Your doctor may describe DCIS as a very early form of breast cancer. Some doctors call it a pre-cancerous condition because it may go on to develop into an invasive cancer if it is not treated.  DCIS is becoming more common. This is because it is being picked up on mammograms when women are screened for breast cancer.

Remember - it is confusing, but invasive ductal breast cancer and DCIS are not the same thing.  In invasive ductal breast cancer, the cells have broken out of the ducts and so can spread. 

Treatment
In the past, the recommended treatment for DCIS was nearly always mastectomy.  This cures virtually all cases of DCIS because all the affected tissue is removed before an invasive cancer has a chance to develop.

Now most centres remove only the area of DCIS, with a border of healthy tissue around it.  This is called wide local excision or conservative surgery.  The DCIS cells are examined under a microscope, and if they are high grade, your doctor will suggest radiotherapy to the rest of the breast tissue.  This is to kill off any abnormal cells left behind.  You may be given tamoxifen (a type of hormone therapy) to try to reduce the risk of developing an invasive breast cancer in the future.   But doctors don't know yet exactly how much help tamoxifen is in stopping DCIS from coming back.  A 2003 trial suggests that it may not provide much extra protection if you've already had radiotherapy.  Your specialist may still prescribe it for you if the DCIS cells are likely to respond to oestrogen.

If you wish to, you can choose to have a mastectomy.  Some women prefer to know that the DCIS is cured.  You may be advised to have a mastectomy because
 

• The area of the DCIS in your breast is large      
• There are several areas of DCIS in your breast      
• You have small breasts and too much of the breast is affected by DCIS to make wide local excision possible

DCIS trials results
There have been clinical trials looking into the treatment of DCIS.   Trial results so far show that

• It is reasonable for some women to have just the DCIS removed      
• Some women will not need any more treatment than that       
• Other women should have radiotherapy after the DCIS has been removed     

A study that reported in 2003 suggests that women over 50 who have had radiotherapy for DCIS won't get any extra benefit from taking tamoxifen.  Another earlier trial compared radiotherapy with no further treatment after wide local excision to remove DCIS.  They found that 4 years after surgery,

• With radiotherapy, 9 women out of every 100 had a recurrence of DCIS or developed breast cancer      
• With no further treatment 16 women out of every 100 had a recurrence of DCIS or developed breast cancer

So there is not all that much difference in the two groups. Some women will be fine with no further treatment. Others should have radiotherapy.  Whether you have more treatment or not is generally decided on the grade of the DCIS cells. 
 

Treatment and DCIS grade
There are now ways of classifying DCIS into high grade (more aggressive) and low grade (less aggressive). Doctors think that the high grade is more likely to come back. So women with high grade should probably have radiotherapy after surgery. While women with low grade DCIS probably do not need further treatment.

Unfortunately the grading of DCIS had not been worked out when the trials were started. The trials need to be repeated using the grading system to confirm that this is the best way of treating DCIS.

Follow up
Whichever treatment you receive, you will have regular follow up appointments to make sure any recurrence of DCIS in the treated breast is picked up as quickly as possible. You should be offered mammograms at least every 2 years. If your DCIS does come back,