Herbal use among cancer patients during palliative or curative chemotherapy treatment in Norway
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- Engdal, S., Steinsbekk, A., Klepp, O. et al. Support Care Cancer (2008) 16: 763. doi:10.1007/s00520-007-0371-3
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Goals of work
This survey aims to explore the differences between cancer patients undergoing chemotherapeutic treatment with palliative or curative intention with respect to concurrent herbal use, experiences of adverse effects, motives of herbal intake, and communication about herbal use with health care providers.
Materials and methods
One hundred and twelve adult cancer patients from the west coast of Central Norway, currently undergoing chemotherapeutic treatment, were recruited to a cross-sectional descriptive survey.
Palliative and curative patients used herbal remedies concurrent with chemotherapy equally frequent (37% and 38%). One palliative patient reported adverse effects when doubling the dose of injected mistletoe used. Garlic was only used by palliative patients (p = 0.009) who also tended to have a more frequent everyday herbal use (78% vs 67%, respectively) than curative patients (p = 0.075). Curative patients, however, used herbal remedies more often to counteract adverse reactions (31% vs 3%, respectively; p = 0.026). A bivariate logistic regression, which was adjusted for age, showed that palliative patients used herbal remedies more frequently to improve their immune system (adjusted OR = 7.5, 95% CI = 1.1–49.7).
This is the first survey comparing concurrent herbal use between cancer patients undergoing palliative or curative chemotherapy. Both groups frequently use herbal remedies concurrent with chemotherapy, but with a slightly different intent. The frequent concurrent use emphasizes the need for clinicians to include questions on complementary and alternative medicine in routine history taking and for further studies on possible herb–drug interactions among the cancer patient.
A high and increasing tendency for the use of complementary and alternative medicine (CAM), including herbal remedies, is seen in the population as a whole  and especially amongst cancer patients . Herbal use gives possibilities for unwanted herb–drug interactions with conventional medicine as chemotherapeutics, which can lead to adverse effects and treatment failure . It is found that the patients knowledge of such possible dangers of CAM/herbal use is limited [4, 5, 15].
Research in this area often refers to the wider term “CAM use”, which, in addition to herbal remedies, includes a variety of different treatment forms as, amongst others, massage, prayer, and acupuncture. This research, which is flourishing [3, 10, 20], shows that cancer patients mainly use CAM to improve the quality of life , boost the immune system [8, 12], and increase the feeling of hope . Furthermore, that family and friends are important factors in recommending herbal remedies [9, 13]. But, although the prevalence of CAM/herbal use is increasing and health care providers are somewhat positive , communication between patients and health care providers is scarce .
Cancer patients undergoing chemotherapeutic treatment may be divided into two distinct groups: palliative patients, treated to prolong life and decrease symptoms, and curative patients, treated to cure the cancer. Having widely different life expectancies, differences in factors as quality of life  and hope  are expected.
There are no previous studies published on differences between these two groups of patients in their use of herbal remedies. Therefore, this survey was undertaken to explore possible differences between cancer patients undergoing chemotherapeutic treatment with palliative or curative intention with respect to parameters as concurrent herbal use, experiences of adverse effects, motive of herbal intake, and communication with health care providers.
Materials and methods
This study was performed as a cross-sectional descriptive survey. The survey was approved by the Regional Committee for Research Ethics, Central Norway and reported to the Norwegian Social Science Data Services. Informed consent was collected from all participating patients and the questionnaires were coded with identification numbers to ensure confidentiality. Patients were recruited by trained nurses at two outpatient clinics in a rural area on the west coast of Central Norway in the period March 2006–March 2007. The patients gave written informed consent before they answered the questionnaire during a scheduled visit at the outpatient clinic, or if desired, at home.
The patients were included if they were able to read and understand the questionnaire, over 18 years old, and currently undergoing chemotherapeutic treatment. The wide inclusion criteria were set to ensure a diverse sample.
To validate the questionnaire and identify herbs to be included, a pilot was carried out with face to face interviews with six cancer patients. The interviews were performed by the first author at one of the outpatient clinics. The responses were not included in the final material.
In addition to demographic data such as sex, age, education, and employment status, the patients were presented with a predefined list of 19 herbal remedies for the identification of herbal use and extra space for the patients to add additional herbs as needed. Herbal products were defined as products of both botanical and animal origin . The list was designed to represent a variety of herbal remedies, including those reportedly used by the cancer patients in the pilot, by the health personnel participating in the survey, in the literature, and those traditionally used by the Norwegian population. The patients were asked to indicate present or earlier use, either before or during chemotherapy. In addition, the patients’ motives for using herbal remedies, their communication with health care providers, adverse effects, and monthly expenditures were requested.
