Predictive value of serum immunosuppressive acidic protein for staging renal cell carcinoma: comparison with other tumour markers

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

Background

Protein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.

Design and methods

The study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.

Results

The methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.

Conclusions

The limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.

Trial registration

Current Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

Serum immunosuppressive acidic protein levels in patients with severe acute pancreatitis

OBJECTIVES

In severe acute pancreatitis (SAP), immunologic impairment in the early phase may be linked to subsequent infectious complications. Immunosuppressive acidic protein (IAP) is an immunosuppressive factor to be present in serum and ascites of cancer patients, and it is used as a tumor marker and an index of immune status of cancer hosts.

METHODS

We measured serum IAP levels in 42 patients with SAP (Japanese severity score [JSS] > or = 2) on admission and analyzed the relationships with disease severity, pancreatic necrosis, blood biochemical parameters on admission, and clinical outcome (infection and death).

RESULTS

Serum IAP level increased 791 +/- 285 microg/mL (range, 159-1430 microg/mL) on admission and recognized abnormal high level (normal range, < 500 microg/mL) in 37 patients (88.1%). Serum IAP level was significantly lower in patients of stages 3 and 4 (JSS > or = 9) (678 +/- 187 microg/mL) than that in patients of stage 2 (2 < or = JSS < or = 8) (848 +/- 311 microg/mL). It was also significantly lower in patients whose Ranson score was 5 or higher (674 +/- 287 microg/mL) than that in patients whose Ranson score was 4 or less (910 +/- 287 microg/mL). Moreover, it was significantly lower in patients with pancreatic necrosis (693 +/- 194 microg/mL) than that in patients without pancreatic necrosis (922 +/- 336 microg/mL). Among the blood biochemical parameters on admission, serum IAP was significantly negatively correlated with hematocrit, serum lipase, and serum interferon gamma and was significantly positively correlated with serum total protein. Serum IAP levels in patients of stage 2 reached higher peak at 7 days after admission and decreased more rapidly than those in patients of stages 3 and 4.

CONCLUSIONS

Serum IAP levels were elevated in patients with SAP but were significantly lower in patients with higher grade of severity or pancreatic necrosis. These results suggest that serum IAP levels may be related to systemic inflammatory response and reflect the immunoresponsiveness in patients with SAP.

A list of candidate cancer biomarkers for targeted proteomics

We have compiled from literature and other sources a list of 1261 proteins believed to be differentially expressed in human cancer. These proteins, only some of which have been detected in plasma to date, represent a population of candidate plasma biomarkers that could be useful in early cancer detection and monitoring given sufficiently sensitive specific assays. We have begun to prioritize these markers for future validation by frequency of literature citations, both total and as a function of time. The candidates include proteins involved in oncogenesis, angiogenesis, development, differentiation, proliferation, apoptosis, hematopoiesis, immune and hormonal responses, cell signaling, nucleotide function, hydrolysis, cellular homing, cell cycle and structure, the acute phase response and hormonal control. Many have been detected in studies of tissue or nuclear components; nevertheless we hypothesize that most if not all should be present in plasma at some level. Of the 1261 candidates only 9 have been approved as "tumor associated antigens" by the FDA. We propose that systematic collection and large-scale validation of candidate biomarkers would fill the gap currently existing between basic research and clinical use of advanced diagnostics.

Immunosuppressive acidic protein detects high nuclear grade localized renal cell carcinoma

OBJECTIVES

To identify a potentially useful preoperative predictor of high nuclear grade renal cell carcinoma (RCC).

METHODS

Our investigation consisted of 181 patients with histologically confirmed clear cell RCC. The positive predictive value, sensitivity, and specificity for detecting nuclear grade RCC were calculated individually for the largest tumor diameter. Hemoglobin, alkaline phosphatase, C-reactive protein, ferritin, and immunosuppressive acidic protein (IAP) levels were also determined in all patients preoperatively.

RESULTS

The distribution of patients by nuclear grade was 74 patients (41%) with grade 1, 75 (41%) with grade 2, and 32 (18%) with grades 3 and 4. With respect to sensitivity, tumor diameter detected 28 (87.5%) of 32 high nuclear grade RCC specimens, and hemoglobin, C-reactive protein, alkaline phosphatase, ferritin, and IAP detected 10 (31.2%), 25 (78.1%), 8 (25.0%), 16 (50%), and 27 (84.3%) of 32, respectively. Multiple logistic regression analysis showed that a higher than normal C-reactive protein and IAP was associated with a 252% and 405% increase in the odds of a high nuclear grade, respectively. In the Stage T1 cases, elevated IAP was also associated with a 989% increase in the odds of a high nuclear grade.

