The Food and Drug Administration will host an outside panel of expertson Tuesday to review breast cancer drug Avastin’s claim that it can slow down the growth of tumor and extend the life of patients.

The decision to review Roche Holding AG’s top-selling cancer drug was based on a follow-up testing of the pill that led FDA to question the benefits of Avastin on breast cancer patients.The FDA’s briefing document submitted to the agency’s.

Oncologic DrugsAdvisory Committee also noted that side effects of Avastin include potential life threatening gastrointestinal perforations, high bloodpressure, and abnormal white blood cell counts.

Avastin was approved by the FDA in 2008 as a metastatic breast cancer treatment after test results showed that the drug slowed the growth of tumors caused by breast cancer in a number of early stage cancer patients. There was no clear evidence that the drug extended patient’s life-expectancies. The FDA approved the drug for breast cancer treatment even though an FDA advisory panel had voted 5-4 against it.

Since FDA’s approval, Avastin, which is also used for other forms ofcancer, became Roche’s top selling cancer treatment with nearly $6billion in sales last year.

In a follow-up study what compared breast cancer patients who are treated with Avastin with chemotherapy and patients who are treated by chemotherapy alone, the results revealed that Avastin did not extend the life of breast cancer patients.