This study looks at how well chemotherapy works when given before and after surgery compared to after surgery alone for treating stage II-III gallbladder cancer. Chemotherapy uses drugs like gemcitabine and cisplatin to stop cancer cells from growing or spreading. In this study, patients will be split into two groups. Group 1 will have surgery first, then chemotherapy. Group 2 will get chemotherapy before and after surgery. Researchers want to know if getting chemotherapy before surgery helps patients live longer or prevents cancer from coming back.

• Participation involves several doctor visits for treatment every 21 days for up to 8 cycles.
• After treatment, follow-up visits are every 3 months for 2 years, and then every 6 months for 1 year.
• Participants must have stage II or III gallbladder cancer and meet certain health criteria to join.

Patients should consider the time commitment and potential side effects of chemotherapy before deciding to join.