It's one of the most important talks a cancer patient can have with a doctor: which treatment option is best. But a new study suggests patients don't always hear what doctors are telling them, and thus may not have all the information they need to make a decision.

In a study of women with early stage breast cancer, researchers from Harvard Medical School and colleagues found that patients often disagree with their doctors about whether all treatment options were discussed. The study was published in the journal Breast Cancer Research and Treatment (Vol. 79, No. 2: 225-231).

The researchers surveyed 1,154 female breast cancer patients in Massachusetts and Minnesota who were eligible for both breast-conserving surgery and mastectomy, treatments which have equivalent survival rates. The researchers chose to study women in these two states because both states have laws that require doctors to discuss treatment alternatives with patients.

Just 71% of the women said their doctors had discussed both mastectomy and breast-conserving surgery with them. When the researchers questioned the doctors, 82% said they had discussed both treatment options.

Why the difference in what doctors reported saying and what patients reported hearing? Lead researcher Nancy Keating, MD, of Harvard Medical School, finds two possible explanations: either the doctor really didn't talk about both treatment options, or the patient didn't understand or absorb the information.

Since only 82% of surgeons reported discussing both options, there clearly were cases where patients were not told about all the treatments available to them. That may be because some doctors may not have realized they are legally required to inform patients of all their choices. Or, some of the patients may not actually have been eligible for both treatments.

But what about the other cases?

"What we think is probably going on is that doctors may be mentioning both (treatment options) but they aren't making sure patients understand both," said Keating.

Patients who are newly diagnosed with cancer may be too upset to fully understand or remember information about treatments, for instance. Or patients simply may not understand what the doctor is saying. The researchers found that women with lower levels of education were more likely to report that their doctors had not discussed both treatment options.

There are things both doctors and patients can do to make sure treatment decisions are based on all the relevant information, Keating said.

Patients should come to the visit equipped with a list of questions, and take notes during the consultation. "Bringing a tape recorder is another great idea," she said, though not many patients do that.

Another option is bringing someone else to the consultation; that person may be able to remember things the patient doesn't, and may think of other questions to ask. And, Keating said, patients should feel comfortable calling the doctor back to get clarification of issues they didn't understand.

Physicians also need to work on their communication skills, Keating said.

"As doctors, we have a responsibility to make sure our patients understand things," she said. "We have to realize that when patients are making these really difficult decisions in really challenging situations, we have to be extra careful to make sure they understand everything we say."

Doctors can encourage patients to ask questions and call if they think of additional questions later. Or they can ask the patient to restate the information. Written materials may also be helpful, she said.