Trends in adherence to the Mediterranean diet in South Italy: A cross sectional study.

BACKGROUND AND AIMS: Increasing literature data show that adherence to the Mediterranean diet is undergoing profound changes in recent years, albeit with marked differences across nations. In Italy, one of the cradles of the Mediterranean diet, the literature regarding the trend for Mediterranean diet adherence is conflicting. Thus, we aimed to explore the trends of adherence to the Mediterranean diet in a large cohort of participants living in South Italy, over 20 years from 1985-86 to 2005-06. METHODS AND RESULTS: Cross-sectional study with two evaluations, one made in 1985-86 and another in 2005-06; all participants were adults aged 30-70 years of age. The adherence to the Mediterranean diet was evaluated using the score proposed by Panagiotakos et al. This score features values ranging from 0 to 55, higher scores reflecting a greater adherence. The data are reported by age (30-49 vs. 50-69 years). Overall, 2451 subjects were included in 1985-86 and 2375 in 2005-06. A significant reduction was observed in the adherence to the Mediterranean diet (age 30-49 years: 31.82 ± 4.18 in 1985-86 vs. 29.20 ± 4.48 in 2005-06, reduction by 8.2%, p < 0.0001; age 50-69: 32.20 ± 4.09 in 1985-86 vs.30.15 ± 4.27 in 2005-06, reduction by 6.3%, p < 0.0001). Among all these items, the most dramatic change was observed for olive oil consumption, that decreased by 2.35 points in younger and 0.89 in older people. CONCLUSION: The adherence to the Mediterranean diet decreased from 1985-86 to 2005-06 in South Italy, particularly in younger people, above all due to a decreased olive oil consumption.

Remnant cholesterol as a risk factor for cardiovascular, cancer or other causes mortality: A competing risks analysis.

BACKGROUND AND AIMS: Cardiovascular diseases (CVDis) are leading causes of morbidity and mortality. Even after the introduction of pharmacological therapy to lower Cholesterol, there is still a residual risk that may be ascribed to remnant cholesterol (RC). We aimed, by analyzing two prospective cohort studies, to estimate the effect of RC on risk and hazard of cardiovascular deaths (CVDs), while accounting for competing risks such as cancer (CDs) and other-causes deaths (OCDs). METHODS AND RESULTS: Cohorts were enrolled in 1992 and 2005. Personal data history was recorded. A fasting venous blood sample was obtained, and RC was calculated at baseline. Cause of Death was coded by using ICD-10th version. Follow-up ended on December 31, 2017. Flexible parametric competing-risks models were applied, with age at death as time-axis. In total, 5729 subjects were enrolled. There were 861 (15.1%) deaths: 234 CVDs (27.2%), 245 CDs (28.5%), 271 OCDs (31.5%) and 111 unknown causes of death (12.8%). RC exposure was a strong risk factor only for CVDs (Risk 2.54, 95% Confidence Interval 1.21; 5.34; Trend 1.26 (1.00; 1.58) for ≥1.29 mmol/L). CONCLUSIONS: RC is a strong independent risk factor for cardiovascular mortality. Competing risk analysis is demonstrably a useful tool to disentangle associations among different competing events with a common risk factor.

Reducing NAFLD-screening time: A comparative study of eight diagnostic methods offering an alternative to ultrasound scans.

BACKGROUND & AIMS: The use of ultrasound scan (US) in non-alcoholic fatty liver disease (NAFLD) screening overloads US waiting lists. We hypothesized and tested a hybrid two-step method, consisting of applying a formula, to exclude subjects at low risk, before US. METHODS: The sample included 2970 males and females (937 with NAFLD) diagnosed by US. We selected eight formulas: Fatty Liver Index (FLI), Hepatic Steatosis Index (HIS), body mass index (BMI), waist circumference (WC), Abdominal Volume Index (AVI), waist-to-height ratio (WHtR), waist/height0.5 (WHT.5R) and Body Roundness Index (BRI), and calculated their performance in the two-step method evaluating percentage reduction of the number of liver US (US reduction percentage), percentage of false negative and percentage of NAFLD identified. RESULTS: The US reductions percentage were 52.2% (WHtR), 52.1% (HIS), 51.8% (FLI), 50.8% (BRI), 50.7% (BMI and WHt_5R), 46.5% (WC) and 45.2% (AVI). The false negative percentage were 8.5% (WHtR), 7.9% (BRI), 7.3% (WHt_5R), 7.2% (BMI), 6.7% (HIS), 6.6% (FLI), 5.6% (WC) and 5.2% (AVI). The best percentage of NALFD identified was obtained using AVI (83.6%) before US, then WC (82.2%), FLI (79%), HIS (78.9%), BMI (77.3%), WHt_5R (76.9%), BRI (74.8%) and WHtR (73%). CONCLUSION: The best formula to use in two-step diagnostic NAFLD screening was AVI, which showed a low false negative rate and a higher percentage of identified NAFLD. Other studies evaluating the economic advantages of this screening method are warranted.

