Ductal carcinoma in situ (or DCIS for short) is the earliest form of breast cancer. It occurs when cells inside your breast ducts become cancerous, but crucially have not spread outside of the ducts.
You may also hear DCIS referred to as ‘non-invasive’ or ‘Stage 0’ cancer. It is generally picked up through cancer screening methods using mammography.
While DCIS by its very definition is not going to spread beyond the breast tissue, it is possible that over time it can spread further, leading to a more invasive cancer. When your surgeon removes DCIS from your breast, it is therefore important to know whether the cancer has spread to other parts of your body, in order to determine the ‘stage’ of the disease.
>> To learn more about either DCIS or cancer staging, we recommend this guide on ‘TNM staging’ by Cancer Research UK
The most common way to find out if the cancer has spread, is to analyse the lymph nodes near your underarm.
If cancer cells break off from their initial position, they will travel through your lymphatic channels to your underarm and collect in the first lymph node(s) they reach – the sentinel lymph nodes(s).
The procedure used to confirm if cancer has spread is a sentinel lymph node biopsy (SLNB). In this procedure, a selection of lymph nodes are removed for testing and analysis.
The challenge for treating patients with DCIS is determining whether a woman has non-invasive DCIS or if parts have broken away to become invasive cancer.
For patients with DCIS alone, a SLNB procedure is an unnecessary procedure as it won’t have spread beyond the cell. However, because there is a small chance that there may be invasive disease, traditional methods have meant all patients receiving a mastectomy to remove their cancer will also be given a SLNB regardless of whether they need it or not.
Fortunately, new medical developments mean that there is now an alternative treatment. A delayed sentinel lymph node biopsy ensures that the only patients who undergo this surgery are those who need their nodes staged.
The Magtrace® lymphatic tracer allows your surgeon to mark the sentinel lymph nodes (the first nodes cancer would migrate to if present) in advance or on the day of your surgery.
These nodes will remain marked in this way for many weeks, allowing a pathologist to look at the tissue removed from your breast and accurately determine if you would benefit from having those marked lymph nodes removed.
The Magtrace® lymphatic tracer will be injected at a time that suits you and your surgeon. It can be administered at the start of your surgery when you’re under anaesthesia, or many days beforehand, timed to coincide with your pre-surgical visit to the hospital.
If done beforehand, local anaesthetic or a numbing gel may be applied, and your surgeon or radiologist will then use a small needle to inject the liquid into your breast.
Shortly after the injection, the Magtrace® tracer liquid will flow through your lymphatic system, taking the route a migrating cancer cell would take. It will then collect in the sentinel nodes in your underarm. You will not be able to feel any of this and can continue on as normal until your operation.
For a small number of patients, you may see a small, bruise-like, brown mark on the skin where the tracer was injected. This is just a tiny amount of the liquid that has remained just under the skin and is completely harmless. Numerous studies have shown this doesn’t affect the vast majority of patients and for those that do experience this mild blushing, it will go away in time – like a bruise.
Once the breast tissue containing DCIS has been removed and examined by a pathologist, your surgeon will share the diagnosis with you. This can take any time between a few days and a couple of weeks.
Hopefully the diagnosis is one of DCIS with no invasive components, meaning the cancer has not spread to the rest of your body. This result will mean you will be able to avoid an unnecessary SLNB procedure. Your body will then take the harmless Magtrace® liquid injected in to your underarm and simply transfer it to the natural iron stores in your body.
If invasive cancer cells have been found, we understand that you may be disappointed with this outcome, but you can have the confidence that the important lymph nodes are still marked, your surgeon will be able to easily find them and your SLNB procedure can be scheduled right away.
If you are a patient requiring a sentinel lymph node biopsy, please take a look at our guide to learn more about this procedure.
The good news is that nearly 80% of patients will have non-invasive DCIS. As a result, they will be able to avoid lymph node surgery altogether, helping to avoid any complications or additional stress that comes with having a SLNB procedure.
For the 20% of patients that need to go on and have an SLNB procedure, the accuracy of that surgery is as sensitive and accurate as a traditional SLNB. It has also spared you from an alternative treament involving radioactive drugs and blue dyes, both of which can cause averse reactions.
Delayed SLNB allows surgeons the time to make well-informed decisions on what’s best for their patients, sparing unnecessary surgery wherever possible, without putting the patient at any additional risk.
If you have any more questions about your Magseed® and Magtrace® surgery, please do ask your surgeon or the hospital team.
Thousands of surgeons and radiologists from across the world now use the Magseed® marker and Magtrace® lymphatic tracer. You can hear our interviews with a selection of these surgeons here. We also have a number of resources and stories on our website which feature more information about Magseed® and Magtrace®.
We hope that the information above has helped you understand a little more about what’s involved in having a delayed SLNB with Magseed® and Magtrace®.