What is cancer?

• Cancer is a diverse group of diseases characterised by the proliferation and spread of abnormal cells, which cannot be regulated by normal cellular mechanisms and grow in an uncontrolled manner. While some cancers share common causes or risk factors, it is believed that most cancers have a unique set of factors responsible for their initiation.

• The National Health Priority Areas initiative has identified a focus on lung, skin, cervix, breast, colorectal, prostate cancers and non-Hodgkin's lymphoma

Size of the problem

• On average, one in three Victorian men and one in four women are likely to develop cancer before the age of 75

• The cancers with the highest incidence in Victoria in 1996 (excluding non-melanocytic skin cancer) were prostate (3,433 cases), followed by breast (3,124), colorectal (3,034), melanoma (2,541) and lung (2,181)

• The cancers which caused the most deaths in Victoria in 1996 were lung (1,906), followed by colorectal (1,355), breast (780) and prostate (721)

• Cancer is responsible for more than 20% of disease burden (127,000 DALYs) in Victoria, mainly lung (23,000 DALYs), colorectal (18,000), breast (16,000) and prostate cancer (9,000)

• Skin cancer is the most common cancer in Australia (by far) when non-melanocytic cancers are included along with melanoma

Historical trends

• Lung cancer death rates in Australia are declining in males (from 66 per 100,000 in 1978 to 53 per 100,000 in 1998), but increasing in females (from 12 per 100,000 in 1978 to 19 per 100,000 in 1998)

• Trends in lung cancer death rates largely reflect smoking trends, with a time lapse of about 20 years

• Since 1950, the male death rate for colorectal cancer remained steady until the mid 1980s, and the declined from 32 per 100,000 in 1983 to 27 per 100,000 in 1998; the female death rate on the other hand showed a steady decline

• There was a steady increase in breast cancer incidence between 1983 and 1989, and a more rapid increase between 1990 and 1994, peaking in 1996 with a slight fall in 1996

• Mortality rates for breast cancer have remained relatively stable since 1983

• Mortality rates for non-melanocytic skin cancers have been increasing since the late 1980s

• Colorectal cancer incidence has been steady over the last two decades, with a small decline in mortality rates

• Age-standardised rates for cervical cancer incidence and death rates in Victoria have dropped by almost half in the past 20 years

International comparisons

• Lung cancer mortality patterns vary internationally, with Australian males having relatively lower death rates, whereas Australian females show a slightly higher ranking in comparison to other countries

• Internationally, colorectal cancer incidence varies by a factor of 20 in men and 15 in women

• Australia's incidence and mortality from colorectal cancer rates rank high

• There is a seven-fold variation in breast cancer incidence internationally

• Australia ranks above average for incidence and average for mortality among women aged 50-74 years

Projections

Cancer is projected to become the largest cause of burden by 2016 (overtaking cardiovascular disease) because improvements in cardiovascular health are expected to outpace the slower improvements in cancer

Special populations

• Young people:

  • Young people are a priority population for lung cancer prevention. The earlier a smoker takes up the habit, the more likely it is they will develop lung cancer.

• Indigenous Australians:

  • The percentage of Indigenous persons who smoke is about twice the national average

• Socioeconomically disadvantaged groups:

  • Smoking rates remain higher in less advantaged socio-economic groups

• People from some culturally and linguistically diverse (CALD) background:

  • Smoking rates are higher among males born in Vietnam, Greece and the Middle East

• High risk groups for colorectal cancer:

  • can be easily identified, usually from having a characteristic family history; screening is available for inherited conditions such as FAP

Evidence-based interventions

Thirteen priority actions for incremental development in cancer control were identified in the National Cancer Strategies Group report 'Priorities for Action in Cancer Control 2001-2003'

Prevention:

• Reducing the prevalence of smoking through a mix of coordinated tobacco control strategies including strengthened national tobacco media campaigns

• Reducing the incidence of skin cancer through the introduction of a nationally co-ordinated Commonwealth, State and Territory SunSmart campaign

• Increasing consumption of vegetables and fruit through introduction of a nationally coordinated Commonwealth, State and Territory campaign

Screening and early detection:

• Improving detection of colorectal cancer through the introduction of a national, coordinated population-based screening program

• Improving the efficiency of the national cervical screening program by increasing the screening interval from two to three years

• Improving the efficiency of skin cancer control through a national program to increase the accuracy of general practitioner diagnosis of skin lesions that might be cancer

• Promoting informed choice by men about prostate-specific antigen (PSA) testing and the early detection of prostate cancer through education for general practitioners and the community

Treatment

• Reorganising breast cancer management to ensure seamless continuity of care from screening, or first presentation with symptoms, to diagnosis, treatment and follow-up care

• Improving outcomes from ovarian and lung cancer by ensuring that all people with these cancers are assessed at a multidisciplinary specialist centre as soon as possible after diagnosis

• Developing, implementing and maintaining clinical practice guidelines for cancer

Support for cancer patients

• Improving the psychosocial care of women with breast cancer through provision of breast care nurses

• Improving the psychosocial care of people with cancer through the provision of psychologists in cancer centres and clinics

Palliative care

• Improving palliative care for people with advanced cancer through implementation of the National Palliative Care Strategy

Cancer risk factors

1. Downstream (biomedical/physiological)
   • excess weight, particularly obesity
2. Midstream (individual/demographic/behavioural)
   • Behavioural: poor diet (10% of cancers due to inadequate consumption of vegetables and fruit); physical inactivity (colorectal); tobacco use (lung)
   • Psychosocial: Low relative position in social hierarchy; Low perceived control; isolation; lack of social support; loss of meaning or purpose
   • Demographic/socio-economic:
   • Low SES; Indigenous; CALD; Rural/remote residence
   • Health services: Inadequate access to or use of cancer screening services
3. Upstream (physical/social environmental conditions; broader determinants of health)
   • Social capital
   • Civic engagement
   • Income inequality
   • Government policies

Reference