Significance of serum iron and ferritin in patients with colorectal adenomas

Serum ferritin and risk of colonic neoplasia: Implications for the workup and treatment of iron deficiency

Iron deficiency is the most common extraintestinal sign of colonic neoplasia, including colorectal cancer (CRC) and other lower gastrointestinal pathology. Both upper endoscopy and colonoscopy is usually recommended in the work-up of patients with unexplained iron deficiency, particularly in men and postmenopausal women. As the incidence of early-onset CRC (age <50 years) rises in the United States, there is an increasing need to identify risk predictors to aid in the early detection of CRC. It remains unknown if serum ferritin (SF), and what specific threshold, can be used as a marker to stratify those at risk for CRC and other lower gastrointestinal pathology. In this current review of the literature, we aimed to review guidelines for diagnostic workup of colonic neoplasia in the setting of iron deficiency and examine the association and specific thresholds of SF and risk of CRC by age. Some of the published findings are conflicting, and conclusions specific to younger patients are limited. Though further investigation is warranted, the cumulative findings suggest that SF, in addition to considering the clinical context and screening guidelines, may have potential utility in the assessment of colonic neoplasia.

Downregulation of TfR1 promotes progression of colorectal cancer via the JAK/STAT pathway

Background: Colorectal cancer (CRC) is one of the most prevalent gastrointestinal malignancies. The incidence of CRC has been rapidly increasing in China. Transferrin receptor 1 (TfR1) is a key regulator of cellular iron homeostasis. Several studies have demonstrated TfR1 overexpression in a variety of human tumors, but the association between TfR1 and CRC remains unclear.

Methods: TfR1 expression was evaluated in six CRC cell lines and tumor tissues. A total of 201 CRC patients were included for immunohistochemistry and 19 pairs of frozen tissues were used for real-time PCR. Cell proliferation, cell cycle, cell migration and invasion, and in vivo carcinogenesis were tested after downregulation of TfR1 by lentivirus. Protein microarray and Western blot analyses were used to explore the underlying mechanisms of TfR1 in CRC.

Results: TfR1 expression was higher in CRC tissues than in normal tissues (57.2% vs 22.9%, P＜0.001). TfR1 expression was obviously higher in CRC tissues with well differentiation (P＝0.008), no lymph node metastasis (P＝0.002), no distant metastasis (P＝0.006), no vascular invasion (P＜0.001) and early TNM stage (P＝0.013). CRC patients with TfR1-positive expression had a better survival than those with TfR1-negative expression (P＝0.044). Downregulation of TfR1 expression inhibited cell proliferation, promoted cells from G1 phase to S phase and facilitated cell migration and invasion. Knockdown of TfR1 also suppressed tumor growth in BALB/C-nu mice. Protein microarray and Western blot analyses showed that the Janus protein tyrosine kinase/signal transducer and activator of transcription pathway was activated along with downregulation of TfR1 expression.

Conclusion: Though TfR1 was overexpressed in colorectal cancer tissues, there was evidence that downregulation of TfR1 could promote cancer progression.

Anatomical distribution and detection rate of colorectal neoplasms according to age in the colonoscopic screening of a Korean population

Purpose

Because data as a basis for the determination of proper age and modality for screening of colorectal neoplasms is lacking, we evaluated detection rates and anatomical distribution of colorectal neoplasms according to age in healthy individuals who underwent total colonoscopy for health checkup.

Methods

A total of 16,100 cases that had received the colonoscopic examination from January to December in 2014 were analyzed. The total number of individuals who received total colonoscopy were divided by the number of individuals harboring colorectal adenoma to calculate the detection rate of colorectal adenoma. Individuals ≤50 years old were classified as young-age group and aged >50 were old-age group. Differences in anatomical locations of colorectal neoplasms were analyzed in the 2 age groups by chi-square test. Risk factors for colorectal adenoma in each age group were analyzed using univariate and multivariate logistic regression analyses.

