The value of serum copper levels in non-Hodgkin's lymphoma

Cuproptosis-related lncRNA signature as a prognostic tool and therapeutic target in diffuse large B cell lymphoma

Cuproptosis is a newly defined form of programmed cell death that relies on mitochondria respiration. Long noncoding RNAs (lncRNAs) play crucial roles in tumorigenesis and metastasis. However, whether cuproptosis-related lncRNAs are involved in the pathogenesis of diffuse large B cell lymphoma (DLBCL) remains unclear. This study aimed to identify the prognostic signatures of cuproptosis-related lncRNAs in DLBCL and investigate their potential molecular functions. RNA-Seq data and clinical information for DLBCL were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Cuproptosis-related lncRNAs were screened out through Pearson correlation analysis. Utilizing univariate Cox, least absolute shrinkage and selection operator (Lasso) and multivariate Cox regression analysis, we identified seven cuproptosis-related lncRNAs and developed a risk prediction model to evaluate its prognostic value across multiple groups. GO and KEGG functional analyses, single-sample GSEA (ssGSEA), and the ESTIMATE algorithm were used to analyze the mechanisms and immune status between the different risk groups. Additionally, drug sensitivity analysis identified drugs with potential efficacy in DLBCL. Finally, the protein-protein interaction (PPI) network were constructed based on the weighted gene co-expression network analysis (WGCNA). We identified a set of seven cuproptosis-related lncRNAs including LINC00294, RNF139-AS1, LINC00654, WWC2-AS2, LINC00661, LINC01165 and LINC01398, based on which we constructed a risk model for DLBCL. The high-risk group was associated with shorter survival time than the low-risk group, and the signature-based risk score demonstrated superior prognostic ability for DLBCL patients compared to traditional clinical features. By analyzing the immune landscapes between two groups, we found that immunosuppressive cell types were significantly increased in high-risk DLBCL group. Moreover, functional enrichment analysis highlighted the association of differentially expressed genes with metabolic, inflammatory and immune-related pathways in DLBCL patients. We also found that the high-risk group showed more sensitivity to vinorelbine and pyrimethamine. A cuproptosis-related lncRNA signature was established to predict the prognosis and provide insights into potential therapeutic strategies for DLBCL patients.

Development and validation of a cuproptosis-associated prognostic model for diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a highly heterogeneous disease. Therefore, more reliable biomarkers are required to better predict the prognosis of DLBCL. Cuproptosis is a novel identified form of programmed cell death (PCD) that is different from oxidative stress-related cell death (e.g., apoptosis, ferroptosis, and necroptosis) by Tsvetkov and colleagues in a recent study released in Science. Cuproptosis is copper-dependent PCD that is closely tied to mitochondrial metabolism. However, the prognostic value of cuproptosis-related genes (CRGs) in DLBCL remains to be further elucidated. In the present study, we systematically evaluated the molecular changes of CRGs in DLBCL and found them to be associated with prognosis. Subsequently, based on the expression profiles of CRGs, we characterized the heterogeneity of DLBCL by identifying two distinct subtypes using consensus clustering. Two isoforms exhibited different survival, biological functions, chemotherapeutic drug sensitivity, and immune microenvironment. After identifying differentially expressed genes (DEGs) between CRG clusters, we built a prognostic model with the Least absolute shrinkage and selection operator (LASSO) Cox regression analysis and validated its prognostic value by Cox regression analysis, Kaplan-Meier curves, and receiver operating characteristic (ROC) curves. In addition, the risk score can predict clinical characteristics, levels of immune cell infiltration, and prognosis. Furthermore, a nomogram incorporating clinical features and risk score was generated to optimize risk stratification and quantify risk assessment. Compared to the International Prognostic Index (IPI), the nomogram has demonstrated more accuracy in survival prediction. Furthermore, we validated the prognostic gene expression levels through external experiments. In conclusion, cuproptosis-related gene signature can serve as a potential prognostic predictor in DLBCL patients and may provide new insights into cancer therapeutic targets.

