Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Circulating biomarker”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Circulating biomarkers for lung cancer.

Ideal characteristics of tumor markers and their role in clinical practice are discussed. Measuring markers in screening programs resulted inefficient, while the pathological elevation of one or more markers may be virtually diagnostic of lung cancer in appropriate clinical setting. The elevation of CEA, NSE, TPA and other presented, appears particularly useful in the evaluation of the extent of disease, and may correlate with prognosis, as well as in postsurgical follow-up and monitoring therapy.

Biomarkers, Tumor↗

[Circulating proteinic biomarkers and breast cancer].

Circulating proteinic biomarkers are secreted by tumor cells or by their environmental cells and they have a variable specificity. In case of breast cancer, carcino-embryonic antigen (CEA) was for a long time the only circulating biomarker used. Nowadays, the most useful biomarkers measure circulating levels of fragments of MUC1-polymorphic epithelial mucin (MUC1-PEM): cancer antigen (CA) 15.3, mucin-like carcinoma-associated antigen (MCA), CA 27-29, CA 549... They are useful for general disease follow-up. Other circulating markers belonging to keratins (tissue polypeptide antigen, TPA, TPS or Cyfra 21.1) are correlated with proliferative activity of breast tumors. More recently, the measure of the c-erb B2 circulating part (extra cellular domain, ECD) was proposed as a prognostic biomarker for breast tumors with c-erb B2 overexpression. Moreover, the determination of urinary level of trefoil factor1 (PS2-TFF1) might be useful for the follow-up of hormonodependent breast cancers. The present review describes the clinical interest of these different circulating biomarkers in case of breast cancer, emphasizing their biological characteristics.

Antigens, Neoplasm↗

Translational Gap in Biomarker Discovery: Tumor Surface Markers Rarely Mirror Circulating Levels.

BACKGROUND: Tumor-associated cell surface proteins are frequently proposed as circulating biomarkers for colorectal cancer (CRC) based on their high tumor expression. However, many candidates identified through tissue-based analyses fail to translate into clinically useful biomarkers. We investigated the translational gap between tissue-level expression and circulating detectability in CRC, focusing on molecular subtypes defined by caudal-type homeobox 2 (CDX2) expression. METHODS: Transcriptomic data from The Cancer Genome Atlas (TCGA) were analyzed to identify cell surface markers differentially expressed between CDX2-Low and CDX2-High CRCs. A clinical cohort of right-sided CRC patients was evaluated using paired tumor tissue and preoperative plasma samples. CDX2 expression was assessed by immunohistochemistry, and circulating concentrations of selected cell surface proteins were quantified using a multiplex ELISA platform. RESULTS: Several tumor-associated cell surface markers exhibited marked CDX2-dependent differences in tissue expression. However, for most markers, circulating plasma levels did not mirror tissue-level patterns. CEACAM1 was the sole marker demonstrating concordant CDX2-dependent differences in both tumor tissue and plasma, with significantly lower levels in CDX2-Low CRCs. In contrast, CEACAM5 showed a dissociation between tissue expression and circulating levels, despite analytical validation against serum carcinoembryonic antigen (CEA). CONCLUSIONS: Our findings demonstrate that tumor overexpression of cell surface markers does not necessarily translate into detectable circulating biomarkers. This translational disconnect underscores limitations of biomarker selection strategies based solely on tissue expression and highlights the importance of integrating systemic biology into biomarker development. While some tumor-associated proteins may lack utility as circulating biomarkers, they may still represent viable therapeutic targets in CRC.

CDX2↗

A systematic review of the effect of the Excebrane dialyser on biomarkers of lipid peroxidation.

