Quality of life of Brazilian and Spanish cancer patients undergoing chemotherapy: an integrative literature review

Objective: characterize the scientific production of Brazil and Spain in regard to methodological aspects and aspects of health-related quality of life experienced by cancer patients receiving chemotherapy in both countries. Method: integrative literature review was conducted using the following databases: CINAHL, MEDLINE, SCOPUS and CUIDEN and the electronic libraries PubMed and SciELO, conducted in September 2013. Results: a total of 28 papers met the inclusion criteria. The synthesis of knowledge was presented in three categories of analysis: assessment of quality of life in different types of cancer; sociodemographic factors that influenced quality of life; and type of cancer and interventions that improve quality of life. Chemotherapy affects health-related quality of life and the most important factors were: age, sex, chemotherapy protocol, type of surgery, stage of the disease, educational level, and emotional intelligence. Complementary therapies such as acupuncture, guided visualization, prayers and exercise were positive and reduced side effects. Conclusion: the results showed a poor level of evidence, since 86% of the studies were cross-sectional descriptive studies; the instrument most frequently used to measure health-related quality of life was EORTC QLQ C-30 and more studies were conducted in Brazil than in Spain.


Introduction
The number of new cases of cancer, a disease relevant to public health, has increased in Brazil and Spain. The incidence and prevalence of cancer, as well as cancer mortality rates, are similar in Brazil to those found in Spain, as are health policies established in the oncological field. The objective of the Brazilian National Oncological Care Policy, established by Decree No. 2.439/GM on December 8, 2005 (1) and the Spanish Cancer Strategy of the National System of Health, Ministry of Health and Social Policy (2010) (2) , is to optimize the prevention, diagnosis, and treatment of cancer, as well as to improve information and encourage scientific investigation. Lines of action also converge, emphasizing health promotion, prevention, diagnosis, treatment, rehabilitation, palliative care, quality of life, and research.
The surgical treatment of cancer and other therapeutic procedures (radiotherapy and chemotherapy) has reduced mortality and morbidity; however, there is a concern regarding the functional status and quality of life of these individuals.

Method
This is an Integrative Literature Review (IR), considered a strategy to identify existing evidence to ground healthcare practices. The IR is a method that enables the search for, clinical assessment of, and synthesis of evidence available on the topic under study (4) . IR enables the inclusion of diverse methodologies (experimental and non-experimental studies) and contributes to the presentation of varied perspectives regarding a phenomenon and is a means to integrate scientific knowledge in a certain field, contributing to clinical practice.
Hence, this review was conducted according to a six stage method: select the hypothesis or review question; select the sample; define the study's characteristics; analyze the studies included in the review; interpret the results; and present the review with a synthesis of knowledge (4) . Exclusion criteria were: theses and dissertations, papers related to methodological research such as the creation and/or validation of QoL instruments, multicenter studies, whose exclusive population was not Brazilian or Spanish, systematic reviews, and those not including human beings.
The same instrument used in a previous study (6) was adopted in the third stage that consists of the definition of the study's characteristics. Three experts assessed the instrument's apparent and content validity. For level of evidence, the following classification was considered: level 1 evidence accruing from systematic reviews or meta-analyses of Controlled Randomized Clinical Trials (CRCT); level 2 refers to evidence obtained from at least one well-delineated CRCT; level 3 refers to evidence from well-delineated non-randomized clinical trials; level 4 originates from well-delineated casecontrol and cohort studies; level 5 refers to systematic reviews of descriptive or qualitative studies; level 6 refers to evidence originating from a single descriptive or qualitative study; and level 7 refers to evidence originating from the opinion of authorities and/or expert committees (7).
A detailed analysis of papers was conducted in the fourth stage, paying attention to inclusion and exclusion items, while a deepened analysis was conducted in the fifth stage in order to achieve the study's objectives and compare data found in the literature. The sixth stage was the final one, in which a synthesis of the knowledge acquired in the review was presented through thematic categories, tables and figures.