Disparities in Trace Metal Levels in Hodgkin/Non-Hodgkin Lymphoma Patients in Comparison with Controls

Lymphoma arises from cells of the immune system and trace metals augment the immune system and their imbalance may promote immunological disorders including tumorigenesis. The primary aim of the present investigation was to evaluate the levels of essential/toxic trace metals in the nails of non-Hodgkin and Hodgkin lymphomas patients in comparison with controls. The samples collected from patients and controls were digested in the mixture of HNO₃-HClO₄ and selected trace metals were analysed using flame atomic absorption spectrometry. The results showed that mean concentrations of some elements (Pb, Ni, Cd, Cu and Cr) in nails of non-Hodgkin lymphoma patients were significantly elevated (p < 0.05) than that of the controls whereas mean contents of Pb, Cu, Cd and Cr were observed to be significantly higher in the nails of Hodgkin lymphoma patients compared with healthy donors. Additionally, correlation study pointed out significantly diverse mutual associations of the trace metals among the patients and controls. The present results revealed noticeable disparities in the metal concentrations based on gender, food habits, tobacco use and types/stages of the donor's groups. Overall, the pathogenesis of disease significantly affected the trace metal balance in both patients' groups.

Disparities in the Concentrations of Essential/Toxic Elements in the Blood and Scalp Hair of Lymphoma Patients and Healthy Subjects

Lymphoma is one of the fastest growing malignancies worldwide and imbalance in the concentrations of trace elements can play a significant role in the onset and progression of the disease. Selected essential and toxic elements (Fe, Zn, Cu, Mn, Ni, Cr, Cd and Pb) were analysed in the blood & scalp hair of lymphoma patients (n = 59 & 58, respectively) and controls (n = 61 & 60, respectively) by atomic absorption spectrometry. On the average, Ni, Cr, Cu and Cd revealed significantly higher contents in the blood and scalp hair of the patients than the controls (p < 0.05). The correlation study showed significantly diverse relationships among the elements in blood & scalp hair of the two donor groups. Variations in the elemental levels with different types of lymphoma (non-Hodgkin and Hodgkin) were also evaluated. Disparities in the elemental concentrations were also investigated for various types of non-Hodgkin (diffuse large B-cell lymphoma, follicular lymphoma and peripheral T-cell lymphoma) and Hodgkin lymphoma (mixed cellularity, nodular lymphocyte predominant and nodular sclerosing), as well as for different stages (I, II, III & IV) of the cancer. Multivariate statistical analysis showed considerably divergent associations of the elements in the patients and controls. The study indicated profound alteration of the elemental levels in the patients; it may be implicated in elemental-induced disorders including lymphoma.

Physiological serum copper concentrations found in malignancies cause unfolding induced aggregation of human serum albumin in vitro

Malignancies are characterized by several drastic metabolic changes, one of which is a progressive rise in the levels of serum copper. This rise in serum copper is documented across all malignancies and across malignancies in several species. This study aims to explore in vitro the effect of increased copper levels on the structure of the blood protein human serum albumin. Exposure of human serum albumin to physiologically relevant copper concentrations for 21 days resulted in structural modifications in the protein which were evident by changes in the intrinsic florescence. A loss of the predominantly alpha helical structure of human serum albumin was recorded along with a tendency to form protein aggregates. This aggregation was characterized by Thioflavin T and Congo Red assays. Rayleigh light scattering and turbidity assays confirmed aggregation. The aggregates were visually confirmed using transmission electron microscopy. This is the first report implicating increased copper levels as a cause of aggregation of blood proteins in malignancies. The physiological and biochemical implications of this phenomenon are discussed.

IS METABOLIC ACTIVATION OF TOPOISOMERASE II POISONS IMPORTANT IN THE MECHANISM OF CYTOTOXICITY?

The antitumor drugs doxorubicin and etoposide, a phodophyllotoxin derivative, are clinically active for the treatment of human malignancies. Because of their extreme effectiveness in the clinic, their modes of actions have been the subject of intense research for over several decades both in the laboratory and in the clinic. It has been found that both doxorubicin and etoposide (VP-16) act on topoisomerase II, induce DNA cleavage, and form double-strand breaks, causing tumor cell death. However, both of these drugs also undergo extensive metabolism in tumor cells and in vivo to various reactive intermediates that bind covalently to cellular DNA and proteins. Moreover, both drugs are metabolized to reactive free radicals that induce lipid peroxidation and DNA damage. However, the role of drug activation in the mechanism of cytotoxicity remains poorly defined. In this review, we critically evaluate the significance of metabolic activation of doxorubicin and etoposide in the mechanism of tumor cytotoxicity.

