A Systematic Review of Worldwide Cancer Nursing Research: 1994 to 2003
The word cancer elicits dread in nearly everyone. Cancer accounts for considerable mortality and morbidity in both men and women (, 2004). Certain genes controlling growth and interactions with other normal cells are apparently abnormal in structure or regulation in cancer cells ( & , 2000). People of all ages develop cancer which could affect a wide variety of body organs. The incidence of many cancers increases with age: which means that as people live longer, many more will develop the disease. Apart from individual suffering, the economic burden to society is immense ( , 2000).
Cancer cells are characterized by three properties: (1) diminished or unrestrained control of growth; (2) invasion of local tissues; and (3) spread, or metastasis to other parts of the body. Cells of benign tumors also show diminished control of growth but do not invade local tissue or spread to other parts of the body (, 2000).
Cancer is caused in all or almost all instances by mutation or by some other abnormal activation of cellular genes that control cell growth and cell mitosis (, 2001). The abnormal genes are called oncogenes ( & , 2000). Cancer tissue competes with normal tissues for nutrients. Because cancer cells continue to proliferate indefinitely, their number multiplying day by day, one can readily understand that the cancer cells soon demand essentially all the nutrition available to the body or to an essential part of the body. As a result, normal tissues gradually suffer nutritive death ( & , 2000).
An abnormal cell mass that develops when controls of the cell cycle and cell division malfunction is called a neoplasm. However, not all neoplasms are cancerous. Benign neoplasms are strictly local affairs. Neoplasms tend to be surrounded by a capsule, grow slowly, and seldom kill its hosts if removed before it compresses vital organs. In contrast, malignant (cancerous) neoplasms are nonencapsulated masses that grow more relentlessly and may become killers. Its cells resemble immature cells, and it invades their surroundings rather than pushing it aside, as reflected in the name cancer from the Latin word for “crab.” Malignant cells also tend to spread via the blood to distant parts of the body, where they form new masses. This last capability is called metastasis (paragraph source from , 2004).
Genetic aspects of cancer are probably receiving the greatest current attention among genetic abnormalities. Genetic abnormalities refer to abnormalities in chromosomes (, 2006), such as those that occur in the process of cancer. Some cancers are caused by oncogenes, genes which are carried in the genomes of cancer cells and are responsible for producing their malignant properties (& , 2000). These genes are derived by somatic mutation from closely related proto-oncogenes, which are normal genes that control their growth. Over 100 oncogenes have been described (, 2001).
The initiation of mitosis and normal cell division depends on the orderly occurrence of events during the cell cycle. There is intense interest in the biochemical machinery that produces mitosis, in part because of the obvious possibility of its relation to cancer. When DNA is damaged, entry into mitosis is inhibited, giving the cell time to repair the DNA; failure to repair damaged DNA leads to cancer (, 2000). The cell cycle is regulated by proteins called cyclins and cyclin-dependent protein kinases, which phosphorylate other proteins (, 2001).
Cell replication involves not only DNA polymerase but a special reverse transcriptinase that synthesizes the short repeats of DNA that characterize the ends (telomeres) of chromosomes. Cells with high telomerase activity, which includes most cancer cells, can in theory keep multiplying indefinitely (Paragraph source , 2001).
Cell Division in normal and cancer cells.
Source:
The stepwise development of a typical colon cancer is as follows:
1
2
3
Cellular changes
Increased cell division
Growth of polyp
Growth of malignant tumor (carcinoma)
DNA changes
Oncogene activated
Tumor-suppressor gene activated
Second tumor-suppressor gene activated
The treatment of choice for either type of neoplasm is surgical removal. If surgery is not possible – as in cases where the cancer has spread widely or is inoperable – radiation and drugs (chemotherapy) are used (, 2004). Chemotherapeutic drugs destroy malignant cells (, 2004).
A process known as ‘adjuvant chemotherapy’ or ‘adjuvant radiotherapy’ is used when chemotherapy or radiotherapy is used in addition to surgery (, 2004). For example, a patient following surgery may be given a course of chemotherapy or radiotherapy. This aims to kill any cancer cells which may have spread away from the primary tumor site. Sometimes, adjuvant chemotherapy or radiotherapy is given before surgery to shrink a large tumor so that the operation to remove the tumor is easier for a surgeon to do, and is more likely to be successful (, 2004).
