Rowan Chlebowski
Harbor-UCLA Medical Center
Tuesday, May 17, 2005
3:00 PM
A new study shows that breast cancer patients can decrease their chances of recurrence by altering their diet in addition to standard treatments. The study examined over 2,400 women and found that those who adhered to a low fat diet were less likely to have their tumors return over the next five years. How will this new study change the way doctors treat first time breast cancer patients? Does a low-fat diet significantly reduce a woman's chance of getting breast cancer?
Rowan Chlebowski of the Harbor-UCLA Medical Center in Los Angeles led the study and was online to answer your questions on this new information about diet and breast cancer.
A transcript follows.
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Washington, D.C.: I recently completed treatment for breast cancer. I am physically fit and have been a vegetarian for a very long time and yet I developed this disease (with no family history). I don't intend to change these habits but I am skeptical of the reported findings about diet. Do they have any theory why a low fat diet would affect recurrence rates and how low is low?
Rowan Chlebowski: Low in the study was 20% of calories from fat, about 31 fat grams per day.
Unfortunately must women who develop breast cancer have no risk factors and any therapy we now have only works in some women.
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Chicago, Ill.: I was heartened to see you mention ER-negative women. We are so often overlooked in most studies. How large was the sample of ER-negative women? Do you have any additional remarks about this rather large risk reduction? The notion that insulin might play a role is interesting...do diabetic women have any more or any less breast cancer incidence? Thank you.
Rowan Chlebowski: There were 448 ER negative tumors in women participants. As the news stories indicate this potential differential effect will need future confirmation.
Women with the metabolic syndrome (obesity and insulin resistance) are at increased breast cancer risk.
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Cincinnati, Ohio: My breast cancer is invasive and non-invasive, carcinoma in-situ. I'm hormone receptor positive. I had a lumpectomy with a mamosite catheter followed by radiation 2 times a day for 5 days and am taking 20 mg. Tamoxifen. They got all of the cancer out. There is no trace in lymph nodes or blood, nor bones. At my 6 month check up I was cancer free. I eat LOTS of fruits, veggies, natural juices, vitamins, BarleyMax, CarrotMax, etc. I just started exercising a little. I don't consume a lot of fat, but sometimes I do eat Dove Dark Chocolates, doughnuts, piece of candy, and a couple of chips.
What can I do, or keep doing to keep me cancer free?
Thank you.
Rowan Chlebowski: Sounds like your on an excellent plan. There seems nothing to add.
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M`da, Venezuela: Please, name the journal in which you are going to publish your Study... Thank you, MD in Venezuela
Rowan Chlebowski: We don't know yet since the manuscript has not been accepted anywhere at this time.
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Fairfax, Va.: I am in the process of researching doctors to give some advice to my mother who is 5+ years into treatment for breast cancer with full skeletal metastasis and liver involvement. Needless to say, we are very grateful that she has made it this long in very good shape, but her doctor is running out of options and supports her search for some other opinions. My question is whether you have advice for identifying doctors who would be worth the trip. Some of the big name breast cancer centers/experts focus on vaccine research, or genetic markers, etc. How do I find a doctor who specializes in the reasonable treatment of advanced metastic breast cancer? I have started looking into the medical literature, and will contact authors, but I am basically guessing at this point.
Rowan Chlebowski: Most oncologists in practice have the same access to proven therapies. Therapies afterwards generally involve protocol participation. One way to find available protocols by stage and regional availability is to go to the NCI Web site.
http://www.nci.nih.gov/cancertopics/pdq
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Pittsburgh, Pa.: Maybe because more women are doing monthly breast exams, or having mammograms, but it seems to me that there have been more reports of breast cancer occurring in younger women (under the age of 40) - many without a family history of the disease. Any reason for this? We hear so much about how our diet is so awful (lots of processed foods, high salt and fat content, etc.). Could this be contributing to it or is the incidence of breast cancer among younger women seeming to be on the rise because we are hearing more about it, especially from celebs who are going public with it (Melissa Etheridge, Brett Favre's wife, etc.)?