The Activation Status of the TGF-ß Transducer Smad2 Is Associated with a Reduced Survival in Gastrointestinal Cancers: A Systematic Review and Meta-Analysis.

Aberrant function of Smad2, a crucial member of transforming growth factor beta (TGF-ß) signaling, is associated with the development of malignancies, particularly in the gastrointestinal district. However, little is known about its possible prognostic role in such tumor types. With the first meta-analysis on this topic, we demonstrated that the lack of the activated form of Smad2 (phosphor-Smad2 or pSmad2), which was meant to be the C-terminally phosphorylated form, showed a statistically significant association with an increased risk of all-cause mortality in patients with gastrointestinal cancers (RR, 1.58; 95% CI, 1.05-2.37, p = 0.029, I2 = 84%), also after having adjusted for potential confounders (RR, 1.65; 95% CI, 1.24-2.18; p < 0.001; I2 = 4%). This finding highlights the importance of the TGF-ß signaling in this type of cancer. In this line, further studies are needed to explore more in depth this important molecular pathway, focusing also on potential therapeutic strategies based on its effectors or molecular targets.

Olive oil and omega-3 polyunsaturated fatty acids suppress intestinal polyp growth by modulating the apoptotic process in ApcMin/+ mice.

The promotion and progression of carcinogenesis are susceptible to nutritional interventions aimed at counteracting cancer development. Lipid metabolism is essential in the onset and progression of tumors and for cancer cell survival. In this study, we tested the effects of diets enriched with natural compounds, such as olive oil and salmon oil, in mice that spontaneously develop intestinal polyps (Apc(Min/+) mice). For this purpose, we evaluated polyp number and volume, intestinal mucosa proliferation/apoptosis, estrogen receptors (ERs) expression, fatty acid synthase and 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase gene expression and enzymatic activity. Compared with the standard diet, the salmon oil-enriched diet, containing a high percentage of omega-3 polyunsaturated fatty acids, and, to a lesser extent, olive oil-enriched diet reduced polyp number and volume through a reduction of proliferation and a marked proapoptotic effect. These biological effects were mediated by an inhibition of fatty acid synthase and HMGCoA reductase gene expression and activity and an increase of ERß/ERα ratio. Our findings suggest that a proper dietary lifestyle could contribute to primary cancer prevention.

Polyunsaturated fatty acids reduce fatty acid synthase and hydroxy-methyl-glutaryl CoA-reductase gene expression and promote apoptosis in HepG2 cell line.

BACKGROUND: n-3 and n-6 polyunsaturated fatty acids (PUFAs) are the two major classes of PUFAs encountered in the diet, and both classes of fatty acids are required for normal human health. Moreover, PUFAs have effects on diverse pathological processes impacting chronic disease, such as cardiovascular and immune disease, neurological disease, and cancer. AIM: To investigate the effects of eicosapentaenoic acid (EPA) and arachidonic acid (ARA) on the proliferation and apoptosis of human hepatoma cell line HepG2 after exposure to increasing concentrations of EPA or ARA for 48 h. Moreover, in the same cells the gene expression of Fatty Acid Synthase (FAS) and 3-Hydroxy-3-Methyl-Glutaryl Coenzyme A Reductase (HMG-CoAR) was also investigated. METHOD: Cell growth and apoptosis were assayed by MTT and ELISA test, respectively after cell exposure to increasing concentrations of EPA and ARA. Reverse-transcription and real-time PCR was used to detect FAS and HMG-CoAR mRNA levels in treated cells. RESULTS: Our findings show that EPA inhibits HepG2 cell growth in a dose-dependent manner, starting from 25 µM (P < 0.01, one-way ANOVA test and Dunnett's post test) and exerts a statistically significant pro-apoptotic effect already at 1 µM of EPA. Higher doses of ARA were need to obtain a statistically significant inhibition of cell proliferation and a pro-apoptotic effect in these cells (100 µM, P < 0.01, one-way ANOVA test and Dunnett's post test). Moreover, a down-regulation of FAS and HMG-CoAR gene expression was observed after EPA and ARA treatment in HepG2 cells, starting at 10 µM (P < 0.05, one-way ANOVA test and Dunnett's post test). CONCLUSION: Our results demonstrate that EPA and ARA inhibit HepG2 cell proliferation and induce apoptosis. The down-regulation of FAS and HMG-CoAR gene expression by EPA and ARA might be one of the mechanisms for the anti-proliferative properties of PUFAs in an in vitro model of hepatocellular carcinoma.

