Should you trust the breast cancer information you read on the Internet? It depends on which Web site you are reading. There are credible sites, and there are snake oil sites. I used to advise people to seek out sites that end in "org" or "edu." Frankly, I don't say that anymore.

Anyone can launch a Web site today and put whatever they want at the end of the URL. Going with names you know and recognize is your best bet. Yahoo!, for example, sought out experts from Johns Hopkins and other reputable organizations and experts for its medical information. That makes sense.

I receive lots of emails from people questioning the validity of information they find using a search engine. There are "doctors" who claim they know the cure for cancer or have just the right supplement to ease your treatment symptoms.

You can also get a distorted view of breast cancer statistics if your only information sources are Web postings by women with breast cancer. One woman wrote to me recently, "I have stage 1 breast cancer, hormone receptor positive and Her2neu negative. I thought that was good but now I realize I am destined to get stage 4 breast cancer. Why didn't the doctor tell me?"

I promptly wrote back, "What are you reading and where?" Sure enough, she had been reading postings from women who fell into a highly unusual group - their cancer had metastasized even after such a favorable prognosis. From their comments she assumed this was the norm for her diagnosis. The fact is that it's not.

If you go to a pregnancy Web site, for example, you may read postings from women who had trouble getting pregnant, a nightmarish pregnancy with many complications, and then a delivery that is destined to be written up in medical books. You probably won't find many postings from women who had normal experiences. They aren't posting on the Web. They don't need to. They did fine and are home rocking their babies.

Go with credible sites that carry information from nationally renowned organizations. An unreliable information source can alter your sense of what is common and what is not. Read with caution, don't assume anything, and visit credible sites.