Chronic Myeloid Leukaemia - From Fatal to Chronic Disease
Major advances in the treatment of chronic myeloid leukaemia (CML) have produced a welcome improvement in its prognosis. CML used to be a universally fatal condition; now, for some patients, it can be considered a chronic illness with little impact on life expectancy. CML has an incidence of one per 100,000 population per year, but with improved treatment enabling longer survival the overall prevalence is increasing.
CML is a blood cancer characterized by abnormal genetic material that can be identified on chromosomes and it is one of the few cancers where the mechanism of genetic abnormality and its effects are well-characterized.
The disease typically goes through a number of phases, starting with the chronic phase. As the number of immature cells increases in the blood, CML starts the accelerated phase and finally enters what is known as blast crisis where there is a large disease burden. At this point, the condition is quickly fatal. Untreated, survival is around four to six years.
Most people with CML present in the chronic phase with non-specific symptoms such as fever, weight loss and general malaise. As the spleen commonly enlarges, the person may feel discomfort in the left upper quadrant of the abdomen. A blood count showing an increase in myeloid cells will usually suggest CML is the cause although a diagnosis is only confirmed with a bone marrow biopsy.
After years of moderate success treating CML with chemotherapy, interferon and bone marrow transplantation, the use of tyrosine kinase inhibitors (TKIs) starting in 2001 represented a major treatment breakthrough. These are small molecules that bind to the protein coded for the abnormal gene and interrupt the uncontrolled cellular growth of the leukaemic cells.
TKI treatment boosted the outlook for people with CML, especially younger patients. One study comparing 2000 with 2005 showed five-year survival rates improved from 72% to 86% in the 15–44 age group and from 38% to 51% in the 65–74 age group.1 This positive story was confirmed by further research that showed people diagnosed with CML lose, on average, fewer than three life-years.2
Advances in survival apply to those who are in the chronic phase; applicants in the accelerated and blast crisis phase have a high mortality rate and cannot be offered terms. Also, information regarding any side effects from medication should be considered because serious conditions – such as pulmonary hypertension – do occur and side effects are a reason to withdraw treatment.
Because of the good response to the new treatments and increasing prevalence, growing numbers of insurance applications can be expected. While survival has improved dramatically, it must be remembered that CML is a serious cancer and applicants need to be carefully assessed. But, on balance, it’s pleasing that many more applicants whose CML has been treated, and who have had a good response, can now be offered life insurance.
- Brunner, A.M., et al. (2013). Trends in all-cause mortality among patients with chronic myeloid leukemia. Cancer, 119 (14), 2620 – 2629.
- Bower, H., et al. (2016). Life expectancy of patients with chronic myeloid leukemia approaches the life expectancy of the general population. Journal of Clinical Oncology, 34 (24), 2851 – 2857.