“Yew as corner stone of chemotherapy”
Who is Hans Nortier and why did you choose this line of work ?
I belong to what is known as the first-generation oncologists or internist/oncologists. When I became an internist during the seventies one had “areas of expertise” within the scope of “internal medicine” instead of proper sub-specialism. I started working in Utrecht, where Bob Pinedo a well-known Dutch oncologist had just come back from the States with a new type of cytotoxic (cell killing) treatment called Platinum. He had been working for a year at the NCI in the United States with this new type of medicine, derived from Platinum that proved to be very effective in testicle cancer. This was a very interesting development; to have a medicine that cured metastasis of the testicles of young men that was incurable before. These new developments sparked my interest in oncology.
During this period, I was also very interested in hormonal disorders and I obtained my doctorate on this subject. During my study “internal medicine” I started working at the oncology clinic. First one day a week, which I ultimately increased to 4 days a week, working as junior staff member at the internal medicine ward.
In 1985 I made a switch from the Academic Hospital Utrecht to another hospital, called “The Diakonessenhuis” also based in Utrecht. Here I worked until the year 2000 as internist/oncologist with breast cancer as a sub-specialism. I also worked on basic oncology. In 2000 I was appointed head of the department “Clinical Oncology” at LUMC (University hospital in Leiden) where I was employed for the following 12 years. Next to more intricate patient care my job in this academic hospital also included management, research, education and refresher courses.
Now I am no longer working with patients and has my task evolved to creating an oncology network in the South West of Holland in cooperation with Erasmus Medical Centre. One of our goals is to upgrade the quality in the oncology field by bringing together knowledge from various parties. In The Netherlands, we strive towards a consensus in treatment and less practice variation. We are now waiting for the revised guideline in breast cancer treatment. Currently there are still a lot of regional differences in which treatment is proposed to the patient. By having a more structured cooperation on national level we can exchange our knowledge and treatment methodology. The ultimate goal being to obtain a more personalized treatment plan. Resulting in a personalized plan per patient, preferably with shared decision making between doctor and patient.
How do oncologists in general view the use of medication with a Yew component (Taxol®/Taxotere®)?
This year the Dutch Society for Oncology (Nederlandse Vereniging voor Medische Oncologie) celebrates its 20th anniversary. The Society was founded in consequence of the Paclitaxel (Taxol®) discussion. Taxol® (paclitaxel) is derived from the bark of the Taxus Brevifolia tree (indigenous to the USA). This product does a marvellous job as a component in chemotherapy (cell-killing medication). However, it does have neuro toxic side effects and is expensive and hard to harvest as you have to chop and therefore destroy an entire (old) tree. Taxotere® (docetaxel) derived from the needles of the Taxus Baccata tree indigenous to Western Europe, has a similar effect on inhibiting certain types of cancer (also neuro toxic) but is less invasive to obtain.
The neurotoxicity proves to be less when (either) treatment is administered on a weekly basis, building up to 3 weeks in a row and then skipping the fourth week. This allows the patient to have some more recovery time in between treatments. And makes the neurotoxic side effects more bearable.
Could you elaborate more on the difference between chemotherapy and hormone therapy also frequently used in treating cancer ?
When looking at colon cancer or cancer in the large intestine we already know that a treatment with either Taxol® or Taxotere® has little to no effect. With breast cancer, however, the prognoses with additional chemo-treatment has significantly improved. Then we are talking about the 1st/2nd/3rd generation chemo-treatment models. Treatment with Yew tree related components are the 3rd generation. There are a lot of academic studies proving that there is an extra advantage to be gained when you create a build-up towards the 3rd generation treatment.
So the 3rd generation has become a standard to administer, unless the patient is not able to endure the neurotoxicity or does not want to take the treatment. Another reason not to administer would be if there is are already an existing neuro pathological indication (such as severe disturbance of the nervous system). However, when a patient is able and willing and there are no contra indications with regard to neuropathology we will always try to opt for chemotherapy with a yew tree component. There is a lot of variation in side effects. This really varies per person.
With hormonal treatment, the environment of the tumour cell is treated. This causes the cell to stop growing. For some reason, certain types of tumours are sensitive to hormone treatment. In these tumours, we find that hormones serve as a stimulant for growth of the malignant cells. For those types of tumours hormone treatment is most effective. If it does not work you have to choose a different approach.
Chemotherapy is a cell-killing treatment that attacks the malignant cells directly and has a longer effect on the cell division.
Yew tree components used in chemotherapy are highly toxic and can lead to neurotoxic reactions (such as severe sensory irritation). If a specialist should decide not to administer or advise against Taxol®/Taxotere® for those reasons it would be under treating the illness. Of course, the constitution of the patient is taken into regard and of course the patient always has the last say in opting for a certain type of treatment. For certain types of cancer that are insensitive to hormonal treatment, chemotherapy with yew tree components is often times a good alternative.
Is Taxotere® (trade name for docetaxel derived from Taxus Baccata) a substance that will continue to be used in the future?
Yes. I do not see how that could be eliminated. Of course, it is true that breast cancer for example is becoming more complicated to treat due to the mutation into subtypes. I mean that there are more subtypes coming into existence that each need a different approach.
We are also working with genetic information, trying to identify people that have a larger risk at cancer or certain types of cancer. Genetic research is now tryi9ng to develop a method to determine which people would have a higher risk at side effects. And with these (future) conclusions we hope to be able to find out what type of chemotherapy would have the best effect on which people. This research is still in developmental stage and will hopefully be available for the future.
Why are you supporting our goals ?
Docetaxel and paclitaxel (derived from Yew trees) will remain the backbone of many types of chemo therapy. I find it fascinating and beautiful how the cycle with nature is therefore so important.