Colonoscopy isn’t as good we thought as a screening test for colon cancer, but it’s a lot better than nothing and people ought to be getting it as per existing guidelines, according to a report in the Annals of Internal Medicine.

In a case-controlled study of 10,292 Canadians who died of colon cancer, scientists found that colonoscopy missed nearly all cancers of the right colon and a third of those on the left. Overall, it prevents 60-70% of colon cancer deaths.

Physicians usually tell patients the procedure prevents 90%.

For comparison’s sake, mammograms prevent 25% of breast cancer deaths and the PSA test has never been shown to reduce prostate cancer mortality.

Internists and family practitioners performed a third of the colonoscopies in this study. Many of them perform the procedure infrequently. The study did not compare their yields against gastroenterologists or those with more experience.

The study also did not address the role played by bowel preparation in determining colonoscopy yields.

Scientists attributed the near complete failure to detect right-sided cancer to location-specific attributes of colon polyps, the cancer-precursor lesions sought after and removed by colonoscopists. In the right colon, these polyps are flat and hard to see.

Left-sided polyps are easier to spot because they tend to be raised and have stalks.

After the study was published, the American Cancer Society said it will not alter its screening guidelines, adding that the procedure’s risk and cost mitigate against more frequent testing.

 “If I was to provide one main message, it would be that colonoscopies are the way that colon cancer mortality gets reduced,” David Ransohoff told the New York Times.

The UNC gastroenterologist added that “colonoscopy is a good test, but it isn’t completely effective. And you know what? We ought to be happy with that.”

It would have been the Tech story of the year but for now at least, a Twitter-Facebook hook-up is not going to happen.

Talks between the social network and the microblogging service began soon after Evan Williams became Twitter’s chief executive in mid-October, according to Claire Cain Miller of the New York Times. But they concluded abruptly after Williams rejected Facebook’s$500 million largely stock offer.

 “We explored it, as we should. We took it seriously,” Williams told the Times, “but it wasn’t the right time.”

It is the right time for Twitter to try making money, something it has not done yet despite its fantastic brand, 6 million registered users and $20 million in VC cash.

That’s not going to cut it during our economic crisis or as Williams put it, “I don’t want to have to raise money in 2009.”

Williams told the Times he wants to avoid an ad-based model and instead convince companies that use his site to interact with customers to pay for the privilege.  Dell, JetBlue, CNN, Whole Foods and others use Twitter this way.
 
Williams might have to buy a suit to pull this off since he candidly admits, “We have no business people in the company, so this isn’t an area we’re focused on.”

Yeesh!

Meanwhile, there’s competition from Yammer, a microblogging service for use by companies that started making money the day it went live, and old-school giants like Microsoft and Yahoo might enter the space.

But Williams remains undaunted. Twitter is after all just a 2 year-old company with 25 employees.  “Give us a minute,” he pleaded.