Insights Into the Biology of Persistent Chemotherapy-Induced Alopecia via Genomic Approaches—An Avenue to Clinical Translation?

Abstract

A major concern among patients with cancer is hair loss secondary to chemotherapy, an adverse effect that occurs among approximately 65% of patients who undergo this form of therapy. 1 The association between chemotherapy and hair loss is well known across society, and chemotherapy-induced alopecia (CIA) can, therefore, induce a sense of violated privacy, or even shame, among those affected. The association of this adverse effect with reduced self-esteem, social confidence, and sexuality is particularly devastating for women. The anticipation of CIA is so distressing that some female patients even seriously consider refusing chemotherapy treatment. 2 A large proportion of chemotherapeutic agents act by targeting specific phases of the cell division process and are thus highly effective in terms of killing rapidly dividing cancer cells. However, the antimitotic assault of these agents also affects other continuously dividing cell types, including the hair matrix keratinocytes, which display intense mitotic activity for continuous hair growth.Until recently, CIA was considered to be typically reversible, with physicians assuming that hair regrowth would occur between 3 and 6 months after the end of therapy. However, over the years, several reports have described cases of persistent CIA (pCIA), in which incomplete or total absence of hair regrowth has been reported several years after the completion of chemotherapy. 3,4 It is assumed that this particular form of alopecia results from damage to the hair follicle stem cells that are responsible for reinitiating follicle growth. 5 Patients with breast cancer seem to be particularly affected by pCIA. 6 Recent research suggests that up to 50% and 10% of patients who survive breast cancer experience minor and severe forms of pCIA, respectively. [7][8][9] Both the likelihood of developing CIA and its extent are determined by the nature of the treatment regimen (eg, drug