Users were defined as patients that have used or were using herbal remedies concurrent with chemotherapy treatment. Not concurrent users were defined as patients that had never used or stopped using herbal remedies before they started the chemotherapy treatment. The nurses reported the diagnosis, treatment regime, and whether the treatment was given with a palliative or curative intent.
SPSS 13.0 (SPSS, Chicago, IL, USA) was used for statistical analysis. Due to small sample sizes, differences between palliative and curative patients were estimated by the Fisher’s exact test. The Mann–Whitney test for nonparametric samples was used to assess the differences in cost and number of herbal remedies used by the two groups. Binary logistic regression was performed controlling for age in 10-year intervals. Variables associated with palliative or curative treatments were explored. p values <0.05 were defined as statistically significant, while tendencies were ascribed differences where 0.05 < p < 0.10.
One hundred and forty four patients were invited to participate in the survey and 121 (84%) gave their written consent. Nine questionnaires were excluded from the final analysis due to incomplete answers. Thus, the results are based on the 112 (78%) eligible patients.
Demographics of all eligible patients and the portions of palliative and curative patients in herbal not current user and user groups
Not current usera
Number of participants
Age (years, range)
Earlier + chemotherapy
Earlier − chemotherapy
All patients were treated with chemotherapeutics. Palliative treatment was given to 78 (70%) of the patients with an equal palliative to curative ratio for herbal nonusers and users, 2.3 and 2.2, respectively. Among the herbal users, there tended to be a difference in the age distribution with the palliative patients being older than the curative patients (p = 0.054; Table 1).
Nearly half of the patients (46%) had some kind of herbal use, either before or during chemotherapy (Table 1). Forty two (38%, 95% CI = 28–47%) of the patients recorded using at least one herbal remedy concurrent with chemotherapy (user), and there was no difference in herbal use between patients treated with palliative (37%) or curative intent (38%), p = 0.916.
None of the patients, except one in the palliative group, reported to have experienced any adverse effects of the herbal remedies. The adverse effect reported was nausea, fever, and headache after doubling the dose of injected mistletoe; the discomfort disappearing when reducing the dose.
Patterns of herbal use
Frequency of herbal use among palliative and curative patients
Palliative, n (%)
Curative, n (%)
Not everyday, but at least once a month
Herbal remedies used by palliative and curative patients’ concurrent with chemotherapy
Total use, n (%)
Herbal remedies used to
Fight cancer generallyb
Strengthen the body/immune systemc
Treat adverse effectsd
Reasons and communication
Comparison of palliative and curative patients with respect to reasons and recommendations for herbal use, communication with care providers, and monthly costs of herbal remedies
Concurrent patients, n
Palliative, n (%)
Curative, n (%)
Improved prospects of living
Improved immune system
Better than nothing
By family and friends
By the doctor
From weekly magazines/press/internet
In a health food store/by an alternative practitioner
Communicated with health care providers
Reasons for never discussing
I was never asked
It is my choice
I do not know if there is any effect of the herb
I have never thought about it
A general practitioner
The health care providers response
Encouraged continued use
Recommended stopping/warned about risks
Although not statistically significant, nearly twice as many curative as palliative patients had never discussed herbal remedies with any health care providers (54% vs 28%, respectively, p = 0.163). More than half of both palliative and curative patients said this was due to never being asked. Among palliative and curative patients discussing herbal remedies with health care providers, oncologists were the most frequently encountered (71% and 60%, respectively) followed by hospital nurses (48% and 40%, respectively). The responses given by the health care providers for both patient groups were, however, mainly neutral or indifferent.
The median of the mean monthly expenditure on herbal remedies was 50 Euro (range 2.5–455 Euro) among palliative patients and 38 Euro (range 6.3–228 Euro) among curative patients, showing that palliative patients tended to spend more money on herbal remedies than curative patients (p = 0.094).
In Table 1, it can be observed that the palliative group was mainly represented by people in the age groups 50–59 and 60–69 years (48.3% and 31.0%, respectively). Therefore, binary logistic regression was performed adjusting each variable for age in 10-year intervals. The use of herbal remedies to improve the immune system was then statistically significantly related to the palliative group (adjusted OR = 7.5, 95%CI = 1.1–49.7), and patients discussing herbal remedies with the health care providers tended to be related to the palliative group (adjusted OR = 3.1, 95% CI = 0.7–14.2). No other questions were associated with either the palliative or curative group when adjusted for age.
