Taxol v. Taxotere
Taxotere is linked to a relatively high incidence of permanent hair loss when compared to most other chemotherapy drugs, including Bristol-Myers Squibb’s Taxol, an earlier drug that Taxotere was originally developed as an alternative to.
The active ingredients in Taxol and Taxotere—paclitaxel and docetaxel, respectively— are structurally similar and operate in a near-identical way, as they’re both taxanes, plant-based chemotherapy agents that attack cancer by inhibiting cell division. Research shows that the two drugs generally demonstrate comparable levels of efficacy in treating breast cancer and other shared FDA-approved indications, but as we’ll see, Taxotere has a much stronger association with permanent alopecia.
Early clinical trials for Taxotere, initiated in the late 90s to test the drug in breast cancer patients, had already revealed an incidence of “persisting alopecia” ranging from 3% to 9%. But the very first research effort to focus on the relationship between Taxotere and permanent hair loss was a 2006 study performed by Dr. Scot Sedlacek at the Rocky Mountain Cancer Centers in Denver, Colorado.
A practicing oncologist specializing in breast cancer treatment, Sedlacek set out to investigate permanent hair loss in breast cancer patients receiving taxane-based adjuvant chemotherapy. Specifically, he was looking for Persistent Significant Alopecia (PSA), which he defines as loss of more than 50% of pre-chemo thickness (as judged by both Sedlacek and by the patients themselves) that lasts longer than 6 months.
At the time, PSA was thought to be an exceedingly rare occurrence in chemotherapy, except in patients receiving harsh, high-dose chemo in preparation for bone marrow transplantation. But strangely, Sedlacek had seen PSA arise in a “small but significant” number of patients he’d treated over the years with standard-dose adjuvant chemotherapy, prompting him to take a closer look.
Over 6% Develop Persistent Alopecia
Collecting data on nearly 500 patients whom he’d treated personally over a period of about 11 years (from Jan. 1994 to Dec. 2004), Sedlacek grouped patients by the adjuvant chemotherapy regimen they were assigned:
- Group A. Doxorubicin regimen without a taxane (258 patients)
- Group B. Doxorubicin plus Taxol (126 patients)
- Group C. Doxorubicin plus Taxotere (112 patients)
In order to ensure that cases of permanent alopecia could be accurately diagnosed, only patients with at least one year of follow-up data were included in the study. However, the average follow-up period was a substantial 4 years—Sedlacek was able to follow up with most of the study participants for at least 2 years post-chemo, and some patients even kept in touch for more than seven years.
Analyzing Group C—all the patients who’d received Taxotere—Sedlacek found that 6.3% developed PSA. By the standards for side effect risk estimates used as guidelines by both the European Medicines Agency (EMA) and the FDA, this figure would solidly rank PSA as a “common” side effect (between 1% and 10% incidence).
Alarmingly, it seemed that patients didn’t even need to receive a complete dose of Taxotere to be stricken with PSA. Two patients who had to stop taking Taxotere after a single infusion due to “unacceptable toxicity” still ended up with PSA lasting at least seven years, even though they’d only taken a fraction of the total Taxotere dosage assigned to them
On the other hand, none of the patients from the other two groups, all treated with Taxotere-free regimens, suffered from PSA.
Conclusion: Taxotere Can Cause “Devastating” PSA
Sedlacek firmly concluded that his study implicates Taxotere as a cause of permanent hair loss. Describing how most of the women who’d developed PSA told him that their hair loss resembled “male pattern baldness” and felt the need to cover up with wigs, Sedlacek urged doctors and patients to carefully consider the risks of the “emotionally devastating” side effect while determining an optimal adjuvant treatment plan.
In addition to its telling results, this study served to pave the way for further research on permanent alopecia in Taxotere users. Sedlacek believes that his work flipped a switch in the minds of many other cancer experts, revealing a connection between Taxotere and persistent hair loss that no one had thought to make before.
Indeed, as he discusses in an interview with A Head of Our Time, whenever he presents his research, oncologists in the audience tell him that they'd suddenly realized that they too had seen Taxotere patients suffer lasting alopecia.
What Causes Permanent Taxotere Hair Loss?
Currently, researchers are still working to understand why Taxotere seems to hold a higher risk of permanent hair loss than any other chemotherapy drug, even the closely-related Taxol.
More Potent: Convenience Vs. Increased Toxicity?
Some scientists believe the greater risk of permanent alopecia and other side effects may be related to the potency level of Taxotere. Taxotere is roughly twice as potent as Taxol, for several reasons:
- Taxotere is more readily taken up by cells
- It binds more tightly once inside the cell
- It's generally retained for longer time periods within the cell than Taxol is
Since the increased potency of Taxotere enables the drug to work in longer intervals, requiring less frequent infusions and a smaller number of total treatment cycles, some doctors consider it an advantage, offering more convenience in terms of scheduling for patients, doctors, and other hospital staff.
However, this higher potency level is also thought to translate into higher toxicity, which may be the root cause of increased risks for permanent hair loss.
Why Chemotherapy Causes Temporary Alopecia
Cancer cells are known to grow and reproduce at a rapid rate. Drugs designed to kill or slow the growth of cancer target these rapidly-dividing cells. But there are normal cells in the body that also reproduce relatively quickly, such as those of hair, blood, bone marrow, and the lining of the stomach.