Cytotoxic therapy regimens are highly toxic to cells, and can result in a range of acute and chronic adverse effects for persons receiving these treatments (, 1996). A number of these adverse effects are potentially life threatening. The safe and effective delivery of these drugs therefore requires highly complex clinical assessment, technical and problem solving skills.
Surgery, radiotherapy, and chemotherapeutic agents are the major modalities used to treat patients with cancer, though various biologic therapies are beginning to have a significant impact. This means that biologic therapies are slowly being used in the realm of cancer treatments. The challenge is to make available drugs (natural products or synthetics) that can kill cancer cells effectively but are not excessively toxic to normal cells. It must be noted that cancer treatments should only kill cancer cells and not the normal cells. This explains the importance of developing drugs and other treatments that can kill cancer cells yet has minimum if not zero harm to the normal cells. Among the many available drugs and compounds used in the treatment of cancer, a few are listed in the table below:
Class of Compound
Example
Site of Action
Treatment Use
Alkylating agents
Melphalan
Alkalytes DNA and other molecules
Myeloma
Antimetabolites
Purine antagonists
Pyrimidine antagonists
Folate antagonists
Mercaptopurine
Fluorouracil
Methotrexate
Converted to a “fraudulent” nucleotide and inhibits purine synthesis
Converted to a “fraudulent” nucleotide and inhibits thymidylate synthetase
Inhibits dihydrofolate reductase
Acute myelocytic leukemia
Colorectal cancer
Choriocarcinoma
Antitumor antibiotics
Doxorubicin
Intercalates in DNA and stabilizes the DNA-topoisomerase II complex
Hodgkin’s disease
Other agents
Cisplatin
Hydroxyurea
Causes strand breakage in DNA
Inhibits ribonucleotide reductase
Carcinoma of the lung
Chronic myelocytic leukemia
Plant compounds
Vinblastine
Binds tubulin and inhibits microtubule formation
Kaposi’s sarcoma
Sex hormones
Estrogens
Block effects of androgens in prostatic tumors
Cancer of the prostate
Corticosteroids
Prednisone
Inhibits proliferation of lymphocytes
Myeloma
Source:
Insofar as unrestrained cell division is a feature that typifies many malignant tumors, many of these agents are used because they inhibit DNA synthesis. For this reason, these agents are also likely to damage normal tissues whose cells divide continuously – e.g. bone marrow (paragraph source , 2000). To explain further, bone marrow which normally divides at a continuous division, could be stopped once exposed to cancer treatments, causing an abnormality in the bone marrow production yet helping combat cancer cells.
Anti-cancer drugs have unpleasant side effects because, as mentioned in the previous paragraph, most target all rapidly dividing cells, including normal ones (, 2000). The side effects include nausea, vomiting, and loss of hair (, 2004). X rays also have side effects because, in passing through the body, the x-rays kill healthy cells that lie in the path to the cancer cells ( 2004). Life threatening adverse reactions and side effects of the treatment include pulmonary fibrosis and anaphylaxis/anaphylactoid reactions ( & , 2004). The most frequent includes fatigue, diarrhea, nausea, vomiting, anemia and neurotoxicity ( & , 2004).
Current cancer treatments – “cut, burn, poison” – are recognized as crude and painful. Promising new methods focus on delivering anticancer drugs precisely to the cancer (via monoclonal antibodies that respond to one type of protein on a cancer cell) and on increasing the immune system’s ability to fend off cancer ( 2004).
In all these events in a cancer patient, the senior oncology specialist nurses are responsible for co-ordinating care following any operations and/or treatment for cancer. A senior oncology nurse is highly qualified, having specialized training in caring for patients who have cancer, and has many years of experience in this field. As well as supporting a patient and his or her family through operation and treatment, the senior oncology nurse provides the patient and his or her caregivers with clear written and verbal information; and can also examine and arrange any tests the patient might need.
The number of patients suffering from cancer worldwide has steadily increased in recent years mainly due to an ageing population (, 2006). Add to this, an increasing number of chemotherapeutic agents (, , 2000) and a multitude of regimes, it therefore becomes very important to the point that it should be imperative to educate the nurse on the care of the patient who has cancer.
