looking into CSF level of Ca15-3 to follow intrathecal leptomeningeal tx efficacy

[Lani]

I had been trying to find someone interested in verifying the utility of the serum (now CSF) her2 ECD test in CSF to see if it reliably detected improvement/worsening of her2+ Leptomeningeal involvement.

Here they are looking into CA 15-3 as a CSF biomarker

Rolepaul?

J Neurooncol. 2014 Jan 28. [Epub ahead of print]
CSF CA 15-3 in breast cancer-related leptomeningeal metastases.
Le Rhun E, Kramar A, Salingue S, Girot M, Rodrigues I, Mailliez A, Zairi F, Bakhache E, Robin YM, Taillibert S, Dubois F, Bonneterre J, Chamberlain MC.
Author information

Abstract
The sensitivity of CSF cytology, the standard method for diagnosis of leptomeningeal metastases (LM), is low. Serum cancer antigen 15-3 (CA 15-3) is frequently used for the monitoring of patients with breast cancer (BC) and is a laboratory test available in most centers. The aim of the current study was to determine the feasibility of measuring CSF CA 15-3 and CA 15-3 CSF/serum ratio in patients with BC-related LM. Serum and CSF CA 15-3 values were evaluated in 20 BC patients with LM (Group 1), 20 patients with LM from other primary cancers (Group 2), 20 BC patients with parenchymal brain metastases only (Group 3) and 20 controls (Group 4). CSF and serum were collected on the same day. Serum and CSF CA 15-3 were assessed by an automatized immuno-enzymatic technology (TRACE® technology, KRYPTOR Automate, Brahms Society, France). In univariate analysis, BC patients with LM (Group 1) compared to other groups, a significantly elevated serum CA 15-3 (median 51 U/ml, range 12-2819) and CSF CA 15-3 (median 8.7 U/ml, range 0.1-251) was observed. Additionally, the CSF/serum ratio of CA 15-3 was significantly higher in this group of patients (median 0.18, range 0.002-4.40). Multivariate analysis identified a cut-off for CSF CA15-3 with 80 % sensitivity and 70 % specificity. Conclusions: The current study confirms the feasibility of determining CSF CA 15-3 using a widely available technology. Evaluation of the CSF CA 15-3 may be useful in the diagnosis and management of BC-related LM but further studies are needed.
PMID: 24469852 [PubMed - as supplied by publisher]

[Rolepaul]

Still at Genentech trying to see about Intrathecal Perjeta alternating with Herceptin for CNS involvement. The problem is that implanting an Ommaya reservoir appears to be more risky than I thought. If the surgeon does not perform 3-4 of these placements every two weeks, the risk of compromise of the implant due to contamination or bad placement is pretty high. The good news is that Nina's is still working well. She is still symptom free. We had MRI scan false positives for the past three visits (determination finally made that no growth of lesion and probably late term radiation necrosis) on this last visit.

I asked four labs about the samples and received no response from any. It sounds worthwhile. As CNS involvement becomes more prominent, things seem to be getting a push. Still only about 200-300 women per year are dying of CNS involvement, but the concern is that it will become more frequent if systemic Perjeta/TDM-1 clears the disease in non-CNS locations. I am pushing hard to get an answer for my wife and all others.

Paul