DCIS is the most common form of non-invasive breast cancer. DCIS usually is treated by surgically removing the cancer -- lumpectomy in most cases. After surgery, hormonal therapy medicine may be recommended if the DCIS is hormone-receptor-positive (most are). Radiation therapy also is recommended for many women.
Routine radiation therapy after DCIS surgery was common in the past, but newer DCIS treatment guidelines say that radiation therapy after surgery doesn't have to be given routinely to all women. At the same time, doctors aren't always sure which women will benefit from radiation therapy, so a test to help guide the decision is helpful.
A genomic test (also called a genomic assay) analyzes the activity of a group of genes that can affect how a cancer is likely to behave and respond to treatment. The test is performed on a sample of breast cancer tissue.
The Oncotype DX DCIS test analyzes the activity of 12 genes and assigns a Recurrence Score -- a number between 0 and 100 -- to the DCIS. Doctors use the following ranges to interpret the DCIS Recurrence Score results:
- Recurrence Score lower than 39: The DCIS has a low risk of recurrence. The benefit of radiation therapy is likely to be small and will not outweigh the risks of side effects.
- Recurrence Score between 39 and 54: The DCIS has an intermediate risk of recurrence. It’s unclear whether the benefits of radiation therapy outweigh the risks of side effects.
- Recurrence Score greater than 54: The DCIS has a high risk of recurrence, and the benefits of radiation therapy are likely to be greater than the risks of side effects.
The Oncotype DX DCIS test is expensive, usually costing more than $3,000 in the United States. Also, the best way to use it isn’t clear: Should all women diagnosed with DCIS have the test or just a certain subset of these women? So researchers analyzed the cost effectiveness of different strategies for using the Oncotype DX DCIS test to guide treatment decisions among women usually considered good candidates for skipping radiation after lumpectomy.
The research was published online on Sept. 19, 2016 by the Journal of Clinical Oncology. Read the abstract of “Cost Effectiveness of the Oncotype DX DCIS Score for Guiding Treatment of Patients With Ductal Carcinoma In Situ.”
The researchers used a statistical model to analyze treatment strategies for two groups of women who were part of the ECOG ES194 study. The ECOG ES194 study looked at how effective lumpectomy alone was for women diagnosed with DCIS.
Group 1 included women who were diagnosed with either low- or moderate-grade DCIS that was 2.5 cm or smaller in size. Group 2 included women who were diagnosed with high-grade DCIS that was 1 cm or smaller in size.
Low-grade DCIS cells look only slightly different from normal cells and grow slowly. Moderate-grade DCIS cells grow faster than normal cells and look less like them than low-grade DCIS. High-grade DCIS cells grow more quickly and look much different from normal breast cells.
The researchers estimated treatment costs to be:
- Oncotype DX DCIS test: $3,416
- radiation after lumpectomy to remove DCIS: $10,538
- lumpectomy and radiation after DCIS recurrence: $13,924
- mastectomy after DCIS recurrence: $6,249
- lumpectomy and radiation after invasive breast cancer recurrence: $15,319
- mastectomy after invasive breast cancer recurrence: $6,610
To do the study, the researchers compared the per-person costs of five treatment strategies:
- strategy 1: no women had Oncotype DX DCIS testing and no women received radiation after lumpectomy -- cost: $1,360
- strategy 2: no women had Oncotype DX DCIS testing and only women in group 2 (diagnosed with high-grade DCIS) were treated with radiation after lumpectomy -- cost: $2,913
- strategy 3: women diagnosed with low-grade DCIS did not have radiation after lumpectomy; women diagnosed with moderate- and high-grade DCIS had Oncotype DX DCIS testing and those who had intermediate- or high-risk Recurrence Scores had radiation after lumpectomy -- cost: $5,695
- strategy 4: all the women had Oncotype DX DCIS testing and those who had intermediate- or high-risk Recurrence Scores had radiation after lumpectomy -- cost: $7,439
- strategy 5: no women had Oncotype DX DCIS testing and all the women had radiation after lumpectomy -- cost: $10,969
Neither of the strategies that used the Oncotype DX DCIS test were cost effective compared to strategy 1.
Still, the statistical model the researchers used assumed that none of the women cared whether or not they were treated with radiation after lumpectomy. When the researchers adjusted the model to take into account patient preferences, they found that strategy 5 -- radiation for all the women -- became more cost effective.
Also, because the goal of radiation after lumpectomy is to reduce the risk of recurrence, as well as the risk of invasive breast cancer being diagnosed, the researchers calculated the costs of preventing each one for strategies 2 through 5:
- strategy 2 -- cost per DCIS recurrence prevented: $108,330; cost per invasive cancer prevented: $214,891
- strategy 3 -- cost per DCIS recurrence prevented: $175,290; cost per invasive cancer prevented: $384,472
- strategy 4 -- cost per DCIS recurrence prevented: $174,855; cost per invasive cancer prevented: $323,000
- strategy 5 -- cost per DCIS recurrence prevented: $135,655; cost per invasive cancer prevented: $307,732
The researchers wrote: “These results confirm the importance of eliciting patient preferences in decision making when there are multiple reasonable management options. In this setting, the benefit of [radiation therapy] depends on the trade-off between the fear and consequences of…both local recurrence of DCIS or invasive carcinoma versus the inconvenience, fear, and adverse effects of treatment. …Physicians should discuss trade-offs associated with omitting or adding adjuvant radiation therapy with each patient to maximize quality-of-life outcomes.”
While treatment strategies using the Oncotype DX DCIS test weren’t cost effective compared to strategies that didn’t use the test, the results make it very clear that a woman’s treatment preferences are extremely important to the value that a treatment has.
If you've been diagnosed with DCIS, your doctor will recommend a treatment plan after surgery tailored to your specific recurrence risk for DCIS or invasive breast cancer that also takes into account your preferences. Your treatment plan may include radiation therapy, hormonal therapy, both, or neither. If you're deciding on treatments after DCIS surgery you might want to ask if the Oncotype DX test might help figure out if you would benefit from radiation therapy. Armed with the best information possible, you and your doctor can decide on a treatment plan that makes the most sense for your unique situation.
The Breastcancer.org DCIS pages contain more information on DCIS symptoms, diagnosis, and treatment.