CONCLUSIONS

IAP level may be a useful predictor for detecting high nuclear grade localized RCC preoperatively.

Long-term outcome of postoperative interferon-alpha adjuvant therapy for non-metastatic renal cell carcinoma

AIM

To investigate the long-term efficacy of postoperative interferon-alpha (IFN-alpha) adjuvant therapy in preventing recurrence in non-metastatic renal cell carcinoma treated with radical nephrectomy and to identify related prognostic markers.

METHODS

Long-term follow-up was conducted to study rates of survival and non-recurrence in 88 subjects following radical nephrectomy for non-metastatic disease.

RESULTS

The overall survival rate was 90% at 5 years and 88% at 10, with corresponding non-recurrence rates of 81% and 74%. Survival rates reviewed by preadministration pT stage showed a falling tendency from T1 through to T3 in line with pathological progression; when cases at stage pT1b or below were compared with those at stage pT2 or above, the latter showed a tendency to lower survival rates (P = 0.0966, Breslow-Gehan-Wilcoxon). Similarly, non-recurrence rates tended to fall in line with pathological progression, with a significant difference found in the comparison of cases at stage pT1b or below with those at stage pT2 or above (P = 0.0265, log-rank, Mantel-Cox). Duration of IFN-alpha administration showed a tendency to positive correlation with long-term survival (P = 0.3765, Breslow-Gehan-Wilcoxon). Non-recurrence rate was not found to differ according to duration of administration. Comparison of groups with normal and abnormal preadministration immunosuppressive acidic protein values showed that the normal group tended to have higher rates of survival and non-recurrence (P = 0.3371, Breslow-Gehan-Wilcoxon).

CONCLUSIONS

Immunosuppressive acidic protein values appear to be a useful predictive marker for recurrence. A randomized trial, examining long-term outcome according to tumor stage and variables such as duration of administration, dose, administration time, and dosing schedule is required.

Relationship between serum ferritin levels and tumour status in patients with renal cell carcinoma

OBJECTIVE

To assess the relationship between serum ferritin levels (a useful marker for diagnosing and staging renal cell carcinoma, RCC) and tumour status in RCC of <or=7 cm diameter.

PATIENTS AND METHODS

Serum ferritin levels were measured using an enzyme immunoassay in 101 patients before treatment for RCC. The largest diameter of the primary tumour was measured in the pathological specimens. The correlation between serum ferritin levels and histopathological status was assessed retrospectively in all patients, and separately in the 67 patients with tumours of <or=7 cm diameter.

RESULTS

For the whole group, lymph node metastasis, distant metastasis, extracapsular invasion, vascular invasion and nuclear grade were significantly different (P < 0.001) between patients with normal and those with elevated ferritin levels. However, in patients with tumours of <or=7 cm, only the presence of distant metastasis was significantly different (P < 0.001) between the groups.

CONCLUSIONS

Elevated serum ferritin levels in patients with RCC of <or=7 cm may suggest the presence of distant metastasis.

Significant prognostic factors for 5-year survival after curative resection of renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) patients occasionally die of RCC even after curative resection. In this study, we investigated prognostic factors between survivors for more than 5 years and patients who died within 5 years after curative resection.

METHODS

We retrospectively studied 111 patients who underwent RCC curative resection and were followed for more than 5 years. Patient survival at 5 years after curative resection was regarded as the end-point of this analysis. Statistical differences of 19 prognostic factors between surviving and deceased patients were determined using logistic regression analysis.

RESULTS

Eighteen of the 111 patients died of RCC during the 5-year follow-up period. Of the 19 prognostic factors evaluated, univariate analysis showed significant differences in the body temperature, hemoglobin, erythrocyte sedimentation rate (ESR), alpha2-globulin, C-reactive protein (CRP), fibrinogen, tumor size, Robson's stage, T classification (renal capsular involvement), pathological grade, and mode of tumor infiltration. Five significant variables (body temperature, ESR, alpha2-globulin, fibrinogen, and tumor size) were excluded from multivariate analysis because greater than 10% of the data was missing. The TNM staging system was selected as the representative variable for stage for multivariate analysis. Using the remaining 5 significant variables (hemoglobin, CRP, T stage, pathological grade, and mode of tumor infiltration), multivariate analysis showed that CRP (P = 0.0126) and T stage (P = 0.0490) were the most important prognostic factors.

CONCLUSION

From this analysis, CRP and renal capsular involvement were the most important factors predicting survival for greater than 5 years after curative resection of RCC.