A breast cancer survivor can easily have the thought in the back of her mind: What if the cancer comes back or spreads?

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But many survivors have misconceptions about their chances of this happening after treatment, with some largely underestimating and others overestimating their risk.

A new University of Michigan Rogel Cancer Center study focuses on this issue with a new angle.

Prior studies have examined breast cancer survivors' understanding of their risk after receiving treatment — but not how they concluded what their risk was, says Kamaria Lee, a research assistant on the study and a co-author of an accompanying paper published in Medical Decision Making.

To Lee's knowledge, it is the largest study to qualitatively analyze reasons for reporting risk of breast cancer recurrence estimates.

Methodology and findings

Patients were sent surveys two to three months after surgery. The study encompassed a diverse pool of 1,754 women.

Researchers identified several main factors that influenced a patient's risk estimate: diagnosis and testing, treatment, uncertainty, personality traits and emotions, communication with a clinician, current and future health, spirituality, religion and faith, family and personal history, statistics, research and stories of others.

The most significant factor for accurately understanding recurrence risk was what a woman's clinician told her, the team learned.

"When patients reported using prior communication with their clinicians in making their estimates, they were more likely to have a reasonably accurate understanding of their risk," says Lee.

Still, she notes, the practice is far from universal: "It was also surprising that more than 80 percent of the women in the sample didn't specifically mention that communication with a clinician influenced their recurrence risk estimate."

Causes for concern

The most common factors influencing perception of risk were diagnosis and testing of their initial breast cancer, and treatment of it, influencing 27 percent and 22 percent of respondents, respectively, the study found.

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Taken together with patient-clinician communication, only about half of the women mentioned at least one of these clinically related factors.

For women who overestimated their risk, a feeling of uncertainty was a major factor, along with family and personal history. On the other hand, 63 percent of the women underestimated risk because of spirituality, religion and faith influences.

Underestimation was considered where a patient thought there was no chance of recurrence, Lee explains.

That, too, can be a problem: "The concern is that if patients are substantially underestimating their risk, then they may be less likely to go to follow-up visits or follow survivorship recommendations," she says.

Among the questions they received, survey participants were asked to estimate the chances that their cancer would spread to other parts of their body within 10 years — and why.

The survey allowed for open-ended responses, which Lee says was critical for the breadth of the results.

"Using this approach, we were able to try to identify as many common factors as possible," she says. "We could have ideas of what we might think they would say, but this looks at themes of what some women actually said influences their estimates. It allowed the breast cancer survivors to express their reasons with their own voice. I believe that was very important."

The importance of dialogue

The results suggest that clinicians should be communicating in depth on systemic recurrence for breast cancer so patients have the facts to make decisions — and for greater peace of mind.

Given the documented negative consequences of overestimation and underestimation of risk, it's critical.

"It doesn't mean clinicians are the only way to understand what a patient is up against," Lee says. "But the numbers clearly are pointing to it being the most reliable."

This work was the last of three U-M studies related to understanding systemic recurrence risk. The others focused on the doctor-patient relationship when communicating about systemic recurrence and the overestimation of risk and its effect on quality of life and frequency of worry.