All Cancers – Worldwide

Lung cancer kills more people worldwide than any other cancer.
Cancers triggered by infections – liver, stomach and cervix cancers – are more prevalent in the developing world.
In richer countries, prostate, breast and colon cancers are more common than in poorer countries.
Cancers that are most often cured are breast, cervix, prostate, colon and skin, if they are diagnosed early.

In most developed countries, cancer is the second largest cause of death after cardiovascular disease, and epidemiological evidence points to this trend emerging in the less developed world.[1]

Age

If you take 9 average people in the UK, then the chances are that 3 of them will receive a diagnosis of cancer at some time in their life. 2 of these will be over the age of 65 and 1 will be 65 or under.[2]

The chance of being diagnosed with cancer is strongly age related as can be seen in the following graph.

This very strong correlation between cancer and age means that many cancer statistics are ‘age standardised’ i.e. the figures are adjusted such that the numbers of people at a certain age would be the same as at a chosen area e.g. Europe and chosen point in time e.g. the year 2000. This then allows for comparisons between cancer statistics from different countries or different periods of time to have more meaning in relation to each other.

CUP

CUP constitutes from 2.3% to 7.8% of all human cancers. In the US the annual age adjusted incidence is 7-12 cases per 100,000 per year. In Australia it accounts for 18-19 cases per 100,000 per year. In some countries CUP is considered to be more common than Non-Hodgkin’s Lymphoma.[3][4]

Estimates from the US tend to be lower than those from other westernised countries possibly because of the healthcare system in the US that may make treatments easier to fund where the cancer is known.

CUP itself can be broken down into 4 subsets [4]

• Adenocarcinomas – well to moderately differentiated (60%)
• Poorly differentiated Adenocarcinoma and Carcinoma (30%)
• Squamous cell carcinoma (5%)
• Undifferentiated neoplasms (5%)

In the approximately 30% of cancers of unknown primary origin in which a full workup eventually established a clear pathological diagnosis, the findings were[5]: –

Deaths from CUP compared to All Cancers

CUP as a percentage of deaths from all cancers in England and Wales from 2004 to 2006
amounted to 7.8%

Rare Cancers

It is difficult to define a boundary as to what falls
into the ‘rare’ category.

There are 200+ types of cancer. The ‘Big 4’ – breast, bowel,
lung and prostate, account for over half of all cancers all by themselves in the UK
leaving the other 196+ to account for the remainder. Given that breast cancer
is very rare in men and prostate cancer is understandably unknown in women,
this means that for the different sexes only 3 types of cancer
account for over half of all cases in the UK and other developed nations.

References

[1] WHO; Facts and Figures
[2] Cancer Research UK; Cancer Stats Feb 2006
[3] Annals of Oncology 14 (Supplement 3): iii11�iii18, 2003
[4] Dept of medicine; University of Alberta
[5] eMedicine Metastatic Cancer, Unknown Primary Site