There are several ways that cancers can cause hair loss. The process may be a direct or indirect action on the hair follicles.
Neoplasms may result in permanent alopecia. There are several types that can be involved and directly affect the skin and hair follicles. Sclerosing basal cell carcinomas are tumors that develop from skin cells. Syringomas develop from cells in sweat ducts and sometimes even cells from within hair follicles themselves can become cancerous and develop into hair follicle hamartomas. These types of cancers limited to skin structures can become quite extensive and affect almost all areas of the skin. Any associated hair loss may be equally extensive.
As with any tumor, the excessive proliferation of cells involved develops as masses of undifferentiated tissue. The tumor destroys hair follicles and any other normally identifiable skin structure. This a form of cicatrical alopecia although there need not be any actual scar tissue around hair follicles. As a cicatrical alopecia the hair follicles are permanently destroyed and there is no hope of hair follicle regrowth – assuming the cancer is successfully treated. Treatment for such skin cancers involves excision of the affected area before the cancer can spread to other tissue and/or use of chemotherapy. Early diagnosis and treatment is vital both for curing the cancer and for limiting the extent of permanent alopecia.
Metastatic cancers may also cause alopecia. Breast, lung, liver, and kidney cancers can spread to the skin and destroy hair follicles and other structures. Lymphomas are a type of cancer where cells of the immune system proliferate out of control. These mutant inflammatory cells often collect in the skin and can target and destroy hair follicles in the process.
If permanent hair loss is apparent after successful remission of the cancer, hair transplantation is the only practical option to cover bald regions.
The rapid, uncontrolled rate of cell growth involved in cancer of internal organs requires utilization of energy, vitamins, and minerals in large quantities. This depletion of resources and the associated anemia may lead to a gradual diffuse hair loss described as a telogen effluvium. The cancers may also disrupt hormone production and in turn this may also cause alopecia. Hair loss induced indirectly by cancer in this way should spontaneously recover once the cancer is successfully treated and its influence removed from the body. Recovery from telogen effluvium forms of hair loss is slow and it may take several months before there is noticeable hair regrowth.
Le terapie antitumorali possono portare alla caduta di capelli?
Chemotherapy for cancer may cause temporary alopecia. Treatment for cancer involves using drugs that slow down the rate of cell proliferation. This means that cells with a high rate of activity and cell division will be the most affected. In healthy individuals some of the most active proliferating cells are those that make hair fiber. Chemotherapy is a nonspecific treatment, it acts on all proliferating cells and not just the cancerous cells. So while chemotherapy slows down or stops cancer cells from multiplying it also stops hair follicle cells from dividing. This results in hair loss as hair follicles shut down hair fiber production.
This form of hair loss is described as an anagen effluvium. In an anagen effluvium type of hair loss, the hair follicles have their hair fiber growth actively blocked. The hair follicles themselves are still ready and raring to go but they can not do much without having rapidly dividing matrix cells to construct the hair fiber. Anagen effluvium develops in a very short space of time. People on intensive chemotherapy may lose all their hair in a few days.
Anagen effluvium is not a permanent form of alopecia. Once the chemotherapy is stopped the hair follicles rapidly reorganize themselves and start growing hair again. New hair can be visible within four weeks of completing chemotherapy. A full head of hair may take a few months.