Cancer Prevention and Screening

Concepts, Principles and Controversies

Rosalind A. Eeles, Christine D. Berg, Jeffrey S. Tobias, Rosalind A. Eeles, Christine D. Berg, Jeffrey S. Tobias

• Editorial: Wiley-Blackwell
• Año: 2018
• ISBN:
  9781118991060
• Edición: 1
• Categoría: Medicine
• Categoría: Oncology

Winner of the Council Chair's Choice Award at the 2019 British Medical Association Awards. Cancer Prevention and Screening offers physicians and all clinical healthcare professionals a comprehensive, useful source of the latest information on cancer screening and prevention with both a global and a multidisciplinary perspective.

• Includes background information on epidemiology, cancer prevention, and cancer screening, for quick reference
• Offers the latest information for clinical application of the most recent techniques in prevention and screening of all major and many lesser cancer types
• Emphasises the importance of multidisciplinary teamwork in cancer screening
• Highlights frequent dilemmas and difficulties encountered during cancer screening
• Provides clear-cut clinical strategies for optimal patient education, communication, and compliance with cancer prevention techniques

CHAPTER 1
Global perspectives surrounding cancer prevention and screening

Peter David Sasieni¹ and Donald Maxwell Parkin²

¹ School of Cancer and Pharmaceutical Sciences, King’s College London, UK

² Nuffield Department of Public Health, University of Oxford, UK

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SUMMARY BOX

• The primary approach to cancer control will always be the provision of basic treatment and care. It is inconceivable that this would not be the case because of the immediacy of caring for a sick patient. Without treatment, increased awareness, early diagnosis, and screening are pointless.
• Globally, the biggest challenges and greatest successes come from tobacco control and vaccination (against hepatitis B virus and human papilloma virus).
• Although not currently associated with any concerted global action, obesity and alcohol control are the next most important challenges for cancer prevention.
• Cervical screening is the exemplar of a simple test with the potential to prevent the majority of a particular cancer. Even so, cervical cancer remains a major health problem in most low‐income countries.
• Most other forms of cancer screening rely on early detection of invasive cancer and their widespread introduction has been restricted to countries with facilities for diagnosis and treatment.
• Screening for early cancers relies on expensive technologies; attempts to use cheap and simple tests have not been successful at a national population level.
• Undoubtedly, early diagnosis of cancer has a large impact on morbidity and survival (and subsequent mortality). There is evidence from developed countries that stage distribution has improved over time (more early‐stage disease with a subsequent decline in late stage at presentation). Today, stage distribution in low‐ and middle‐income countries lags behind that of high‐income countries.
• Stage at diagnosis can be improved by awareness campaigns, but only when care is available, accessible, and affordable.

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Principles of cancer control strategy

Noncommunicable diseases, including cancer, are a current challenge to health services, and one which will increase with the ageing of the world population and changes in lifestyles [1]. The World Health Organization (WHO) strategy is to promote National Cancer Control Programmes (NCCPs) as the most effective approach for reducing the morbidity and mortality from cancer [2]. The development of an NCCP requires adequate information in order to evaluate the nature and magnitude of the cancer burden (and the availability of health‐care infrastructure), as well as the potential impact of the various possible strategies in prevention, early diagnosis/screening, treatment, and palliative care.

Prevention of cancer has to be set within the context of prevention of other noncommunicable diseases, because they have many (but not all) risk factors in common, notably those that are lifestyle related, such as smoking, alcohol, diet, overweight/obesity, and lack of physical exercise. We do not, in this chapter, discuss biomedical approaches to prevention (medication, surgery), because globally they have no role at present.

Early diagnosis is a public and health professional awareness activity, to encourage people to recognize early signs of the cancer and to seek prompt medical attention. Screening involves encouraging asymptomatic individuals to undergo tests to detect early cancer, or precancerous states. Both early diagnosis and screening have to be set within an existing health infrastructure that provides adequate resources for the management of detected cancers (without which such programmes would be ineffective). Because of the considerable resources involved, population screening programmes should be undertaken only when the prevalence of the disease to be detected is high enough to justify the effort and costs of screening, and where resources (personnel, equipment, etc.) are sufficient to cover diagnosis, treatment, and follow‐up of those with abnormal results.

Magnitude of the problem: Proportion of cancer globally attributable to preventable causes

Noncommunicable diseases accounted for about two‐thirds of deaths occurring in the world in 2008 [1]. Considering cancer as a single group, the estimated 7.9 million deaths in that year constituted the leading cause of death (Figure 1.1). In 2012, the most commonly diagnosed cancers were lung cancer (13% of all cancers), breast cancer (11.9%), and colorectal cancer (9.7%); the most common causes of cancer death were lung cancer (19.4% of cancer deaths), liver cancer (9.1%), and stomach cancer (8.8%) [3]. Figure 1.2 shows the numbers of cases and deaths for the most common cancers for males and females.

Figure 1.1 The estimated 7.9 million deaths attributed to cancer in comparison to other causes of death. COPD, chronic obstructive pulmonary disease.

