What is the difference between being unmutated and mutated? When people are discussing treatment, this seems to be very important.

[kathymac52]

I realize I should know the answer, but my husband is 11q deletion. Is that mutated? Is one better than the other? I know my husband is more high risk because of this.

[AussieNeil Partner Administrator]

They are independent prognostic indicators. Reading my answer to this similar recent question should answer much of your question: healthunlocked.com/cllsuppo...

Basically, we have 23 chromosomal pairs (inherited from each of our parents). Chromosomes have short (p region) and long arms (q region). Deleted arms lost in the clonal copying process are described by giving the chromosome number and the p or q arm. Hence 11 q deletion means your husband's CLL cells lack a long arm on chromosome 11.

(Hyper)mutation status is a measure of the maturity of the B-lymphocyte. There are a range of B-lymphocyte blood cancers. The earlier they occur in the B-lymphocyte life cycle, the more acute they are. If CLL develops after the clonal B-lymphocyte has gone through the hypermutation stage so that its B Cell Receptor is specific to a given antigen, then that correlates to a longer time to treatment and a longer remission time after treatment. Those that are (hyper)mutated and treated with FCR can look forward to very long remission times. Conversely, those with unmutated CLL are likely to do better on the new, non-chemo treatments (if they are available to them where they live).

Chromosome deletions can also influence treatment, more so than mutation status. Those with a 17p deletion should not be given chemo based treatments (some of us don't have a choice unfortunately). That's because the 17p arm contains the TP53 gene, termed 'the guardian of the genome'. If CLL cells don't have a functional TP53 gene, then CLL cells damaged by treatment lack the ability to self destruct (apoptosis), so the patient can develop even more aggressive CLL that is harder to treat.

Neil