BACKGROUND: Oxidative stress is prevalent in dialysis patients and has been implicated in the pathogenesis of cardiovascular disease and anaemia. We conducted a systematic review and meta-analysis to examine the effect of Excebrane, a vitamin E-coated cellulose-based dialyser, on circulating biomarkers of lipid peroxidation, as surrogate markers of oxidative stress. METHODS: The primary sources used to identify candidate studies included PubMed, the Cochrane Central Register of Controlled Trials, a bibliography provided by the dialyser manufacturer, and a manual search of abstracts from proceedings of scientific meetings and review articles. Studies were selected for analysis if their design included a comparator group (primarily within patient comparison, i.e. pre- and post-study evaluations). For the meta-analysis, we computed the overall change of the outcome from baseline using a random-effects model. A supplemental analysis was performed in which the absolute levels of these biomarkers of lipid peroxidation were converted to a common unit by calculating standardized effect sizes. RESULTS: Fourteen peer-reviewed articles met the criteria. The studies consisted of 11 single arm, one randomized crossover and two randomized controlled trials, with a total of 37 to 158 evaluable patients, according to the outcome of interest analysed. Due to the paucity of randomized trials, the meta-analysis was limited to the Excebrane arm of each study. When the studies were combined according to similar measurement units, the overall mean decrease in malondialdehyde (MDA) level was -0.3 mM (95% CI, -0.5 to -0.1 mM; seven studies) and -0.8 nmol/mg low-density lipoprotein (LDL) (95% CI, -1.3 to -0.4 nmol/mg LDL; three studies), respectively. The summary estimate revealed a non-significant decrease in pre-dialysis thiobarbituric acid reactive substances (TBARS) level of 0.4 microM (95% CI, -1.2 to 0.4 microM; three studies). When the MDA and TBARS studies were combined using the standardized effect size, the mean decrease in these biomarkers of lipid peroxidation was statistically significant at -1.7 units (95% CI, -2.7, -0.7 units; 13 studies). A meta-analysis on the effect of Excebrane on pre-dialysis levels of oxidized-LDL could not be performed due to study heterogeneity. CONCLUSION: The conversion of dialysis patients to a vitamin E-coated dialyser is associated with an improvement in circulating biomarkers of lipid peroxidation, which is of potential clinical benefit.

Antioxidants↗

Predictive biomarkers in cancer immunotherapy for genitourinary malignancies.

Immunotherapy has transformed the management of genitourinary cancers, offering durable responses in selected patient groups. However, the clinical benefit of immune checkpoint inhibitors varies significantly across renal cell carcinoma, urothelial carcinoma, and prostate cancer, underscoring the need for reliable predictive biomarkers. This review summarizes current knowledge on established and emerging biomarkers, including PD L1 expression, tumor mutational burden, molecular subtypes, genomic alterations, tumor microenvironment characteristics, circulating biomarkers, microbiome influences, and multi omic integrative approaches. We discuss their potential clinical relevance, limitations, and applicability across different tumor types. Future directions emphasize the development of composite biomarkers, standardization of testing platforms, real time monitoring strategies, and the integration of advanced technologies such as artificial intelligence and spatial profiling. Understanding and validating these biomarkers will be essential for optimizing personalized immunotherapy in genitourinary cancers.

Circulating tumor DNA↗

Cyclin-dependent kinase 4 and 6 inhibitors and the breast cancer immune ecosystem: immune remodeling, resistance, and therapeutic reprogramming.

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6 inhibitors) combined with endocrine therapy have become a therapeutic backbone for hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer, yet durable disease control is frequently limited by intrinsic and acquired resistance. Canonical tumor-cell mechanisms, including retinoblastoma-pathway escape, cyclin E-cyclin-dependent kinase 2 (CDK2) activation, endocrine adaptation, and phosphoinositide 3-kinase (PI3K)-AKT-mechanistic target of rapamycin (mTOR) signaling, explain only part of this failure because they do not fully capture dynamic immune and stromal remodeling. Preclinical and translational studies indicate that early CDK4/6 inhibition can enhance antigen presentation, activate interferon-related programs, restrain regulatory T cells, and promote a T-cell-inflamed state. These effects are conditional and may not persist during prolonged treatment. Sustained therapy can instead drive heterogeneous resistant niches characterized by stromal remodeling, myeloid recruitment, checkpoint adaptation, and T-cell dysfunction. This immune-state dependence provides a rationale for immune checkpoint blockade, although clinical combinations have shown mixed efficacy and clinically relevant hepatic, pulmonary, and hematologic toxicities. Sequential or lead-in strategies therefore warrant prospective evaluation. Oxidative phosphorylation (OXPHOS) and redox adaptation may sustain selected resistant states and expose context-dependent ferroptotic vulnerabilities. Ferroptosis may connect tumor-cell killing with immune regulation, whereas nanomedicine may improve tumor-selective delivery. Both strategies remain largely preclinical and require further evaluation of pharmacokinetics, biodistribution, toxicity, manufacturability, and immune-cell safety. This Review distinguishes intrinsic from acquired resistance across interpatient, intratumoral, spatial, and temporal dimensions. It integrates tumor-cell escape with cytokine, immune, stromal, vascular, and metabolic remodeling and summarizes emerging therapeutic strategies. We further propose a candidate biomarker-informed framework that integrates genomic profiling, spatial immune architecture, circulating biomarkers, T-cell receptor (TCR) dynamics, transcriptomic and single-cell analyses, artificial intelligence (AI)-assisted multimodal integration, and longitudinal sampling. This framework is intended to support biomarker development and prospective trial design rather than current clinical decision-making, providing a translational basis for testing state-informed and sequence-aware therapeutic strategies.