Source: Global Health Observatory Data Repository.

Figure 1.2 The most commonly diagnosed cancers in 2012 for males and for females.

According to Danaei et al. [4], the major environmental causes of cancer death (in 2001) were tobacco, alcohol, and low consumption of fruit and vegetables.

Tobacco smoking is undoubtedly the most important preventable cause of cancer. As estimated by the WHO [5], tobacco was responsible for 22% of the deaths from cancer in 2004 (32% in men, 22% in women), with the major contribution (58% of cancer deaths) coming from lung cancer.

Second in importance in terms of preventable causes of cancer is infection. In 2008, it was estimated that about 16% of the global cancer burden (around 2 million cancers per year) was attributable to infectious agents [6]. The fraction is much larger in low‐income than in high‐income countries. Each of the three principal infectious agents – Helicobacter pylori (stomach cancer), human papilloma virus (HPV; ano‐genital, especially cervical, and oropharyngeal cancer), and the hepatitis viruses HBV and HCV (liver cancer) – is responsible for approximately 5% of the global cancer burden. Much smaller fractions are due to Epstein‐Barr virus (nasopharynx cancers and some lymphomas) and human herpes virus 8 (Kaposi sarcoma), as well as to parasites such as Schistosoma haematobium (liver cancer) and liver flukes (cholangiocarcinoma).

The International Agency for Research on Cancer (IARC) [7] considers that there is sufficient evidence that alcohol consumption causes cancers of the oral cavity, pharynx, larynx, oesophagus, colorectum, liver (hepatocellular carcinoma), and female breast, and also that an association has been observed between alcohol consumption and cancer of the pancreas. The IARC estimated that alcohol was responsible for some 337 400 cancer deaths in 2010, 4.2% of all cancer deaths, with the largest contributions from cancers of the liver and oesophagus (about 23% of such deaths), breast, oral cavity, and colorectum (about 12% each) [7].

Approximately 2.8% of deaths worldwide are attributable to low fruit and vegetable consumption [8]; adequate consumption of fruit and vegetables reduces the risk for cancers of the oral cavity, oesophagus, stomach, and colorectum [9].

Dietary contaminants are a significant problem in some regions; for example aflatoxins, produced by moulds that contaminate cereals and nuts, cause liver cancer, especially in individuals infected with HBV. Aflatoxin has been estimated to have a causative role in 5–28% of all hepatocellular cancers [10].

In 2002, the IARC concluded that overweight and obesity are related to cancers of the colon, endometrium, kidney, and oesophagus (adenocarcinoma), as well as postmenopausal breast cancer. In addition, the report by the World Cancer Research Fund [11] considered that there was convincing evidence for an association with cancers of the pancreas and rectum, and a probable association with cancers of the gall bladder. Overweight and obesity are generally evaluated in terms of body mass index (BMI), with, in ‘western’ countries, a BMI of 25–29.9 kg/m² being considered overweight, and over 30 kg/m² obese. Using this definition, Renehan et al. [12] estimated that 5.7% of cancers in Europe in 2008 (3.2% of those in...

Índice

• Cover
• Table of Contents
• Foreword
• CHAPTER 1: Global perspectives surrounding cancer prevention and screening
• CHAPTER 2: Public health perspectives surrounding cancer prevention and screening: The Ontario edition
• CHAPTER 3: Cancer screening: A general perspective
• CHAPTER 4: The balance of cancer screening risks and benefits
• CHAPTER 5: Cancer screening issues in black and ethnic minority populations
• CHAPTER 6: Public awareness of cancer screening
• CHAPTER 7: Public understanding of cancer prevention
• CHAPTER 8: Cervical cancer screening: An exemplar of a population screening programme, and cervical cancer prevention
• CHAPTER 9: Prevention of and screening for anal cancer
• CHAPTER 10: The prevention of breast cancer
• CHAPTER 11: Breast cancer: Population and targeted screening
• CHAPTER 12: Prostate cancer prevention
• CHAPTER 13: Population screening for prostate cancer
• CHAPTER 14: Colon cancer prevention
• CHAPTER 15: Colon cancer screening
• CHAPTER 16: Lung cancer prevention
• CHAPTER 17: Lung cancer screening
• CHAPTER 18: Mesothelioma: Screening in the modern age
• CHAPTER 19: Skin cancer prevention and screening
• CHAPTER 20: Screening and prevention of oral cancer
• CHAPTER 21: Oesophageal cancer
• CHAPTER 22: Hepatocellular carcinoma: Prevention and screening
• CHAPTER 23: Ovarian cancer prevention and screening
• CHAPTER 24: Screening for testicular cancer
• CHAPTER 25: Issues in paediatric cancers
• CHAPTER 26: Obesity and dietary approaches to cancer prevention
• CHAPTER 27: Risk profiling for cancer prevention and screening – lessons for the future
• CHAPTER 28: Cancer prevention and screening: Advances to carry forward
• Index
• End User License Agreement