When patients are diagnosed with cancer, their most stressing question is not about how the disease occurred nor even what the best treatment is. It is usually “Is it treatable” or “How much time do I have?” and “How much time will this therapy give me?”. Cancer is as old as humanity itself, and it has always been a disease with a grim outcome. It is even considered a normal cause of death just like heart conditions and strokes. Each year, more than half a million humans die of cancer, making it the 6th commonest cause of death in most countries. Modern medicine has allowed cancer patients to have better outcomes, survive for longer, or even achieve complete remission in some cancers.
Acute myeloid leukemia: the answer is more complex
Cancer is far from being a homogenous disease, and different cancers have different presentations and outcomes. This is not only seen in cancers arising from different tissues, but also in the same cancer arising from the same tissue depending on its biological behavior which, in turn, depends on the following factors:
- The type of genetic mutation present in that cancer.
- Whether targeted therapy has been developed for it.
- Patient-related factors like age and overall health status.
- Whether a vital organ is affected by the cancer or its metastases.
› In acute myeloid leukemia, the most significant factors that affect the outcome are:
- The patient’s age: Older patients tend to have more resistant cancer to chemotherapy as well as a high rate of complications and poor tolerance to such medications. They also tend to have other blood disorders that either led to acute leukemia in the first place or coexist with it, worsening the patient’s general condition.
- Genetics: when you are diagnosed with leukemia, your doctor will usually ask for a bone marrow biopsy which also entails several genetic and cellular analyses. Detection of certain mutations in the genetics of the cancer is crucial to treatment decisions and evaluating the outcome. Some mutations like the TP53 and FLT3 are associated with worse outcomes, while other mutations like t(8;21) and t(15;17) are associated with very good outcomes – the “t” here refers to the translocation of genetic material between two chromosomes whose numbers are mentioned-.
- White blood cells count: White blood cell count is one of the main indicators of survival in acute myeloid leukemia since infection is the commonest cause of death, and its occurrence is directly proportional to the fall of white cell count.
- Initial response to chemotherapy: This is a general theme in blood disorders and cancer. The earlier a patient responds to chemotherapy, the more likely they are to survive on the long term. Response to chemotherapy is assessed by what we call a complete remission, which is the disappearance of all signs of the cancer whether clinical symptoms or lab findings.
How can acute myeloid leukemia kill me?
Acute leukemia mainly affects the bone marrow, causing a severe decrease in the number of its cells. This results in anemia, decreased white blood cell and platelet count. Anemia is usually not severe enough to cause death -although it can occur-, but the main causes of death in AML are:
- Severe overwhelming infections: Decreased white blood cell count leaves the body defenseless against even minor infections. Infection becomes severe enough that bacteria spread freely by the blood and produce their toxins, a condition termed septicemia. Septicemia is evidenced by high sustained fever and an overall deterioration of the general condition. Such toxins affect the heart, kidneys, brain, and gastrointestinal tract. They also produce a severe drop of blood pressure called a septic shock which causes brain death and kidney failure.
- Hemorrhage: The fall of platelet counts impairs our coagulation and causes spontaneous bleeding from all surfaces. When platelet count falls below 20,000 per microliter, spontaneous bleeding can occur into the brain which results in increased intracranial pressure with brain herniation and death. Severe bleeding can also occur from the nose, mouth, and gastrointestinal tract.
What are the odds of survival?
Several factors come into play when estimating a survival period for acute leukemia. Overall, about 20-25 % of people diagnosed with AML survive for more than 5 years. This, however, varies widely depending on age. For instance, patients younger than 20 years old at diagnosis have a 70% 5-year survival rate, but since acute myeloid leukemia affects older people with a higher prevalence, the overall ratio tends to be lower.
Another critical factor is the therapy introduced to the patient. In young patients, the option for stem cell transplantation is viable and can increase survival rate dramatically when done in the first 5 years of the disease. On the other hand, it is usually avoided in patients older than 60 years old since they are likely to develop tissue rejection, which can be fatal. High doses of chemotherapy introduced to younger individuals also increase the chances of a complete remission, while they may be contraindicated in older individuals in whom it can cause a lethal toxic effect.
What do the final stages of acute myeloid leukemia feel like?
The final stage of acute myeloid leukemia is the one that precedes death by a few days to a few weeks. At this stage, the body is frail, and patients are often unable to help themselves eat or take care of their hygiene. Patients have also been regularly receiving blood transfusions to compensate for their extremely deranged bone marrow and severe cellular deficiencies. They are mostly in a hospital setting because of a complication that occurred.
In most cases, the complication that caused their admission is a severe infection or hemorrhage. Severe infections cause an overall sense of weakness, and high fever. Fever can cause delirium and loss of consciousness. The commonest infection in such patients is pneumonia. In such case, patients will spend their final days on a ventilator to support their failing lungs. Hemorrhage, on the other hand, can be sudden and severe that the patient might die before reaching the hospital. If they reach the hospital in time, they are mostly saved unless a severe organ damage occurred from the blood loss. If the brain is that organ, then they may enter a coma, and doctors may consult the family on whether they should disconnect the life support machines.
What is better in leukemia is that there is usually no severe pain as in other cancers that erode nerves and muscles and patients are spared narcotics which come with dose limitations and their own set of side effects. However, in some cases, patients may receive analgesia if they suffered a bone fracture. In elderly patients, doctors will present the option of not going through aggressive chemotherapy and instead depending on palliative care to spare the patient the complications of chemotherapy that are unlikely to result in a satisfactory response. The decision remains in the patient’s hands after all. Patients will be informed of the possibility of an effective palliative care which is designed to decrease their psychological and physical suffering.