In line with the previous paragraphs describing the current situation with cancer, its patients, and the health care professionals, it was only fitting that a study was made to assess the cancer nursing research papers published in the past decade. This also aims to identify their characteristics in terms of country of origin, participants, settings, diagnostic foci, and methodologic choices. Additionally this study evaluates their quality as this would significantly help cancer treatments.
A systematic review was carried out of all published papers in the Cumulative Index of Nursing and Allied Health Literature between the years 1994 and 2003, using the keywords “cancer,” “nursing,” and “research.” A total of 619 papers met inclusion criteria and were evaluated by 5 researchers. Almost half the papers were derived from the United States (49.1%), followed by the UK, Sweden, Canada, and Australia.
Of all the published papers, more than half of these (52.2%) had health professionals (mostly nurses) as the studies’ participants. Also, much of the published research used patients with mixed diagnosis, or patients with breast or hematologic cancers. Two-thirds of the studies were quantitative, whereas most studies were descriptive in nature. The quality of both quantitative and qualitative studies was low, with only a small percentage meeting the highest quality criteria. Studies reporting funding and those published in journals with an impact factor showed a higher quality score than those not reporting funding or not published in journals with an impact factor.
Concern for global health issues goes with a global perspective in nursing knowledge. As nations become increasingly interdependent, health for all is a worldwide goal, and the framework of health care constrained by national boundaries does not fit nursing (, 2001). A widely recognized advantage of globalization is improved access to information. Global communication in the field of nursing increases through print journals, electronic journals, online educational materials, and international conference proceedings. Worldwide dissemination of nursing information represents a novel opportunity to expand the reach and effect of professional nursing. Accordingly, interest in international collaboration has increased in the published literature in the past decade.
International collaborations are important because it would (a) improve knowledge and understanding of human needs across geographic boundaries, (b) support a global perspective for nursing by fostering worldwide inclusiveness, and (c) expand the cultural and ethical values underpinning goals in nursing ( & , 2004). Globalization in knowledge development is linked to international publication in the field of nursing. Knowledge about the international content of nursing journals is a necessary part of understanding the trend toward globalization of nursing knowledge. The systematic study of the international content of highly ranked nursing journals in 2000 was a way to benchmark the status of international publication in nursing (, 2004).
Many issues about globalization have been raised in the nursing literature. Consensus is apparent that the development of international nursing requires a global focus and international collaboration. Leaders question whether Western science can be adapted to a global health framework and whether Western nursing is appropriate for global nursing practice (, 2000). Nurses realize that Western science does not have answers in all areas of nursing practice (., 2000) because knowledge and research development are embedded within cultural contexts (, 2000). In a global nursing framework, nurses should emphasize the concept of cultural sensitivity. International comparisons of cultural values are necessary because it helps researchers become aware of how different values influence the development of nursing knowledge and practice (, 2000). Scholars are aware of their own knowledge and cultural values, and they are encouraged to understand alternative ways of thinking (., 2000).
International collaboration is important for the following reasons: (a) it provides alternative modes of thinking for nursing scholars, (b) it enables wide-range testing of theories in practice, (c) it facilitates scholarly maturity through self-assessment, and (d) it leads to advancement of nursing science (, 2004). Journals have to be identified in order to investigate the international focus in journals.
The advancement in biotechnology is also helping to speed up and improve cancer research in many parts around the world. Technology has allowed many medical institutions to do what these institutions are doing today. In cancer research, getting the data and results from DNA sample of patients is important in helping them understand why some people have cancer (, 2001). In the past, this process was tedious and would take up days, months, and even years before the researcher can get the data and results, let alone the analysis (, 2005). But with the existence of machines like the DNA sequencer and the microarray technology, cancer research has been sped up and can be done at a higher throughput. For instance, DNA sequencing is now quite a routine procedure in many laboratories and research centers (, 2003).
