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Many women use complementary and alternative medicine (CAM) to maintain or improve their health. We describe CAM use among the first 1,000 participants enrolled in the Pathways Study, an ongoing prospective cohort study of women diagnosed with breast cancer (BC).
Participants, identified by rapid case ascertainment in Kaiser Permanente Northern California, are women ≥21 years diagnosed with first invasive BC. Comprehensive baseline data are collected on CAM use through in-person interviews.
Study participants include 70.9% non-Hispanic whites, 10.2% Hispanics, 9.0% Asians, 6.5% African-Americans, and 3.4% others. Most women (82.2%) were diagnosed with AJCC stage I/II BC, at average (±SD) age 59.5 (±12.0) years and reported prior use of at least one form of CAM (96.5% of participants). In the five years before diagnosis, CAM therapies used at least weekly by >20% of women included green tea, glucosamine, omega-3 fatty acids, prayer and religion. CAM use was high (86.1% of participants) in the period immediately following diagnosis; 47.5% used botanical supplements, 47.2% used other natural products, 28.8% used special diets, 64.2% used mind-body healing, and 26.5% used body/energy/other treatments. In multivariable analyses, frequent use of each CAM modality before and after diagnosis was associated with use of other CAM modalities and other health behaviors (i.e., high fruit/vegetable intake, lower BMI).
CAM use before and after BC diagnosis is common in this diverse group of women. Our results emphasize the need for clinicians to discuss CAM use with all BC patients.
In 2008, an estimated 182,460 women will be diagnosed with breast cancer in the US . There are currently over two million breast cancer survivors, and the number continues to grow as women are being diagnosed at earlier stages of disease and conventional breast cancer treatments are prolonging survival. Many women want to know, in addition to conventional therapies, what proactive steps they can take to positively impact their prognosis after diagnosis, including adaptation of lifestyle changes and use of complementary and alternative medicine (CAM).
Lifestyle changes encompass nutrition and physical activity, and CAM includes pharmacologic and non-pharmacologic therapies. Pharmacologic CAM therapies include botanical supplements, other natural products, and special diets, while non-pharmacologic therapies include mind-body approaches, body-based therapies, energy-based therapies, and other systems of healing . CAM use by women with breast cancer has been increasing over time , yet little is known about how lifestyle factors and CAM use after diagnosis impact prognosis.
We examined data on CAM use before and immediately after diagnosis in the Pathways Study, a prospective cohort study of women diagnosed with invasive breast cancer within Kaiser Permanente Northern California (KPNC) . This information can improve our understanding of CAM use patterns and motivations, as well as identify CAM practices that may affect cancer-related prognosis, quality of life, and adherence to breast cancer treatment. This paper describes CAM use before and after breast cancer diagnosis among the first 1,000 Pathways Study participants.
The Pathways Study is an ongoing prospective cohort study of women who are newly-diagnosed with invasive breast cancer and who are members of KPNC. Women are recruited as soon after diagnosis as possible (usually within two months), as described elsewhere . Briefly, cases are ascertained on a daily basis by automatic scanning of electronic pathology reports with subsequent verification of cancer diagnosis and patient notification. Eligibility criteria include: current KPNC membership; at least 21 years of age at diagnosis; recent diagnosis of first primary invasive breast cancer; no prior history of cancer other than non-melanoma skin cancer; ability to speak English, Spanish, Cantonese, or Mandarin; and residence within a 65-mile radius of a field interviewer. Written informed consent is obtained from all participants at the time of the in-person baseline interview. This study is approved by the institutional review boards of all collaborating institutions involved with data collection and analysis.
As of January 6, 2009, 2,357 breast cancer patients have been enrolled. The mean time from diagnosis to enrollment is 1.8 months (range: 0.3- 7.2 months). The overall recruitment rate among eligible subjects is 51%. The present analysis includes information from the first 1,000 women enrolled in the cohort.
During the baseline interview, interviewers administer detailed questionnaires on demographics, diet, exercise, CAM use, psychosocial, and quality-of-life measures. Anthropometry measures are taken, and blood and saliva samples are obtained.