D-penicillamine and other low molecular weight thiols: review of anticancer effects and related mechanisms

Low molecular weight thiols (LMWTs) like N-acetyl cysteine, D-penicillamine, captopril, Disulfiram and Amifostine, etc. have been used as chemo-preventive agents. Recent studies have reported cell growth inhibition and cytotoxicity in several different types of cancer cells following treatment with several LMWTs. Cytotoxic and cytostatic effects of LMWTs may involve interaction of the thiol group with cellular lipids, proteins, intermediates or enzymes. Some of the mechanisms that have been proposed include a p53 mediated apoptosis, thiyl radical induced DNA damage, membrane damage through lipid peroxidation, anti-angiogenic effects induced by inhibition of matrix metalloproteinase enzymes and angiostatin generation. LMWTs are strong chelators of transition metals like copper, nickel, zinc, iron and cobalt and may cause metal co-factor depletion resulting in cytotoxicity. Oxidation of thiol group can also generate cytotoxic reactive oxygen species (ROS).

Copper, zinc, and Cu/Zn ratio in carcinoma of the gallbladder

INTRODUCTION

The exact role of copper and zinc in the etiology of carcinoma of the gallbladder is unclear. Some studies suggest the Cu/Zn ratio is a good indicator of the extent and prognosis in carcinoma of the gastrointestinal tract. The aim of the present study is to estimate the micronutrient profile and Cu/Zn ratio in the serum, tissues, and bile of patients with benign and malignant gallbladder diseases.

METHODS

The present study was carried out in 60 patients comprising 30 each of carcinoma of the gallbladder and cholelithiasis, and 30 age and sex matched controls. Copper and zinc levels were estimated in blood, bile, and tissue using a Perkin Elmer Model 2380 Atomic absorption Spectrophotometer.

RESULTS

The mean serum zinc levels were significantly lower in patients with carcinoma of the gallbladder than in patients with cholelithiasis and in healthy controls (P < 0.001). The mean serum copper levels were significantly higher in patients with carcinoma of the gallbladder as compared to patients with cholelithiasis and healthy controls (P < 0.001). Biliary and tissue zinc levels were significantly lower in patients with carcinoma of the gallbladder than in patients with cholelithiasis. Biliary and tissue copper levels were higher in patients with carcinoma of the gallbladder than in patients with cholelithiasis. The serum Cu/Zn ratio showed a gradual and significant increase from 1.11 in healthy controls to 1.35 in patients with cholelithiasis and 2.12 in patients with carcinoma of the gallbladder. The biliary and tissue Cu/Zn ratios were also significantly increased in patients with carcinoma of the gallbladder than in patients with cholelithiasis (P < 0.001).

CONCLUSIONS

Our data support an association between lower zinc levels and consequently an increased Cu/Zn ratio and carcinoma of the gallbladder. Whether zinc supplementation has a protective effect in preventing carcinoma of the gallbladder needs to be studied further.

Erythropoietin response is inadequate in cancer patients receiving chemotherapy

The level of serum erythropoietin (EPO) is inappropriately decreased in cancer patients and has been advocated as the main cause of their anemia. In cancer patients, chemotherapy results in a cumulative anemia severe enough to require transfusion. We investigated the changes in serum EPO, hemoglobin, ceruloplasmin, and copper levels in cancer patients receiving chemotherapy. There was a weak but significant inverse relationship between hemoglobin and log[EPO] (r = -0.41; P < .001). Observed/expected serum EPO ratios decline with repeated chemotherapy indicating inadequate EPO response for the degree of anemia. There was no difference in the severity of anemia and in the degree of EPO response between platinum- and non-platinum-treated patients. Ceruloplasmin, copper, and ferritin levels did not change during chemotherapy. Our results suggest that the EPO response is inadequate for the degree of anemia and justifies the use of recombinant human EPO in cancer patients receiving chemotherapy.

Nutritional assessment and serum zinc and copper concentration in leukemic children

CONTEXT

Malnutrition in childhood cancer is commonly a serious problem. Changes in blood zinc and copper have also been found in malignant diseases.

OBJECTIVE

To describe the protein-energy nutritional status and serum zinc and copper of children with newly diagnosed leukemia.

DESIGN

Cross-sectional study.

SETTING

University referral center.

PARTICIPANTS

23 children with newly diagnosed acute lymphocytic leukemia (ALL) or acute non-lymphocytic leukemia (ANLL) between the ages of 1 and 10 years. The control subjects were 31 healthy school children of similar age from local schools.

