Doctors at Massachusetts General Hospital are planning to start genetic testing on cancer patients' tumors in an effort to more effectively focus treatment.

The goal of the plan to be instituted within a year is to spare patients from the traditional treatment approach, when drugs with harmful side effects are often given without knowing whether they will work.

Dr. Leif Ellisen, a breast cancer specialist, tells The Boston Globe that current procedures are "barely educated guesswork."

Doctors will look for 110 abnormalities carried on 13 major cancer genes, that can predict whether drugs will work, using technology that can identify genetic quirks.

Mass. General is one of the first hospital's to make gene testing standard in cancer treatment.