This news release covers a randomized trial of 54 women with early-stage breast tumors that studied the safety and efficacy of a vaccine that uses messenger cells in the immune system, called dendritic cells, to target a protein on cancer cells. The study’s main goal was to compare the safety and immune responses using varying routes of vaccination, including a lymph node, a breast tumor, or both. The news release quantifies some benefits and mentions harms, but it doesn’t spell out costs, availability or study limitations, leaving the reader to wonder why these findings are significant. The headline of a “promising” treatment for early stage breast cancer patients isn’t supported by the facts.
News releases that don’t spell out study limitations are bound to spawn misleading replications across the internet, particularly when they purport to advance the idea of harnessing the body’s immune system to fight cancer. That’s the case here, where we found numerous online blurbs based on this news release, such as:
“Vaccine Shows Promising Results for Early-Stage Breast Cancer Patients: Moffitt Cancer Center is working on a new vaccine that would help early-stage breast cancer patients who have HER2 positive disease.”
The bottom line: there’s no evidence that this procedure produces a long-term benefit such as reduced mortality. All but one patient who responded to this treatment had been diagnosed with a noninvasive condition called ductal carcinoma in situ (DCIS), which poses a very low risk of death from breast cancer. Further, this study was designed mainly to compare various paths of vaccination, not to determine the broader question of whether the treatment actually saves lives.
There’s no mention of how much this treatment costs.
The news release states that “approximately 80% of evaluable patients had a detectable immune response in their peripheral blood and/or in their sentinel lymph node wherein their cancer is most likely to spread to first.” It also states that 13 patients achieved an absence of disease after treatment, though it doesn’t give a percentage, and that patients who had early non-invasive disease called ductal carcinoma in situ (DCIS) achieved a higher rate of disease absence than patients who had early-stage invasive disease.
Further, it says those patients who saw absence of disease had a higher immune response in their lymph nodes, which, says a researcher, “may serve as a more meaningful immunological endpoint.”
The news release states that immune responses were similar regardless of whether the vaccine was administered into a lymph node, a breast tumor, or both, though it doesn’t explain why this is an important finding.
The news release states that the vaccines were “well-tolerated and patients only experienced low-grade toxicities. The most common adverse events were fatigue, injection site reactions, and chills.” The release would have been better if it had told us how often these side effects occurred in the patient volunteers.
This news release doesn’t point out study limitations, such as the fact the 80 percent immunological response rate did not necessarily translate to an elimination of cancer. While 12 of the patients with DCIS saw their disease go away, 30 experienced no such benefit.
Moreover, the news release does not caution that the study was not designed to study whether or not the vaccine therapy is an effective long-term treatment for patients with DCIS or early invasive breast cancer. It was primarily designed to determine if the Her2 vaccine is safe, which method of injection generated a better immune response, and to evaluate the relationship between immune response and clinical response.
There’s no evidence that this procedure produces a long-term benefit such as reduced mortality. Most of the patients who showed a response to this treatment had been diagnosed with a noninvasive condition called ductal carcinoma in situ (DCIS), which poses a very low risk of death from breast cancer. According to the National Institutes of Health, “treating these lesions may help prevent a recurrence in the breast but does not appear to decrease the already-low risk of dying from the disease, even after 20 years of follow-up.”
The news release implies that DCIS is breast cancer, but that’s a controversial assertion. We cover this more in the section on Unjustifiable Language.
The study states the funding sources of the study. According to the paper, the researchers reported no conflicts of interest.
This was a close call. The study was not looking at using the vaccine as an alternative to standard therapy; the research is too preliminary for that so we don’t fault the release for its lack of a comparison with surgery/radiation. However, we’re rating this Not Satisfactory for not noting that an alternative for early-stage cancers is no treatment or “watchful waiting.”
There’s no information on where to get this treatment, whether it’s widely available, and if not yet available when it might be approved as a treatment for breast cancer.
The news release acknowledges that this treatment is not a unique approach when it states: “Many therapeutic strategies aim to re-stimulate the immune system to recognize cancer cells and target them for destruction.”
According to the study paper, its main goals were to compare the safety and efficacy of using various vaccination sites and explore relationships between immune and clinical responses.
The lead says the vaccine targets “early-stage breast cancer” but calling the abnormal cells present with DCIS “breast cancer” is misleading. They’re abnormal cells that line the milk ducts of the breast, with the potential to advance to an invasive cancer but they have not spread outside the breast.
Also, the news release states that patients “only” experienced low-grade toxicities. We don’t like the word “only” because it downplays adverse effects that could be significant for patients who experience them.
Finally, we take issue with the headline, “Vaccine Shows Promising Results for Early-Stage Breast Cancer Patients.” With less than a third of patients seeing a tangible result in their tumors and no data on long-term outcomes versus a control group, there’s no way to justify the description “promising.”