Use of complementary and alternative medicine by cancer patients : systematic review

Interest in complementary and alternative medicine has increased, especially among oncology patients. A systematic literature review of the profi le of patients who choose to use this type of medicine, as well as their motivations, was carried out on the PubMed database. For this search, the key words used were ?cancer and complementary alternative medicine? and ?oncology and complementary alternative medicine?, covering the period between 1995 and 2005. The selection criteria were the following: key words were present in the article title; article was written in either English, Portuguese, or Spanish; and study was performed with an adult population. From the 43 articles analyzed, it could be concluded that the use of complementary and alternative medicine is part of these patients? social scope. Moreover, its use plays an important role in the identity construction of cancer patients, helping them to make decisions related to conventional treatment.


INTRODUCTION
Despite remarkable advances achieved by conventional medicine, there has been an exponential growth in interest in and use of complementary and alternative medicine (CAM), especially in developed western countries.The literature shows that non-conventional medicine is a signifi cant element of treatment in poor and developing countries as well. 44e integration of CAM into the national health systems has been the subject of constant debates and relevant reference can be found in documents from the World Health Organization (WHO) as Estrategía de la OMS sobre medicina tradicional 2002-2005, a which recommends the need to investigate the following: national integration policies of complementary and alternative therapies in the national health systems; safety, effi cacy, and quality of these therapies; access to these therapies; rational use by professionals and CAM users.Disponível em: http://www.opas.org.br/medicamentos/site/UploadArq/trm-strat-span.pdfCAM therapeutics, studies on certain complementary and alternative therapies being clinically proved for cancer treatment (32%; N=84); perspective of health professionals as regards the use of CAM in cancer treatment (9%; N=24); doctor-patient relationship (2%; N=5).A total of 150 works related to patients' perspective were analyzed, as information that could provide answers to this study's question might be found.Out of these, 43 articles that dealt with the characteristics and motivations of the population who uses CAM alongside conventional treatment for cancer were effectively included in this study (Table ).

RESULTS
In the analysis of all the 263 articles, a growing number of publications about the CAM-cancer treatment relation were noted, as it is shown on Figure 1.
By observing all the 43 articles on patients' profi les and their motivations to use CAM, as well as the publication date (Figure 2), it was verifi ed that the fi rst works focusing on this began to appear in 1997.
As regards the methodology used, it was observed that 40 articles were of a quantitative nature, while three of them were of a qualitative nature.The United States performed more studies (30%; N=12), followed by Canada (11.6%; N=5) Austria and Hawaii (9.3%; N=4).No works with this focus were registered in Latin-American countries.
All the 43 articles were classifi ed according to the main theme developed: socioeconomic, clinical, ethnic-racial and gender-oriented profi le of patients who use CAM; patients' perceptions of the disease and experiences; and motivations to use CAM.
The growth in use of such therapies is evident in the specifi c case of patients with cancer.An increase in the number of scientifi c works can be observed and these seek to answer the following: requests about information regarding the clinical use of a number of CAM interventions by patients with cancer and family members; the need to provide information through the media, especially in relation to the cost of treatments for cancer patients; toxicological potential of interventions in two moments: when CAM is used alone or alongside conventional treatments; the need to assess the functionality of some interventions and the possibility to incorporate them into conventional medical practice; the governmental agencies' responsibility for the legal representation of these patients. 4,6wever, specifi c debate over the socioeconomic, ethnic and gender-oriented profi le, as well as the patients' motivations for the use of CAM in the treatment of cancer, was not identifi ed in the literature.The objective of the present study was to analyze the profi le of people who use complementary and alternative medicine and their motivations, based on biomedical literature review of this theme.

