UPDATE 3-Study boosts Roche's Avastin in breast cancer

* Avastin meets goal in breast cancer clinical trial

* Study: Avastin can be added to common chemotherapies

* Roche stock up 7.6 percent, Genentech up 6.7 percent (Adds analyst comment, Genentech stock price)

ZURICH, Nov 24 (Reuters) - Roche Holding AG (ROG.VX), the world's largest maker of cancer drugs, said on Monday that Avastin met its primary endpoint in a Phase III breast cancer trial.

Roche said Avastin, which it markets with U.S. biotechnology giant Genentech Inc DNA.N, increased the time breast cancer patients live without the disease worsening and the study confirmed that Avastin can be combined effectively with commonly used chemotherapies.

Avastin was tested in combination with either taxane-based, anthracycline-based or Xeloda (capecitabine) chemotherapies. The full results will be submitted for presentation at a future medical meeting, the company said.

Sanford Bernstein analyst Geoffrey Porges said that while he expected positive data from the study the results should come as a relief to investors.

"If Avastin had failed in this study it might have compromised the existing 'conditional' approval in the U.S. for metastatic breast cancer and this threat is reduced if not removed," Porges said in a research note.

Avastin was first developed for colon cancer but its use in breast cancer is expected to be a key driver of future sales.

Analysts at Morgan Stanley said the data provided another confirmation of Avastin's role in breast cancer, and would give doctors a wider choice of background therapies for use with the drug.

"We expect the stock to trade up on this news, as Street expectations for Avastin penetration in MBC (metastatic breast cancer) increase," they wrote in a research note.

"However, given the still-unresolved Genentech minority take-out, we anticipate near-term Roche upside to be limited."

Roche is seeking to buy the 44 percent of Genentech it does not already own for $43.7 billion. But Genentech's share price has fallen well below the $89 offer price as concerns mount about Roche's funding of the bid, given the credit crisis.

Roche stock was up 7.6 percent at 162 Swiss francs, outperforming a 5.5 percent rise in the European drugs sector. .SXDP

Genentech shares were up $4.86, or 6.7 percent, to $77.60 on the New York Stock Exchange. (Additional reporting by Bill Berkrot in New York) (Reporting by Jason Rhodes and Ben Hirschler; Editing by Rupert Winchester, Dave Zimmerman)