If your cancer is HER2 positive, you may also be given a targeted therapy to attack the protein that's overproduced in these cancers.

CNN: Recurrent breast cancer

"To prove that a targeted therapy even worked was incredible a few years ago, " says Len Lichtenfeld, deputy chief medical officer of the American Cancer Society.

FORBES: Magazine Article

And no drug company has yet perfected a standardized test to determine which particular genetic flaws lie behind an individual patient's cancer, a key prerequisite to targeted therapy.

FORBES: Conquering Cancer

So far Innogene has produced TherCIM, a monoclonal antibody for targeted cancer therapy that is already marketed in Southeast Asia.

FORBES: Indonesia's Kalbe Farma Expands From Health Care To Juice Drinks and Beyond

Targeted therapy: Targeted therapy looks at whether the cancer cells respond to a group of drugs that block the growth and spread of cancer by interfering with the biology of the cancer cells.

BBC: Q&A: Breast screening

The work is significant because it goes a long way towards proving that the concept of gene-targeted therapy can work in major common tumors.

FORBES: Gene Predicts Cancer Drug Effectiveness

That targeted cancer therapy, which helped most patients who took it for a rare leukemia, made it through the U.S. Food and Drug Administration in a lightning-fast three months.

FORBES: Why Cancer Drugs Need Genetic Testing

Insert Therapeutics and Intradigm are also working on targeted treatments, but both companies are also exploring the use of a Nobel Prize-winning therapy based on RNA interference (RNAi).

FORBES: Nanotech Puts Cancer In The Cross Hairs

Given the billions of cancer cells in a patient, some cells will likely evolve that lack the targeted genetic alterations or that are resistant to the targeted therapy.

FORBES: Cancer's New Era Of Promise And Chaos