Rowan Chlebowski: I think that your last sentence describes situations. When someone like Kylie Minogue goes public with a public diagnosis at age 36, it increases awareness, but younger women are generally at low risk unless they have a very strong family history.
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New York, N.Y.: Is it true that the low-fat diet also provided a real benefit for the 25% - 30% of women with hormone negative breast cancer? If so, did the study provide any clues as to the reason(s)? Thanks,
BC Survivor
Rowan Chlebowski: At this time although the results are very interesting they do require confirmation with longer follow-up and a second supportive study. So at this time we can't be completely sure of a different effect in women with tumors having different ER status.
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Vienna, Va.: When breast cancer has spread to other organs/bone, is there any benefit to a vincristine only treatment?
Rowan Chlebowski: Generally vincristine has only modest activity in advanced breast cancer.
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Arlington, Va.: Thank you for coming online. My mother recently had cells removed from her breast that were classified as "zero stage" cancer. Her oncologist is recommending chemo and/or tamoxifen. I am trying to encourage her to overhaul her diet, reducing her animal protein intake and eating more fruits/veg with antioxidants. Wanted to get a word of assurance from you that this is a path to take or perhaps a suggestion in another direction. Greatly appreciate your input.
Rowan Chlebowski: The course you propose seems fine. One doesn't want to make someone feel guilty regarding their dietary pattern even at this time since the results we showed do require confirmation.
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Alexandria, Va.: Do you think a diet high in fat actually aids the growth of malignant cells? Or are there valuable components found in low-fat foods that help to shrink or prevent growth of cancerous tissue/cells?
Also, are there any implications for low fat diets being useful for other cancers?
Rowan Chlebowski: We don't know the mechanism of action at this time but changes in hormones like insulin or factors associated with inflammation might be involved.
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Alexandria, La.: Its been five years and four months since I was diagnosed with stage 1 breast cancer. When can I stop worrying that it will come back and kill me?
Rowan Chlebowski: It is impossible to provide risk information on an individual basis. Your oncologist would be in a better position to address your legitimate concern.
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Arlington, Va.: What are the study's implications for women who are "longer-term" survivors of breast cancer? My mother was diagnosed and treated (lumpectomy and radiation) in 1997 and then took tamoxofin. She has not had a recurrence. Should she focus on reducing fat intake after 7 years?
Also, does type of dietary fat matter? For example, olive oil and omega-3 oils are considered generally healthy. Are they still okay in this context?
Thanks
Rowan Chlebowski: In the WINS study to get to 20% of calories from fat oil use was marketability decreased so as a result all fat were decreased. We can't make a recommendation for one particular oil in this context.
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Anonymous: Mr. Chlebowski, How did you separate other factors like exercising in order to isolate a low fat diet? Generally, they go hand and hand in terms of a more "healthier lifestyle. Also, did you research turn up anything related to LCIS or DCIS?
Rowan Chlebowski: LCIS and DCIS tumors were not included. The average age 62 year old women participating in the trial were not very physically active regardless of treatment group.
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Reston, Va.: Do you have any info on Paxol reducing the effectiveness of Tamoxifin?
Rowan Chlebowski: I'm not aware of any direct information on that question.
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Arlington, Va.: Isn't estrogen also stored in fat? If so, could this be a reason why a low fat diet may help prevent recurrence? (Also maybe why your statement that obese women have a higher rate of breast cancer?)
Rowan Chlebowski: Fat tissue has an enzyme (aromatase which converts androgens into estrogen), so postmenopausal women who are obese have higher estrogen levels which maybe related to breast cancer risk.
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Rowan Chlebowski: Conclusion regarding reduced fat diet, while we have generated some evidence for efficacy in women 48 years of age or older, the issue is not settled. Having said that, the diet was associated with nutritional adequacy and could be recommended for other health reasons. If a woman with previously diagnosed breast cancer is interested, she should discuss the study and her situation with her oncologist who is in the best position to provide advice.
Rowan T. Chlebowski, MD, PhD
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