1
|
Lai IL, You JF, Tsai WS, Hsu YJ, Chern YJ, Wu MY. Metformin increases pathological responses to rectal cancers with neoadjuvant chemoradiotherapy: a systematic review and meta-analysis. World J Surg Oncol 2023; 21:224. [PMID: 37491250 PMCID: PMC10369710 DOI: 10.1186/s12957-023-03087-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 06/28/2023] [Indexed: 07/27/2023] Open
Abstract
BACKGROUND To summarize the chemo-radio effect of metformin in rectal cancers with neoadjuvant chemoradiotherapy on pathological response, tumor regression grade (TRG), and T/N downstaging. METHODS PubMed, MEDLINE, Embase, and Cochrane Database of collected reviews were searched up to June 30, 2022. This study conducted systematic review and meta-analysis based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) sheet. Odds ratios (ORs) and confidence intervals (CIs) which calculated by random-effects models were displayed in forest plots. Newcastle-Ottawa scale was used to assess the risk of bias of the observational cohort studies. RESULTS This systematic review and meta-analysis comprised eight cohorts out of seven studies, with 2294 patients in total. We performed two-way comparison for metformin in diabetic patients vs (1) non-metformin drugs in diabetic patients and (2) nondiabetic patients. In diabetes patient studies, the metformin group had a significantly increased pathological response on TRG (OR: 3.28, CI: 2.01-5.35, I2 = 0%, p < 0.001) and T downstaging (OR: 2.14, CI: 1.24-3.67, I2 = 14%, p = 0.006) in comparison with a non-metformin group. When compared with nondiabetic patients, the pathological response on TRG (OR: 2.67, CI: 1.65-4.32, I2 = 43%, p < 0.001) and T downstaging (OR: 1.96, CI: 1.04-3.71, I2 = 66%, p = 0.04) were also higher in metformin group. The limitation was that no randomized controlled trials were available based on current literature review. Small sample sizes for diabetic metformin or non-metformin users in rectal cancer patients reduced the power of the study. CONCLUSIONS For patients with rectal cancer and treated with neoadjuvant chemoradiotherapy, metformin administration in diabetic patients increased the pathological response on tumor-regression grade and T downstaging. Further well-designed, high-quality randomized controlled trials are required to reveal the actual effect of metformin.
Collapse
Affiliation(s)
- I-Li Lai
- Division of Colon and Rectal Surgery, Chang Gung Memorial Hospital, Guei-Shan District, Linkou Branch, No. 5, Fu-Hsing Street, Taoyuan City, Taiwan
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, No. 259, Wenhua 1St Rd, Guei-Shan District, Taoyuan City, Taiwan
- Department of SurgeryTen-Chen Medical GroupZhongli Dist., Zhong-Li Metropolitan Hospital, Yanping Rd, No. 155, Taoyuan City, Taiwan
| | - Jeng-Fu You
- Division of Colon and Rectal Surgery, Chang Gung Memorial Hospital, Guei-Shan District, Linkou Branch, No. 5, Fu-Hsing Street, Taoyuan City, Taiwan
| | - Wen-Sy Tsai
- Division of Colon and Rectal Surgery, Chang Gung Memorial Hospital, Guei-Shan District, Linkou Branch, No. 5, Fu-Hsing Street, Taoyuan City, Taiwan
| | - Yu-Jen Hsu
- Division of Colon and Rectal Surgery, Chang Gung Memorial Hospital, Guei-Shan District, Linkou Branch, No. 5, Fu-Hsing Street, Taoyuan City, Taiwan
| | - Yih-Jong Chern
- Division of Colon and Rectal Surgery, Chang Gung Memorial Hospital, Guei-Shan District, Linkou Branch, No. 5, Fu-Hsing Street, Taoyuan City, Taiwan
| | - Ming-Ying Wu
- Department of Dermatology, Chang Gung Memorial Hospital, Guei-Shan District, Linkou Branch, No. 5, Fu-Hsing Street, Taoyuan City, Taiwan.
- Institute of Epidemiology and Preventive Medicine, Zhongzheng Dist., National Taiwan University, Xuzhou Rd, No. 17, Taipei City, Taiwan.
| |
Collapse
|
2
|
Metformin combined with local irradiation provokes abscopal effects in a murine rectal cancer model. Sci Rep 2022; 12:7290. [PMID: 35508498 PMCID: PMC9068771 DOI: 10.1038/s41598-022-11236-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 04/18/2022] [Indexed: 11/20/2022] Open
Abstract
Although preoperative chemoradiation therapy can down-stage locally advanced rectal cancer (LARC), it has little effect on distant metastases. Metformin exerts an anti-cancer effect partly through the activation of host immunity. LuM1, a highly lung metastatic subclone of colon 26, was injected subcutaneously (sc) in BALB/c mice and treated with metformin and/or local radiation (RT). Lung metastases and the primary tumors were evaluated and the phenotypes of immune cells in the spleen and lung metastases were examined with flow cytometry and immunohistochemistry. Local RT, but not metformin, partially delayed the growth of sc tumor which was augmented with metformin. Lung metastases were unchanged in metformin or RT alone, but significantly reduced in the combined therapy. The ratios of splenic T cells tended to be low in the RT group, which were increased by the addition of metformin. IFN-γ production of the splenic CD4(+) and CD8(+) T cells was enhanced and CD49b (+) CD335(+) activated NK cells was increased after combined treatment group. Density of NK cells infiltrating in lung metastases was increased after combination treatment. Metformin effectively enhances local and abscopal effects of RT though the activation of cell-mediated immunity and might be clinically useful for LARC.
Collapse
|