Oncological benefit of metformin in patients with pancreatic ductal adenocarcinoma and comorbid diabetes mellitus

Metformin use and pancreatic ductal adenocarcinoma outcomes: a narrative review

BACKGROUND

Metformin is a diabetes medication with anti-mitotic properties. A narrative review was performed to investigate people using metformin and the risk of developing pancreatic ductal adenocarcinoma (PDAC) as well as survival outcomes in established PDAC.

METHODS

Relevant studies on metformin use and PDAC were retrieved from PubMed including observational studies on metformin and the risk of developing PDAC and survival outcomes in PDAC, and randomized controlled trials of metformin as a treatment in PDAC.

RESULTS

Of the 367 studies searched, 26 studies fulfilled the criteria for this review. Metformin was not consistently associated with a reduced risk of developing PDAC. However, metformin use, especially higher cumulative doses, in some studies was associated with longer survival in patients with established PDAC, especially in the subgroup with resectable PDAC. Metformin use was not associated with longer survival in more advanced (non-resectable metastatic) PDAC.

CONCLUSION

Metformin was not consistently associated with a reduced risk of developing PDAC. Metformin may be associated with overall survival benefits in patients with PDAC including the resectable PDAC subgroup but not in the metastatic PDAC subgroup. The evidence to date does not support the routine use of metformin as an adjuvant therapy for advanced PDAC.

Five-year recurrence/survival after pancreatoduodenectomy for pancreatic adenocarcinoma: does pre-existing diabetes matter? Results from the Recurrence After Whipple's (RAW) study

BACKGROUND

Diabetes mellitus (DM) has a complex relationship with pancreatic cancer. This study examines the impact of preoperative DM, both recent-onset and pre-existing, on long-term outcomes following pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

METHODS

Data were extracted from the Recurrence After Whipple's (RAW) study, a multi-centre cohort of PD for pancreatic head malignancy (2012-2015). Recurrence and five-year survival rates of patients with DM were compared to those without, and subgroup analysis performed to compare patients with recent-onset DM (less than one year) to patients with established DM.

RESULTS

Out of 758 patients included, 187 (24.7%) had DM, of whom, 47 of the 187 (25.1%) had recent-onset DM. There was no difference in the rate of postoperative pancreatic fistula (DM: 5.9% vs no DM 9.8%; p = 0.11), five-year survival (DM: 24.1% vs no DM: 22.9%; p = 0.77) or five-year recurrence (DM: 71.7% vs no DM: 67.4%; p = 0.32). There was also no difference between patients with recent-onset DM and patients with established DM in postoperative outcomes, recurrence, or survival.

CONCLUSION

We found no difference in five-year recurrence and survival between diabetic patients and those without diabetes. Patients with pre-existing DM should be evaluated for PD on a comparable basis to non-diabetic patients.

The relationship between the use of metformin and the risk of pancreatic cancer in patients with diabetes: a systematic review and meta-analysis

OBJECTIVE

We aim to evaluate the relationship between the use of metformin and the risk of pancreatic cancer in type 2 diabetes patients.

METHOD

We systematically searched the observational studies on PubMed, Embase, Web of Science, Cochrane Library, clinicalrials.gov, and CNKI databases, extracted relevant data, combined the OR value and 95% CI using the random effect model, and conducted a sensitivity analysis, subgroup analysis, and meta-regression to evaluate the size and stability of this relationship.

RESULT

Twenty-nine studies from twenty-four articles met our inclusion criteria, including more than 2 million subjects. Overall analysis showed that compared with no use of metformin, the use of metformin could reduce the risk of pancreatic cancer in patients with type 2 diabetes (OR = 0.82, 95% CI (0.69, 0.98)). Subgroup analysis showed that compared with the use of hypoglycemic drugs, the use of metformin could reduce the risk of pancreatic cancer in patients with type 2 diabetes (OR = 0.79, 95% CI (0.66, 0.94)). However, compared with no drugs or only diet therapy, metformin users might increase the risk of pancreatic cancer (OR = 2.19, 95% CI (1.08, 4.44)). Sensitivity analysis confirmed the stability of the study, and there was no significant publication bias.

CONCLUSION

Compared with the no-use of metformin, metformin users with diabetes can reduce the risk of pancreatic cancer. More research is needed to prove it works.

Magic of a Common Sugar Pill in Cancer: Can Metformin Raise Survival in Pancreatic Cancer Patients?

Pancreatic cancer is one of the common cancers globally, with a poor survival outcome. Metformin, a popular anti-diabetic drug, has gained popularity for its use in the chemoprevention of cancer. However, results regarding the survival benefit of metformin in pancreatic cancer have been unpredictable. In this review, we aim to analyze the use of metformin in pancreatic cancer patients with pre-existing diabetes mellitus for survival benefit. We systematically conducted a literature search in PubMed, Science Direct, and Scopus databases to collect the relevant articles and reviewed them. Eventually, 11 quality appraised articles were included accessing overall survival as the primary outcome. Our results concluded that metformin can efficaciously improve survival in pancreatic cancer patients with coexisting diabetes mellitus, but the results are still incongruent. Hence, further prospective studies and clinical trials are essential to provide a strong evidence-based recommendation that will help prolong the lifespan of patients.