Background: Over recent years, there has been an increasing focus on the repurposing of existing, well-known medications for new, novel usage. One such drug is metformin, typically utilized in the management of diabetes, which demonstrates a positive relationship between its administration and lower cancer morbidity and mortality. Based on this finding, numerous studies and clinical trials have been conducted to examine the potential usage of metformin as an anticancer agent.

Objective: This article aims to summarize metformin’s anticancer effects through reviewing its literatures and patents, with a focus on its potential to be repurposed for cancer therapy.

Methods: Various databases were examined using keywords, ‘Metformin’ and ‘Cancer’. Research articles were collected through the PubMed database, clinical trials were obtained from the Clinical Trials database, and patents were collected through the Google Patents database.

Results: Metformin shows antineoplastic activity in various models. These anticancer properties appear to synergize with existing chemotherapeutics, which allows a reduction in drug dosage without losing potency while minimizing adverse effects. Numerous patents on metformin have been filed which claim various combination therapies, delivery methods, and uses for cancer therapy, displaying an increasing interest in metformin’s anticancer potential.

Conclusion: Preclinical studies, along with early phase clinical trials, have examined the antitumor properties of metformin on a variety of cancers. Metformin’s anticancer effects are well documented, demonstrating a great promise in improving current cancer therapies. However, there is a significant lack of late phase clinical trials, specifically those involving nondiabetic cancer patients, and therefore further research in this area is required.

背景：近年来，人们越来越关注将现有的知名药物重新用于新的、新颖的用途。一种这样的药物是二甲双胍，通常用于治疗糖尿病，这表明其给药与降低癌症发病率和死亡率之间存在正相关关系。基于这一发现，已经进行了大量的研究和临床试验来检验二甲双胍作为抗癌剂的潜在用途。

目的：本文旨在通过回顾二甲双胍的文献和专利，总结二甲双胍的抗癌作用，重点关注其重新用于癌症治疗的潜力。

方法：使用关键字“二甲双胍”和“癌症”检查了各种数据库。研究文章通过 PubMed 数据库收集，临床试验来自临床试验数据库，专利通过谷歌专利数据库收集。

结果：二甲双胍在各种模型中显示出抗肿瘤活性。这些抗癌特性似乎与现有的化学治疗剂具有协同作用，可以减少药物剂量而不会失去效力，同时最大限度地减少副作用。已经提交了许多关于二甲双胍的专利，这些专利要求保护各种联合疗法、递送方法和癌症治疗的用途，这表明人们对二甲双胍的抗癌潜力越来越感兴趣。

结论：临床前研究以及早期临床试验已经检验了二甲双胍对多种癌症的抗肿瘤特性。二甲双胍的抗癌作用是有据可查的，在改进当前的癌症治疗方面显示出巨大的希望。然而，缺乏晚期临床试验，特别是那些涉及非糖尿病癌症患者的临床试验，因此需要在该领域进行进一步研究。