Changes in serum acute phase proteins in ovarian cancer patients receiving cis-diamminedichloroplatinum (CDDP) infusion therapy

ProApolipoprotein A1: a serum marker of brain metastases in lung cancer patients

BACKGROUND

Central nervous system (CNS) diagnostics is a promising tool for detection of neurological disorders, including brain metastases. One of the earliest applications of CNS diagnostics was based on serum markers of blood-brain barrier (BBB) dysfunction, which often correlates with acute, chronic, or incipient brain disease. In the case of brain metastases, serum levels of S100beta demonstrated a good negative predictive value comparable to radiologic investigations. However, a confounding factor was the presence of BBB changes due to cerebrovascular disease.

METHODS

Of 103 patients enrolled in a lung cancer study, greater than 50% presented with magnetic resonance imaging (MRI) changes consistent with chronic cerebrovascular disease and reflected by elevated serum S100beta. To unveil serum protein, the authors used proteomic techniques that allow discrimination between patients with brain metastases and lung cancer patients affected by cerebrovascular ischemic changes without infiltrating tumor.

RESULTS

ProApolipoprotein A1, transferrin, haptoglobin, and transthyretin were upregulated in patients affected by chronic cerebrovascular disease and brain metastases compared with those affected only by vascular diseases. ProApolipoprotein A1 was significantly increased (p<.05) in patients with CNS disease.

CONCLUSIONS

In conclusion, these data support the use of serum markers for the early detection of brain metastases. ProApolipoprotein A1 may be used in conjunction with S100beta for serum-based, MRI-independent diagnosis of metastatic brain tumors.

Clindamycin-paclitaxel pharmacokinetic interaction in ovarian cancer patients

INTRODUCTION

Plasma protein binding is an important factor for many drugs that can influence the tissue distribution and pharmacokinetics. alpha(1)-acid glycoprotein (AGP) is an acute-phase protein that can increase in plasma of patients with several pathological conditions including cancer. Studies performed in cultured cells indicate that paclitaxel cytotoxicity is reduced by adding AGP and the sensitivity to paclitaxel is restored by displacing its binding to AGP with clindamycin, resulting in an increased paclitaxel cell uptake. The purpose of this study was to evaluate whether clindamycin modifies paclitaxel pharmacokinetics also in cancer patients.

PATIENTS AND METHODS

Sixteen patients with advanced ovarian cancer, previously treated with surgery and chemotherapy were enrolled in this study. A pharmacokinetic study of paclitaxel was performed in the first three cycles of the consolidation therapy (paclitaxel and carboplatin) in each patient. In these cycles paclitaxel was administered alone and with two different doses (600 and 1,200 mg) of concurrent clindamycin. The sequence of the three treatments was randomly assigned in each patient in order to avoid the same order of treatments.

RESULTS

Paclitaxel pharmacokinetics were partly modified by the concurrent administration of clindamycin. C (max) and AUC(0-last) of paclitaxel were significantly higher when the drug was given alone than when it was coadministered with 1,200 mg clindamycin. Moreover, AGP concentrations seem to have a small but statistically significant influence on paclitaxel pharmacokinetic, since AUC(0-last) showed a positive significant correlation with AGP plasma concentration when paclitaxel was given alone. The linear relation was lost when paclitaxel was coadministered with 1,200 mg clindamycin. Toxicity was not influenced by the coadministration of clindamycin.

CONCLUSION

The hypothesis that clindamycin could affect paclitaxel pharmacokinetics seems to be verified with this study. Nevertheless, changes induced by giving the combination of the two drugs are minimal and thus of questionable clinical relevance.

Mass spectrometry as a diagnostic and a cancer biomarker discovery tool: opportunities and potential limitations

Serum proteomic profiling, by using surfaced-enhanced laser desorption/ionization-time-of-flight mass spectrometry, is one of the most promising new approaches for cancer diagnostics. Exceptional sensitivities and specificities have been reported for some cancer types such as prostate, ovarian, breast, and bladder cancers. These sensitivities/specificities are far superior to those obtained by using classical cancer biomarkers. In this review, I concentrate more on questions that cast doubt on the results reported and propose experiments to investigate these questions in detail, before the technique is used at the clinic. It is clear that the method needs to be externally and thoroughly validated before clinical implementation is warranted.

Genetic study of orosomucoid by isoelectric focusing and immunoprinting in patients with carcinoma

The carbohydrate moiety of the orosomucoid (ORM) molecule shows microheterogeneity [1] and the pteridine-containing variant seems to be tumor-specific [2-4]. However, there also exists a genetic (protein-related) polymorphism coded by the ORM1 and ORM2 loci on chromosome 9 [5, 6]. To investigate the relationship between ORM1 gene products and the development of carcinoma, we analyzed the ORM1 phenotypes of desialated sera from 125 patients with carcinoma. The allele frequencies were estimated for ORM1*F1 0.556, ORM1*F2 0.012 and ORM1*S 0.432. In comparison to healthy individuals from the same geographical area [6] the ORM1 S phenotypes are significantly more frequent in carcinoma patients. The patients' sera frequently showed additional ORM-positive proteins which focused slightly cathodically to the ORM 2 A band. These proteins may represent posttranslational modifications of the ORM1*S allele product. Whether these modifications are tumor-specific and related to the carbohydrate moiety of the molecule must be confirmed in further studies.

Serum alpha 1-acid glycoprotein in epithelial ovarian cancer

Fifty-six patients with ovarian adenocarcinoma receiving chemotherapy were monitored with serum alpha 1-acid glycoprotein (AGP) levels. The mean and standard deviation of serum AGP levels for 63 healthy controls were 0.88 +/- 0.469 mg/ml. A serum level above 1.80 mg/ml was considered as above normal level. Five patients had evidence of persistent ovarian carcinoma and had elevated AGP levels. Sixteen patients had normal serum AGP levels and had no evidence of persistent ovarian cancer at second-look laparotomy. However, 35 patients had false-negative AGP levels at the time they had persistent tumor. Although the specificity of the AGP level was 100%, the sensitivity was only 12.5% and the overall accuracy 37%. Therefore, it would appear that serum AGP levels are not of value in monitoring patients with ovarian adenocarcinoma.

Acute phase glycoproteins in sera of patients with sarcomas receiving methotrexate infusion therapy

The serum concentrations of alpha-1-acid glycoprotein, haptoglobin and alpha-1-antitrypsin have been estimated serially in eight patients with malignant tumours of bone and soft tissue, who received a total of thirty-four intravenous infusions of high-dose methotrexate. The serum glycoprotein levels taken before the first drug exposure did not relate with the prognosis of these patients. A tumour mass (40 mm) did not influence the serum levels of these glycoproteins. The presence of a pleural effusion was associated with increased serum levels of these glycoproteins. These assays appear to be of no value in monitoring the course of the disease in this group of cancer patients.