Dietary Supplement Strengthens Immuno-Therapy Against Breast Cancer

November 7, 2005

An American study has shown that the pioneering cancer medicine against breast cancer, Herceptin, can be made 30-40 times more effective when used in conjunction with a harmless dietary supplement: gamma-linolenic acid (GLA). The study’s results are preliminary but calls for further investigation.

Every year, almost 3,500 Danish women get breast cancer. Approx. every fifth of them have a particularly aggressive form of cancer, which you may fear in particular, if you find cancer in the lymph nodes of the armpit during surgery. The aggressive cancer is due to a gene in the affected women which is particularly active and forms large amounts of HER2, a protein. When HER2 adheres to the surface of a breast cell, it reacts with growth agents in the blood that can transform the cell into a cancerous cell and stimulate it to growth.

However, since 1998, there have been medicine available that, in the same way as an antibody, have been able to block HER2 and thus weaken the growth stimulation. The name of the drug is Herceptin® (Trastuzumab) and so far only women have been offered this, who in addition to being “HER2 positive”, have had recurrence of breast cancer that has spread.

More recently, however, research has shown that Herceptin also helps when it is given much earlier, namely as soon as it is known after the operation that the woman is HER2-positive. In Denmark, the treatment can be relevant for approx. 450 women annually. In an experiment with approx. In 3,350 women who received Herceptin for one year, the risk of recurrence of the disease was halved and mortality was reduced by a third. In a Belgian trial with just over 5,000 women, the risk of relapse was also halved – to approx. 6%. Overall mortality was also reduced in this trial, but only slightly and not statistically significantly.

The Danish Cancer Society is now calling on women who have had surgery for breast cancer to find out whether they are HER2-positive and should have the treatment. But unfortunately it is not as risk-free as it sounds. HER2 also plays a role in the heart, and chemotherapy along with blocking HER2 is a cocktail that can cause heart failure. This happens in up to 20%, many of whom have to stop the treatment. How they fare in the long term is not known.

GLA and Herceptin collaborate
All this is mentioned only to say that HER2 can apparently – sensationally – also be attacked from a completely unexpected angle. The vital fatty acid gamma-linolenic acid (GLA), used by many as a dietary supplement, also (in laboratory experiments) inhibits HER2, but by a different mechanism than Herceptin. According to researchers from Northwestern University in the USA, GLA enhances the effect of Herceptin no less than 30-40 times, without affecting healthy cells. The combination means that many more cancer cells die, while others are inhibited in their growth.

The way it works is complicated. The experiments suggest that GLA stimulates the formation of a protein (PEA3), which in turn inhibits the gene that must produce HER2. Since GLA and Herceptin therefore intervene separately – one blocks the formation of HER2, the other blocks the effect – they reinforce each other. Previous experiments have shown that GLA can also independently inhibit cancer in the laboratory.

If even a little of this applies to living people, it is a sensation. But it must be emphasized that these are only laboratory experiments at the cellular level. Further extensive research is needed. It is, as the authors write, on the other hand required. What women with HER2-positive breast cancer must do here and now is, among other things, for now up to the individual.

By: Vitality Council

1. Piccart-Gebhart et al. Trastuzumab after adjuvant chemotherapy in HER2-positive breast cancer. N Engl J Med 2005;353:1659-72.
2. Romond EH et al. Trastuzumab plus adjuvant chemotherapy for operable HER2-positive breast cancer. N Engl J Med 2005;353: 1673-84.
3. Menendez JA et al. Effect of gamma-linolenic acid on the transcriptional activity of the Her2/neu (erbB-2) oncogene. J Natl Cancer Inst 2005;97:1611-15.