Progress in the understanding of genetics, and its role in disease and cancer epidemiology, have encouraged scientists that they are on the brink of major advances in methods and treatments (, 2005). This progress includes the ability to target cancerous cells without harming healthy tissue as well as better targeted treatments for specific cancers based on understanding of their genetic structure (, 2005). While the billions of dollars being spent on cancer research by governments around the world is significant, it seems that now is the time to aggressively push forward, not cut back on spending (, 2006). Overall worldwide spending for cancer research is growing. This is good news for the health care consumer, who probably doesn’t care where therapies are developed as long as their treatment is successful.
New understanding of how cancer cells survive, thrive, and metastasize has enabled researchers to create new targeted therapies for cancer treatments, such as melanoma and Kaposi’s sarcoma, to minimize the harmful systemic effects (therapy on healthy cells. The specific and selective targets of future oncology drugs will require a detailed understanding of cancer cell biology, genetics, immunology, and biotechnology (paragraph source , 2005).
The search for anti-cancer therapies which target cancer cells specifically and selectively with less toxicity has been a quest in oncology for many years. Conventional chemotherapeutic agents do not target cancer cells selectively, leading to widespread adverse systemic effects. Chemotherapy, radiation therapy, and biological agents all target cells that are in the process of proliferation. Therefore, both cancer cells and mitotically active healthy cells are subject to the cytotoxic effects of these therapies (paragraph source, 2000).
The diagnosis of cancer and other life-threatening diseases can be devastating to patients and their families. While many complex, disease-focused medical procedures are routinely prescribed for patients, often little or no consideration is given to prescribing comfort measures and sustaining optimal quality of life (, 1996). Nurse educators are on the front lines in promoting the holistic care that is essential for the nurturing of patients with cancer and other serious illnesses (, 2004).
Among the many challenges faced by individuals affected by life-threatening illnesses are profound changes in social roles and interpersonal relationships ( & , 2004). Maintaining employment is difficult, and parenting, socializing with friends, and spiritual well-being are all affected. The whole person suffers by a threat to any one of four dimensions: physical, psychological, social, or spiritual. However, nurses who possess effective communication skills can positively influence rate of recovery, optimize pain control interventions, and better facilitate emotional well-being ( & , 2004).
Little empirically based information is available describing the extent to which the above problems also affect oncology nurses when referring to the nursing workforce specializing in the care of patients with cancer. Because most people who have cancer are older, the aging of the baby boom generation is expected to increase the number of people with cancer substantially, and hence the future demand for oncology nurses. Cancer is the second leading cause of death in many countries, exceeded only by heart disease. Today, however, reports of shortages of oncology nurses are not uncommon, and because many cancer facilities report difficulty retaining nursing staff, information is needed on the adequacy of the oncology nurse workforce (, 2001).
A study confirms long-held suspicions that lung cancer, the leading cancer killer of both men and women, is seriously underreported when compared to other major cancers. In an analysis of 600 randomly selected cancer stories that appeared between August 1999 and July 2000, 61 percent reported on breast cancer, 23 percent on prostate, 17 percent on colorectal cancer and only 9 percent focused on lung cancer outside of tobacco and smoking issues (, 2004). This is especially significant since more people die each year of lung cancer than the combined deaths from breast, prostate and colorectal cancer (, 2004).
Studies on cancer also further demonstrate the overwhelming ability of celebrities to draw attention to cancer issues (, 2004). Breast, prostate and colorectal cancers generated significant news attention through a number of celebrities who were affected, either directly or indirectly, by the disease. Television host Katie Couric significantly raised awareness of colorectal cancer on her program The Today Show; New York Mayor Rudolph Giuliani’s prostate cancer diagnosis drove coverage to peak levels. Only one celebrity was quoted speaking out for lung cancer, cyclist and cancer survivor Lance Armstrong, who was involved in the Lung Cancer Awareness Campaign in 1999 (, 2003).
Cancer nurses report a rising workload and concerns about a national shortage of nurses in the speciality. A federal government report had found there was a shortage of oncology and palliative care nurses in every state and territory except the Northern Territory, the Cancer Nurses Society of Australia (CNSA) told the inquiry into cancer services (, 2001). Recent research into the workloads of cancer nurses found 50% of cancer nurses did not have time to get through their work, and 70% said they were experiencing ‘moderate to high levels of emotional exhaustion’, the society said in its submission (, 2001).
