This content has been medically reviewed by:
Barry Rosen, MD, FACS
Breast Surgical Oncologist and Senior Medical Advisor for Learn Look Locate
A diagnosis of DCIS (ductal carcinoma in situ) often leads quickly to conversations about treatment—especially radiation therapy after lumpectomy.
For many women, those conversations begin long before there has been time to fully understand what DCIS is, how it behaves, or how decisions about radiation for DCIS are made.
So it is natural to ask:
Do I need radiation after being diagnosed with DCIS?
Or more specifically:
Will radiation therapy actually help me?
This is one of the most important—and often most overwhelming—questions in DCIS treatment. Understanding your biology is the key so you can know if radiation will truly help you.
This page is here to help you understand that question clearly, in a way that feels steady and grounded, so you can move forward with more confidence and less uncertainty.
For years, radiation after lumpectomy for DCIS was considered standard of care along with using Clinical Pathology features (age, size, margin status, palpability) to assess initial DCIS risk.
The goal was always to reduce the risk of recurrence.
But today, we understand something more important:
Not all DCIS behaves the same way.
This is where things can begin to feel confusing.
When your care team discusses radiation, they are weighing:
Radiation reduces these risks—but not equally, because every patient’s biology is different.
Before deciding on treatment, it helps to clearly understand what DCIS is.
DCIS (ductal carcinoma in situ) means:
For this reason, DCIS is classified as:
In a Normal Duct:
With DCIS:
Why DCIS Can Behave Differently
Even though all DCIS is labeled as Stage 0, the behavior of these cells can vary.
Some cases:
Other cases:
After a DCIS diagnosis, the next step is often a discussion with your surgeon about how to remove the abnormal cells.
For many women, this involves a surgery called a lumpectomy.
This is not a one-size-fits-all process.
Each step is based on your individual situation.
A lumpectomy is the most common surgical treatment for DCIS. (Also referred to as Breast Conserving Surgery)
It involves:
This difference in an individual’s biology is the reason treatment is not the same for every patient.
It is not just about identifying DCIS.
It is about understanding:
What is my individual risk, and will radiation therapy help to reduce my risk of recurrence?
DCISionRT is a biology-based test for women diagnosed with DCIS.
DCISionRT evaluates a patient’s individualized biology with other risk factors to provide a personalized risk assessment.
With DCISionRT, decision-making shifts from generalized guidance to a more personalized understanding of risk and benefit.
Why This Matters
DCISionRT helps you better understand:
What the test provides:
“Low risk” means:
This can feel counterintuitive.
Many women feel that doing more treatment will always provide more protection.
But in some cases:
More treatment does not necessarily mean more benefit.
“Elevated risk” means:
This helps clarify when radiation may truly be beneficial.
Why This Matters
Even though two women may both be told:
“You have Stage 0 Breast Cancer.”
Their level of risk—and their benefit from radiation—may be very different.
And that difference is what makes this decision feel so complex.
Your DCISionSCORE gives you your personalized risk assessment after treatment with surgery alone or surgery and Radiation Therapy.
Based on the Biology of your DCIS, the DCISionRT test provides you and your physician the information needed to make a shared treatment decision and the appropriate direction to take.
This patient has a DCISionRT score of 0.8 and is classified as having a low risk of a recurrence of DCIS or Invasive Cancer in the same breast.
Alexia DCISionSCORE 0.8 “Low Risk”
“I want to ensure other people diagnosed with DCIS can also find the sweet spot between over- and undertreatment.”
“Tools like DCISionRT help make that possible.”
– Alexia Vernon, DCIS Breast Cancer Survivor
This patient has a DCISionRT score of 7.4 and is classified as having an Elevated Risk of a recurrence for DCIS or Invasive Cancer in the same breast.
Rachel DCISionSCORE 6.2 “Elevated Risk”
“I felt a lot more confident moving forward with Radiation
Therapy knowing the decision was based on my personal tumor biology. I have 100% peace of mind with these test results.”
-Rachel, DCIS Breast Cancer Survivor
The data is clear:
Vicini, F et al. Limitations in the Application of Clinicopathologic Factors Alone in Predicting Radiation Benefit for Women with Low-Risk Ductal Carcinoma in Situ (DCIS) after Breast Conserving Surgery.
The decision should reflect:
This is what shared decision-making looks like.
Not based on fear.
Not based on what is typically done.
But based on:
Bringing It Back to You
Two people can have similar scores—and still make different decisions.
What matters is that you understand:
This is where the question becomes clearer.
Not: “What is usually done?”
But: “What is likely to help me?”
“I got a little bit of pushback,” LeeAnne says.
“The doctors weren’t familiar with the test and said I needed to follow the ‘standard of care’ — radiation after surgery.
But in my gut, this just seemed like too much.”