Results

Detection rates of colorectal adenoma were 13.7% in all cases and 12.8% for those in their 40's. The main anatomical location of colorectal adenoma was proximal colon in both age groups (P < 0.001). Hyperplastic polyp was mainly distributed to the distal colon in both age groups (P < 0.001). Distal colon was the major site for colorectal cancer in the old-age group (P = 0.001). Proximal location of neoplasms was a risk factor for colorectal adenoma in both age groups with multivariate analysis.

Conclusion

These data could be the bases for earlier initiation of screening for colorectal neoplasms with total colonoscopy to detect clinically significant colorectal polyps.

Pre-operative anaemia in colon cancer patients became normal after more than a year post-operatively but did not influence oncological outcome in the final analysis

BACKGROUND

Pre-operative anaemia has been related to adverse outcomes after surgical management of colorectal cancer. How various factors may contribute to anaemia and also its post-operative recovery has not been extensively investigated.

METHODS

Two hundred and thirty five colon cancer patients treated surgically in a community teaching hospital in Norway between 2007 and 2009 were prospectively examined.

RESULTS

Anaemia was detected in 53.8%, which was dependent on tumour location, albumin level and female gender. More than 60% of all patients were overweight or obese. Pre-operative BMI was negatively associated with age and positively associated with albumin level (p = 0.018 for both). Haemoglobin levels slowly returned to normal during the first year in significant incremental steps, coincidental with an increase in BMI. At 6 months post-operative, age, albumin, female gender and TNM stage (p = 0.010; p = 0.020; p < 0.001; p = 0.028, respectively) were significantly connected with anaemia, whereas only age and albumin (p = 0.016; p = 0.004, respectively) were associated with a reduced BMI. Pre-operative anaemia gave a significantly worse overall survival (p = 0.040) in the univariate analysis but was not significant in the multivariate analysis.

CONCLUSION

Beside the influence of tumour location, it appeared that pre-operative Hgb had some relation to a reduced nutritional state. The post-operative recovery of anaemia was more closely related to an improved nutritional state. The relation between anaemia and oncological outcome should undergo further studies.

Urinary hepcidin level as an early predictor of iron deficiency in children: A case control study

Background

The ideal screening test would be capable of identifying iron deficiency in the absence of anemia. We tried to detect role of urinary hepcidin-25 level in early prediction of iron deficiency in children.

Methods

This is a case control study performed on 100 children in Hematology Unit of Pediatric Department, Zagazig University Hospital, Egypt. Our study included 25 cases of iron deficiency (ID) stage-1 (iron depletion), 25 cases ID stage-2 (iron-deficient erythropoiesis), 25 cases ID stage-3 (iron deficiency anemia) and 25 healthy children as a control group. Estimation of iron status parameters was done. Urinary hepcidin-25 level was detected.

Results

Urinary hepcidin-25 level was significantly lower in all stages of iron deficiency than in control group, more significant reduction in its level was observed with the progress in severity of iron deficiency. Urinary hepcidin showed significant positive correlation with hemoglobin, mean corpuscular volume, hematocrit value, serum iron and ferritin and transferrin saturation. In contrary, it showed significant negative correlation with serum transferrin and total iron binding capacity.

Urinary hepcidin at cutoff point ≤0.94 nmol/mmol Cr could Predict ID stage-1 with sensitivity 88% and specificity 88%. Cutoff point ≤0.42 nmol/mmol Cr could predict ID stage-2 with sensitivity 96% and specificity 92%. Cutoff point ≤0.08 nmol/mmol Cr could Predict ID stage-3 with Sensitivity 96% and specificity 100%.

Conclusions

We can conclude that detection of urinary hepcidin-25 level was a simple and non invasive test and could predict iron deficiency very early, before appearance of hematological affections.

