patients were evaluated (January 2012 to December 2022) (CTRT=40%, NACT:60%). The median age was 52 years (IQR 45-60 years), M:F ratio was 1:2, underwent prior stenting (n=63,27%). Pretreatment CT scans revealed involvement of liver>2cm (162, 75%), duodenum (92, 42%), colon (63, 29%), CBD (79, 36%), CHD/primary confluence (99, 45.6%), Hepatic Artery (70, 31%), portal vein (46, 21%), N0 (54, 24.5%) N1 (31, 17%), N2 (38, 17%), retroperitoneal LN (87, 40%). After NACT response rates were CR:27, PR:120, SD:33, PD:37. Radiological downstaging was evident in liver (13%), duodenum (13%), colon (7%), CBD (14%), CHD/confluence (7%), Hepatic Artery (20%), portal vein (7%) (fig1a). The proportion of nodal involvement after NACT were N0 (37.5%) N1 (20%), N2 (8%), RPLN (20%). 22 patients (10 %) underwent surgical resection (Extended Cholecystectomy:16, Extended Cholecystectomy with hepatectomy:1, Extended Cholecystectomy with multi-visceral resection: 4, Simple Cholecystectomy =1), {12 after NACT and 10 after CTRT}. 3 patients (one after NACT and two after CTRT had complete response and did not undergo surgery (after NACT: not keen on surgery, after CTRT: not resectable (n=1), lack of funds and Covid(n=1)). All except two were R0 (91%) and ypTCR rate of 27% (n=6) and ypNCR rate of 48%. Patients with liver involvement, duodenal involvement, CBD involvement and lymphadenopathy have possibility of resectability after NAT, whereas those with