The CNSA called for governments to improve cancer nurse staffing models; provide financial support to nurses to pursue further studies; and fund research into innovative models of cancer care involving specialist cancer nurses. A national approach is needed to address the workforce shortages of cancer nurses, particularly improving the available data on cancer nurses in the workforce and developing a national plan to improve staff retention and support strategies (, 2005).
As a result of improved diagnosis and treatment, more people are surviving cancer (, 2003). Cancer survival, however, can be attended by negative physical and psychological syndromes, including weight gain, lowered aerobic capacity, depression, anxiety and an overall decrease in quality of life ( & , 2004). In addition, cancer survivors are at increased risk for developing other chronic conditions such as cardiovascular disease, obesity and diabetes. Reasons for these risks are complex and include genetics, treatment factors, lifestyle factors and a sedentary lifestyle (, 2004).
Research on cancer survivors suggests that weight gain, depression, anxiety and other issues contributing to decreased longevity and quality of life can continue long after the course of treatment. In a study of breast cancer survivors eight years postsurgery, it was also reported that women had persistent symptoms of psychological and somatic disturbance (, 2004). Most studies on the physical and psychosocial effects of cancer have focused on the period during treatment or within two to three years of diagnosis (, 2004). Very little is known regarding the longevity of these sequelae, their impact on the aging survivor or the interventions that will improve quality of life (, 2004).
Findings from studies that focused on cancer suggest that these health issues may persist beyond the period of chemotherapy and radiation treatments (, 2003). These studies highlight the longevity of mental and physical changes, depression and decreased quality of life among cancer survivors. The findings emphasize the need for improved systems of care to minimize health disparities, and further research on interventions to improve health outcomes.
Research evaluation is currently enjoying a favored position in many countries as research budgets expand but there is also pressure from those who fund them to ensure value for money (, 1999). In several European countries, for example, there is a move to more competitive funding both of laboratories and of individual research projects (, 2000). The ultimate test of the utility of research is that it will give rise to new products and processes or, in the biomedical field, to better health for humans and animals. However, the route to these tangible benefits is often lengthy, especially for basic research (, 1999), so that proxy indicators are needed to show whether given expenditures have been worthwhile. The main proxy indicator is the esteem in which research is held by other researchers, which can be measured by the counting of citations. However, these suffer from some disadvantages:
- they are somewhat costly to determine – typically about US per paper;
- it takes time for them to accumulate, so that fair comparisons can be made – perhaps five years; and
- comparisons between different fields and sub-fields are difficult because citation norms differ greatly (, 1999).
In some ways, the analysis of the factors which lead to high quality research is comparable with epidemiology. In this subject, the factors that lead to ill-health are analyzed. The problem in both analyses is that there may be missing factors, some of which are correlated with the ones used for analysis, and which can confound the apparent conclusions. For example, ill-health is positively associated with smoking, a poor diet, lack of exercise and a low-status job ( and , 2000). Each of these factors is strongly associated with the three others and indeed with yet more factors that can plausibly lead to ill-health, such as low income, low education level, poor housing and living in a polluted area. If public health measures are to be soundly based, it is essential that the individual effects of all these factors, and probably many more, are teased out, so that policies can be targeted on the most important ones.
Similarly, the factors that lead to high quality research may plausibly include:
- the subject area of the research;
- whether it is applied or basic (in biomedicine, clinical or basic);
- whether it is carried out in an industrial or academic setting (in biomedicine, in a hospital or a university);
- whether the team of authors is large and multi-disciplinary or small;
- whether there is inter-laboratory collaboration;
- whether there is international collaboration and, if so, with which country or countries;
- whether the research has been reviewed by a peer-review committee for funding and, if so, by how many;
- whether the research has been funded by a particular sector (government, private-non-profit, industry); and
- the city in which the research has been conducted.
Cancer nursing research is still in a developmental stage, although it has made a considerable contribution to the evidence base of the discipline. A number of issues need to be tackled before we improve our output, such as organizational or workforce issues, infrastructure support, funding, and methodologic challenges. Acquisition of new knowledge is essential in contributing to nursing practice for cancer. The expansion of technology, changes in the health care delivery system, and aging of the population all require nurses to review and apply research findings to identify and solve not only cancer issues but other clinical nursing problems and issues as well.
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