CAM use is assessed with a two-part self-administered questionnaire based on those used in previous studies [5-8]. Part 1 is a checklist asking about ever use of five general CAM modalities and specific CAM therapies within each modality, including botanical supplements such as black cohosh, ginseng, and mistletoe (90 items); other natural products such as co-enzyme Q10, DHEA, and melatonin (26 items); special diets such as low-fat, macrobiotic, and vegan (12 items); mind-body healing approaches such as hypnosis, support groups, and yoga (17 items); and body-based, energy-based, and other treatments such as acupuncture, naturopathy, or Reiki (23 items). Space is available for women to report use of other CAM therapies that are not specified on the questionnaire. Part 2 solicits information on total length of use, use in the five years prior to diagnosis, and use since diagnosis. Data on frequency of use collected for the five years before diagnosis are categorized as never use, occasional use (up to four times per month), and frequent use (greater than four times per month). On the baseline questionnaire, assessment of CAM use since diagnosis is recorded as yes/no.
Fruit and vegetable intake is assessed by food frequency questionnaire (FFQ) (NutritionQuest, Berkeley, CA) [9, 10], which provides a summary measure for the average number of servings of fruits and vegetables consumed per week.
KPNC electronic medical records are abstracted to collect data on body mass index (BMI) at diagnosis and breast surgery. The KPNC Cancer Registry (KPNCCR)  is accessed to obtain diagnostic tumor characteristics such as hormone receptor status, HER2/neu expression, tumor size, number of positive nodes, American Joint Committee on Cancer (AJCC) stage, and initial course of treatment, including chemotherapy, radiation therapy, and hormonal therapy.
Multivariable analyses were performed using logistic regression to identify independent predictors of ever use of separate CAM modalities and post-diagnosis use in the period between diagnosis and study enrollment. Variables that were selected a priori to include in the models were age, race/ethnicity, education, and income. Additional variables were included in the models based on univariate analyses between each demographic, lifestyle, and clinical variable with CAM use. Analyses were conducted using Statistical Analysis Software (SAS) version 9.1.
Women enrolled in the Pathways Study are ethnically diverse. The first 1,000 participants included 70.9% non-Hispanic whites, 10.2% Hispanics, 9.0% Asians, 6.5% African-Americans, and 3.4% others (Table 1). The average age (mean ± SD) at breast cancer diagnosis was 59.5 ± 12.0 years. Women were enrolled in this study an average (mean ± SD) of 56.3 ± 22.2 days after breast cancer diagnosis.
Most (96.5%) women reported a history of using at least one form of CAM, and 57.3% reported ever using four or more of the general CAM modalities. Each of the five general CAM modalities (botanicals, other natural products, special diets, mind-body healing, body/energy/other treatments) was used by 63-75% of participants at least once in their lives.
In general, women age 50-69 years at breast cancer diagnosis were more likely to use CAM (specifically botanical supplements, other natural products, special diets, and body/energy/other treatments) in the previous five years than younger or older women (Table 1). Postmenopausal women were more likely to report recent use of other natural products than premenopausal women (Table 1). Higher education and higher income were both associated with using all CAM modalities in the previous five years, except that income was not associated with the use of mind-body healing (Table 1). When comparing women who did and did not use each of the CAM modalities in the five years prior to diagnosis, there were no differences in use based on family history of breast cancer, stage at diagnosis, tumor characteristics, or course of breast cancer treatment (Table 1). Women who on average ate more than the recommended five servings of fruits and vegetables per day prior to diagnosis were more likely to report using botanical supplements compared to women who ate less than five servings per day (Table 1).
Non-Hispanic whites and African-Americans were more likely to report using other natural products in the past five years than Hispanics and Asians (Table 1). Non-Hispanic white women were more likely to report using special diets in the past five years than women in the other racial/ethnic groups (Table 1). Overall, use did not differ substantially across racial/ethnic groups for use of botanical, mind-body, or body/energy/other therapies.
