Personal Story: A “flu shot” against breast cancer? Not so fast

This article is most relevant for:
Women diagnosed with Ductal Carcinoma In Situ (DCIS)

This article is also relevant for:

Checked Breast cancer survivors

Checked ER/PR +

Checked Her2+ breast cancer

Checked Women under 45

Checked Women over 45

Checked Newly diagnosed

Be a part of XRAY

Relevance: Medium-Low


Research Timeline: Human Research

Research Timeline

Rating Details

Printer Friendly Page

There have been multiple reports in the media of a Florida woman who had a "shot" to treat her DCIS with a promising outcome. This XRAY reviews the underlying story about this early breast cancer vaccine trial. (10/25/19)


At a glance Clinical trials                       
Behind the headlines      Guidelines            
Vaccines and prevention Questions to ask your doctor   
What does this mean for me? Resources and references


This article is about: 

the story of one patient in an early-phase breast cancer vaccine trial.

The headlines

Many media outlets picked up a story about a woman with DCIS (stage 0) who participated in a clinical trial of a breast cancer vaccine.  Headlines included:

  • “Florida Woman Recovers from Breast Cancer with Trial Vaccine: ‘I Feel Like I Walked on the Moon’”
  • “Trial Vaccine Wipes Out Breast Cancer in Florida Patient”
  • “Has Florida clinic developed the cure for cancer?”
  • “Mayo Breast Cancer Vaccine Could Be Available in Less Than a Decade”
  • “Cancer Vaccine Showing Promise in Early Trials”

Behind the headlines 

Media outlets covered the story of Lee Mercker, who was recently diagnosed with ductal carcinoma in situ (DCIS). DCIS is a noninvasive form of breast cancer. This means the cancer cells formed in the milk duct but haven't spread beyond to invade other parts of the breast. Although DCIS is not life-threatening, it can turn into invasive breast cancer if it is not treated.

In most cases, DCIS is treated with breast-conserving surgery (BCS). A surgeon removes the tumor and a small amount of surrounding normal tissue. BCS is usually followed by radiation therapy. For some women, including Mercker, mastectomy is a better option for treating DCIS.

Walking on the moon: Lee Mercker’s story

Mercker said she went to the Mayo Clinic in Jacksonville, FL to start treatment for DCIS.  However, her doctor asked if she’d like to try something else first: an experimental vaccine intended to fight off early-stage breast cancer and prevent future breast cancer.

Mercker said that she jumped at the chance, and she was the first patient enrolled in the clinical trial. Over 12 weeks, she received shots of a vaccine designed to train her own immune system to find and attack her precancerous cells, similar to the way flu vaccine works.

Mastectomy or lumpectomy with radiation are standard-of-care treatments for DCIS. It is important to note that Mercker received the vaccine then had a double mastectomy. Even without the vaccine, mastectomy that removed Mercker’s breast tissue would have eliminated her DCIS. However, because she has a mastectomy, researchers were able to carefully examine her breast tissue to see if the vaccine affected her breast cancer cells.

Development of medications and vaccines for cancer prevention

Several studies are looking at medications and vaccines in an effort to prevent or lower the risk for cancer. Similar to the study in which Ms. Mercker participated, it is common for these clinical trials to begin enrolling people who have very early stages of cancer and plan to undergo surgery. The medication or vaccine is given before surgery; afterward, a pathologist looks closely at the removed tissue to see how the drug affected the cancerous cells.

According to, the current Mayo study is small, enrolling just 43 women who will be followed for a couple of years to observe the vaccine’s safety and side effects. Much larger and longer-term studies will be needed in order to show whether the vaccine ultimately prevents DCIS from becoming invasive breast cancer. Because the research is still early and the effectiveness of the vaccine is still unproven, women who participate will also receive standard-of-care treatment for DCIS.

What does the future hold?

There are several different types of breast cancer. The vaccine in this study was created to prevent breast cancers that make too much of the Her/neu protein (or HER2 for short), which plays a large role in the development of many breast cancers. If successful, this vaccine may help prevent many—but not all—breast cancers. Currently, clinical trials are testing several approaches to preventing breast cancer or recurrence.

Because the immune system helps people to fight infection and cancer, researchers are very interested in ways to harness it to treat or prevent cancer. New immunotherapy drugs are approved to treat several types of cancer, including breast cancer. Still, although the immune system is a natural part of our body’s defense against disease, like any other treatment, vaccines and immunotherapies must be thoroughly tested to prove they are safe and effective before they become standard of care.

What does this mean for me?

While several headlines suggested that Mercker was “cured” by the vaccine, she did not receive it as a breast cancer treatment. While this research is promising, it is far too early to assume or to state that this is an effective way to prevent or treat breast cancer. It is misleading and dangerous for the media to promote this as a cure. Women diagnosed with DCIS should follow the recommendations of their health care team. Participating in a research study such as this one is the best way to get access to experimental agents, advance science and assure that you receive quality care.

Share your thoughts on this XRAYS article by taking our brief survey.

(back to top)

Expert Guidelines

The National Comprehensive Cancer Network (NCCN) has guidelines for treatment of DCIS. You should talk about which option is best for you with your health care provider. NCCN DCIS 2019 treatment guidelines include:

  • Breast-conserving therapy (lumpectomy followed by radiation therapy) without lymph node surgery.
  • Total mastectomy with or without lymph node surgery.
  • Breast-conserving surgery without lymph node surgery followed by accelerated partial breast irradiation.
  • Breast-conserving surgery without lymph node surgery (and without radiation therapy).   

Following surgery, the NCCN recommends that patients:

  • Consider endocrine (hormonal) therapy for 5 years.
  • Receive counseling regarding risk reduction.

Questions To Ask Your Health Care Provider

  • What are the best options for treating my DCIS given my age and/or family background?
  • Will my family history of cancer affect my treatment options for DCIS?
  • What other tests can be used to help decide how to treat my DCIS?
  • I was diagnosed with DCIS before age 50, ­should I consider genetic counseling or genetic testing?
  • What are my options for reducing my risk of a recurrence?
  • Do I qualify for any clinical trials?

Open Clinical Trials

Mayo Clinic trial covered in this article:

Other breast cancer prevention trials:


Back to XRAY Home

Search XRAY studies and articles

Back to XRAY Home

FORCE:Facing Our Risk of Cancer Empowered