Humans↗

Progression of airway dysplasia and C-reactive protein in smokers at high risk of lung cancer.

RATIONALE: Chronic inflammation has been implicated in the development of airway dysplasia and lung cancer. It is unclear whether circulating biomarkers of inflammation could be used to predict progression of airway dysplasia. OBJECTIVE: We determined whether circulating levels of C-reactive protein (CRP) or other inflammatory biomarkers could predict progression of bronchial dysplasia in smokers over 6 mo. METHODS: The plasma levels of CRP, interleukins 6 and 8, and monocyte chemoattractant protein 1 were measured at baseline in 65 ex- and current smokers who had at least one site of bronchial dysplasia > 1.2 mm in size. Additional bronchial biopsies were taken after 6 mo from the same sites where dysplastic lesions were discovered at baseline. Progressive dysplastic lesions were defined as worsening of the dysplastic lesion by at least two grades or development of new dysplastic lesions. RESULTS: Half of the participants developed progressive dysplastic lesions after 6 mo. The baseline CRP levels in these participants were 64% higher than those without progressive disease (p = 0.027). Only one of eight (13%) participants with CRP < or = 0.5 mg/L developed progressive disease, whereas 31 of 57 (54%) participants with CRP > 0.5 mg/L developed progressive disease (p = 0.011). The odds of developing progressive disease were 9.6-fold higher in the latter than in the former group. CONCLUSION: Plasma CRP, in concert with lung function and pack-years of smoking, appears to have excellent predictive powers in identifying participants with bronchial dyplastic lesions whose lesions progress to more advanced stages of dysplasia.

Biomarkers↗

Microvascular damage in systemic sclerosis: detection and monitoring with biomarkers.

Vascular disease is universal in patients with systemic sclerosis (SSc), but there is a wide variability in its severity. It is clear that there is an early insult to the microvasculature, followed-up by on-going chronic process. This results in profound vascular damage in a subset of patients who develop severe events such as digital loss and pulmonary arterial hypertension. Although there is abundant evidence of vascular perturbation from studies of peripheral blood in SSc, there are few data about the ability to use these biomarkers to predict vascular outcomes. This paper examines the possibility of using circulating biomarkers to assess vascular disease activity and to predict severe vascular events among patients with SSc.

Biomarkers↗

Early positive biomarker in relation to myocardial necrosis and impaired fatty acid metabolism in patients presenting with acute chest pain at an emergency room.

BACKGROUND: Measurement of circulating biomarkers has enabled early diagnosis and risk assessment of acute coronary syndrome. This study sought diagnostic values of the first single-point data of biomarkers obtained soon after patient arrival by comparing with scintigraphically quantified myocardial injury in patients presenting with acute chest pain at an emergency room. METHODS AND RESULTS: Serial blood samples were taken soon after arrival in an emergency department in 74 patients with suspected acute coronary syndrome to quantify blood levels of troponin-T (TnT), heart-type fatty acid-binding protein (H-FABP), myocardial-bound creatine kinase (CK-MB), and myoglobin. Myocardial perfusion and metabolic defects were scintigraphically quantified. The first single-point data had high positive predictive values for detecting the defects (80-100%) but low negative predictive values (15-41%). CK-MB and TnT had higher specificities (73-100%) but significantly lower positive rates (22-27%) than the others (61-68%), resulting in greater sensitivities of H-FABP and myoglobin (75-80%) than those of CK-MB and TnT (29-35%). Among biomarkers, TnT peak concentrations most closely correlated with scintigraphic abnormalities. CONCLUSION: H-FABP can contribute to early detection of myocardial injury and TnT is most likely to correlate with injured myocardial mass. The differential features of biomarkers are complementary in patients with acute chest pain presenting at an emergency room.

