The Cancer Council Queensland is dedicated to eliminating cancer and diminishing suffering
from cancer through research, treatment, patient care and prevention and early detection.1 Part
of this commitment includes informing Queenslanders of the latest available data on cancer.
This report is the fourth in a series, following earlier publications on prostate cancer,2 lung
cancer3 and colorectal cancer.4 The most recent data from the Queensland Cancer Registry5
is used to describe breast cancer incidence, survival, mortality and prevalence among women in
Queensland. Comparisons against Australian and international data are presented where
applicable. Comment boxes throughout the report provide additional details from scientific
literature to supplement the statistical information presented.
An outline of each section of the report, focusing on the main results, is given below:
Section 1 – Introduction
This section contains a brief description of the anatomy of the female breast, how cancer
develops, differences between invasive and non-invasive breast cancers, and definitions for the
different stages of breast cancer. An overview of the contents and limitations of the report is
Section 2 – Risk Factors
The main risk factors that have been consistently demonstrated to influence the development of
breast cancer are age, family history associated with genetic mutations, hormonal factors linked
to reproductive and menstrual history, breast density, benign breast disease, obesity, and
certain health-related behaviours, such as excessive alcohol consumption and insufficient
Section 3 – Screening
More than 202,000 women were screened by BreastScreen Queensland during 2007, with a
participation rate of 56% among women aged 50-69 years (the target group) over the two year
period 2006-2007. This participation rate was slightly higher than the corresponding Australian
average, but fell short of the goal of 70%. Participation rates within BreastScreen Queensland
tended to be higher in rural and remote areas (60% among women aged 50-69). The number
of women being screened each year is continuing to rise, although participation rates have
stabilised in recent years across all age groups.
While the majority of women who were screened (93%) did not have any sign of breast cancer,
population screening detected 913 cases of invasive breast cancer among women in
Queensland during 2007. The majority (60%) of invasive breast cancers detected by screening
were small (15mm or less).
Section 4 – Incidence
Breast cancer was the most commonly diagnosed cancer among females in Queensland,
accounting for 27% of all diagnoses between 2002-2006. A total of 2,491 women were
diagnosed with breast cancer in Queensland during 2006, equating to an age-standardised rate
of 116 cases per 100,000 females. The incidence of breast cancer in Queensland was similar
to the national average, while Australia had the twelfth highest rate of breast cancer in the
Median age at diagnosis was younger for breast cancer patients (58 years) compared to most
other types of cancer, with around one-quarter (26%) of female breast cancers diagnosed under
the age of 50. Age-specific incidence rates were highest in the 65-69 age group at 360 cases
per 100,000 females.
Stage I breast cancers (47%, 1101 cases per year) were only slightly more common than
tumours which were more advanced at diagnosis, with 45% (or 1053 cases per year) classified
as Stages II/III/IV.
Incidence rates of breast cancer in Queensland peaked in the year 2000, and have remained
fairly stable since then (non-significant decrease of 0.9% per year between 2000-2006). There
was a particularly strong downwards trend in incidence rates among women aged 50-69 years
with Stage I tumours between 2001-2006. In contrast, the overall number of women diagnosed
with breast cancer has continued to increase, and has almost tripled from 861 in 1982 to 2491
in 2006. Ongoing increases in the number of new cases is due to a combination of factors,
including the introduction of population screening, changes in the prevalence of risk factors, and
population growth and ageing.
There were wide variations in incidence rate trends for breast cancer among the countries for
which data was available.
Section 5 – Survival
Survival among women with breast cancer in Queensland has shown ongoing improvement
over the last few decades. Five-year relative survival increased from 74% for women who were
at risk between 1982-1988 to 89% between 2001-2006.
Unlike most other types of cancer, there was generally only a small amount of variation in
survival among breast cancer patients by their age at diagnosis. Women aged 40-69 years
experienced the highest survival rates (5-year relative survival of 90%).
Stage at diagnosis has a large influence on breast cancer survival. Women with Stage I
tumours had 5-year relative survival of 98%, compared to 83% for Stage II/III/IV breast cancers
and 50% where stage was unknown.
Survival rates for breast cancer patients in Queensland were similar to the rest of Australia, and
were higher than those reported in many other countries throughout the world.
Section 6 – Mortality
There were 432 female deaths caused by breast cancer in Queensland during 2006, resulting in
an age-standardised mortality rate of 20 deaths per 100,000 females. Breast cancer accounted
for 15% of all cancer deaths among females, and was the second most common cause of
cancer-related mortality, following lung cancer.
The majority (85%) of breast cancer deaths in Queensland occurred among women aged 50
years or older, with a median age at death of 66 years. This was much younger than the
median age of 73 years for all cancer deaths among females. Breast cancer mortality rates
increased sharply with age, and were highest in the 85 years and over age group (163 deaths
per 100,000 females).
Breast cancer was the leading cause of premature mortality due to cancer among females,
causing 6,278 years of life lost per year (or 18% of all cancer-related premature mortality). The
average amount of life expectancy lost due to breast cancer was 14.0 years per death.
Most States and Territories within Australia, including Queensland, reported a similar mortality
rate for breast cancer. From an international perspective, the mortality rate for Australia was
close to the average for all developed countries.
Breast cancer mortality rates have been decreasing by 2.7% per year in Queensland since
1994, although the number of deaths caused by breast cancer is continuing to rise by 0.7% per
year (again due to population growth and ageing). Declines in mortality rates have been
observed across all age groups. Downward trends in breast cancer mortality have also been
reported throughout Australia, North America and many European countries.
Section 7 – Prevalence
As at the end of 2006, there were 26,361 women (1,219 per 100,000) living in Queensland who
had been diagnosed with breast cancer at some time during the previous 25 years and 10,565
women (494 per 100,000) who had been diagnosed within the previous 5 years. Breast cancer
was the most prevalent type of cancer among females, accounting for around a third (34%) of
all 5-year cancer prevalence in Queensland.
Section 8 – Geographical areas and socio-economic status
Incidence rates of breast cancer were significantly higher among women living in a major city
compared to those from outer regional or remote parts of Queensland. There were also large
differences in survival for breast cancer by rurality, with 5-year relative survival around 40%
lower for women residing in remote areas compared to those living in a major city.
Variation was also observed for breast cancer incidence and survival by socio-economic status.
Women living in more advantaged parts of Queensland had higher rates of diagnosis for breast
cancer, but they also tended to experience better survival than women in either the middle or
disadvantaged socio-economic categories.
Most of the variation in incidence was due to higher rates of Stage I tumours among women in
major cities and from more advantaged areas, with less difference in the distribution of more
advanced or unknown stage breast cancers. Adjustment of survival by stage accounted for
some, but not all, of the area-based variation in survival.
The contrasting differentials for incidence and survival resulted in little variation in breast cancer
mortality by either rurality or socio-economic status.