A breast cancer test with saliva: when the news is far from reality

News about a new treatment that will cure the most aggressive subtype of cancer or a new technique to diagnose cancer early through a simple and harmless test happen periodically, creating a great media stir and enormous expectation in society.

There is no doubt that, as a society, we crave positive news about progress against cancer, since in a direct or indirect way, we are all going to be in contact with this disease.

However, the truth is that many of these news are far from reality, or, at least, from a current or short-term reality.

Recently, news has been reported about how a saliva test could diagnose breast cancer, even venturing to suggest that it could relegate the use of mammography as a screening technique, a technique that has been shown to reduce mortality from breast cancer in large and rigorous clinical trials.

This news has generated a great media impact, but, as in many other cases, the truth is that the real scientific impact of this supposed advance is limited today.

In this specific case, we are talking about a device that determines a tumor marker in saliva with great sensitivity.

It should be noted that the determination of tumor markers has not been proven to be a valid strategy for screening for breast cancer or for its diagnosis, and that this study was carried out in 17 patients.

Any advance in diagnostic techniques or treatments requires a long and rigorous process of clinical trials, with the participation of hundreds or thousands of patients, in order to guarantee its safety and effectiveness.

This news is just one more example of the many that are communicated annually in relation to the cure or diagnosis of cancer.

In many cases there is talk of “miraculous” therapies against cancer, and when analyzed, these are results in the preclinical phase, in cell lines or mice, or in a very limited number of patients.

Although some of these therapies may end up making the news, it is essential to be aware that many of these promising therapies unfortunately do not reach satisfactory clinical development, due to not achieving significant benefits in clinical trials or due to a toxicity profile that limits their use.

That is why from the Spanish Society of Medical Oncology we want to insist on the need to cautiously evaluate this type of news, and we appeal to an exercise of responsibility before its dissemination, carefully analyzing its validity and scientific evidence.

Sensational news far from reality can have a negative impact on cancer patients and their families, a particularly vulnerable population, in which they can generate false expectations, increase their anxiety or even, in the worst case, keep them away from diagnostic techniques. such as mammograms or treatments that do have solid scientific evidence.

Dr. César A. Rodríguez

is president of the Spanish Society of Medical Oncology (SEOM).

Dr. Isabel Echavarría

is scientific secretary of SEOM.

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