Acute Disease↗

Correlation between tamoxifen elimination and biomarker recovery in a primary prevention trial.

We have shown previously that a reduction from the conventional dose of tamoxifen is associated with a comparable modulation of circulating biomarkers, including insulin-like growth factor-I and cholesterol. In the present study, we have correlated serum tamoxifen elimination with biomarker recovery in healthy subjects completing a 5-year intervention period. Tamoxifen, N-desmethyltamoxifen, and biomarker levels were measured at 0 (baseline), 2, 4, and 6 weeks after completion of treatment in 23 healthy postmenopausal women allocated to tamoxifen 20 mg/day and in 6 women allocated to placebo. Mean (+/-SD) serum tamoxifen and N-desmethyltamoxifen concentrations were, respectively, 141 +/- 50 and 226 +/- 77 ng/ml at baseline, 36 +/- 19 and 99 +/- 46 at 2 weeks, 20 +/- 15 and 61 +/- 37 at 4 weeks, and 12 +/- 9 and 36 +/- 26 at 6 weeks. Serum tamoxifen and N-desmethyltamoxifen half-lives were 9 and 13 days, respectively. Body mass index was associated positively with drug's serum half-life. Compared with baseline values, the percentage increase in total cholesterol, low-density lipoprotein cholesterol, and insulin-like growth factor-I 4 weeks after treatment completion was 5, 9, and 14%, respectively. No change during the 6-week period was observed in the placebo arm. Our findings indicate that the biomarker recovery is slower than serum tamoxifen elimination, suggesting that low tamoxifen concentrations may still exert a biological effect. In addition, the prolonged half-life of tamoxifen and metabolite provides the rationale for a weekly administration of the drug in a preventive context. However, the clinical implications of our findings remain to be defined.

Aged↗

Aptamer-Based Platforms for Human Aging Biomarkers: Multiplexed Proteomics, Biosensors and Translational Perspectives.

Aptamer-based multiplexed proteomic platforms, especially the SOMAmer-based SomaScan assay, are widely used for large-scale discovery of circulating biomarkers relevant to human aging. This review summarizes 42 original research articles published from 2020 through 2026 in which aptamers or aptamer-derived biosensors were used to characterize aging-related biomarkers in human samples or clinically relevant human-disease contexts. The eligible literature falls into several thematic areas: whole-plasma and organ-specific proteomic aging clocks; inflammaging and senescence-associated secretory phenotype (SASP) markers; cardiovascular, metabolic, renal, hepatic, musculoskeletal and neurodegenerative biomarker panels; and aptasensor platforms for detection of individual analytes. Only a small number of studies have compared aptamer- and antibody-based platforms in the same specimens; we tabulate these and show that median between-platform agreement is low to moderate, which constrains the pooling of findings across technologies. We also make explicit an interpretive point that is usually left implicit: because proteomic clocks are trained against chronological age, their correlation with chronological age measures fit to the training target rather than biological validity, and the informative quantity is the residual age gap. In the reviewed literature, SomaScan-based studies are concentrated in cardiovascular, neurodegenerative, frailty, and proteomic aging-clock research, whereas de novo SELEX campaigns targeting aging-specific epitopes and longitudinal human validation of wearable aptasensors were not identified. The main barriers to translation are cross-platform discordance, limited replication across ancestries, under-reported pre-analytical variability, cost, and the research-use-only status of most assays.

Humans↗

Novel and potential future biomarkers for assessment of the severity and prognosis of chronic heart failure : a clinical review.

Over the last two decades, the pathophysiology and biomolecular basis of heart failure syndrome has reached sound and more comprehensive understanding. This knowledge has allowed expert researchers and clinicians to explore an entirely new spectrum of potential biochemical markers derived from different cellular and signaling pathways that lead to myocardial hypertrophy, chronic damage of the myocyte, apoptosis, and, ultimately, myocardial remodeling. Indeed, the link between myocardial remodeling and adverse outcomes, as well as the recognition of the myocardial interstitium as a multifunctional dynamic entity strongly influenced by systemic neurohormonal and inflammatory activation, has provided a solid ground for research of biomarkers that might correlate with severity and prognostication in chronic heart failure. This paper reviews and summarize recent literature on some of the most interesting circulating biomarkers with potential use for the stratification of patients with chronic heart failure.

