What are the implications of diabetes and cancer?
Implications of diabetes and cancer are common diseases with a tremendous impact on health around the world. Epidemiological evidence suggests that people with diabetes are at a significantly higher risk of developing many forms of cancer. Type 2 diabetes and cancer share many risk factors, but the potential biological links between the two diseases are not fully understood. Additionally, evidence from observational studies suggests that some medications used to treat hyperglycemia are associated with a higher or lower risk of cancer. In this context, the American Diabetes Association and the American Cancer society convened a consensus-building conference in December 2009. Following a series of scientific presentations from experts in the field, the writing group independently developed this consensus report to address the following questions:
- Is there a significant association between diabetes and cancer incidence or prognosis?
- What risk factors are mutual to together diabetes and cancer?
- What are the possible biological links between diabetes and cancer risk?
- Do diabetes treatments inspire cancer risk or cancer prognosis?
What risk factors are common to together diabetes and cancer?
Potential risk factors (adaptable and non-modifiable) common to both diabetes and cancer contain aging, sex, obesity, physical activity, diet, alcohol, and smoking.
Diabetes and cancer risk ratio
In recent decades, diabetes has been consistently associated with an increased risk of a wide variety of malignancies. Studies reporting an increase in all cancer sites carry the risk of missing a modest association of site-specific cancers. Furthermore, discrepancies in results between studies may be partially explained by the varied prevalence of specific cancers they accounted for in various study populations. On the other hand, the increase in general cancer incidence may not be accompanied by transparent increases in organ-specific malignancies and should still be a reason to improve cancer surveillance among diabetic patients.
The meta-analysis combining 12 cohort studies with a total number of 257,222 participants showed a significant elevation of the pooled adjusted risk ratio (RR) for the incidence of all cancers; The RRs were 1.14 (95% CI, 1.06-1.23) and 1.18 (95% CI, 1.08-1.28) for men and women, respectively . Another meta-analysis conducted in studies originating in Japan (with a total of 250,479 subjects from four cohorts and a case-control study) demonstrated a slightly higher overall cancer risk with adjusted RR 1.25 (95% CI, 1.06- 1.46) for men and 1.23 (95%% CI, 0.97-1.56) for women. This can be attributed to a different proportion of specific cancer prevalence in Japan, with substantially higher rates of gastric, pancreatic, and hepatocellular cancers. On the other hand, subjects with diabetes who received treatment for hypertension and/or dyslipidemia (assuming this group reflects a more intensive medical examination) showed a higher HR of 1.37 . Though, a large retrospective study on a total of 985,815 subjects demonstrated that the risk of cancer occurrence in diabetes (RR 1.56, 95% CI 1.43-1.71) is independent of hypertension, dyslipidemia, and gout. Additionally, another large retrospective cohort study (895,434 DM cases) showed a slight increase (HR = 1.19, 95% CI, 1.17-1.19) in cancer risk at most sites. The risk was also more influential in the younger age group, so it is reasonable to suspect that this may be attributable to metabolic dysfunction prior to DM diagnosis. Concurrent with the previous findings, the results of a prospective cohort study in the German population (26, a total of 742 subjects) showed an increased risk of cancer with SIR 1.14 (95% CI, 1.10-1, 21), but the duration of diabetes was inversely associated with cancer risk, which was markedly higher in the first year after a diabetes diagnosis.
Observations from two retrospective cohort studies from Belgium (4012 diabetic subjects) and China (7950 diabetic subjects) were consistent with previous reports, although overall cancer risks were slightly higher with an HR 1.84 (95% CI; 1.51-2.24)  and SIR 1,331 (95% CI, 1,143–1,518) in men and 1,737 (95% CI, 1,478–1,997) in women. According to the inclusion criteria of most studies, the risk of cancer was assessed among patients with IMDM and non-melanoma skin cancers were excluded from the analysis. In summary, diabetes and hyperglycemia were shown to be associated with an overall elevated risk of cancer. Exact values of estimated risk may vary due to study design, the impact of confounding factors, and ethnic differences, including genetic susceptibility, lifestyle behaviors, specific environmental exposures, and variable biological effects of diabetes. in populations. All these factors are summarized in several cohorts, prospective, and meta-analysis studies from different countries.
Incidence of dissimilar types of cancer among diabetic patients
According to various meta-analyzes, a higher frequency of malignant neoplasms in diabetic patients has been attributed to various general and local mechanisms.
The strongest association between DM and increased risk of cancer is with cancer of the pancreas and liver, two major target organs of insulin metabolism involved in the metabolic disorders typical of diabetes.
The incidence of hepatocellular carcinoma (HCC) is higher in those with DM2 in both sexes, with a higher risk in men and in those with concomitant infection by the hepatitis C virus (HCV): as in most epidemiological studies indicate a 2 to 3-fold increase in liver cancer in diabetic patients, diabetes may also act synergistically with other well-established risk factors for HCC, such as hepatitis B virus infection and HCV, nonalcoholic fatty liver disease (also considered as a liver manifestation of diabetes and metabolic syndrome), nonalcoholic steatohepatitis, and chronic alcohol use leading to steatosis and cirrhosis.
