Less advanced stages of colon cancer in patients with type 2 diabetes mellitus: an unexpected finding?

INTRODUCTION: Epidemiological studies have found an increased risk for colon cancer and faster disease progression in patients with type 2 diabetes mellitus (T2DM). We aimed to determine whether patients with T2DM are diagnosed with more advanced stages of colorectal cancer, i. e., metastasized disease (UICC III and IV), at the time of diagnosis, since such a finding may have an impact on future guidelines for patients with T2DM. MATERIALS AND METHODS: A cross-sectional analysis of colorectal cancer patients was performed. Stages at diagnosis in patients with (18.0%) or without (82%) T2DM were compared using logistic regression analysis to correct for confounders. RESULTS: Patients with T2DM were older, more obese, and more often male (each p<0.05). Unexpectedly, patients with T2DM had a lower risk for metastasized disease at diagnosis (p=0.023). Correction for age, gender, BMI, smoking and aspirin intake in a multiple logistic regression analysis did not change the result (OR=0.57, p=0.037). When looking at individual cancer stages rather than collapsed categories, there was a trend for less advanced stages in patients with T2DM (p=0.093). Excluding stage I because of potential screening bias due to the introduction of (insurance-covered) colonoscopy screening improved model fit, and confirmed less advanced cancer stages (p=0.0246). CONCLUSIONS: Possibly because of earlier detection, patients with T2DM may be at lower risk for advanced stages of colon cancer at diagnosis. Further studies are warranted to confirm our results and to investigate the impact of closer medical surveillance in patients with type 2 diabetes mellitus.

[Colorectal carcinoma screening in patients with type 2 diabetes mellitus]. / Diabetes mellitus Typ 2--ein Risikofaktor für kolorektale Karzinome.

Colorectal carcinoma is one of the most common tumour entities in Western countries. Colorectal carcinoma and type 2 diabetes mellitus share common risk factors. Recent epidemiological studies show an increased risk for colorectal carcinomas in patients with type 2 diabetes mellitus, even more pronounced at therapy with sulfonylureas or insulin. Moreover, a 3-fold risk increase for patients with insulin-dependent type 2 diabetes mellitus in comparison to the general population has been observed. The hyperinsulinaemia hypothesis is based on the premise that elevated plasma levels of insulin and free IGF-1 promote the proliferation of colon cells and lead to a survival benefit of transformed colon carcinoma cells. This is reflected by an altered tumour biology; in patients with type 2 diabetes, tumour progression is more rapid and tumour-associated mortality is increased. Colorectal carcinoma represents an entity that is well amenable to and can potentially be avoided by screening colonoscopy. Recommendations for colorectal carcinoma screening should employ the recent epidemiologic evidence. All patients with type 2 diabetes should be recommended to undergo colonoscopy before starting insulin therapy, and screening intervals should not exceed 5 years. This work provides a review of the evidence, and an algorithm is proposed for a modified screening in patients with type 2 diabetes.

Construction cost and invasive potential: comparing Lythrum salicaria (Lythraceae) with co-occurring native species along pond banks.

Lythrum salicaria (purple loosestrife) is a nonindigenous invasive species characterized by prolific growth and abundance in marshy and riparian habitats across North America. Given its invasive success, we hypothesized this species may require less energy and/or use energy more efficiently for biomass construction than co-occurring noninvasive plant species. We measured leaf construction cost (CC), leaf mass per unit area (LMA), and leaf organic nitrogen and carbon content of L. salicaria and the five most abundant co-occurring species, Parthenocissus quinquefolia, Erigeron philadelphicus, Asclepias syriaca, Spiraea latifolia, and Solidago graminifolia, along dammed ponds in the Black Rock Forest, Cornwall, New York, USA. Lythrum salicaria, which was highly abundant (2.52 individuals/m(2)), exhibited significantly lower area-based leaf CC (44.47 ± 4.24 g glucose/m(2) leaf) than relatively less abundant species, suggesting energetics may influence its invasive success. Conversely, least abundant Solidago graminifolia (0.67 individuals/m(2)) exhibited the significantly highest leaf CC per unit leaf area (141.87 ± 39.21 g glucose/m(2) leaf). Overall, a negative correlation between species abundance and area-based leaf CC (r(2) = 0.73) indicated low energy requirements and/or high energy efficiency may influence relative abundance in the plant species studied. As it correlates with species abundance in this study, CC may be a useful tool for evaluating invasive potential.