Biomarkers↗

Circulating tissue kallikrein levels correlate with severity of carotid atherosclerosis.

BACKGROUND: Vascular growth factors are upregulated in stroke patients, but it remains unknown if they correlate with carotid atherosclerosis. METHODS AND RESULTS: A case-control study was conducted to determine: (1) possible association between biomarkers of angiogenesis or inflammation and carotid stenosis; and (2) the impact of revascularization on the same biomarkers. Circulating vascular endothelial growth factor (VEGF), basic fibroblast GF (bFGF), tissue kallikrein (tK), and high-sensitivity C-reactive protein (hs-CRP) were measured in 89 patients with carotid obstruction and 45 age-matched controls. Patients were stratified as <50% carotid stenosis (CAS; n=16); 50% to 69% CAS (n=12); 70% to 99% CAS (n=43); and carotid occlusion (CAO; n=18). No association was found between VEGF, bFGF, or hs-CRP and obstruction grading. TK augmented from 360+/-30 in <50% CAS (P=NS versus controls) to 509+/-72 in moderate CAS (P<0.05), 1159+/-178 in high-grade CAS (P<0.02), and 1616+/-403 pg/mL in CAO (P<0.01). A threshold of 508 pg/mL provided the maximized predictive value of high-grade obstruction. After revascularization, tK decreased from 1410+/-352 to 782+/-86 pg/mL (P<0.01), whereas no change was detected in nonoperated cases. Hs-CRP was unaffected by revascularization. CONCLUSIONS: Angiogenic factors are heterogeneously expressed in patients with carotid atherosclerosis. The tK measurement may be useful for the diagnosis and monitoring of atherosclerotic disease.

Adult↗

Endocrine markers of aging.

Sophisticated methods available to quantitate hormone secretion and hormone action provide opportunities to identify potential endocrine biomarkers of aging. However, there are many challenges facing the investigator who wishes to establish an endocrine biomarker. Circulating levels of many hormones fluctuate on a circadian rhythm, and a variety of other short-term fluctuations may occur. Hormone secretion is generally tightly regulated and often affected by multiple, redundant feedback mechanisms. Interpretation of circulating hormone levels must also take into account factors affecting hormone metabolism and degradation which may be influenced by age. The rate of hormone secretion and circulating hormone levels are related to the sensitivity to hormone action by feedback control mechanisms. Thus interpretation of potential circulating endocrine markers of aging must take into account changes in sensitivity to that hormone as well.

Aging↗

Genomic and proteogenomic insights into Spontaneous Coronary Artery Dissection (SCAD): A systematic review of emerging multi-omic evidence.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is a major cause of myocardial infarction in young women without traditional cardiovascular risk factors (Hayes et al., 2018; Adlam et al., 2018 [1, 2]). Despite growing awareness, its biological underpinnings remain incompletely understood, and clinical management is largely based on observational evidence rather than mechanistic insight (Saw et al., 2014; Lettieri et al., 2015; Steg et al., 2024 [3-5]). OBJECTIVES: To systematically integrate genomic, epitranscriptomic, proteomic, and metabolomic data in order to characterize the multi-omic architecture of SCAD and identify potential biomarkers and therapeutic targets. METHODS: A systematic review was conducted in accordance with the PRISMA 2020 statement (Arbelo et al., 2023 [6]). PubMed/MEDLINE was searched for original studies investigating genomic and multi-omic features of SCAD. Data were extracted on study design, patient characteristics, identified variants, circulating biomarkers, and implicated biological pathways. Functional enrichment analysis was performed using the DAVID bioinformatics resource (Page et al., 2021 [7]). RESULTS: A total of 16 studies were included. Genome-wide association studies consistently identified susceptibility loci related to arterial structure and extracellular matrix integrity, including ADAMTSL4, PHACTR1/EDN1, LRP1, and FBN1 (Huang et al., 2009; Saw et al., 2020; Turley et al., 2020 [8-10]). Rare variant analyses further supported the role of genes involved in extracellular matrix remodeling and vascular smooth muscle cell function, including COL3A1, COL4A1/2, SMAD3, and TLN1 (Adlam et al., 2023; Turley et al., 2021, 2019; Carss et al., 2020; Zekavat et al., 2022; Wang et al., 2022 [11-16]), while ancestry-specific signals such as TSR1 variants were observed in distinct populations (Turley et al., 2023 [17]). Proteogenomic approaches linked genetic susceptibility loci to circulating proteins involved in matrix remodeling and inflammation, including cathepsin B and ECM1 (Maioli et al., 2010 [18]). Epitranscriptomic analyses identified differential microRNA expression profiles associated with vascular injury and repair pathways (Sun et al., 2019 [19]). CONCLUSIONS: SCAD is characterized by a complex, multi-layered biological architecture involving genetic susceptibility, extracellular matrix dysregulation, and vascular signaling pathways. Integration of multi-omic data provides novel insights into disease mechanisms and highlights potential biomarkers and targets for precision medicine approaches in SCAD.