Modified WCRF/AICR Score and All-Cause, Digestive System, Cardiovascular, Cancer and Other-Cause-Related Mortality: A Competing Risk Analysis of Two Cohort Studies Conducted in Southern Italy.

BACKGROUND: In real life, nutrition goes beyond purely biological domains. Primary prevention is the most efficient approach for reducing the risk of mortality. We aimed to study the association of lifestyle, as measured by a modified World Cancer Research Fund/American Institute for Cancer Research (mWCRF/AICR) scoring system with all-cause, digestive system disease-related (DSD-related), cardiovascular disease-related (CVD-related), cancer-related and other cause-related mortality using data from two population-based cohort studies conducted in Southern Italy. METHODS: A random sample of 5271 subjects aged 18 years or older was enrolled in 2005-2006 and followed up until 2020. Usual food intakes were estimated using a validated dietary questionnaire. Competing risks survival models were applied. RESULTS: High adherence to the mWCRF/AICR score was found to be statistically significant and negatively associated with all-cause mortality (HR 0.56, 95%CI 0.39; 0.82), DSD-related mortality (SHR 0.38, 95%CI 0.15; 0.97) and cancer-related mortality (SHR 0.43, 95%CI 0.19; 0.97) in the male sub-cohort and other-cause mortality (SHR 0.43, 95%CI 0.21; 0.88) only in the female group. CONCLUSIONS: This mWCRF/AICR score can be seen as a simple, easy tool for use in clinical practice to evaluate both qualitative and quantitative aspects of the diet.

Synergic effect of eicosapentaenoic acid and lovastatin on gene expression of HMGCoA reductase and LDL receptor in cultured HepG2 cells.

BACKGROUND: PUFAs are potent inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, an enzyme catalyzing the conversion of HMGCoA to mevalonate, the rate limiting step in cholesterol biosynthesis. Statins represent a class of drugs that are widely used to treat hypercholesterolemia for their ability to inhibit cholesterol biosynthesis and to up-regulate the synthesis of Low Density Lipoprotein (LDL) receptors in the liver. PUFAs mediate many, if not all, actions of statins and this could be one mechanism by which they lower cholesterol levels. The purpose of this study was to investigate whether combined treatment with Eicosapentaenoic acid (EPA) and lovastatin enhanced the regulatory effect on gene expression of HMGCoA reductase and LDL receptor in HepG2 cell line. RESULTS: The combined treatment with EPA and lovastatin enhanced the regulatory effect on gene expression of HMGCoA reductase and LDL receptor in HepG2 cell line. Moreover, we detected a synergistic effect on the inhibition of cancer cell proliferation obtained by combination of EPA and Lovastatin. CONCLUSIONS: The use of EPA, in combination with low doses of Lovastatin may have potential value in treatment of neoplastic diseases.

Serum levels of galectin-3 and its ligand 90k/mac-2bp in colorectal cancer patients.