Of the 168 individual CAM therapies/approaches listed on the questionnaire, only 37 were ever used by more than 10% of the population, and only 30 were used by more than 10% of the population in the five years prior to diagnosis (data not shown). For simplicity of presentation, Table 2 shows the individual CAM therapies ever used by more than 20% (rather than 10%) of participants within any of the four ethnic groups, and shows use during the past five years and use in the period between diagnosis and study enrollment. In the five years prior to diagnosis, pharmacologic therapies (i.e., botanical supplements, other natural products, and special diets) used at least weekly by more than 20% of women included green tea, glucosamine, and omega-3 fatty acid supplements, while the non-pharmacologic approaches (i.e., mind-body healing and body/energy/other treatments) used at least weekly by more than 20% of women were prayer and religion. In the period between diagnosis and study enrollment, 86.1% of participants reported using any form of CAM; 47.5% of participants reported using herbal and botanical supplements, 47.2% reported use of natural products, 28.8% reported using special diets, 64.2% reported using mind-body healing, and 26.5% reported using body/energy/other treatments.
We found that a history of CAM use was common among the 97 participants who reported annual household income <$25,000 and had a high school-level education or less; 56% reported ever using botanicals, 61% reported ever using other natural products, 51% reported ever using special diets, 72% reported ever using mind-body healing, and 54% reported using body/energy/other treatments (data not shown).
The most commonly used botanical therapies included green tea (40.9%), Echinacea (32.2%), flax seed (23.5%), cranberry (23.5%) and chamomile (22.5%). Frequent use of botanicals during the five years prior to diagnosis was associated with high fruit and vegetable intake and using other forms of CAM (Table 3), whereas frequent use in the months following diagnosis was associated with being younger, having a BMI <25 kg/m2, and using other forms of CAM (Table 4).
The most commonly used other natural products included glucosamine (36.9%), omega-3 fatty acid supplements (33.7%), laxatives (27.1%), chondroitin (22.7%), and fiber supplements (19.7%). Frequent use of other natural products in the five years prior to diagnosis was associated with being older and using other forms of CAM (Table 3). However, frequent use of other natural products after diagnosis was associated with being older, more educated, and using other forms of CAM; Asians, obese women, and women with “triple-negative” tumors were less likely to frequently use other natural products after diagnosis (Table 4).
Commonly used special diets included low-fat (25.7%), weight loss (22.5%), low-carbohydrate (18.9%), Atkins (18.4%), and high-protein (13.0%); the latter three may be seen as variations of one another. Frequent use of special diets in the five years before breast cancer diagnosis was associated with higher education, being overweight, eating >35 servings of fruits and vegetables per week, and use of other forms of CAM; Hispanics were less likely to have frequently used special diets (Table 3). Frequent use of special diets after breast cancer diagnosis was associated with higher education, higher intake of fruits and vegetables, and use of other forms of CAM (Table 4).
Popular mind-body healing approaches included prayer (45.4%), meditation (24.2%), religion (24.0%), deep breathing exercises (23.4%), and yoga (22.2%). Frequent use of mind-body healing approaches in the five years before breast cancer diagnosis was associated with higher education, lower income, and use of other forms of CAM (Table 3). Frequent use of mind-body healing approaches after breast cancer diagnosis was associated with being Hispanic, higher education, lower income, and use of other forms of CAM (Table 4).
Frequently used body/energy/other therapies included massage (44.6%), chiropractic care (34.1%), acupuncture (24.5%), acupressure (13.6%), and aromatherapy (10.9%). Frequent use of these treatments before and after diagnosis was associated with being younger, lower income, and use of other forms of CAM (Tables 3 and and4).4). In addition, frequent use of these treatments after diagnosis was also associated with having a hormone receptor-positive and HER2/neu-negative tumor (Table 4).
At study enrollment, most women had received or were receiving treatment for their breast cancer, including lumpectomy (67.6%) or mastectomy (27.9%), chemotherapy (15.2%), radiation therapy (6.9%), or hormonal therapy (11.1%). Of the women who received chemotherapy, 63.8% reported using a pharmacological form of CAM (botanicals or other natural products) between diagnosis and study enrollment. In general, the proportion of users for each type of CAM modality in the five years prior to diagnosis was only slightly greater than the proportion who reported using in the post-diagnosis period between diagnosis and study enrollment (Table 2).