MAIN MEASURES

Anthropometric measurements of height/age and weight/height, food intake and serum levels of zinc and copper.

RESULTS

Almost the entire group of children were eutrophic. Zinc and copper intake were below the recommended values. Serum zinc levels were significantly lower and serum copper levels were significantly higher in the leukemic group when compared to normal children.

CONCLUSION

At the time of diagnosis the children suffering from leukemia were not overtly malnourished but blood analysis showed alterations in concentrations of the trace elements zinc and copper.

Efficiency of serum copper/zinc ratio for differential diagnosis of patients with and without lung cancer

We examined serum copper (Cu), serum zinc (Zn), and the serum copper/zinc ratio (Cu/Zn) in 162 patients. All of them were seen to have an abnormal shadow in the chest X-ray films, that is, 109 patients with lung cancer (LC) and 53 patients with no lung cancer (NLC). The mean Cu and Cu/Zn in LC patients were significantly higher than those in NLC patients (p < 0.05). In LC patients, Cu and Cu/Zn were higher and Zn was lower in advanced tumors than early ones. There was a significantly clear relation between Cu or Cu/Zn and the tumor (T) stages. When the relative risk (RR) of LC was estimated, it was seen that the higher Cu and Cu/Zn became, the higher RR became. Furthermore, we showed the sensitivity of the receiver operator characteristic of the test (ROC) curve for Cu, Cu/Zn, and carcinoembryonic antigen (CEA) to diagnose LC, as explained in a paragraph of methods. The determinations of Cu, Zn, and Cu/Zn are simple and inexpensive. They also appear to have a great diagnostic value in determining the local invasion of LC and as a screening test in the high-risk patients for LC.

Serum and tissue trace elements in colorectal cancer

Serum copper, zinc, and Cu/Zn ratio were measured using atomic absorption spectrophotometry in 30 patients with colorectal cancer and compared with 30 healthy control subjects. In the patients with colorectal cancer, the tissue copper and zinc levels were also measured in paired histologically normal and malignant colorectal tissue samples obtained at surgery. The mean serum copper levels were higher in patients with colorectal cancer (165.99 vs. 98.84 micrograms/dl) (P < 0.001). The mean serum zinc levels were lowered only in advanced (Dukes stages C and D) colorectal cancer compared to controls (89.94 vs. 115.08 mu/dl) (P < 0.001). However, the Cu/Zn ratio progressively increased with the advancing stage of malignancy (1.86 vs. 0.86) (P < 0.001). The cancerous colorectal tissue showed a higher concentration of both copper (2.78 vs. 1.79 micrograms/g) (P < 0.001) and zinc (27.16 vs. 18.98 micrograms/g) (P < 0.01) compared to non-cancerous colorectal tissue. The exact mechanism responsible for the alterations in trace element levels in patients with colorectal cancer is largely unclear and requires further evaluation. However, the serum copper level and the Cu/Zn ratio are of value in estimating the extent of the carcinoma as well as in determining the prognosis of these patients.

Hair zinc and copper concentrations and zinc: copper ratios in pediatric malignancies and healthy children from southeastern Turkey

Twenty-eight healthy and forty-six children with malignancy admitted to the Pediatrics Oncology Clinic and Outpatient Clinic of Dicle University, Medical Faculty, Department of Pediatrics in 1989-1990 were included into this study. The children under investigation were divided into three groups. Group 1 consisted of 28 healthy children. Twenty-eight children with newly diagnosed malignant disease, before the start of treatment, formed Group 2. Group 3 consisted of eight of these 28 children together with 18 other children with malignancy in complete remission. 1. Mean hair zinc and copper levels, and zinc/copper values for Group 2 were found to be 100.7 +/- 6.8 micrograms/g, 11.0 +/- 0.8 micrograms/g, and 10.0 +/- 0.8, respectively. 2. The corresponding values for Group 3 were obtained as 143.5 +/- 6.3 micrograms/g, 7.6 +/- 0.4 micrograms/g, and 20.2 +/- 1.4. 3. The values for Group 1 were 142.6 +/- 4.5 micrograms/g, 8.4 +/- 0.5 micrograms/g, and 19.0 +/- 1.4, respectively. 4. The differences between control-active-phase and active-phase-remission groups were statistically significant (p < 0.01), whereas almost the same values were obtained for the control and remission groups (p > 0.05). These results were valid in cases where the comparisons of these three groups were performed also for the subgroups. It was shown that hair zinc and copper levels and zinc/copper values are useful parameters for the diagnosis and treatment of the children with malignancy because of the fact that hair reflects the integrated trace element concentrations of the body, not the present one.