Galectin-3 is an endogenous lectin that binds glycan epitopes of cell membrane and some extracellular glycoproteins such as integrins and laminin. Galectin-3 is involved in several biological activities including regulation of cellular cycle, modulation of adhesion and tumor progression and metastasis. 90K/Mac-2BP glycoprotein is also a serum galectin-3 ligand. 90K is able to modulate the immune reaction against tumors and viruses and its level increases in sera of several neoplastic diseases. In our study, we have evaluated levels of both glycoproteins in sera of non metastatic colon cancer patients. Interestingly, galectin-3 ranged higher in cancer patients than in controls (p<0.0001), particularly in more differentiated tumors (p<0.04). Moreover, 90K mean values ranged higher in right-side than in left-side colon cancer. In conclusion, serum galectin3 might represent a useful biomarker to evaluate colon cancer transformation and, together with its ligand 90K, could contribute to the characterization of colon cancer.

The Effect of Three Mediterranean Diets on Remnant Cholesterol and Non-Alcoholic Fatty Liver Disease: A Secondary Analysis.

BACKGROUND: Elevated fasting remnant cholesterol (REM-C) levels have been associated with an increased cardiovascular risk in patients with metabolic syndrome (Mets) and Non-Alcoholic Fatty Liver Disease (NAFLD). We aimed to estimate the effect of different diets on REM-C levels in patients with MetS, as well as the association between NAFLD and REM-C. METHODS: This is a secondary analysis of the MEDIDIET study, a parallel-arm Randomized Clinical Trial (RCT). We examined 237 people with MetS who underwent Liver Ultrasound (LUS) to assess the NAFLD score at baseline, 3-, and 6-months follow-up. Subjects were randomly assigned to the Mediterranean diet (MD), Low Glycemic Index diet (LGID), or Low Glycemic Index Mediterranean diet (LGIMD). REM-C was calculated as [total cholesterol-low density lipoprotein cholesterol (LDL-C)-high density lipoprotein cholesterol (HDL-C)]. RESULTS: REM-C levels were higher in subjects with moderate or severe NAFLD than in mild or absent ones. All diets had a direct effect in lowering the levels of REM-C after 3 and 6 months of intervention. In adherents subjects, this effect was stronger among LGIMD as compared to the control group. There was also a significant increase in REM-C levels among Severe NAFLD subjects at 3 months and a decrease at 6 months. CONCLUSIONS: fasting REM-C level is independently associated with the grade of severity of NAFLD. LGIMD adherence directly reduced the fasting REM-C in patients with MetS.

Liquid Biopsy as Surrogate for Tissue for Molecular Profiling in Pancreatic Cancer: A Meta-Analysis Towards Precision Medicine.

Liquid biopsy (LB) is a non-invasive approach representing a promising tool for new precision medicine strategies for cancer treatment. However, a comprehensive analysis of its reliability for pancreatic cancer (PC) is lacking. To this aim, we performed the first meta-analysis on this topic. We calculated the pooled sensitivity, specificity, positive (LR+) and negative (LR-) likelihood ratio, and diagnostic odds ratio (DOR). A summary receiver operating characteristic curve (SROC) and area under curve (AUC) were used to evaluate the overall accuracy. We finally assessed the concordance rate of all mutations detected by multi-genes panels. Fourteen eligible studies involving 369 patients were included. The overall pooled sensitivity and specificity were 0.70 and 0.86, respectively. The LR+ was 3.85, the LR- was 0.34 and DOR was 15.84. The SROC curve with an AUC of 0.88 indicated a relatively high accuracy of LB for molecular characterization of PC. The concordance rate of all mutations detected by multi-genes panels was 31.9%. LB can serve as surrogate for tissue in the molecular profiling of PC, because of its relatively high sensitivity, specificity and accuracy. It represents a unique opportunity to be further explored towards its introduction in clinical practice and for developing new precision medicine approaches against PC.

Women in LOVe: Lacto-Ovo-Vegetarian Diet Rich in Omega-3 Improves Vasomotor Symptoms in Postmenopausal Women. An Exploratory Randomized Controlled Trial.