Animals↗

Rationale and methods of the integrated biomarker and imaging study (IBIS): combining invasive and non-invasive imaging with biomarkers to detect subclinical atherosclerosis and assess coronary lesion biology.

Death or myocardial infarction, the most serious clinical consequences of atherosclerosis, often result from plaque rupture at non-flow limiting lesions. Current diagnostic imaging with coronary angiography only detects large plaques that already impinge on the lumen and cannot accurately identify those that have a propensity to cause unheralded events. Accurate evaluation of the composition or of the biomechanical characteristics of plaques with invasive or non-invasive methods, alone or in conjunction with assessment of circulating biomarkers, could help identify high-risk patients, thus providing the rationale for aggressive treatments in order to reduce future clinical events. The IBIS (Integrated Biomarker and Imaging Study) study is a prospective, single-center, non-randomized, observational study conducted in Rotterdam. The aim of the IBIS study is to evaluate both invasive (quantitative coronary angiography, intravascular ultrasound (IVUS) and palpography) and non-invasive (multislice spiral computed tomography) imaging techniques to characterize non-flow limiting coronary lesions. In addition, multiple classical and novel biomarkers will be measured and their levels correlated with the results of the different imaging techniques. A minimum of 85 patients up to a maximum of 120 patients will be included. This paper describes the study protocol and methodological solutions that have been devised for the purpose of comparisons among several imaging modalities. It outlines the analyses that will be performed to compare invasive and non-invasive imaging techniques in conjunction with multiple biomarkers to characterize non-flow limiting subclinical coronary lesions.

Adult↗

Quality control for HPLC assay and surrogate end point biomarkers from the fenretinide (4-HPR) breast cancer prevention trial.

The Fenretinide (4-HPR) Breast Cancer Study is a randomized multicenter clinical trial designed to evaluate the effectiveness of the synthetic retinoid 4-HPR, at a dose of 200 mg per os every day for 5 years, in reducing the incidence of contralateral breast cancer in patients previously operated on for T1-T2 N-M0 breast cancer. During the trial, blood samples were collected at baseline and on a yearly basis from most of the patients. Evaluation of drug and retinol concentrations by HPLC assay has been performed for all the samples to obtain 4-HPR pharmacokinetic information as well as information on the effect of 4-HPR in lowering retinol plasma levels. The most important criteria for validation and quality control of the HPLC assay are summarized in order to provide a guide and practical recommendations for analytical procedures to be performed during prevention trials. Studies have been performed on subsets of patients participating in the trial in order to identify circulating biomarkers predictive of breast cancer. Evidence has been obtained on a lowering effect of 4-HPR on biologically active IGF-I only in premenopausal women. This was due to a decrease of IGF-I, associated with a trend to an increase in IGF-I binding protein 3 (IGFBP-3). An interim analysis of the ongoing trial indicates that 4-HPR reduces the incidence of contralateral breast cancer only in premenopausal women. Analyses of total and unbound IGF-I are being performed on plasma samples collected at baseline and during intervention from women < or = 50 years old. The relationship between the incidence of a second breast cancer and the changes in IGF-I plasma levels will be assessed in order to validate IGF-I as a surrogate end point of contralateral breast cancer. The preliminary results of other studies on the effects of 4-HPR on tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), and urokinase plasminogen activator (uk-PA) and on the relevance of circulating p53 antibodies with relapse will be also presented.

Anticarcinogenic Agents↗