Chemosensitization means enhancing the sensitivity of
tumor cells to
chemotherapy with certain methods for better efficacy.
Tumor progression depends on stimulation of multiple
hormones, decrease in
hormones during
chemotherapy induces G0/G1 arrest of
tumor cells, which may be the main cause for chemoresistance. Some of the
choriocarcinoma and
testicular tumors are curable with
chemotherapy only, underlying mechanism may refer high level of
human chorionic gonadotropin, which has
thyroid stimulating hormone like effect and even induce
hyperthyroidism in these patients. Some of these patients usually have high levels of
thyroid hormones or suffer
thyroid crisis during
chemotherapy. Possibly owning to the proliferative or metabolic promotion effect of
thyroid hormones and/or other endocrine
hormones, which can promote
tumor cells in G0 phase metabolizing actively or stepping into division cycle again,
tumors are more sensitive to
chemotherapy. Both endocrinotherapy and
chemotherapy are major
therapies for
tumor, traditional endocrinotherapy suppresses
tumor progression through decreasing
tumor-dependent
hormones or competitively combining and blocking
hormone receptors. While,
chemotherapy mostly killed
tumor cells that proliferate actively, because
tumor cells retardant in G0 phase by endocrinotherapy are no more sensitive to
chemotherapy, endocrinotherapy cannot be concurrently used with
chemotherapy. Nevertheless, decrease in
hormones during
chemotherapy is similar to concurrently using endocrinotherapy and
chemotherapy. It has been found in some basic researches that some chemotherapeutics concurrently combined with endocrine
hormones can achieve better efficacy compared with
chemotherapy only. It is therefore hypothesized in this article that decrease in
hormones during
chemotherapy causes cell cycle arrest and renders
tumor cells insensitive to
chemotherapy; addition of endocrine
hormones to mimic the
hormones and microenvironment changes during
chemotherapy for patients with
choriocarcinoma or
testicular tumor-curable with
chemotherapy only, will rescue
tumor cells from cell cycle arrest rendering them sensitive to
chemotherapy. This new combinative
therapy of concurrently using endocrine
hormones and
chemotherapy is defined as
choriocarcinoma-mimic
chemotherapy or neo-endocrinochemotherapy to distinguish the routine term of endocrinochemotherapy and is expected to be a novel approach to enhance chemotherapeutic efficacy in clinic.