The Pathways Study is a prospective cohort study of women diagnosed with primary invasive breast cancer, and a major aim is to examine how lifestyle factors and CAM use affect prognosis. Here, we report on CAM use among the first 1,000 women enrolled in the cohort. We found that frequent use of pharmacologic (botanical supplements, other natural products, and special diets) and non-pharmacologic (mind-body approaches and body/energy/other therapies) forms of CAM before and after diagnosis was very common among study participants, although use of different types of modalities differed by demographic, clinical, and other characteristics. Prevalence of CAM use was high regardless of socioeconomic status. In general, use of any of the CAM modalities was strongly associated with the use of other forms of CAM, which suggests that women were not using the different CAM modalities in isolation. CAM use did not decrease substantially from the five years prior to diagnosis to the time between diagnosis and study enrollment.
Our results are similar to other studies that have described CAM use by women in the general US population and by women after breast cancer diagnosis. Among respondents to a 2002 National Health Interview Survey in the United States, 69% of women reported using at least one form of CAM, and 24% of women reported using biologically-based therapies . A recently published paper from the American Cancer Society's Study of Cancer Survivors-I showed that among cancer survivors, those with breast cancer are the most likely to use CAM in the 10-24 months following cancer diagnosis ; 55.9% used biologically-based practices, 85.7% used mind-body methods, 20.2% used manipulative and body-based practices, 13.5% used energy medicine, and 4.4% used alternative medical systems. The Nurses' Health Study reported that 62% of breast cancer survivors used at least one form of CAM during the two years prior to assessment, a mean of 3.2 years post-diagnosis , and the Women's Healthy Eating and Living (WHEL) Study reported that 80.9% of study participants used dietary supplements at study enrollment, which was within four years of diagnosis . A recent review paper  suggested that CAM use by breast cancer patients after diagnosis has increased over the past 20 years, yet few studies have examined CAM use immediately after diagnosis and into the post-treatment period.
Recent studies suggest that use of different CAM modalities varies by demographic, clinical, and behavioral characteristics . In general, we found that CAM use was associated with various factors (e.g., having a higher level of formal education and household income, eating more fruits and vegetables, having a lower BMI, and using other forms of CAM). In addition, use prior to diagnosis was associated with use in the few months after diagnosis. However, while we identified several characteristics that describe a profile of frequent CAM users, CAM use was still high in women without these characteristics. This emphasizes the need for clinicians to discuss CAM use with all breast cancer patients.
To our knowledge, the Pathways Study is the first prospective cohort study to comprehensively collect CAM use information from women around the time of breast cancer diagnosis, including use in the immediate post-diagnosis period. Follow-up questionnaires are being administered to collect information on how CAM use may change as a woman moves through treatment and enters into follow-up care. Future analyses will examine how CAM use affects treatment-related side effects, recurrence, and survival. We also plan to investigate the effects of using some controversial dietary supplements, including antioxidants  and soy isoflavones , after a breast cancer diagnosis and during treatment. This study is also one of the first designed to examine factors associated with frequent CAM use, as frequent use may have the most impact on biological, clinical, and quality-of-life endpoints.
In summary, our current analyses show that use of pharmacological and non-pharmacological forms of CAM before and after diagnosis is highly prevalent among women with breast cancer in this ethnically-diverse cohort. These data suggest that clinicians should discuss CAM use with all patients, regardless of ethnic background or socioeconomic status. Future analyses from this cohort study will be able to describe patterns of CAM use in the years after breast cancer diagnosis, and how CAM use may impact breast cancer recurrence and survival.
We gratefully acknowledge all Pathways Study participants, as well as the office and field staff. This work was supported by the National Institutes of Health (CA094061, CA105274); the American Cancer Society (RSG-06-209-01-LR); and the Department of Defense (BC043120). The contents of this manuscript are solely the responsibility of the authors and do not necessarily represent the official views of the funding agencies.