[Billy1]

Plasma cell labeling index

by Billy1 on Wed Feb 01, 2012 2:05 pm

Why is the plasma cell labeling index (PCLI) not used often at the major cancer centers for possible risk of progression in MGUS and smoldering multiple myeloma? The Mayo Clinic has published some papers on the use of PCLI for smoldering myeloma patients and offers it as a adjunct test. ASCO published a paper titled "Incorporation of the plasma cell labeling index into the International Staging System of Multiple Myeloma" at the 2008 annual meeting. Apparently nothing has ever come of this. Some independent laboratories offer this test . An example: Quest Diagnostics test no.
17849X.

Apparently this test evaluates PC's by a flow cytometry process while at the the same time determining the FLC population. A PCLI no.is assigned which gives risk stratification for progression to multiple myeloma and OS. A percentage number greater than 1 is of a higher risk for progression and overall survival.

Why is this test not used more often? Is it because of cost or lack of accuracy, or does the medical community not feel comfortable releasing this information to patients? What is the confidence level of the multiple myeloma experts at the major cancer centers of this protocol, and, finally has anyone ever had this test?

Regards from the west coast:

Billy1

[suzierose]

Re: Plasma cell labeling index

by suzierose on Wed Feb 01, 2012 8:24 pm

Hi Billy,

I suspect that the reason is PCL's require bone marrow biopsies. That is very uncomfortable and at the moment they have found that FLC assays provide better accuracy sooner and only requires a blood sample vs. a bone marrow aspiration.

Also FLC have a greater sensitivity than even M spike, which detect at the 1 mg level vs. the 1,000 mg minimum for the M spike. So progress shows far sooner.

Just a guess.

[Dr. Edward Libby]

Re: Plasma cell labeling Index

by Dr. Edward Libby on Wed Feb 01, 2012 9:57 pm

Hello from sunny (at least today) Seattle,

I think that most, if not all, myeloma investigators agree that the PCLI has value, but it does not replace other available testing and the results do not generally change management. This is especially true now that routine cytogenetics allow doctors to risk stratify patients easily. Costs and ease of testing as well as reproducibility are important as well.