The term 'breast cancer' is a general description which covers a group of different cancers that occur in the different cells that make up the breast. Several separate types of tumour may develop within these cells.

This section describes breast cancer types in a little more detail so that you can be familiar with the terms when they are used to describe your illness. 

Ductal Carcinoma in Situ (DCIS)

Ductal carcinoma in situ (DCIS) is an early type of breast cancer and is the most common non-invasive form diagnosed.  This manifestation of the disease develops within the milk duct but generally has no symptoms.  This is why it has been diagnosed more frequently since screening has been introduced.

These descriptions mean that whilst abnormal cancer cells are present they are confined specifically to the breast milk-ducts.  In other words, the cancer cells have remained where they originated  in this case, within the milk duct - hence intraductal.  They have not developed the ability to spread either within the breast or outside  they are non-invasive.

DCIS may also be referred to as a Stage 0 breast cancer: that is the earliest form of breast cancer  - in fact, some medical practitioners believe it to be pre-cancerous.

However, if left untreated there remains the possibility that these cells may eventually spread into the surrounding breast tissue and become invasive.  Treatment therefore aims at preventing this.

DCIS itself describes a family of cancers that occur in the breast ducts.  You may hear other words to describe this by your medical team.  For example, the term comedo may be used.

Comedo refers to necrosis or necrotic tissue - an area of dead cancer cells, which are a consequence of rapid tumour growth.  Slower tumour growth without necrosis is more common and is termed a non-comedo tumour.

Other terms such as solid, cribiform, papillary can describe the appearance of this cancer but do not affect the way it is treated.

Invasive ductal carcinoma

This cancer of the milk-duct cells is known as invasive or infiltrating because, in contrast to DCIS, it has the ability to penetrate the duct, invading the fatty tissue of the breast and possibly other regions of body.

It is the most common type of breast cancer and accounts for over 80% of instances diagnosed.

Lobular carcinoma

This type of condition is less common.  It originates in the cells making up the lobules of the breast.  As with cancer in the cells of the breast duct, this can be non-invasive or invasive, depending on its ability to penetrate and invade.

Invasive or infiltrating lobular carcinoma accounts for 10-15% of breast cancers and is most commonly seen in women in the 45-55 age group.  Although men can get this too, it is exceedingly rare.

It can sometimes be found in both breasts simultaneously and it does have a slightly higher risk of recurring in the adjacent breast at a later date.

Unlike ductal cancer, this form of the disease is more likely to show up as a thickening of breast tissue rather than as a hard lump.

Inflammatory breast cancer

Inflammatory breast cancer is a rare condition (1-2% of the total incidence) that is not generally detected using a mammogram.  This is because this particular type grows in sheets rather than as a confined solid tumour  hence it may not produce a lump that can be felt or detected in the conventional way.

These symptoms are caused by cancer cells clogging up the lymph vessels just below the skin of the breast.

This is a fast-growing cancer and requires quite aggressive treatment to control it.  Often chemotherapy is given as a first course of action.

Less common forms of breast cancer

Medullary  an invasive type that forms a distinct boundary between tumour and normal tissue.

Mucinous/colloid cancer  this develops in mucus-producing cancer cells.

Pagets disease of the nipple  this rare invasive cancer begins in the milk ducts but first shows up as changes to the nipple.  A common sign is a red scaly rash involving the nipple area.  Whilst it may have similarities in appearance to eczema, the crucial point to look out for is that eczema would affect the areola first not the nipple.  Pagets disease appears on one side only.

Phylloides tumour  this rarity develops in the connective tissue of the breast and can be benign or malignant.

02/06/2009