CHAPTER 27 Cancer
When you have completed this chapter you will be able to:
INTRODUCTION
Cancer is chronic and a complex set of diseases. It arises from any cell in the body that is capable of evading normal regulatory processes, affecting one in three men and one in four women before the age of 75 years in Australia and New Zealand (Australian Institute of Health and Welfare (AIHW) & Australasian Association of Cancer Registries (AACR), 2007). While cancer continues to be one of the most common causes of death among adult Australians and New Zealanders, considerable progress has been made in controlling this disease in recent years. The five-year relative survival rate in Australia is around 56.8% for men and 63.4% for women (up from 43.8% for males and 55.3% for females in the preceding five years) (AIHW & AACR, 2001). In New Zealand, five-year relative survival rates are 59.2% for men and 60.5% for women (New Zealand Health Information Service, 2006). This progress means that there are an estimated 267,000 Australians alive today who have a history of cancer (The Cancer Council Australia (TCCA), 2006). These developments mean that cancer today is considered a chronic disease.
Cancer is a set of diseases that have a natural history, a course of progression, treatments and outcomes in the short and long term which vary markedly. This means that the experiences and needs of people at risk or affected by cancer will vary considerably. While it is a disease that does not have a series of well-marked events, critical points at which health professionals may intervene to improve cancer outcomes can be identified. For well communities these critical points include opportunities for reducing the risk of cancer and detecting the cancer early. For those with a diagnosis of cancer, critical points include opportunities for ensuring the best possible treatment and support during and after treatment and providing best care at the end of life for those whose disease progresses (National Health Priority Action Council (NHPAC), 2006).
REDUCING RISK AND DETECTING CANCER EARLY
BEHAVIOURS THAT CONTRIBUTE TO THE DEVELOPMENT OF THE CANCER
The cellular changes that characterise cancer are initiated by various degrees of interaction between endogenous biological and exogenous carcinogenic factors, including tobacco, alcohol, occupational exposure, environmental pollution, food contaminants, medicinal drugs, radiation, chronic infections, diet and nutrition, immunosuppression, genetic susceptibility and reproductive factors and hormones (International Agency for Cancer Control (IARC), 2003). Modifiable behavioural factors can thus play an important role in the development of cancer. The prevention of cancer, especially when integrated with the prevention of chronic diseases and other related problems, offers the greatest public health potential and the most cost-effective long-term method of cancer control (IACRC, 2003).
Evidence to support the implementation of strategies to prevent cancer is growing. The World Health Organization (WHO) claims that we now have sufficient knowledge to prevent around 40% of all cancers (WHO, 2006), with evidence to support the effectiveness of interventions to address modifiable behavioural risk factors in the following areas: tobacco control; exposure to ultraviolet radiation; diet; physical activity; overweight and obesity; and alcohol. The Cancer Council of Australia has thus defined evidence-based policy targets for cancer prevention, and recommended actions for health and community organisations and individual health professionals to achieve their proposed targets (TCCA, 2007). A summary of these recommended actions is presented in Box 27.1.
BOX 27.1 Cancer prevention aims
Tobacco
Prevent the uptake of smoking.
Encourage and assist as many smokers as possible to quit as soon as possible.
Eliminate harmful exposure to tobacco smoke for non-smokers.
Ultraviolet radiation
Develop strategies for the early detection and effective diagnosis of skin cancer.
Achieve health settings, organisations, products, policies and practices thatpromote sun protection.
Strengthen the community’s capacity for coordinated action on skin cancer prevention.
Inform the design, implementation and evaluation of skin cancer prevention strategies.
Physical activity
Maintain a healthy body weight through a balance of food intake and physical activity.
Overweight and obesity
Consume nutritionally adequate and varied diets based primarily on foods of plant origin such as vegetables, fruit, pulses and wholegrain cereals, as well as lean meats, fish and low-fat dairy products.
Adopt a physically active lifestyle.
PARTICIPATION IN CANCER SCREENING PROGRAMS
For the majority of cancers, outcomes are dramatically improved when the cancer is detected early. Promoting participation in early detection programs is a critical concern for health professionals in all areas of practice. In the context of cancer, early detection can be achieved through population screening programs (such as screening mammography, cervical cancer screening, or Faecal Occult Blood Testing), opportunistic screening (such as through informal health checks) and diagnostic screening (that is, when a person presents with symptoms for investigation). While familial cancers that are caused by inherited genetic mutations account for only around 5–10% of cancers, the growth in understanding of many of the genes responsible for heritable mutations is also raising a range of issues in relation to cancer screening (National Health and Medical Research Council (NHMRC), 1999).
Despite the importance of early detection, rates of participation in screening programs vary between different social demographic groups. For example, women from a non-English-speaking background, and Aboriginal and Torres Strait Islander women, have lower participation rates in mammographic screening programs (AIHW, 2006). Understanding barriers to cancer screening enables health professionals to implement targeted intervention strategies to promote participation. For example, barriers to cancer screening that are potentially amenable to intervention include financial concerns, concern about radiation, embarrassment, poor access, anxiety about test results, inconvenience, forgetting or procrastination, and discomfort associated with the screening test (TCCA, 2007). The National Service Improvement Framework for Cancer (NHPAC, 2006) has defined principles that should underpin optimal services in relation to cancer screening. These principles are described in Box 27.2. They provide a framework for health professionals to consider areas in which they may intervene to ensure optimal outcomes from cancer screening at the population and individual level.
BOX 27.2 National Service Improvement Framework for Cancer: Optimal Services: Finding Cancer Early
People will have information about population screening programs for cancer including:
ENSURING BEST POSSIBLE TREATMENT AND SUPPORT DURING AND AFTER ACTIVE TREATMENT
QUALITY OF LIFE
The presence and severity of the effects will vary from individual to individual, although the factors underlying these differences are not completely understood. Quality-of-life concerns for the person affected by cancer thus include many physical, psychosocial and practical issues and, for some, end-of-life concerns. Box 27.3 provides a summary of the key quality-of-life concerns that may be experienced by people affected by cancer, many of which persist during and after treatment.
BOX 27.3 Summary of the major issues faced by people with cancer
Source: National Breast Cancer Centre and National Cancer Control Initiative (2005).
With improvements in cancer treatment, survival from cancer has been extended. A growing body of research has highlighted that cancer survivors have a unique set of health and support needs. For the majority of people diagnosed with cancer, the disease and its effects thus become chronic in nature. The specific risk of recurrence or late effects experienced by an individual who has undergone treatment for cancer will usually depend on the specific site, and histology of their disease, the treatments they received, when those treatments were delivered (since regimens and techniques change over time), the length of time that has elapsed since those exposures, and underlying risk factors independent of their cancer or its treatment (Institutes of Medicine [IOM], 2006). Moreover, as cancer is largely a disease of the elderly, determining the late effects of the cancer disease and treatment process from unrelated co-morbid conditions can be difficult (IOM, 2006). While there is considerable heterogeneity in post-treatment experiences for people with cancer, a number of common quality-of-life concerns have been identified for cancer survivors. These are summarised in Box 27.4.
