FISH for del11q and del17p Test Cost & Procedure

A doctor's prescription is required to do CLL FISH PANEL (FISH [del(11q), trisomy 12, del(13q), del(17p)]). Prescriptions do not cover pregnancy, surgery, and international travel cases.

To argue that there shouldn't be a "one size fits all" approach to treating people with chronic lymphocytic leukaemia is a significant understatement.

Prognostic signs can give patients and their clinicians a better understanding of typical outcomes for patients with similar markers in this setting. Some of these, such as ZAP-70 expression or the rearrangement of the immunoglobulin heavy chain gene, you may have read or heard about. 

Describe the FISH test:

Chromosomes are the 23 strands of DNA that make up each of our cells. Each chromosome is present in two copies in each cell, one of which was initially inherited from each parent. These chromosomes change in the cancer cells of many different cancer types. Sometimes entire sections of a chromosome transfer to another, are copied, go missing, or are "deleted" in some other way.

The most frequent chromosomal abnormalities seen in CLL patients are a portion of chromosome 11 (Del11q), an additional copy (Trisomy 12), a portion of chromosome 13 (Del13q), and a portion of chromosome 17 (Del17q) (Del17p). A method of searching for those alterations is the FISH test. FISH, or "Fluorescence In Situ Hybridization," refers to combining fluorescent tags with DNA sequences of interest.

For instance, instead of the expected two signals, if a cell contains Del17p, there is either no signal or only one option visible with that probe.

What makes Del17p so crucial?

• Due to the distinct DNA sequence in that region of the chromosome, each chromosomal mutation has a unique effect.
• A crucial gene that produces the protein p53 is among the DNA deleted in Del17p.
• When a cell notices a small amount of DNA damage, p53 directs it to stop replicating quickly to repair the damage rather than passing it on to its progeny.
• Yet, if the DNA damage is too significant to repair, p53 will orchestrate the cell's death.
• It turns out that p53 is crucial to how well chemotherapy and other cancer treatments work. Numerous of these therapies rely on causing harm that is later recognised by p53, which results in cancer cell death Del 11q

How may these findings be applied clinically?

Given the apparent link between Del17p and resistance to conventional chemotherapy, I believe it is imperative to perform a FISH test (and chromosome analysis) whenever we choose a treatment course. Throughout the illness, Del17p and other chromosomal abnormalities might also manifest. I transmit the FISH test from the blood or bone marrow at every treatment stage since it might not be present or identifiable when someone is first diagnosed but might be later on. Del17p is detected in even a small percentage of cells (>10% is the conventional limit), in which case I advise patients against standard chemo-immunotherapy therapy.

Other critical pathways are suppressed by medications like the B-cell receptor (BCR) antagonists (ibrutinib, acalabrutinib, idelalisib, and others). At the same time, the BCL-2 inhibitor (venetoclax) works around p53 and activates the cell death pathway.