The comparison between Australia and China raises two questions:
1. Why is the incidence of breast cancer in China and India so much lower than in Australia?
2. Why is the mortality rate among those with breast cancer so much higher in China and India than in Australia?
Several answers suggest themselves as possible.
a. Much more widespread screening for breast cancer in Australia than in China and India detects a lot of early-stage breast cancers in Australia and drives up Australia’s total breast cancer figures. (If there is any other reason apart from much higher early diagnosis for Australia’s breast cancer figures being so high then what is the reason?)
Mortality rates among women with breast cancer are then higher in Chinaand India because they are primarily among women with late stage breast cancer.
b. There are dietary differences between Australia and China such as high intake of dairy products in Australia (which have high levels of growth hormones) and low levels of dairy products in China.
However India unlike China consumes quite a lot of dairy with its cow-based culture.
c. If breast-cancer occurs more in older women differences in longevity would need to be considered. In some countries women may have died of other causes before they get old enough for breast cancer to be a high risk. What is the prevalence of breast cancer per 100000 women aged 60 (for example) in Australia versus China versus India?
Question: If we leave out all the early-stage breast cancers (with low mortality rates if left untreated) in Australia what would our breast cancer incidence and mortality rates look like?
Question: What is the development path of early-stage breast cancer if left untreated?
Question: What are the incidence rates for breast cancer in Australia by age of the women at diagnosis?
Question: What are the mortality rates for breast cancer in Australia by age of women at diagnosis?
Question: What is the expected mortality rate by age in the general female population in Australia and how does a diagnosis of breast cancer vary this? For example if you are 54 what is your life-expectancy? If you are 54 and have just had a breast-cancer diagnosis what is your life-expectancy?
Question: What is the life-expectancy for women in Australia with a breast-cancer diagnosis by stage of the breast cancer at diagnosis?