Take a look at the clinical trials underway for gallbladder cancer and you'll see that a number of drugs taken together (called a cocktail) may provide the best treament. The standard drugs are chemo (chemical) and the addition of a target drug (like Erbitux or Avastin) act together but in different ways. The additional advantage to using a target drug is that once the cancer is stable, it can be used alone as a maintenance treatment.
I learned all of this too late for a family member so don't hesitate. Get going.
Art