Misdiagnosis or misinformation about the disease can hinder treatment response, proving that when it comes to cancer, knowledge really is power
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Knowledge is power, but when it comes to cancer it could mean the difference between life and death. Patients who are given information about their diagnosis and prognosis are twice as likely to survive their illness than those who are left in the dark, according to a new British study of over 10,000 people with all types of the illness.

Patients who are given accurate, detailed information about their cancer type, treatment plan, and how they should expect their life to be effected were nearly two times more likely to have a positive health outcome (meaning that they successfully completed their treatment with no further signs of illness). (For example, learning about The Bad Habits that Increase Your Risk for Cancer.)

There was one area where this was not true, however: People given detailed information about potential side effects were 35 percent less likely to have a positive outcome. The doctors speculated that this type of knowledge increased fear and stress, burdening an already over-stressed immune system.

How mood and attitude effects cancer patients' health can be tricky. For instance, a study published earlier this year by the Australian Medical Association found that cancer patients who became depressed had a lower chance of survival-yet those who were highly optimistic did not have higher survival rates. Rather it was the people who had a realistic view of their situation who did the best. The Aussie docs said the key was giving people enough, and the right kind, of information to motivate them to follow their treatment plans to the letter.

The fact that there is a certain amount of information that can help your survival rates, but also a line that, once crossed, can actually harm your health really emphasizes the importance of getting the right diagnosis from the right doctor. (10 Questions Your Doctor Is Too Afraid to Ask You (and Why You Need the Answers).) Nobody is questioning doctors' devotion to their patients but cancer can be a complicated disease and even the best doctors underestimate how often they misdiagnosis. A 2013 study in Boston that found the majority of docs thought the rate of misdiagnosis was between zero and 10 percent.

But in fact, getting a misdiagnosis of cancer is surprisingly common, reports a 2014 study in MJ Quality & Safety with about 28 percent of all news delivered being incorrect in some way. Some cancers are much more likely to be missed, the Boston study found, with researchers finding errors in up to 75 percent of mammograms for breast cancer and 71 percent of scans for lung cancer.

But before you freak out, the main message, the British researchers said, is the importance of correct information. So don't be afraid to seek a second opinion (a good doctor will even give you a referral to another professional), ask questions about your diagnosis, or speak up if something just doesn't feel right. Because when it comes to your health, nothing is more powerful than knowledge.