Trends and Variation in the Use of Radiotherapy in Non-metastatic Rectal Cancer:a 14-year Nationwide Overview from the Netherlands

Aims: This study describes nationwide primary radiotherapy utilisation trends for non-metastasised rectal cancer in the Netherlands between 2008 and 2021. In 2014, both colorectal cancer screening and a new guideline specifying prognostic risk groups for neoadjuvant treatment were implemented.Materials and methods: Patients with non-metastasised rectal cancer in 2008–2021 (n = 37 510) were selected from the Netherlands Cancer Registry and classified into prognostic risk groups. Treatment was studied over time and age. Multilevel logistic regression analyses were carried out to identify factors associated with (i) radiotherapy versus chemoradiotherapy use for intermediate rectal cancer and (ii) chemoradiotherapy without versus with surgery for locally advanced rectal cancer.Results: For early rectal cancer, the use of neoadjuvant radiotherapy decreased (15% to 5% between 2008 and 2021), whereas the use of endoscopic resections increased (8% in 2015, 17% in 2021). In intermediate-risk rectal cancer, neoadjuvant chemoradiotherapy (43% until 2011, 25% in 2015) shifted to radiotherapy (42% in 2008, 50% in 2015), the latter being most often applied in older patients. In locally advanced rectal cancer, the use of chemoradiotherapy without surgery increased (2–4% in 2008–2013, 17% in 2019–2021). Both neoadjuvant treatment in intermediate disease and omission of surgery following chemoradiotherapy in locally advanced disease varied with increasing age (odds ratio>75vs<50: 2.17, 95% confidence interval 1.54–3.06) and treatment region (Southwest and Northwest odds ratio 0.63, 95% confidence interval 0.42–0.93 and odds ratio 0.65, 95% confidence interval 0.44–0.95, respectively, compared with the North).Conclusion: Treatment patterns in non-metastasised rectal cancer significantly changed over time. Effects of both the national screening programme and the new treatment guideline were apparent, as well as a paradigm shift towards organ preservation (watch-and-wait). Observed regional variations may indicate adoption differences regarding new treatment strategies

The relation between in vitro ß-carotene bioaccessibility and lipid digestion: Influence of the structural build-up of plant-based emulsions

Vegetable-based foods such as soups and sauces, are good sources of water, fibers (e.g. pectin), micronutrients and lipids. In foods, lipids are often considered as negative since an excess uptake of lipids is linked with a risk of obesity. It should however be noted that lipids are important macronutrients providing energy and essential fatty acids and facilitating the uptake of lipid soluble micronutrients such as carotenoids. The general objective of this PhD was to gain more insight in the relation between in vitro β-carotene bioaccessibility and lipid digestion and to understand the specific role of the structural build-up of plant-based emulsions in β-carotene bioaccessibility and lipid digestion. To reach these objectives, all experimental chapters studied the influence of different emulsifiers in an oil-in-water emulsion containing 5% β-carotene enriched olive oil (no natural barriers such as chromoplast membrane and/or cell wall). The emulsifiers used were citrus pectin (CP) (added in a concentration of 1% or 2%, with a degree of methyl-esterification (DM) of 14%, 30%, 57%, 66% or 99%), sugar beet pectin (added in a concentration of 1% with a DM of 32% or 58%), L-α-phosphatidylcholine (added in different concentrations: 1%, 2%, 3% or 4%), or a combination of citrus pectin and phosphatidylcholine. Based on the results, no general relation was found between the in vitro β-carotene bioaccessibility and lipid digestion. It seems that the type, the amount and the surface activity of the present emulsifiers are determining which compounds can be incorporated into the micelles. The DM and concentration of citrus pectin were influencing the micellar incorporation of both β-carotene and lipids, whereas the DM of sugar beet pectin was not. Probably, in this type of pectin, the other pectin properties are more important than the DM. By increasing the phosphatidylcholine concentration, the lipid micellar incorporation remained whereas the β-carotene bioaccessibility increased. This lead to the idea that phosphatidylcholine may dissolve β-carotene so that an increase of phosphatidylcholine concentration in the micelles leads to an increase of β-carotene bioaccessibility. When phosphatidylcholine was present together with citrus pectin as emulsifier, the β-carotene bioaccessibility was dependent on the pectin DM whereas the lipid digestion remained again. Since carotenoids and lipids have different structures and polarities, their incorporation may be different, which can be used to engineer targeted (digestive) functionalities in food products. Sugar beet pectin can be chosen as emulsifier if high lipid digestion and reasonable β-carotene bioaccessibility are desired, whereas 4% phosphatidylcholine can be chosen if high β-carotene bioaccessibility and lower lipid digestion are desired. The lowest lipid digestion was found in the emulsions containing pectin with a high DM (2%CP99) or with a low DM (2%CP14) as emulsifier.status: publishe

The effect of pectin on in vitro B-carotene bioaccessibility and lipid digestion in low fat emulsions

In this work, we investigated how pectin with different DM, with or without the presence of an additional emulsifier (L-α-phosphatidylcholine), influences on the one hand the in vitro bioaccessibility of β-carotene, loaded in the oil phase of an oil-in-water emulsion, and on the other hand the lipid digestion. As a consequence, the relation between the β-carotene bioaccessibility and the lipid digestion was investigated as well. For this research, two types of oil-in-water emulsions have been investigated. The first type contained 5% olive oil enriched with β-carotene and water in which only 2% citrus pectin (CP) (with a DM of 99%, 66% or 14%) was dissolved. In this type, only pectin is present that can function as emulsifier. The second type contained 5% enriched oil and water in which 1% L-α-phosphatidylcholine and 0 or 2% CP (with a DM of 99%, 66% or 14%) were dissolved. Results show that the influence of pectin DM on the in vitro β-carotene bioaccessibility (incorporation of β-carotene in the micelles) and the lipid digestion (incorporation of free fatty acids (FFAs) and monoacylglycerols (MAGs) in the micelles) was dependent on the presence of phosphatidylcholine but was less dependent on the particle size (distributions) or the viscosity. In the emulsions with phosphatidylcholine, an increase of on the one hand the incorporation of β-carotene and on the other hand the incorporation of FFAs and MAGs in the micelles was seen by decreasing the DM of the citrus pectin from 99% to 66%, whereas both incorporations decreased again by decreasing the DM further to 14%. In the emulsions without phosphatidylcholine, an increase of the incorporation of β-carotene into the micelles was seen by decreasing the DM. On the contrary, the incorporation of FFAs and MAGs into the micelles remained. This means that there was a clear relation between the incorporation of β- carotene and the incorporation of FFAs and MAGs in the micelles for the emulsions without phosphatidylcholine, whereas this was not the case for the emulsions containing phosphatidylcholine.status: publishe