Oncotype DX For DCIS

what radiation side effects scare you? long and short term

“Deadly side effects?” Secondary cancers are very, very rare with breast radiation--they usually occur with much larger areas (such as for lymphoma) irradiated, with higher doses and for longer periods. Desquamation is not common--all I had was painless redness--and there are precautions that can be taken during therapy to minimize skin effects. Fibrosis, at least in my case, was really no big deal and can be reduced considerably or even eventually eliminated. Lymphedema is generally a crapshoot, the only truly predisposing factors being removal of lymph nodes (regardless of radiation), injury and infections, and obesity. I have no chronic pain issues. Many with DCIS don’t even get radiation--and with your low Oncotype DX for DCIS you probably wouldn’t, either. But even if you do, I think you are unnecessarily catastrophizing,

Kar324:

I didn't have the test, but I am not sure that the gynecologist really understands the test outputs, based on the test outputs and her related comment:

"It showed the risk of DCIS recurrence to be 11% and for anything invasive to be 4%. (With lumpectomy alone) These percentages are similar to the background "noise" for everyone according to my gyn."

According to NCI, the lifetime risk of breast cancer for the average woman is 12.4%. That number is a life-time risk (likely up to age 80 at least):

http://www.cancer.gov/types/breast/risk-fact-sheet

In contrast, the outputs of the Oncotype test for DCIS are not life-time risk measures, but 10-year risk measures:

http://breast-cancer.oncotypedx.com/en-US/Professi...

"[T]he DCIS Score quantifies: (1) the likelihood of local recurrence (DCIS or invasive carcinoma) at 10 years; and, (2) predicts specifically the risk of an invasive carcinoma local event at 10 years."

Based on the above information, unless you are older, your risk is probably not the same as that of the general population or the background noise. For example, based on the NCI information, the average never-diagnosed 50-yr old would have an approximately 10% risk over the next thirty years.

I have seen a few women here who have incorporated the information about recurrence risks from the DCIS test into their decision-making regarding radiation following breast conserving surgery. However, my layperson's understanding is that the test is not a stand-alone test, and its outputs should still be considered along with other factors that affect personal risk profile. Whether other women who received the test ultimately declined radiation after consideration of all applicable factors is probably not very informative for you personally, both due to differences in presentation and related validation considerations (e.g., they may have had more or less extensive disease than you (tumor size), different/better margins, different multi-focality status, architectural subtypes, ages, menopausal status, family history, known mutation status, etc.).

I realize that you understand the test is not included in the NCCN guidelines, but I note it for completeness. While the National Comprehensive Cancer Center (NCCN) guidelines for Breast Cancer (Professional Version 1_2016) include the use of the other Oncotype DX test (21-gene test) for invasive disease in certain cases of invasive disease, the NCCN guidelines do not include the Oncotype test for DCIS. This likely reflects a lesser degree of validation of and lower level of consensus surrounding its clinical utility.

With this type of test, the weight accorded to the risk assessment outputs should probably reflect an understanding of the scope and quality of validation of the test; how well your clinical and pathological features were represented in the study populations used to validate the test (age, tumor size, margin status, etcetera); and an understanding of the proper use of the test outputs in light of other relevant factors. Perhaps you would find a second opinion from an expert MO and/or radiation oncologist with solid familiarity with the strengths and weaknesses of the test to be helpful to you, as well as further discussion of the impact on risk of particular features of your disease, including tumor size, margin status, etc.

Please confirm all information above with your MO, to ensure that you receive accurate expert advice. You may also wish to inquire with your current MO what specific findings/considerations are the basis for his recommendation to you.

BarredOwl

Validation Studies [edit: for Oncotype test for DCIS]:

Rakovitch (2015): http://link.springer.com/article/10.1007/s10549-01...

Solin (2013): http://jnci.oxfordjournals.org/content/105/10/701

Commentary:

Berg (2013): http://jnci.oxfordjournals.org/content/105/10/680....

Duggal (2013): http://jnci.oxfordjournals.org/content/105/10/681....

Recent studies of interest in DCIS (not comprehensive):

(To obtain the full-length article at no charge, click on "full-text", select Patient ACCESS option, register with the Copyright Clearance Center, and request a copy of a pdf via email)

"Surgical Excision Without Radiation for Ductal Carcinoma in Situ of the Breast: 12-Year Results From the ECOG-ACRIN E5194 Study"

Solin (2015): http://jco.ascopubs.org/content/early/2015/09/14/J...

"Patient Prognostic Score and Associations With Survival Improvement Offered by Radiotherapy After Breast-Conserving Surgery for Ductal Carcinoma In Situ: A Population-Based Longitudinal Cohort Study"

Sagara (2016): http://jco.ascopubs.org/content/early/2016/01/28/J...

Commentary:

Smith (2016): http://jco.ascopubs.org/content/early/2016/02/11/J...

(Noting mortality benefit in group of patients with high-risk factors as defined)

(All patients considering scientific publications in their decisions should confirm their understanding of the information and its applicability to their particular case with their providers to ensure sound thinking.)

Best of luck with your treatments.