earn more about hair during chemotherapy and how to prevent hair loss.
In a normal state, the majority of our hair on our scalp is in the growing phase, or what is called the “anagen” phase. These hairs are actively growing from stem cells in the hair root in our scalp, and lasts about 3-5 years. These hairs transition to what is called “catagen” phase where the active growth phase ends. This lasts about 10 days. The hairs then transition to the “telogen” or resting phase, where they rest and then shed. This can last about 3-5 months.
Below is a picture of the normal hair cycle.
Although different regimens have different effects, the common effect of many chemotherapy drugs are to attack rapidly dividing cells.
The upside is that the chemotherapy attacks the tumor cells, which are actively dividing, but the downside is that it also attacks other rapidly dividing cells in the body such as the hair follicles and stem cells in the body. When the stem cell growth is affected, the hair root separates and sheds.
Depending on the regimen, if the chemotherapy medicine has low toxicity, it may lead to less shedding and more thinning, but longer time to regrowth. If the regimen is more toxic, it will lead to more dramatic hair loss but possibly faster hair regrowth. Also chemotherapy can thin the hair shaft leading to breakage of the the hair.
The crown, frontal scalp and the temples are most at risk for hair loss from chemotherapy. In many regimens complete loss can be expected, although some lighter regimens can lead to patchy hair loss.
When will I lose my hair?
In regimens that are given every 2-3 weeks, hair loss can be expected around 2 weeks after chemotherapy, and typically most hair has shed by the second cycle of chemotherapy. In lighter regimens such as taxol that are given weekly, hair loss may be slower and hair may even regrow during treatment.
Loss of eyebrows, eyelashes and groin and armpit hair is also common but is more variable, and may even occur at the very end of chemotherapy.
What about eyebrows and eyelashes?
The reason why lashes and eyebrows are the last to go is because they are on a different growth cycle than the scalp hair. Where as the scalp stays in the growth phase for many years, the eyelashes are primarily in the resting phase during chemotherapy. Only 40% are in the growing phase. The growth phase lasts 30 days, the resting phase approximately 3-4 months. For this reason you may see your scalp hair falling out sooner than your eyelashes.
How can I prevent hair loss?
What chemo regimens cause hair loss?
See table below.
|Agents that cause hair loss||Agents that cause milder hair loss|
Myleran or Busulfex (busulphan)
5-FU, Fluorouracil, Adrucil (5-fluorouracil)