In this survey, the use of herbal remedies among cancer patients receiving chemotherapy was equally frequent in those treated with palliative or curative intent. However, among the herbal users, garlic was highly preferred by the palliative group, while the curative group wished to counteract chemotherapeutic side effects by a concomitant herbal intake. Only one patient in the palliative group reported adverse effects due to doubling the dose of injected mistletoe used. When adjusting for age, palliative and curative patients were similar in most aspects except for the improvement of the immune system, which was more important for palliative patients than for curative patients.
The survey has two main limitations. First, all patients are from a confined, mostly rural area, which may limit the external validity of the results. Second, all prevalences are based on self-reported herbal use, which may result in inaccuracies due to possible recall bias and varying definitions of what to report as herbal products.
The prevalence of herbal use of 38% in this survey is moderate compared to prevalences of total CAM use but high compared to prevalences of herbal use. Yates et al.  registered a 91% total CAM use in their group of cancer patients but only 9% were using herbal remedies. Indeed, higher prevalences of biological therapies have been reported [12, 15], but these also included the use of vitamins. However, the use of herbal remedies is reported to depend on tradition and is varying between countries  and ethnic groups .
The high prevalence of herbal remedies used concurrent with chemotherapeutics, both for patients treated with a palliative or a curative intent gives the risk of clinically relevant interactions . However, only one of the patients in this survey reported discomfort or adverse effects due to the use of herbal remedies. During cancer treatment, patients are likely to experience adverse effects due to the received chemotherapy. This may blur possible herbal interactions or adverse effects, emphasizing the importance of elucidating possible herb–drug interaction mechanisms also for the individual patient. The belief among a large group of users that herbal remedies are safe  and lack of knowledge about possible adverse effects  may further reduce this awareness.
Although the prevalence of herbal use among patients treated with palliative and curative intent was equal, the patterns of herbal use tended to differ. The tendency for more frequent use of herbal remedies among palliative patients may be attribute to a wish to improve the quality of life  or increase the feeling of hope . The age difference with most palliative patients being older than 50 years may explain why the palliative patients preferred garlic, the herb with longer traditions in anticancer treatment. Curative patients, on the other hand, did not use garlic at all, but preferred green tea. Palliative patients had a somewhat higher monthly expenditure on herbal remedies than curative patients, suggesting that palliative patients are more willing to use some more money on herbal remedies. However, the expenditure on herbal remedies was low, equal to 35 l of gasoline pr month. Reports indicate that cancer patients perceive that boosting of the immune system will increase the chances of healing or survival and that it will support the body through tough chemotherapeutic treatment . This might be the reason why, after adjusting for age, palliative patients, more often than curative patients, used herbal remedies to “improve the immune system.” Curative patients, however, used herbal remedies to counteract adverse effects.
As for other cancer patients, both palliative and curative patients reported that family and friends advised them to use herbal remedies, suggesting that personal relations are important in the process of giving advice. This confirm earlier reports where family and friends are shown to be important in the decision process , both for the patients, but also for the family members as a way to contribute in a difficult situation.
Almost half of the patients in the curative group had never talked to any health care providers about herbal remedies, which is comparable with recent literature [5, 9, 20]. However, after adjusting for age, palliative patients tended to talk to the health care providers more often than the curative patients. This suggests that palliative patients might have a longer history with the health care provider due to a more progressed disease, thus feeling more confident in talking about herbal use. The main reasons for not talking to health care providers were in both groups “I was never asked”, as have also been reported in other studies [9, 12, 20]. Patients want health care providers to initiate the discussion  possibly so because they are uncertain of the oncologists response  or they are afraid to jeopardize their relationship with the oncologist. The fear of rising the issue of CAM and herbal use with the oncologist and health care providers might, however, be unfounded because more than half (53% of men and 79% of women) of the health care providers in a Norwegian study seemed to be positive toward alternative medicine . The indifferent/neutral responses given by the health care providers may be explained by the physicians’ attitudes toward CAM. In fact Giveon et al.  surveyed 165 primary care physicians’ attitudes toward CAM and found that 51% of the physicians thought that herbal remedies had no or only mild interactions with conventional medicine. Nevertheless, as long as herbal medicine may have the potential to interact with conventional medicine , clinicians ought to show interest in the patient’s herbal use and in CAM as a topic.
This is the first survey comparing herbal use between cancer patients, currently undergoing chemotherapy, treated with palliative or curative intent. Two out of five patients in both groups used herbal remedies concurrent with chemotherapy. The frequent concurrent use emphasizes the need for clinicians to include questions on complementary and alternative medicine in routine history taking and for further studies on possible herb–drug interactions among cancer patient.
We wish to thank the nurses and patients at the Department of Oncology at Sunnmøre Public Hospital Enterprise, Ålesund Ward and Volda Ward. This research was founded by the Norwegian Cancer Society.