In particular, it is unlikely that the mitogenic insulin pathway is involved considering that healthy liver cells, due to bursts of insulin secretion in the portal circulatory system, are physiologically exposed to higher insulin concentrations compared to other tissues. peripherals, especially those resistant to insulin. Type 2 hyperinsulinemia states (whereas in individuals with insulin-deficient DM1 treated with exogenous insulin, the liver is exposed to the same levels of insulin as the other organs).
In addition, in a large nested case-control study of liver cancer in patients with DM2, it was shown that the use of any antidiabetic medication was not favorably or adversely associated with liver carcinogenesis, although the use of metformin alone was associated with a protective effect, although not statistically significant, compared to non-use. In conclusion, the exact mechanisms underlying a putative oxidative stress condition remain controversial and the increased incidence of liver cancer is well documented among diabetic patients.
Most of the previous meta-analyses address diabetes as an independent risk factor for pancreatic cancer (18-20). A recent study shows that a 30% excess risk perseveres for more than two decades after diabetes diagnosis, secondary the causal role of diabetes in pancreatic carcinogenesis and also claiming that oral antidiabetics may lower risk, while insulin exhibits inconsistent duration. However, these studies are misleading as they do not distinguish between pre-existing and new-onset diabetes (possibly due to undiagnosed pancreatic cancer-causing functional damage). Furthermore, given the negative correlation of the duration of DM with the risk of pancreatic cancer (increased risk of cancer was found among the studies during the first year of follow-up and gradually decreased thereafter), the controversy about the causal role of diabetes has increased, generating the theory of reverse causality in which pancreatic cancer-induced a diabetic state regardless of smoking status or BMI.
Though, when epidemiological evidence suggests a reciprocal link between diabetes and pancreatic cancer, the temporal patterns of association and the causal link between the two were unclear. Though larger additional studies are needed to further examine the potential confounding effect of smoking and obesity on the connotation between diabetes and cancer, the unclear biological mechanisms underlying this association suggest that hyperinsulinemia is an Important key factor, as exocrine pancreatic cells are exposed to extremely high levels of insulin. concentrations due to common blood supply with adjacent insulin-secreting islets.
Treatment for diabetes and cancer
Some cancer treatments can affect your diabetes and make it harder to control blood glucose (blood sugar). In partnership with Macmillan, we have produced an informational brochure for anyone who has been diagnosed with cancer and is living with diabetes. With tips to help you cope with the side effects of cancer treatment, it is designed to help you deal with some of the questions or feelings you may have after diagnosis and during treatment.
Sometimes cancer treatment, especially steroids in high doses, can cause a person to develop diabetes. Organizations will vary liable on many factors such as age, weight, etc.
Reduce your risk of cancer
By maintaining a healthy weight for your height, eating right, staying active, and not smoking, you can help reduce your risk of developing cancer.
How can diabetes cause cancer?
Plumpness is a common risk factor for diabetes and cancer. Cancers consistently associated with obesity include breast, endometrium, pancreas, esophagus, kidney cells, colorectal cells, and liver. Weight loss may reduce the risk of cancer in obese subjects, although the effect is not marked. While bariatric surgery can reduce or even reverse the development of diabetes, the significant weight loss seen with bariatric surgery does not appear to reduce cancer risk as dramatically. The link between diabetes, obesity, and cancer may be mediated by insulin and the insulin-like growth factor (IGF) axis.
Insulin and IGF
Insulin is a growth factor, and elevated insulin levels have been shown to be a risk factor for several cancers. The meta-analysis shows an excess risk of colorectal, pancreatic, and breast cancer associated with higher levels of circulating C-peptide / insulin and blood glucose markers. Elevated plasma insulin is also associated with poorer cancer outcomes and recurrence of the disease. Insulin itself exerts a mitogenic effect in various tissues, including breast cancer cell lines, which are estrogen receptor-positive. In breast cancer, insulin induces aromatase activity and reduces globulin sex hormone transporter (SHBG), which leads to increased levels of free estrogen, which in turn increases mitogenicity. Interestingly, breast cancer cells appear to have high levels of insulin receptors, compared to normal breast tissue.
Insulin can exert a mitogenic effect through receptors for insulin-like growth factor 1 (IGF-1). Prospective studies have shown that people with circulating IGF-1 are at increased risk for common epithelial cancers such as breast, colon, and prostate. A recent large-population survey showed that women with high levels of IGF-1 in their blood have more likely than those with low concentrations to develop breast cancer; Women with the highest concentration of IGF-1 were found to have a 28% higher risk of emerging breast cancer than women with the lowest attentiveness [OR 1.28 (95% CI: 1.14-1, 44)]. Hyperinsulinemia also produces reduced levels of IGF binding protein-1 (IGFBP-1), thus increasing levels of bioactive IGF-1.
Is diabetes associated with cancer?
Although diabetes and cancer are common conditions, they are diagnosed together more often in the same person than you might expect. Many epidemiological studies suggest a frequent coexistence of diabetes and cancer, a selection of which is tabulated in Table 1. Meta-analyzes suggest that several cancers, including liver, pancreas, endometrial, colorectal, breast, and bladder, are associated with diabetes (see below) and diabetes appears to protect against prostate cancer. Lung cancer appears not to be associated with diabetes, and the data are inconclusive for renal cell cancer and lymphoma.