18 August 2023 – Varkie van Zyl

How the Pacific Yew Tree Became a Lifesaver

The Pacific yew tree, or Taxus brevifolia, has played a significant role in changing cancer survival rates through the discovery of taxol. Taxol is a chemotherapy drug derived from the bark of the Pacific yew tree that has been used to treat various types of cancer since the early 1990s. This article will explore the history of taxol and the Pacific yew tree, as well as its impact on cancer treatment and survival rates.

The Discovery

The discovery of taxol is a story that begins with the Pacific yew tree, a slow-growing evergreen tree that is native to the Pacific Northwest region of North America. The tree was first noticed by European settlers in the 19th century, who used it for ornamental purposes. However, it was not until the 1960s that researchers began to take notice of the tree’s potential medical properties.

At the time, the National Cancer Institute (NCI) was looking for new compounds that could be used in the fight against cancer. In 1962, the NCI launched a program called the National Cancer Chemotherapy Program, which aimed to screen natural products for their potential anti-cancer properties. One of the compounds that showed promise was a substance found in the bark of the Pacific yew tree, which was later named taxol.

However, extracting taxol from the bark of the Pacific yew tree proved to be a difficult and expensive process. The tree grows very slowly and only produces a small amount of bark each year, which means that large quantities of bark would be needed to produce enough taxol for clinical use. Furthermore, the extraction process was complex and required specialized equipment and expertise.

Despite these challenges, researchers continued to work on developing taxol as a cancer treatment. In the 1970s, a chemist named Monroe E. Wall developed a new method for extracting taxol from the bark of the Pacific yew tree. Wall’s method was more efficient than previous methods and allowed for larger quantities of taxol to be produced.

The Effects

In the 1980s, clinical trials began to test the effectiveness of taxol in treating various types of cancer. The trials showed that taxol was effective in treating ovarian cancer, which had previously been difficult to treat with chemotherapy. Taxol was also found to be effective in treating breast and lung cancers.

In 1992, taxol was approved by the U.S. Food and Drug Administration (FDA) for the treatment of ovarian cancer. The drug was later approved for the treatment of breast cancer and other types of cancer as well. Taxol was a significant breakthrough in cancer treatment because it worked in a different way than other chemotherapy drugs. Taxol works by blocking the ability of cancer cells to divide and grow, which slows down or stops the growth of the cancer.

The discovery of taxol had a significant impact on cancer survival rates. Before taxol, ovarian cancer had a five-year survival rate of only 5-10%. However, with the introduction of taxol, the survival rate increased to 30-40%. Similarly, the survival rate for breast cancer increased from 75% to 85% with the addition of taxol to the treatment regimen.

Taxol is still used today in the treatment of various types of cancer. In addition to its use as a chemotherapy drug, taxol has also been used to develop other cancer treatments. For example, researchers have used taxol as a starting point for developing other drugs that target cancer cells in different ways.

The Aftermath for the Trees

The discovery of taxol also had a significant impact on the Pacific yew tree. Before taxol, the Pacific yew tree was not considered particularly valuable. However, with the demand for taxol, the tree became a valuable resource. This led to concerns about over-harvesting and the potential impact on the environment. To address these concerns, researchers began looking for alternative sources of taxol.

One alternative source of taxol is the European yew tree, Taxus baccata, which is also found in North America. However, the European yew tree also grows slowly and produces small amounts of bark, which makes taxol extraction difficult and expensive.

Another alternative source of taxol is the cell culture of the Pacific yew tree. In the late 1990s, researchers developed a way to grow Pacific yew cells in the lab and produce taxol from them. This method is more efficient and less damaging to the environment than harvesting bark from the tree. However, it is still expensive and has not yet been widely adopted.

In conclusion, the discovery of taxol from the Pacific yew tree has had a significant impact on cancer treatment and survival rates. Taxol was a breakthrough in chemotherapy because it worked in a different way than other drugs and was effective in treating previously difficult-to-treat cancers. The discovery of taxol also had a significant impact on the Pacific yew tree and raised concerns about over-harvesting and the impact on the environment. Alternative sources of taxol, such as the European yew tree and cell culture, have been developed but are still not widely used. The story of taxol and the Pacific yew tree is a reminder of the importance of natural products in the search for new cancer treatments and the need to balance medical advances with environmental sustainability.