This page concentrates on female breast cancer incidence statistics by age, geographic variation, trends over time and prevalence. The ICD code for breast cancer is ICD9 174 (female), 175 (male) and ICD10 C50.
Breast cancer is the most common cancer in the UK despite the fact that it is rare in men. In 2004 there were 44,659 new cases of breast cancer diagnosed in the UK: 44,335 (99%) in women and 324 (1%) in men.
Table 1.1 1-4 shows the numbers and rates of new cases of breast cancer in the UK and its constituent countries. The lifetime risk of being diagnosed with breast cancer in women is 1 in 9.5
Breast cancer risk is strongly related to age,with more than 80% of cases occurring in women over 50 years old. The highest number of cases of breast cancer diagnosed is in the 50-64 age group (Figure 1.1 1-4): these women are targeted in the national screening programme. From 2004, routine screening was extended to include women up to the age of 70. For more information on breast cancer screening go to the screening section.
Although very few cases of breast cancer occur in women in their teens or early 20s, breast cancer is the most commonly diagnosed cancer in women under 35. By age 35-39 almost 1,500 women are diagnosed each year. Breast cancer incidence rates continue to increase with age, with the greatest rate of increase prior to the menopause; this supports a link with hormonal status.
Worldwide, more than a million women are diagnosed with breast cancer every year, accounting for a tenth of all new cancers and 23% of all female cancer cases.6 Breast cancer incidence rates vary considerably, with the highest rates in the developed world and the lowest rates in Africa and Asia (Figure 1.2).6
Around 430,000 new cases of breast cancer occur each year in Europe and an estimated of 212,920 in the USA. The lowest European rates are in Romania and Latvia and the highest are in northern and western Europe.(Figure 1.3).7,18
Migrants from low to high risk countries acquire the risk of the host country within two generations.8,9
For example, Japanese migrants to the USA acquire an increased breast cancer risk compared with the population in Japan and there is evidence that the earlier in life a woman takes up residence in a ‘high risk’ country, the higher her risk of breast cancer compared to that in her country of origin.8, 10
The incidence of breast cancer has been increasing for many years in economically developed countries. In Britain the age-standardised incidence of breast cancer per 100,000 women increased from 74 in 1975 to 120 in 2004. Over the twenty five year period 1980-2004 the incidence rate increased by 53% (Figure 1.4 1-3).
The historically low rates of breast cancer in eastern Europe and the Far East have begun to rise rapidly.13,14,15
Introduction of the national screening programme in the UK in 1988 led to a transient additional increase in breast cancer incidence in women aged 50-64 as early undiagnosed cancers were detected. This lasted for the first 4-7 years of the programme (see screening section). The underlying increase in incidence predates screening, continues today, and is evident particularly in the older age groups (Figure 1.6 1-3). 16
As the incidence of breast cancer is high, and five-year survival rates are over 75%, many women are alive who have been diagnosed with breast cancer. The most recent estimate suggests around 172,000 women are alive in the UK having had a diagnosis of breast cancer.17
Virtually all invasive breast cancers are adenocarcinomas (derived from glandular tissue), either ductal (85%) or lobular (15%.)
Ductal carcinoma in situ (DCIS), a non-invasive cancer, is now detected more frequently because of the widespread use of mammography. This picks up telltale dots of chalk (microcalcifications), which can be a sign of DCIS.