OBJECTIVES: In the postmenopausal period, most women suffer vasomotor symptoms (VMS). It is well-known that VMS can worsen the quality of life. Diet seems to play a relevant role in the development of VMS, but the effect of diet on VMS is mainly limited to observational studies, and analyses of nutritional supplements. The aim of this study was thus to determine the efficacy of a lactoovo- vegetarian (LOVe) diet rich in omega-3 fatty acids vs. a lacto-ovo-vegetarian diet rich in EVO (extra-virgin olive oil) in reducing VMS frequency in postmenopausal women. METHODS: A two-arms (lacto-ovo-vegetarian diet with EVO vs. lacto-ovo-vegetarian diet rich in omega-3) randomized-controlled trial with a follow-up period of 16 weeks. We considered as primary outcome the change in the Kupperman index (follow-up vs. baseline evaluation, reported as delta, D) and in its subscales. Secondary outcomes included changes in common anthropometric and biohumoral measurements. RESULTS: Among 54 women randomly assigned to a study group, 40 (mean age 55.1±5.4 years) completed the study and complied with their assigned diet. Women randomized to the omega-3 group (n=18) showed significant improvements, compared to the EVO group (n=22), in Kupperman index (Δ=-11.4±9.8 vs. -5.9±8.2; p=0.045), hot flashes (Δ=-3.3±3.4 vs. -1.3±2.6; p=0.04), and a marginally significant improvement in nervousness (Δ=-1.7±1.7 vs. -0.8±1.5; p=0.07). No significant differences were observed for the secondary outcomes. No relevant side effects were reported. CONCLUSION: After 16 weeks, a lacto-ovo-vegetarian diet rich in omega-3 reduced VMS frequency in postmenopausal women more than the lacto-ovo-vegetarian diet rich in EVO.

Tissue Fatty Acid Profile is Differently Modulated from Olive Oil and Omega-3 Polyunsaturated Fatty Acids in ApcMin/+ Mice.

BACKGROUND: Fatty acid profile can be considered an appropriate biomarker for investigating the relations between the patterns of fatty acid metabolism and specific diseases, as cancer, cardiovascular and degenerative diseases. OBJECTIVE: Aim of this study was to test the effects of diets enriched with olive oil and omega-3 Polyunsaturated Fatty Acids (PUFAs) on fatty acid profile in intestinal tissue of ApcMin/+ mice. METHOD: Three groups of animals were considered: control group, receiving a standard diet; olive oilgroup, receiving a standard diet enriched with olive oil; omega-3 group, receiving a standard diet enriched with salmon fish. Tissue fatty acid profile was evaluated by gas chromatography method. RESULTS: Olive oil and omega-3 PUFAs in the diet differently affect the tissue fatty acid profile. Compared to control group, the levels of Saturated Fatty Acids (SFAs) were lower in olive oil group, while an increase of SFAs was found in omega-3 group. Monounsaturated Fatty Acids (MUFAs) levels were enhanced after olive oil treatment, and in particular, a significant increase of oleic acid levels was detected; MUFAs levels were instead reduced in omega-3 group in line with the decrease of oleic acid levels. The total PUFAs levels were lower in olive oil respect to control group. Moreover, a significant induction of Saturation Index (SI) levels was observed after omega-3 PUFAs treatment, while its levels were reduced in mice fed with olive oil. CONCLUSION: Our data demonstrated a different effect of olive oil and omega-3 PUFAs on tissue lipid profile in APCMin/+ mice.

Prognostic value of tissue polyamine levels in human colorectal carcinoma.

BACKGROUND: Polyamines are aliphatic cations that play critical roles in cell proliferation and differentiation and in cancer development. Abnormally high polyamine levels have been demonstrated in various types of cancer, but few studies have investigated the prognostic significance of tissue polyamine levels. In this study we evaluated the disease-free survival of patients with colorectal adenocarcinoma according to the polyamine levels in neoplastic tissue and uninvolved surrounding mucosa. PATIENTS AND METHODS: A total of 111 patients with colorectal carcinoma were included in this study. Tissue polyamine levels were evaluated by high performance liquid chromatography (HPLC). RESULTS: Significantly higher single and total polyamine levels were found in colorectal carcinoma compared to those from normal surrounding mucosa. Further, tumor spermine levels were a significant prognostic factor for disease recurrence. CONCLUSION: Differences in tumor spermine levels may affect the biological properties of the tumor and such differences could have a significant role in determining the outcome of colorectal cancer patients.

N6-isopentenyladenosine improves nuclear shape in fibroblasts from humans with progeroid syndromes by inhibiting the farnesylation of prelamin A.

