Hardy said many patients may be opposed to chemotherapy if they know someone who had taken the last generation of chemotherapy drugs, which tended to have harsher side effects than current treatments. And others have different reasons.
"For a lot of people it's just denial -- 'I'm just not that sick,'" said Hardy. "You have to pick through which of the issues is driving this decision to address the issue that's really there," she said. "If you don't address those issues, you can't do any treatment planning."
She noted that in some cases the fear may be driven by the length of the treatment, which might explain why some people avoid chemotherapy or follow-up treatment, but are willing to undergo surgery.
Dr. David Gorski, a surgical oncologist at Wayne State University, said that while medical oncologists may have to convince patients to use conventional medical treatments, the patients rarely decline surgery.
"I can only recall maybe once or twice in the past 10 years where somebody refused surgery," he said. "I don't know what it is about surgery, but I can almost always persuade patients at least to let me take the tumor out."
But while some patients may shun conventional therapies, doctors say some can be convinced to use them if their fears are understood.
Anne Coscarelli, director of the Simms/Mann -- UCLA Center for Integrative Oncology, said she recalls this type of patient, a mother of young children, who was worried about the possible "unnatural" changes to her body.
"I listened to her about what she was saying," Coscarelli said. "After listening to her, I was able to reframe it."
Coscarelli recalls she told the mother, "Your natural body actually created something, and that's the cancer. I wonder if doing something that disrupts the natural order of your body might actually be a better choice for you."
She said the patient took the therapy.
In Grace's case, her concern about her mother's alternatives is that they are unproven and seem dangerous. Many of her mother's diets have been to remove folic acid from her body.
Grace also worries that her mother's diet has led to a cognitive decline. Her mother recently had to transfer to a less demanding job.
"Cognitive decline has been reported and is not rare [in breast cancer cases] -- but every patient doesn't have the same level of difficulty," said Hardy. "Folic acid is needed for cognitive function. I am not sure why she is on a low folic acid diet -- that part doesn't really make sense to me."
Grace said if her mother followed her advice, she would do things differently.
"The first thing is to get in contact with her cancer doctor and have her see a nutritionist he suggests," she said. "He's got a medical degree for a reason. This chiropractor -- he's always suggesting off the wall stuff that I don't even think he should have a profession."
Gorski noted that while Grace's mother has forgone treatment, it might not mean her cancer will recur -- particularly since she took tamoxifen for the first two years.
"She's already gotten some of the benefit from it. She may already have gotten most of the benefit for it," he said, explaining that patients who stick with tamoxifen reduce the risk of recurrence by about 50 percent. "I wouldn't advise it, I'd advise her to finish the whole course, but she's probably reduced her risk of recurrence some already."