Determination of the minimal essential serum folate concentration for reduced risk of colorectal adenoma

BACKGROUND & AIMS

There are no data regarding basal folate levels in patients without colorectal adenoma. This study aimed to determine the minimum serum folate concentration that associates with reduced risk of colorectal adenoma.

METHODS

1510 consecutive patients underwent total colonoscopy for suspected colorectal lesions after barium enema examination. Prior to colonoscopy, history of alcohol consumption was noted and blood serum analyzed for folate and vitamin B12 levels. Polypoid lesions were evaluated histologically. We excluded patients with anemia, history of colonoscopy, overconsumption of alcohol, or malignancies. In all, 458/1510 patients (male/female; 258/200, 40-75 years) were determined eligible. Variables were compared between patients with adenoma and those without adenoma.

RESULTS

Serum folate concentration was the variable with the most significant statistical variation between males with adenoma (8.0 ng/ml) and males without adenoma (9.2) (p = 0.001). Serum folate concentrations in females with adenoma did not differ significantly from those in females without adenoma (10.7 versus 10.9). When subjects were stratified into groups according to serum folate, we found no significant difference in the prevalence of adenoma in patients with folate levels greater than 8.0 ng/ml.

CONCLUSION

Patients with serum folate concentrations above 8.0 ng/ml had the lowest risk of developing colorectal adenoma.

Evaluation and treatment of iron deficiency anemia: a gastroenterological perspective

A substantial volume of the consultations requested of gastroenterologists are directed towards the evaluation of anemia. Since iron deficiency anemia often arises from bleeding gastrointestinal lesions, many of which are malignant, establishment of a firm diagnosis usually obligates an endoscopic evaluation. Although the laboratory tests used to make the diagnosis have not changed in many decades, their interpretation has, and this is possibly due to the availability of extensive testing in key populations. We provide data supporting the use of the serum ferritin as the sole useful measure of iron stores, setting the lower limit at 100 microg/l for some populations in order to increase the sensitivity of the test. Trends of the commonly obtained red cell indices, mean corpuscular volume, and the red cell distribution width can provide valuable diagnostic information. Once the diagnosis is established, upper and lower gastrointestinal endoscopy is usually indicated. Nevertheless, in many cases a gastrointestinal source is not found after routine evaluation. Additional studies, including repeat upper and lower endoscopy and often investigation of the small intestine may thus be required. Although oral iron is inexpensive and usually effective, there are many gastrointestinal conditions that warrant treatment of iron deficiency with intravenous iron.

Hemochromatosis Gene Mutations and Distal Adenomatous Colorectal Polyps

Iron has been suggested to be a risk factor for colorectal neoplasia. Some individuals who are heterozygous for mutations in the hemochromatosis gene (HFE) have higher than average serologic measures of iron. We therefore investigated whether heterozygosity for HFE mutations was related to risk of advanced distal adenoma and whether the relationship was affected by dietary iron intake. In the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, 679 persons with advanced distal adenoma and 697 control persons were genotyped for the two major HFE mutations (C282Y and H63D), one HFE polymorphism (IVS2+4), and one polymorphism (G142S) in the transferrin receptor gene (TFRC). HFE haplotypes were also created to examine the effect of haplotype on risk. Food frequency questionnaire data were used to estimate daily iron intake. There was no relationship between any HFE genotype or haplotype and advanced adenoma. Stratification of HFE genotype by TFRC genotype did not change the results. In addition, there was no relationship between dietary iron intake and risk of adenoma or between HFE genotype and risk of adenoma, stratified by iron intake. These results do not support a relationship between HFE heterozygosity and risk of advanced distal adenoma.