Results
The search for papers in the CINAHL, MEDLINE,  After reading the abstract, a total of 48 full-text papers were selected, of which 32 appeared more than once; only 28 met the inclusion criteria and composed the IR. Figure 1 shows the references of the papers, the database in which they were found, the study design and level of evidence, background and affiliation of the primary author, language, and country of origin.      a Master's Degree in the nursing field was implemented in the 1970s and doctoral programs were implemented in the 1908s (9) . This is a topic of great interest in the nursing field, as shown in Figure 1: the primary authors of 11 (39.2%) of the 28 papers under study were nurses. These findings show that QoL of cancer patients undergoing chemotherapy is still a predominant topic among physicians and nurses, professionals who directly provide care to these patients and witness the problems experienced by cancer patients. Another element that becomes apparent is that most scientific production is linked to universities and university hospitals. According to one study (10) , the production of knowledge is centered clinical trials would be infeasible or unethical (11) .
In regard to language, 50% of the studies were written in English and the remaining studies were written either in Portuguese or Spanish. These findings are related to the databases in which the papers were identified. Most papers were found in SCOPUS, MEDLINE and CINAHL, which require papers to be written in English.
In regard to QoL aspects (12) , we stress the importance of authors establishing a concept of QoL and this definition should be coherent with the type of instrument used and theoretical framework grounding the instrument and the nature of the study's discussion.
The lack of an explicit theoretical model to guide the development of studies addressing quality of life limits the use and generalization of QoL in clinical studies with cancer patients (13) .
The instruments most frequently used to assess the QoL of cancer patients undergoing chemotherapy in the papers included in this IR were similar to those found in another IR (6) .
Category 1 -assessment of QoL in different types of cancer, gynecological cancers, showed that the QoL factors most frequently affected among patients undergoing chemotherapy were sexual function due to malaise, pain and vomiting that compromised physical well-being, and reduced ability to meet family needs.
The patients also experienced weakness, nausea and nuisance caused by the chemotherapy's side effects, which corroborate data of a similar study (14) .
All four studies were developed in Brazil; no Spanish study was found addressing the QoL of patients with breast cancer undergoing chemotherapy. This finding confirms the Systematic Review (15) that reports that studies addressing HRQL among patients with breast cancer are seldom conducted in Spain.
In regard to the studies addressing head and neck cancer, the physical domain was the domain most frequently affected, in which patients presented impaired swallowing, speech, compromised teeth, and dry mouth, in addition to pain and fatigue. This information corroborates another international study that also reports swallowing problems, pain, teeth problems, and other comorbidities with onset after treatment for head and neck cancer, compromising the QoL of patients (16) .
In these studies, even though one was conducted in Brazil and the other in Spain, sociodemographic data are similar in regard to the average age, and those older than 50 years old. Additionally, most were male, had basic education, and in regard to the clinical characteristics of study 5, most had stage II laryngeal cancer and were predominantly treated with radiotherapy and chemotherapy. In study 11, most had a tumor located in the oral cavity, stage II, and had undergone surgery.
These results are similar to those reported in another study (17) that also assessed association of synergism of smoking, alcoholism and depression. Socioeconomic factors are in agreement with systematic reviews (18) of studies conducted in the United States, India, Italy, France, Canada, Germany, Spain, Denmark, England, and Brazil, where an association between head and neck cancer and socioeconomic conditions was more frequently found.
The results found in the study addressing colorectal cancer show that post-operative complications compromised social and professional roles and those who underwent colonoscopy experienced worse QoL than those who did not. These findings are similar to those found in another study (19) which identified the following as risk factors: poor QoL, psychological stress, advanced stage of the disease, and having a stoma.
The study addressing lung cancer reports that after the third cycle of chemotherapy, symptoms such as fatigue, nausea and vomiting, constipation, and loss of appetite become more intense, compromising the functional scale and performance of roles. One study (20) that investigated the symptoms and QoL of patients with lung cancer report that fatigue was the most frequently experienced among these patients and detected that Sawada NO, Nicolussi AC, Paula JM, Garcia-Caro MP, Marti-Garcia C, Cruz-Quintana F this symptom influenced the functional performance of patients, worsening their QoL.
Assessing and improving the quality of life of patients during and after cancer treatment is essential and a factor that elicits recognition of good practices in oncological services worldwide; many services are recognized and awarded because of this aspect (21) .
In Category 2, the four studies addressing QoL among patients undergoing chemotherapy shows that age, being a woman, stage of the disease, and chemotherapy protocols, and adjuvant chemotherapy cause more symptoms and worsen QoL of patients.
Various Brazilian and international studies have shown the influence of these factors in the HRQL of patients undergoing chemotherapy (22)(23)(24) .
The study conducted in Spain that assessed association of satisfaction with a service and QoL reports that the domains related to care provided by physicians were lower, while those related to nurses were higher. One study (25)  another study (26) that was conducted in Brazil.
The relationship between emotional intelligence and physical and mental health was demonstrated in a review (27) that found that high levels of emotional intelligence are related to improved mental health, while low emotional intelligence is related to certain emotional disorders, which was also reported by the paper found in this IR.
Studies regarding breast cancer report that the factors that influence QoL were psycho-emotional, physical, gastrointestinal, age, level of education, type of chemotherapy, surgical treatment, stage of the disease, body image, and level of anxiety and depression. Many studies report these factors (14)(15) .

Malignant neoplasia cause metabolic alterations in
patients and have been classified as a state of nutritional risk. Malnutrition among adult cancer patients ranges from 40% to 80%, while it ranges from 6% to 50% among child patients. It is directly associated with worsened QoL due to a lower response to specific treatment (28) . This information was found in a paper included in this review, where nutritional state was a positive factor for improved QoL.
The studies that assessed colorectal cancer report that sex influences QoL, where women present more deficits and symptoms than men, while patients younger than 50 years old experience fewer problems with urination. Radiotherapy influenced symptoms such as pain, insomnia, and the performance of roles.
The chemotherapy protocol influenced the cognitive functions and symptoms of pain and loss of appetite.
In another study (19)  Years of schooling influenced the social function scale and financial difficulties, while those with fewer years of schooling experienced more financial hardships.
One international study (29)  The use of complementary and alternative medicine has increased in recent years. The Systematic Review (30) showed that the profile of patients is as A study that assessed physical exercise among women with cancer reports that the benefits are reduced fatigue. The Systematic Review (32) reports that the effects of resistance training on the QoL of patients with cancer also showed that training programs benefit patients and, consequently, improve QoL. Note, however, that the type, intensity, and quantity of exercise should be appropriate to patients' conditions.
Body/mind techniques have gained attention in the treatment of cancer patients. One study (33) emphasizes discoveries regarding the biochemical interaction that takes place among the neurological, endocrine and immunological systems, together with emotional modulation of response to stress. Relaxation and creative visualization and the relationship between health and spirituality are discussed as useful tools to acquire balance between stress and relaxation.
Acupuncture has also been greatly used in the treatment of chemotherapy side effects, such as nausea and vomiting, fatigue, loss of appetite, insomnia, pain, constipation, and depression and anxiety, improving the QoL of patients with cancer (34)