Significance of PSA and PAP in patients with or without prostatic cancer

Cerebrospinal Fluid (Vascular Endothelial Growth Factor) and Serologic (Recoverin) Tumor Markers for Malignant Glioma

BACKGROUND

Clinically useful tumor markers have yet to be identified for malignant glioma. We report on two potential novel tumor markers, vascular endothelial growth factor (VEGF) and recoverin (protein A). VEGF is a highly specific endothelial cell activator that induces angiogenesis both in vivo and in vitro. Our study was designed to assess whether VEGF could be measured in the cerebrospinal fluid (CSF) of patients with cerebral neoplasms and used as a marker of particular tumors. We also studied serum recoverin levels in patients with various brain tumors and compared these to controls. Recoverin is a detectable serologic protein that is expressed in patients with cancer-associated retinopathy, a paraneoplastic syndrome.

METHODS

In the VEGF arm, we used a solid-phase ELISA to determine the levels of VEGF. CSF samples from patients with anaplastic astrocytoma and glioblastoma multiforme (GBM) and with metastatic and nonastrocytic brain tumors were compared with nontumor control samples. In our recoverin study, an immunoenzymetric assay was used to measure the serum recoverin levels patients with glioma and compared with controls.

RESULTS

In the VEGF arm, 89% of samples with malignant astrocytoma and 27% of nonastrocytoma samples had detectable levels of VEGF. VEGF was not detectable in normal CSF samples. The levels of VEGF were significantly higher in high-grade astrocytomas than in nonastrocytic tumors. Recoverin levels were 10-fold higher in patients with recurrent GBM relative to controls. In patients with low-grade glioma, anaplastic glioma, and GBM with no evidence of recurrence, a 3- to 5-fold increase was observed.

CONCLUSIONS

VEGF is detectable in CSF and may be a potential marker for differentiating astrocytic from nonastrocytic tumors. Recoverin is detectable in serum and may be a useful glioma tumor marker, especially for recurrent active disease. These markers may have application for tumor diagnosis, surveillance, and treatment response.

Elevated prostate markers in metastatic small cell carcinoma of unknown primary

Numerous ectopic hormones and markers have been described in small cell carcinoma of the lung as well as in extrapulmonary small cell carcinomas. The authors report a case of a patient with metastatic small cell carcinoma of unknown primary who had very high prostatic acid phosphatase (PAP) and prostatic specific antigen (PSA) levels. Results of multiple prostate examinations, as well as blind biopsies, were normal. His course was significantly longer than that of the usual patient with extensive small cell carcinoma. At autopsy the prostate showed only mild benign prostatic hypertrophy. There are no previous reports in the literature of abnormal prostate markers in small cell carcinomas. Physicians should be aware of the increasing complexity and the unusual biologic markers associated with neuroendocrine carcinomas. In some of these cases, the tumors ability to produce an ectopic product may portend an improved prognosis.