Serum trace elements and Cu/Zn ratio in breast cancer patients

Serum copper, zinc, and the Cu/Zn ratio were measured in 55 patients with breast disease (20 with benign breast diseases and 35 patients with breast cancer) and 30 controls. The mean serum copper levels were higher in breast cancer than in benign breast diseases (167.3 micrograms/dl vs. 117.6 micrograms/dl) (P less than 0.001) and controls (167.3 micrograms/dl vs. 98.8 micrograms/dl) (P less than 0.001). Patients with advanced breast cancer had higher serum copper levels than did patients with early breast cancer (177.9 micrograms/dl vs. 130.4 micrograms/dl) (P less than 0.001). The mean serum zinc levels were lowered only in patients with advanced breast cancer as compared with controls (88.6 micrograms/dl vs. 115.1 micrograms/dl) (P less than 0.001). Serum zinc levels were not decreased in patients with early breast cancer and benign breast diseases. The Cu/Zn ratio was increased in breast cancer patients (1.91 vs. 0.86) (P less than 0.001) but not in patients with benign breast diseases. The precise mechanisms responsible for the alterations in trace element levels in breast cancer patients are still unclear and require further evaluation. However, the serum copper levels and the Cu/Zn ratio may be used as biochemical markers in these patients.

Use of the copper/zinc ratio in the diagnosis of lung cancer

Serum zinc (Zn), copper (Cu), and the Cu/Zn ratio were evaluated in 84 patients with pulmonary lesions before surgery and in 100 healthy normal controls. There were 20 patients with benign and 64 with malignant lung tumors. Only the mean (+/- SD) Cu/Zn ratio was significantly higher in malignant tumors (2.24 +/- 0.78) than in benign tissue (1.63 +/- 0.33) (P less than 0.001). In the normal group, the Cu/Zn ratio was significantly lower (1.43 +/- 0.29). Patients with advanced disease (Stage III) had higher Cu/Zn ratio than patients in Stages I and II (2.65 +/- 0.86 versus 1.9 +/- 0.27) (P less than 0.001). At a cutoff value of 1.72, Cu/Zn ratio had a sensitivity of 89%, specificity of 84%, positive predictive value of 78%, and negative predictive value of 92% between controls and lung cancer patients. Between lung cancer patients and patients with benign pulmonary lesions the aforementioned values were 89%, 70%, 90%, and 70% respectively. A correlation between increasing Cu/Zn ratio and tumor extension and postoperative survival was observed. These findings suggest that Cu/Zn ratio may be used as a diagnostic test in lung cancer patients.

Copper distribution among serum proteins in paediatric liver disorders and malignancies

Fractionation of normal serum on Sephadex G-150, followed by determination of copper, caeruloplasmin and albumin concentrations, indicated that only approximately 71% of total serum copper was associated with caeruloplasmin; less than previously reported values. Seven per cent was associated with a high molecular weight protein, designated 'transcuprein', 19% with albumin and 2% with amino acids. Compared with adult serum the concentrations of caeruloplasmin and of copper associated with caeruloplasmin were low both in serum from neonates and in serum from patients with symptomatic Wilson's disease. However, in contrast to the neonate, Wilson's disease patients exhibited a raised total serum copper and raised non-caeruloplasmin-copper. In Indian Childhood Cirrhosis serum caeruloplasmin and caeruloplasmin-copper levels were normal, whilst the non-caeruloplasmin-copper was raised. Elevated non-caeruloplasmin-copper in Wilson's disease and Indian Childhood Cirrhosis may therefore represent an overspill into the serum from a copper-laden liver. Children with malignancy showed increased serum concentrations of copper and caeruloplasmin. Both caeruloplasmin-bound and non-caeruloplasmin-bound copper concentrations were elevated. It remains to be determined whether increased 'transcuprein'- and albumin-bound copper result from a sequestering of copper released from peripherally utilized caeruloplasmin, or are associated with increased rates of caeruloplasmin synthesis.

