There are several different types of breast cancer, which can develop in different parts of the breast.
Breast cancer is often divided into:
non-invasive breast cancer (carcinoma in situ) – found in the ducts of the breast (ductal carcinoma in situ, DCIS) and hasn't developed the ability to spread outside the breast. It's usually found during a mammogram and rarely shows as a breast lump.
invasive breast cancer – usually develops in the cells that line the breast ducts (invasive ductal breast cancer) and is the most common type of breast cancer. It can spread outside the breast, although this doesn't necessarily mean it has spread.
Other less common types of breast cancer include:
invasive (and pre-invasive) lobular breast cancer
inflammatory breast cancer
Paget's disease of the breast
It's possible for breast cancer to spread to other parts of the body, usually through the bloodstream or the axillary lymph nodes. These are small lymphatic glands that filter bacteria and cells from the mammary gland.
If this happens, it's known as secondary, or metastatic, breast cancer.
Being overweight may not be as unhealthy as it was 40 years ago," BBC News reports. New research has found a body mass index (BMI) of 27 is linked to the lowest rate of death – but someone with a BMI of 27 is currently classed as being overweight. BMI is a score calculated by dividing your weight (usually in kilograms) by the square of your height (usually in metres and centimetres). Currently, a BMI of 25 to 29.9 is classified as being overweight. Researchers looked at 120,528 people from Copenhagen, recruited from 1976 to 2013, and separately compared those recruited during the 1970s, 1990s and 2000s. They were followed up until they died, emigrated, or the study finished. The BMI linked to the lowest risk of having died from any cause was 23.7 in the 1970s group, 24.6 in the 1990s group, and had further risen to 27 in the 2003-13 group. It may be the case that the suggested upward shift in optimal BMI is the result of improvements in preventative treatments for weight-rela...