NEW YORK (Reuters Health) –
Estrogen could help women diagnosed with advanced colon cancer to survive longer, a new study out in the journal Clinical Cancer Research suggests.

While younger, presumably premenopausal women lived longer after being diagnosed with metastatic colon cancer than men of the same age, women 55 and older had worse survival than their male peers, Dr. Heinz-Josef Lenz of the Keck School of Medicine in Los Angeles and his colleagues found.

The findings, they say, offer strong evidence that hormonal status - in other words, whether a woman has gone through menopause, is taking birth control pills, or is taking hormone replacement therapy -- is a key factor in determining the fate of women with colon cancer.

Women are known to be at lower risk of developing colon cancer than men, Lenz and his team note in their report, while studies showing that hormone replacement therapy and birth control pills both cut colon cancer risk suggest that estrogen is the reason why.

To investigate whether hormone status might be a factor in survival too, the researchers looked at records for almost 53,000 people diagnosed with colon cancer that had spread elsewhere in the body between 1988 to 2004.

For women 18 to 44, the average survival after such a diagnosis was 17 months, compared to 14 months for men the same age. For patients 55 and older, average survival was 7 months for women and 9 months for men.

African Americans and Native Americans had the worst survival of any ethnic group, while Hispanics and Asian Americans did better than whites. But within a given ethnic group, women still fared better than men. "I think it's a very consistent picture," Lenz said.

Lenz and his team also found that survival started improving for young women after 2000, when several new, aggressive treatments were introduced, such as Avastin (bevacizumab). But survival for young men stayed about the same, suggesting that these medicines are more beneficial for women, the researchers say.

Giving estrogen to women with colorectal cancer "would be a very obvious thing, but I don't think it would be the smartest," Lenz said, noting that estrogen can promote breast cancer and carries other health risks.

Instead, he added, researchers should look into how the hormone might influence tumor development. Understanding these pathways could offer clues to new treatments, he said.

SOURCE: Clinical Cancer Research, October 15, 2009.

NEW YORK (Reuters) –
Goldman Sachs Group Inc (GS.N) and Vanguard Group Inc are among U.S. companies opposed to rules proposed by U.S. regulators to limit short selling, according to letters filed by the companies.

The U.S. Securities and Exchange Commission had asked for comments on a proposal to reinstate the "uptick" rule, under which investors can short a stock only after it had moved higher.

In a short sale, an investor sells borrowed stock in anticipation of a price decline that will allow him to repurchase the shares at a lower price.

Some lawmakers and financial industry executives say short selling has worsened the financial crisis and driven down share prices.

Goldman and Vanguard were among several companies and exchange operators opposing new restrictions on short sales.

" he available empirical data suggest that short selling may benefit the market by exposing financial misconduct and aligning market prices with fundamental analysis," Paul Russo, Goldman's head of U.S. equity trading, wrote in a comment latter to the SEC.

Other investors, including T.Rowe Price, submitted letters expressing support for the new rules.

" e believe appropriate short selling serves a valid purpose and can enhance liquidity and price discovery," T.Rowe Price said in a letter signed by Michael Gitlin, head of global trading. "However, short selling has also been utilized as a device to manipulate stock prices in an abusive manner and has negatively impacted investor confidence."

(Reporting by Steve Eder; additional reporting by Ajay Kamalakaran in Bangalore; Editing by Dan Lalor and John Wallace)