Zinc and copper accumulation and isometallothionein induction in mouse ascites sarcoma S180A cells

To investigate Zn and Cu accumulation and isometallothionein (iso-MT) induction in ascites-sarcoma S180A cells, 5 micrograms of Zn2+ or Cu2+/g body weight was administered to tumour-bearing mice intraperitoneally. In the tumour cells the Zn or Cu concentration increased more than in the host liver, which is the target organ for those metals; the maximum Zn or Cu level was about 2-3 times that in the host liver. The amounts of Zn-MT or Cu-MT accumulated in the tumour cells and host liver were proportional to such dose accumulation levels in the each cytosol; the maximum level of Zn-MT or Cu-MT was 4 or 2 times higher than in the host liver. MT accumulated in the tumour cells showed two subfractions (MT-1 and MT-2); the ratio of Zn (or Cu) bound to MT-1 to that bound to MT-2 in the host liver and tumour cells was 1.0 (or 1.0) and 0.7 (or 0.25) respectively, suggesting that the induction level of MT-2 in the tumour cells is more than that of MT-1. The h.p.l.c. profiles (using an anion-exchange column) of the isolated MT-1 and MT-2 subfractions from Zn-treated normal-mouse liver showed a single peak (MT-1-1) and two peaks (MT-2-1 and MT-2-2) respectively; mouse MTs were separated into three isoforms. In the ascites cells, the MT fraction obtained by a gel filtration was also separated into three isoforms; however, the amount of MT-2-1 isoform was 3 times that in the Zn-treated normal-mouse liver.

Observations of serum trace elements in chronic lymphocytic leukemia

Serum trace elements (STE) were measured in 50 patients with chronic lymphocytic leukemia (CLL) and 100 normal subjects. Copper was higher in patients than in controls (1.50 +/- 0.06 versus 1.10 +/- 0.02 micrograms/ml, P less than 0.001), increased steadily from Stage 0 to Stage 4 (P = 0.002), and correlated with the lymphocyte count and serum lactate dehydrogenase (P less than 0.01) but not with acute phase reactants. Zinc was lower in patients than in controls (0.94 +/- 0.03 versus 1.10 +/- 0.02 micrograms/ml, P less than 0.001). Zinc (NS), selenium (P = 0.039), and calcium (P = 0.033), were decreased in Stages 3-4 as compared to Stages 0-2. The copper-to-zinc ratio (CZR) increased continuously from Stage 0 to Stage 4 (P less than 0.001). Discriminant analysis between two groups, Stage 0-2 and Stage 3-4, based on serum copper, zinc, calcium, and protein levels, allowed for a correct classification of 94% of the patients. Moreover, the clinical staging of the remaining 6% was modified retrospectively according to the results of discriminant analysis. It was concluded that (1) serum copper and CZR are useful indices of the extent of disease, (2) they are independent of a nonspecific acute phase reaction, (3) STE determination could be helpful in the staging of a limited number of CLL patients, and (4) zinc deficiency could contribute to immune dysfunction in CLL.

Serum and tissue copper content in two mammary adenocarcinomas with different biological behaviour

We have determined serum copper levels in BALB/c female mice subcutaneously inoculated with two related mammary adenocarcinoma tumors. Serum copper content increased progressively with tumor size in animals bearing either variant, and reached levels up to four times those of control mice. In contrast, copper levels detected by cytochemistry in tumor cells are higher in the slow growing tumor variant. It is suggested that the stronger angiogenic effect previously described for this variant could be related to its higher cellular copper content.

Copper, zinc and copper/zinc ratio in chronic pancreatitis and pancreatic cancer

Serum copper and zinc levels and their ratio were evaluated in 48 control subjects, 29 patients with pancreatic cancer, 46 with chronic pancreatitis and 32 with extra-pancreatic diseases, with the purpose of ascertaining modifications in chronic pancreatic disease. Hepatic involvement and age were also investigated as possible factors influencing results. Cu/Zn ratio was found to be significantly increased in pancreatic cancer (2.66 +/- 0.16, mean +/- SE) as compared to controls (1.39 +/- 0.06, p less than 0.001), chronic pancreatitis (1.82 +/- 0.09. p less than 0.001) and extra-pancreatic diseases (1.81 +/- 0.18, p less than 0.001), but without practical clinical value. Serum zinc levels appear to decrease with age, while copper and Cu/Zn ratio increase. However, covariance analysis demonstrated that age does not play an important role in influencing copper and Cu/Zn ratio. A decreased liver synthetic function, at least in part age-related, seems to be an additional factor in decreasing serum zinc values.