Hi Colin
I understand the confusion. In the first stages, everything's confusing as it's all so new.
Briefly, myeloma is either heavy chain or light chain. If they're talking Bence Jones and kappa/lambda values, then you have light chain. The treatment's the same, but the tests to check on response and progression of the disease are slightly different.
As Gill says above, the best people to ask are your consultant or specialist nurse. I'd say that for any personal medical questions.
Having said that, a huge jump in your light chain numbers is not a good sign, particularly if the ratio between the kappa and lambda values increases. I wrote about my own test results last year here, which may help you understand a bit better: http://jetblackliving.wordpress.com/2011/04/20/good-results/, which includes a link to a booklet that Myeloma UK publish: http://www.myeloma.org.uk/files/4213/4331/5775/Myeloma_UK_Serum_Free_Light_Chain_Infoguide_July_2012.pdf
And a slightly more technical/clarifying update: http://jetblackliving.wordpress.com/2011/04/21/further-clarity-for-the-geeks-out-there/
It's not an easy journey, but it is very interesting and in some ways quite inspiring and liberating, at the times when you're not feeling like s**t.
I wish you well.
Good luck!
Jet
