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Frontiers in Oncology 2021Hypoxia is an important characteristic of most solid malignancies, and is closely related to tumor prognosis and therapeutic resistance. Hypoxia is one of the most...
Hypoxia is an important characteristic of most solid malignancies, and is closely related to tumor prognosis and therapeutic resistance. Hypoxia is one of the most important factors associated with resistance to conventional radiotherapy and chemotherapy. Therapies targeting tumor hypoxia have attracted considerable attention. Hypoxia-activated prodrugs (HAPs) are bioreductive drugs that are selectively activated under hypoxic conditions and that can accurately target the hypoxic regions of solid tumors. Both single-agent and combined use with other drugs have shown promising antitumor effects. In this review, we discuss the mechanism of action and the current preclinical and clinical progress of several of the most widely used HAPs, summarize their existing problems and shortcomings, and discuss future research prospects.
PubMed: 34395270
DOI: 10.3389/fonc.2021.700407 -
Expert Opinion on Drug Metabolism &... Dec 2012Cervical cancer is the second-most common malignancy in women worldwide. Cisplatin was introduced as a radiosensitizer in 1999 to improve chances of survival. Tumor cell... (Review)
Review
INTRODUCTION
Cervical cancer is the second-most common malignancy in women worldwide. Cisplatin was introduced as a radiosensitizer in 1999 to improve chances of survival. Tumor cell hypoxia, however, remains a major limiting factor in the treatment of solid tumors with chemotherapy and radiation. There has since been significant interest in the use of bioreductive agents to overcome the hypoxia and improve survival. The addition of tirapazamine (TPZ) to conventional chemoradiation protocols in the management of cervical cancer held promise in the initial Phase I and II clinical trials in delaying recurrence and improving survival. However, GOG recently announced early closure of the Phase III trial of tirapazamine in cervical cancer due to a lack of increased survival.
AREAS COVERED
This article covers the definition of hypoxic tumor cells, the markers of tumor hypoxia, methods for measuring hypoxia as well as the pharmacologic action of tirapazamine in hypoxic media. Furthermore, it critically evaluates TPZ's role in cervical cancer treatment and the drawbacks to the GOG study. The authors review all clinical trials published to date with special emphasis on cervical cancer. A systematic review of the literature was also undertaken with PubMed and Ovid.
EXPERT OPINION
Despite the promising results from early clinical trials, it has been shown that the addition of tirapazamine appears to confer no benefits on progression-free or overall survival in patients with cervical cancer. Success in the future will require smaller randomized trials with biologic targets that have acceptable toxicity and efficacy.
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Hypoxia; Cisplatin; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Disease Models, Animal; Drug Evaluation, Preclinical; Female; Humans; Radiation-Sensitizing Agents; Secondary Prevention; Tirapazamine; Triazines; Uterine Cervical Neoplasms
PubMed: 23033890
DOI: 10.1517/17425255.2012.730518