Unfortunately, the development of chemotherapy drugs that target cancer cells exclusively is extremely challenging, and so these normal cells are typically also damaged during treatment, resulting in the common chemotherapy side effects of nausea, digestive problems, low blood cell counts, susceptibility to mouth sores, and hair loss.
However, chemotherapy is administered for only relatively short amounts of time and then discontinued. When a patient’s chemotherapy cycles are over, hair and other healthy cells typically grow back. Most patients will see their hair grow back to a pre-chemo thickness in 6 months to a year after ending therapy.
How Permanent Hair Loss Occurs
Scientists are still working to understand the root causes behind aging-induced hair loss. As a person ages, more and more hair follicles start to lose their functionality, either by producing only thin, short vellus hairs (sometimes referred to as “peach fuzz” hair) rather than long, thick “terminal” hairs or by halting production of hair altogether.
Hair And Hair Follicles
To better understand the causes of hair loss in general, as well as what researchers are discovering about Taxotere hair loss, it’s helpful to know the anatomy of hair and hair follicles and how each component works.
Hair grows from follicles, miniature organs that lie in the epidermis, comprised of several parts:
- Papilla. Situated at the base of the hair follicle, this structure contains connective tissue and blood vessels which serve to nourish hair as it grows.
- Hair matrix. The area where hair actually grows from.
- Bulb. The only living part of the structure, which stores stem cells.
In addition to the follicle, there are many other hair-related structures:
- Hair sheath. This is what people commonly think of as hair — the actual visible part of the hair that extends beyond the skin. The shape of the molecules that make up the hair sheath affects hair type and texture.
- Root sheath. A 3-part structure that protects the hair follicle and other associated structures.
- Arrector pilli. Tiny muscles connected to the hair follicle that allows hair to stand up (causes "goosebumps").
- Sebaceous glands. The hair sheath is lubricated and protected from the elements by sebum, an oily substance produced by these glands.
Looking closely at hair follicles that no longer function, researchers find them both smaller in size and possessing a different composition from normal working follicles, particularly in the bulb area. Rather than the usual healthy stock of stem cells that are used to grow hair or rebuild damaged follicles, these aged follicles merely have inert skin cells in their bulbs.
According to the latest medical research, Taxotere-induced permanent alopecia appears to damage hair follicles in a similar way to permanent hair loss from aging. The stem cells responsible for hair growth are killed or replaced by non-functional cells. Both permanent chemotherapy-induced hair loss and hair loss from aging are active areas of research that hopefully will provide answers and solutions for individuals struggling with permanent alopecia.
Though many cancer patients dread the temporary hair loss caused by chemotherapy, they know that it’s an expected and unavoidable side effect, and can prepare themselves emotionally and psychologically for the change. For one thing, they can focus on getting better and looking forward to the end of a successful chemotherapy treatment - to the return to a normal life.
When A Patient’s Hair Never Returns
But for patients who took Taxotere and experienced permanent hair loss, life never returned to normal. Their hair never grew back, and many experience considerable social anxiety and depression from the unexpected permanent change.
Grappling With Self-Esteem And Identity
For many people, especially women, hair is an important part of self-image and self-esteem. To have one’s hair taken away forever without any warning is a terrible injustice, especially when a just-as-effective alternative that carries a much lower risk of such hair loss—Taxol—is readily available.
Victims frequently report feelings of shock and anger after discovering that hair loss, which they thought they'd only have to experience during chemotherapy, will likely persist for the rest of their lives. Affected patients typically retain either complete baldness or zones of hair loss that resembles male pattern baldness. Many women feel they were unfairly robbed of their femininity and suffer from anxiety and lack of confidence in social situations, sometimes to the point where it impacts their ability to function optimally at work, thus negatively affecting them financially as well as emotionally and psychologically.
A Constant Reminder Of Cancer
Chemotherapy patients often harbor hopes that the end of their treatment cycles will usher in a new chapter of their lives as cancer survivors — a welcome ending or abatement of the stress and pain they suffered due to their cancer — so that they can move on with their lives with a renewed sense of vigor.
But many Taxotere victims, even those whose chemotherapy was successful and ended long ago, feel that their hair loss permanently and publicly marks them as cancer patients. They lament the fact that they still look like they're going through chemotherapy, and must face a slew of distressing questions in social situations, constantly reminding them of their experience with cancer even when they'd prefer to focus on the present.
Can Taxotere Hair Loss Be Prevented Or Reversed?
Unfortunately, reversal of hair loss is currently a difficult task. The only possible approach is hair transplantation, which is the transplant of hair follicles from a more populated area of the scalp to a less populated area. Transplantation isn’t always successful, and besides, it’s not a viable approach for individuals who have lost all of their hair.
Prevention of hair loss is a field that’s seen more success in recent years. There are topical treatments such as minoxidil, the active ingredient in Rogaine hair treatments, but the approach that seems to offer the best results is scalp cooling.
In scalp cooling, chemo patients are given “cold caps,” tight-fitting hats meant to keep the scalp at low temperatures. The idea is that low temperatures slow down the induction of Taxotere into the cells of the scalp and slow down or inhibit activity. A number of studies have been performed on various types of cold caps and have demonstrated a modest level of success. The more a cold cap is able to reduce the temperature, the better it can work in general. Trials have shown more success for patients with thinner hair than those with thick hair due to the insulating effect of the hair.
Learn More About Taxotere Side Effects