Pediatric Chronic myelogenous leukemia

Disease information

Overview
Causes
and Symptoms
Treatment

Overview

Chronic myelogenous leukemia, or CML, is a type of blood cancer that comes on slowly and sticks around for a long time. It starts off when some of the cells that are supposed to grow into white blood cells go off-track. This leads to too many white blood cells being made in the bone marrow, which can cause organs like the liver and spleen to get bigger than normal. In most folks with CML, this is because of a mix-up in the cells' genetic code, specifically something called the Philadelphia chromosome, which causes the cells to multiply more than they should, leading to a high number of white blood cells and platelets. Even though CML likes to take its time, if it doesn't get the attention it needs, it can turn into a more aggressive kind of leukemia. It's pretty rare in kids, making up less than 5% of all leukemia cases in the pediatric crowd.

Causes and Symptoms

CML happens because a piece of one chromosome (number 9) gets stuck onto the end of another chromosome (number 22). This creates what's known as the Philadelphia chromosome. Imagine it like a bad recipe in the body's cookbook, where parts of two different recipes are mistakenly combined to create something harmful. This mix-up brings together the BCR and ABL1 genes to form a new, abnormal gene called BCR-ABL1. The protein this gene makes causes stem cells in the bone marrow to go into overdrive, making blood cells like there's no tomorrow. We're not exactly sure why this gene fusion happens. There are suspicions that things like viruses, radiation, chemicals, or other environmental factors might play a role, but for each person, especially kids, the trigger is a bit of a mystery.

As for symptoms, CML sneaks up on you. It can take months before you notice anything's off. Some kids feel just a bit tired and might be diagnosed by accident when they have a blood test for something else. These are some signs to watch out for:

Feeling worn out, having night sweats, or a fever without a clear reason.
Unexplained weight loss, feeling of fullness, or pain in the upper left side of the belly due to an enlarged spleen.

▲ A symptom of feeling worn out

CML has three stages: chronic, which is the initial slow-moving phase; accelerated, where things start to pick up; and blast crisis, which is an urgent situation where the disease acts like an aggressive acute leukemia. If CML isn't treated, it can move from the chronic phase to the blast crisis, and that's something doctors work hard to prevent.

Treatment

Treating CML really depends on whether the Philadelphia chromosome shows up and how far along the disease is.

Hydroxyurea

Think of this as an old-school pill that doctors might turn to first to get those white blood cells and platelets back in line. It's not the top choice, but it's there when other options aren't on the table.

Targeted anticancer drugs

These are the go-to for kids who've just found out they have CML. They're like guided missiles that zero in on the cancer cells, and they're much friendlier to the body than some of the heavy-duty treatments. Instead of one-size-fits-all, they come in generations—first, second, third, and fourth—each one a little different in how it works and what side effects it might have. But when it comes to kids, doctors have a shorter list of these drugs to choose from. When these medications are on the front line, they usually take the lead over something called hematopoietic stem cell transplantation, which is a bigger, more complex treatment that doctors save for when they really need it.

①
1st generation (Imatinib)
- Gleevec, the pioneer in precision medicine for cancer, has been a game-changer since the FDA gave it the green light in 2001. It's been working wonders for patients by targeting cancer cells without harming the good ones.
②
2nd generation (Nilotinib (Tasigna), Dasatinib (Sprycel), Bosutinib (Bosulif), Radotinib (Supect))
- Our next wave of cancer fighters includes Tasigna, Sprycel, Bosulif, and Supect. These drugs are mighty warriors, picking up the baton from Gleevec and tackling even the tougher cancer cells that didn't respond to the first round of treatment. Over in Korea, doctors are using them as their go-to or backup plan depending on the situation.
③
3rd generation (Ponatinib (Iclusig))
- Then there's Iclusig, our third-gen contender. This one's special because it can take on cancer cells that have learned to dodge other treatments, even those sneaky ones with a specific change called the T315I mutation.
④
4th generation (Asciminib (Scemblix))
- And not to be outdone, we've got Scemblix from the fourth generation. It's like it has a secret handshake with cancer cells that lets it attach in a unique way, showing promising results where others might not.

Allogeneic Hematopoietic Stem Cell Transplantation

When these medications have tried their best but haven't been enough, or if someone's body isn't getting along with them, that's where allogeneic hematopoietic stem cell transplantation comes into play. It's a big name for a big procedure where doctors replace the bad cells with healthy ones. It's a serious step and is especially considered for young warriors battling through the tough stages of their fight, aiming to get them back to a more manageable level of disease.