Hutchinson-Gilford progeria syndrome is caused by mutations in the lamin A/C gene that lead to expression of a truncated, permanently farnesylated prelamin A variant called progerin. The accumulation of progerin at the nuclear envelope causes mis-shapen nuclei and results in progeroid syndromes. Previous studies in cells from individuals with Hutchinson-Gilford progeria syndrome have shown that blocking of farnesylation of prelamin A ameliorates the nuclear shape abnormalities. Here we observed that an inhibitor of farnesyl diphosphate synthase, N6-isopentenyladenosine, impeded the farnesylation of prelamin A, causing a decrease in the frequency of nuclear shape abnormalities and redistribution of prelamin A away from the inner nuclear envelope. A combination of lovastatin and N6-isopentenyladenosine significantly improved nuclear shape in fibroblast cell lines from atypical progeria patients. These findings establish a paradigm for ameliorating the most obvious cellular pathology in lamin-related progeroid syndromes, and suggest a potential strategy for treating children with Hutchinson-Gilford progeria syndrome.

Antiproliferative, antioxidant and anti-inflammatory effects of hydroxytyrosol on human hepatoma HepG2 and Hep3B cell lines.

BACKGROUND: Olive oil intake has been shown to induce beneficial effect on health. This study aimed to investigate the effects of olive oil polyphenol hydroxytyrosol (HT) on cell proliferation and its antioxidant and anti-inflammatory capacity in human hepatoma Hep3B and HepG2 cell lines. MATERIALS AND METHODS: Cell growth after HT treatment was measured by 3-(4,5 di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. Lipogenic enzyme activity was evaluated by radiochemical assay. Cell total antioxidant activity and cell interleukin-6 (IL-6) levels were measured by enyme linked immunosorbent assay (ELISA) methods. RESULTS: HT caused an evident antiproliferative effect mediated by inhibition of lipogenic enzymes. Moreover, HT induced activation of the cell antioxidant system and reduced cellular IL-6 levels. CONCLUSION: Our findings provide insights into the mechanisms of action of HT in the context of inhibition of cancer cell proliferation and prevention of oxidative stress in human hepatoma cells. Our results also show a down-regulation of lipogenic enzymes involved in cell proliferation.

Reduced fructosamine-3-kinase activity and its mRNA in human distal colorectal carcinoma.

Fructosamine-3-Kinase (FN3K) is an enzyme phosphorilating fructoselysine (FL) residues on glycated proteins, resulting in the production of protein-bound FL-3-phosphate. The pathological role of the non-enzymatic modification of proteins by reducing sugars has become increasingly evident in various types of disorders, including the cancer. In this study, our aim was to study FN3K enzyme activity, as well as its mRNA in human colorectal cancer (CRC). Thirty consecutive CRC patients undergoing surgery of the colon were enrolled in the study. FN3K enzymatic activity and gene expression were analyzed using a radiometric assay and quantitative RT-PCR, respectively. FN3K is a functionally active enzyme in human colon tissue, without significant differences between normal mucosa and cancer. The mean level of FN3K mRNA was significantly lower in cancer than in the corresponding normal colorectal mucosa The colorectal tumors located on the left side showed lower levels of both enzymatic activity and mRNA FN3K than tumors located in the right side of colon. This paper is the first studying FN3K enzyme activity in human CRC, showing a significant relationship between enzymatic activity, its mRNA and tumor side.

Serum lipid profile in colorectal cancer patients with and without synchronous distant metastases.

OBJECTIVE: In this study, the serum lipid profile, including total cholesterol (TC), triglycerides (TG), high-density (HDL-C) and low-density lipoprotein cholesterol (LDL-C), has been investigated in colorectal cancer patients (CRC) with and without synchronous distant metastases. The aim of this study was to verify whether the presence of metastases was associated to serum lipid abnormalities, and whether lipoprotein abnormalities were linked to the nutritional status. METHODS: The fasting serum lipid profile was examined in 84 CRC patients using colorimetric methods. To determine the nutritional status, the body mass index (BMI) was calculated and serum albumin was measured. RESULTS: Patients with distant metastases showed significantly higher levels of TC, LDL-C and the LDL-C/HDL-C ratio than patients without metastases (p< 0.05). The presence of metastases was positively associated with TC, LDL-C and the LDL-C/HDL-C ratio, being independent of sex, age and BMI. CONCLUSIONS: Elevated serum lipid levels may facilitate the development of distant metastasis in CRC patients.