Perioperative Therapy Preoperative Chemotherapy Versus Chemoradiotherapy in Locally Advanced Gall Bladder Cancers

Introduction:

Adenocarcinoma of the gallbladder (GBCA) is the most common malignancy of the biliary tract and its incidence is alarmingly high in the Indian subcontinent. Complete surgical excision is the standard of care for both gallbladder and pancreatic cancers. Unfortunately, majority of these cancers are diagnosed at an advanced, inoperable stage and only 10-30% of the patient present with resectable disease.

Gall bladder cancers which are T3/T4 with liver infiltration, with or without visceral/vascular infiltration or having large local lymph node metastases; in the absence of distant metastases are generally considered as locally advanced. There prognosis in terms of resectability and survival remains dismal in most of the reports.

Even with aggressive surgery like extrahepatic bile duct resection or pancreaticoduodenectomy the 5 year survival rate for stage III disease ranges 30% to 42% in best of the reports. But these results are often not reproducible.

Locally advanced Gall bladders cancers not amenable for curative resection are often treated with chemotherapy alone which is the current standard of care. Randomized trials have shown survival benefit with combination chemotherapy in gallbladder cancers. In a randomized trial combination chemotherapy of Gemcitabine and cisplatin was superior to Gemcitabine chemotherapy alone and local tumor response in terms of partial downsizing or stable disease was achieved in 81% of cases. With Gemcitabine and Cisplatin based Neoadjuvant chemotherapy (NACT) some locally advanced GB cancers do get downstaged to undergo resection. Recent publication from Tata Memorial Centre, where NACT alone was given which resulted in surgical resection rate of 43% median OAS and PFS being 13 months and 8 months.

Study methodology:

All patients with diagnosis of non metastatic locally advanced Gall bladder cancers who fulfill the study eligibility criteria will be evaluated for study participation and will undergo Positron emission tomography and contrast enhanced computerized tomography (PETCECT) scan and staging laparoscopy to rule out metastatic disease. Patients will undergo upfront randomization into one of the study arms.

A proportion of patients are expected to have jaundice or cholangitis at presentation. At study inclusion there should be no clinical evidence of active cholangitis or unresolved biliary obstruction. Liver Function Tests, Renal Function Tests and CA 19-9 within 4 weeks of treatment initiation.

Systemic Chemotherapy arm (Standard Arm or Arm A)

Those randomized to NACT will proceed to receive systemic gemcitabine 1000 mg/m2delivered day 1 and 8 every 3 weeks and cisplatin 25 mg/m2 for and 4 cycles (week 1- week 11).

Chemoradiation arm (Study Arm or Arm B)

The radiation dose will be 50-55 Gy/ 25 fractions to the gross disease and 45 Gy/ 25 fractions to suspected microscopic disease along with weekly gemcitabine (300 mg/ m2). Radiotherapy will be for 5 weeks which will be followed by 2 cycles of chemotherapy (week 7 to week 11)

These radiotherapy (RT) doses have found to be safe in the investigators pilot study.

During week 12-13 patients will undergo repeat PETCECT scan. If the scan shows partial or good response then patients will be evaluated for surgery. Surgery if possible will be done between weeks 13-15. In case of inoperable disease patients will receive further chemotherapy. With locally progressive/systemic disease on chemotherapy patients may be considered for second line palliative chemotherapy or best supportive care. The use of radical dose chemoradiation is not allowed on disease progression in the systemic chemotherapy arm. However palliative radiation may be used.

Surgery

Surgical procedure will be en-bloc resection including cholecystectomy with a liver wedge excision and periportal lymph node clearance. Nodal clearance from station number 8, 12, 13 with sampling of inter aortocaval node will be done. Extrahepatic biliary excision or additional organ excision will be done as per the discretion of operating surgeon.

Post Surgery all patients will receive additional adjuvant chemotherapy

Number of patients enrolled: Screened 350 Enrolled 314

Inclusion criteria

Locally advanced T3 or T4 tumors with one or more of the following:

-> 2 cm but < 5 cm liver invasion

• Radiological involvement of antropyloric region of stomach, duodenum, hepatic flexure of colon or small intestine, but without infiltration of the mucosa on endoscopy.
• Type I/II invasion -Involvement of bile duct (common hepatic duct or proximal 1/3 of the common bile duct) causing obstructive jaundice
• Radiological suspicion of lymph node involvement N1 {stations 8, 12, 13) Hepatic artery (Station 8), hepatoduodenal ligament (Station 12), retropancreatic/retroduodenal (Station 13) i.e. size>1cm in short axis, round in shape, and heterogenous enhancement on PET scan.
• Vascular involvement : impingement/ involvement (<180 degree angle) of one or more of the following blood vessels common hepatic artery/ right hepatic artery/main portal vein/right portal vein (stage III disease)
• Patient who have undergone prior cholecystectomy having residual disease with at least one of the above features.
• Biopsy/ cytology proven adenocarcinoma
• More than 18 years of age
• Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2 Normal hematological and renal and hepatic functions (serum bilirubin < 3mg/dl)

Exclusion criteria

• Resectable disease
• Evidence of distant metastasis (Liver, Lung, peritoneum, port site etc)
• Involving major part of the liver precluding restriction of full RT doses
• Received any prior radiation or chemotherapy.