METHODS
A literature review of this theme was performed on the PubMed of the National Library of Medicine for the ten-year period between 1995 and 2005.The key words used were: "cancer and complementary alternative medicine" and "oncology and complementary alternative medicine".
The selection criteria were the following: key words were present in the article title; article was written in either English, Portuguese, or Spanish; and study was performed with an adult population (19 years of age or older).
A total of 378 articles were initially identifi ed, out of which 115 were removed for having no relation to the review theme or for being duplicates.Next, the 263 articles selected were classifi ed in four thematic categories, according to their analysis: use of CAM from the perspective of patients or groups of patients (57%; N=150); The main complementary and alternative therapies used are: homeopathy, 9,24 Ayurvedic medicine, 8 traditional Chinese medicine, 6,20,41 herbal therapies 1,5,6,14,18,24 (including teas), psychological therapies, 25,45 spiritual therapies, 1,3,14,24,43 support groups, 6,25,26 relaxation and meditation, 3,14,18,24,35,43 diets (vitamins and minerals, mushrooms, shark cartilage, mistletoe), 3,5,6,18,23,27,35,42 and refl exology. 41These complementary and alternative therapies need to be separated into therapeutic techniques and rationality, as this means the incorporation of elements from some other medical rationality.a The other therapies are only techniques, which can, as a result, be more easily incorporated to complement conventional treatments.
In relation to the patients' perception of the disease and their experiences, studies show that those who use CAM perceive a higher risk of death or recurrence of the disease.In this sense, there are studies that relate the use of CAM to the level of anxiety and depression, showing that the higher the mental stress, the more frequent the use of CAM.Moreover, patients who use CAM are more likely to become depressed. 26,29,39However, the relation between self-knowledge promoted by CAM and the development of depressive symptoms has not been suffi ciently looked into, and, consequently, this is a theme open to investigation.
In general, patients view the use of CAM in a positive manner, as useful and non-toxic, and believe they provide a change in life style and quality, thus infl uencing the course of the disease positively. 2,32Another signifi cant perception is related to the sensation of better control over the body and the treatment itself after using some form of alternative therapy. 10,16,21,29,36,41,46Studies show that the number of patients who use some form of alternative therapy after the diagnosis of cancer is high. 9,15,16,24,26,47garding the motivations to use CAM, technical, psychological, and biological reasons were identifi ed.Biological reasons are related to the increase in the body's ability to fi ght against the disease, 13,24,45,46 promote the strengthening of the immunological system, 9,24,34,35 relieve side effects caused by chemotherapy, thus enabling people to hope for a "cure" 5,8,9,35,41,46 and the prevention of recurrence. 1,9,24,40,45In relation to the psychological motivation, the promotion of well-being, control of stress and improvement of life quality were described. 2,5,6,9,14,23,27,46The technical reasons for the use of CAM in the treatment of cancer are intimately connected to the dissatisfaction with conventional treatment, 1,8,12,36,37 especially concerning side effects and the interaction that is formed with health professionals, 33 besides the autonomous, humanizing process promoted by non-conventional practices.
The literature analyzed in this study acknowledges the substantial increase in the use of CAM by cancer patients, even though it accepts them merely as complementary practice to a treatment that has already been established or as an alternative to treat side effects caused by surgery, radiotherapy or chemotherapy.In this sense, the authors of these works point out that patients must be investigated as regards the use of CAM, always arguing that there is little scientifi c evidence.This theme is disregarded by the majority of studies and ends up becoming a highly recurrent reason to ignore the use of CAM in cancer treatment, despite high levels of satisfaction with alternative therapies. 2,6,9,11,22,31,36art from the connection between motivations to use CAM and the "dissatisfaction" with conventional techniques, it can be observed that patients seek a different type of logic to relate to their body, their disease and even the health service they go to.If, on the one hand, biomedicine has its paradigm regulated by the biomechanical, positivist and representationalist model,   CAM goes against this model, bringing a new perspective to the disease and the individual.Thus, complementary and alternative therapies have contributed to: bring the sick person back to the center of care; reset the doctor-patient relationship as fundamental for the therapy; seek simple therapeutic means; and build up the patient's autonomy. 5,42,47

CONCLUSIONS
The theme of CAM use by cancer patients has attracted investigators and surpassed exclusive interests of specifi c disciplines.However, the majority of studies identifi ed in the literature result from quantitative studies, performed in the northern hemisphere, with the perspective of discussing how this use takes place.Few studies qualify why CAM is used, enabling the preparation of complementary and alternative strategies in cancer treatment.
The use of CAM is part of the social scope of oncology patients.This use has an important socio-cultural meaning in the construction of the cancer patient's identity.Moreover, it also helps them to make decisions in relation to conventional treatment itself.Such evidence cannot be disregarded by health services so that strategies which promote dialogue about CAM between professionals and patients are developed, thus improving service quality.
The urgency to make more investigations is emphasized when taking into consideration the complexity of factors that lead cancer patients to use CAM.Such investigations would have the objective of analyzing health professionals' perspective on the use of CAM, the possibility to introduce these practices into conventional health services, and the position of public health policy makers and managers as regards its incorporation into the Brazilian Health System.

Figure 2 .Figure 1 .
Figure 2. Annual distribution of publications on cancer patients' characteristics and their motivations to use complementary and alternative medicine.N=43

Table .
Studies on the profi le of cancer patients and their motivations to use complementary and alternative medicine, obtained in review carried out inPubMed, 1995-2005.
36nada 251 patients under treatment in an outpatient ward of a cancer center.Singh et al362005Hawaii 18 CAM users and 9 non-CAM users under prostate cancer treatment.