-LeeAnne, DCIS Breast Cancer Survivor
Your biology → Your score → Your understanding → Your path
You do not need to interpret every detail perfectly.
You just need to understand:
Is radiation likely to make a meaningful difference for me?
Turning understanding into the next step.
At this point, you have a clearer understanding of how DCIS can behave, how risk is evaluated, and how tools like DCISionRT can help bring more personalized insight into your care.
But even with that understanding, it is completely normal to still feel unsure about what to do next.
This is where your next step begins—not by having all the answers, but by asking the right questions and understanding your options.
The goal is not to rush a decision.
It is to move forward with clarity, confidence, and a better understanding of what is right for you.
Questions that can help guide your conversation
‘But asking the right questions can help you feel more grounded, more informed, and more in control of your care.
You are allowed to ask questions.
You are allowed to take time to understand.
And you are allowed to make a decision based on what is right for you.
Dr. Barry Rosen, a Learn Look Locate Medical Advisor, is dedicated to helping patients understand complex decisions with clarity and confidence, ensuring that each patient feels informed and supported throughout their care.
We have always known that not everyone with DCIS requires radiation therapy after a lumpectomy; our problem was determining who would or would not benefit. We now have a test, DCISionRT that can help us avoid radiation for many of these patients.
-Barry Rosen MD, FACS
Senior Medical Advisor
No. Not all women with DCIS need radiation after surgery.
While radiation has historically been recommended for many patients, we now understand that DCIS is not the same for everyone due to individual tumor biology. Some women have a low risk of recurrence and may not benefit significantly from radiation, while others may have a higher risk where radiation can play an important role.
The key is understanding your individual risk so you can make the decision that is right for you.
If you choose not to have radiation, there is a risk that DCIS—or in some cases invasive breast cancer—could return in the same breast.
However, that risk varies widely depending on:
For some women, the risk is already low, and radiation may not significantly change the outcome. For others, radiation can meaningfully reduce that risk.
Radiation can reduce the risk of recurrence:
However, the actual benefit depends on your individual tumor biology.
This is why personalized tools, like DCISionRT, can be helpful in understanding what radiation may mean specifically for you.
For some women with low-risk DCIS, skipping radiation may be a reasonable option.
This decision should be made carefully with your care team, based on:
The goal is not to avoid treatment—it is to choose the treatment that truly benefits you.
Radiation is generally well tolerated, but side effects can include:
Your experience can vary, and your care team will help you understand what to expect based on your individual treatment plan.
While DCIS is highly treatable, understanding its potential behavior is important in preventing recurrence or progression.
Yes, in some cases DCIS can return as invasive breast cancer.
This is one of the main reasons radiation is considered after surgery—to reduce the chance of recurrence, including invasive recurrence.
Understanding your individual risk helps guide how important radiation may be in your situation. (See DCISionRT Reports ) What is my potential 10-Year Recurrence Risk for Invasive Breast Cancer?
DCISionRT is a genomic test that looks at the biology of your tumor. It is a test that utilizes 7 Biomarkers along with key pathways responsible for the progression of Breast Cancer.
Standard pathology tells us:
DCISionRT goes further by helping to predict:
It adds another layer of personalized information to support shared decision-making.
Yes. If you have been diagnosed with DCIS and are deciding about radiation, it is reasonable to ask your doctor if genomic testing like DCISionRT is appropriate for you. If you decide to ask your physician to run the DCISionRT test, it is most benefical to ask for it to be run on the presurgical biopsy sample. Results can then be reviewed prior to additional procedures.
Having a shared conversation regarding your DCISionRT result can help you better understand your options.
Results are typically available within 3–5 days after the laboratory receives your tissue sample. This allows the information to be used in real time when making treatment decisions.
This is one of the most important and personal questions.
The right decision is based on:
When you feel informed and supported, the decision often becomes clearer.
Over 3,500 patients have validated this test with over 10 publications. To see more, go to: https://preludedx.com/our-publications/
Breast cancer care is evolving, and tools like DCISionRT are part of a growing movement toward more personalized treatment.
Not every patient is introduced to these options early in the process. Be sure to ask your physician about DCISionRT at your first consultation.
At Learn Look Locate, part of our mission is to ensure people are aware of all available tools—so they can make decisions with confidence, not uncertainty.
This decision is not about doing everything.
It is about doing what is right and what is personalized you.
Understanding your options—including tools like DCISionRT—helps you move forward with clarity, not uncertainty.
At Learn Look Locate, we believe understanding your options should never feel out of reach—and that awareness of tools like DCISionRT is an essential part of more confident, personalized care.
To learn more about DCISionRT and where you can locate a physician near you, please visit our website page at: www.preludedx.com
This guide is provided as educational information through a paid collaboration between Learn Look Locate and PreludeDx.