The value of a complete blood count in predicting cancer of the colon

Mortality from colon cancer could be reduced with routine screening, yet screening rates are low. Current screening tools are limited by expense and suboptimal acceptance. A retrospective case-control study of all cases of colon cancer diagnosed at our institution over a 5-year period was performed to determine the frequency of blood count abnormalities in these patients upon presentation. One hundred twenty-seven patients had right-sided colon cancer: 107 (84%) had an elevated red cell distribution width (RDW); 87 (69%) had anemia; and 70 (55%) had a low mean corpuscular volume (MCV). Ninety-eight patients had left-sided colon cancer: 49 (50%) had an elevated red cell distribution width; 43 (44%) had anemia; and 22 (22%) had a low mean corpuscular volume. The red cell distribution width was 84% sensitive and 88% specific for right-sided colon cancer. An elevated red cell distribution width may help better identify those patients who should be referred for full colonoscopy.

Reference distributions for serum iron and transferrin saturation: a comparison of a large cohort to the world's literature

The appropriate clinical use of serum iron and transferrin saturation (TSAT) requires satisfactory reference intervals from birth to old age, and for males and females. This study identified 54 publications from 1974 to 2001 that met the criteria used in three prior meta-analyses, and these were analyzed statistically. A summary of our review is presented along with our reference population data on these measurements. This analysis places previous publications in perspective and suggests possible reasons for the observed differences. Previous studies of the individual analytes, serum iron, transferrin, and TSAT values agree with the reference ranges presented in this study, although the entire experience over time and between sexes has not been available before. Our 95% reference ranges are somewhat broader than those of the smaller studies, but they agree well with those of the larger ones.

Iron and colorectal cancer risk: human studies

Some reports have associated iron with cancer risk, particularly of the colorectum. This review will focus on the human studies that have investigated this association. Comparative studies were sought in which people with and without colorectal neoplastic lesions, either cancers or adenomatous polyps, were assessed for iron exposure. Iron exposure variables included dietary iron intake, iron vitamin supplementation, body iron stores as measured by ferritin or transferrin saturation, and gene status for hereditary hemochromatosis. Medline was searched for published reports using the key words iron, cancer, colon, rectum, ferritin, transferrin, and hemochromatosis. In addition, the Cochrane Library was searched for relevant studies and several authors were contacted to investigate their awareness of unpublished studies. Studies were categorized by study design and ranked for quality of innovation in design, sample size, and thoroughness of iron status ascertainment. Thirty-three studies were reviewed in 26 publications. Of the larger studies, approximately three-quarters supported the association of iron, in all three strata of exposure, with colorectal neoplasia risk. Because iron is broadly supplemented in the American diet, the benefits of iron supplementation need to be measured against the long-term risks of increased iron exposure, one of which may be increased risk of colorectal cancer.

Mean corpuscular volume may be a useful index of risk for colorectal adenoma in middle-aged Japanese men

OBJECTIVE

It has been reported that alcohol intake and folate deficiency are associated with an increased risk of colorectal adenomas and carcinomas. Mean corpuscular volume (MCV) of red blood cells has been reported to be increased in these conditions. The purpose of this study was to assess the association between MCV and risk of colorectal adenoma.

METHODS

The subjects were 497 middle-aged (45-65 yr old) men who underwent both barium enema examination and total colonoscopy. The subjects answered a questionnaire regarding their alcohol consumption history, and their blood samples were analyzed. The subjects were divided into four groups three times: with or without alcoholism, and with or without adenoma according to alcohol intake, and according to the MCV value. Various variables were compared among the groups, and the odds ratios of adenoma were calculated.

RESULTS

The MCV was higher in the alcoholic group than in the nonalcoholic group (p < 0.01) and in patients with adenoma than in those without adenoma (p < 0.0001). When the subjects were stratified by alcohol intake, the MCV value had a higher significant difference than alcohol intake, between patients with adenoma and those without adenoma. As for the MCV value, the odds ratio (95% confidence interval) of adenoma was 1.00 (referent); (<92), 1.20 (0.71-1.69); (> or =92 but <95), 2.61 (2.07-3.15); (> or =95 but <98); and 3.62 (2.99-4.25); (> or =98).

CONCLUSION

A high MCV value may be used as a simple index of the risk of colorectal adenomas, regardless of alcohol consumption.