Brief Answer:
extended life expectancy

Detailed Answer:
Hello and thank you for your question.
Both of these drugs, capecitabine and gemzar are anti-cancer drugs in the category of antimetabolite chemotherapies.
In the history of treating many types of cancers it was found that combiining two or more drugs often works better than high doses of one drug.
There are several reasons for this. Each drug has its own unique mechanism of action so even if they are in the same class of drug they act in slightly different ways that may compliment each other.
Another advantage is that sometimes using combinations of drugs can allow the doctors to use lower doses of each drug resulting in less overall toxicity.
The combination of capecitabine and gemzar has been show to extend the life expectancy of patients with several cancer types compared to using one drug alone.
Please let me know if you have further questions.
Dr. Robinson

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