Myelofibrosis Prognosis and Survival

Management Approach and Challenges

The primary goals of therapy in primary myelofibrosis (MF) include prolongation of survival, and when possible, cure, which may be achieved by allogeneic stem-cell transplantation. Palliation of symptoms and improved quality of life also represent important management goals.1

Clinical challenges in patients with primary MF1:
  • Shortened survival
  • Increased risk of leukemic transformation
  • Severe anemia, often creating the need for frequent red blood cell transfusions
  • Severe constitutional symptoms
  • Marked leukocytosis or thrombocytosis
  • Thrombohemorrhagic complications
  • Marked hepatosplenomegaly often accompanied by related symptoms
  • Nonhepatosplenic extramedullary hematopoiesis that could lead to complications
  • Recurrent gout

Prognosis

Because myelofibrosis has a heterogeneous presentation, determining a patient’s prognosis can be difficult.2 However, progress in understanding the clinical variables associated with MF has led to the development of several prognostic scoring systems.2,3

Prognosis based on risk factors at diagnosis

Early prognostic models, such as the International Prognostic Scoring System (IPSS) developed by the IWG-MRT, estimate prognosis based on risk factors present at diagnosis.3 The IPSS and similar models are therefore appropriate for newly diagnosed cases.1 The 5 adverse prognostic factors included in IPSS are3:

  • Age >65 years
  • Constitutional symptoms
  • Hemoglobin <10 g/dL
  • WBC count >25 × 109/L
  • Blood blasts ≥1%

Patients are assigned into 1 of 4 risk categories based on the number of risk factors present.3

Prognosis based on disease progression

The Dynamic International Prognostic Scoring System (DIPSS), also developed by the IWG-MRT, takes into account progression of disease over time and can be used to evaluate prognosis as a patient’s condition evolves.2

DIPSS uses the same adverse prognostic factors as IPSS but weights them differently. In determining the risk categories, hemoglobin below 10 g/dL is given a score of 2, while the other risk factors are counted as 1.2

IPSS risk and survival3
Risk category
Number of risk factors
Median survival, years
Low
0
11.3
Intermediate-1
1
7.9
Intermediate-2
2
4.0
High
≥3
2.3
DIPSS risk and survival2
Risk category
Number of risk factors
Median survival, years
Low
0
Not Reached
Intermediate-1
1–2
14.2
Intermediate-2
3–4
4
High
5–6
1.5

Survival

MF, similar to other malignancies, is a serious disease.1

Published estimates of median survival in primary MF range from 2.25 to 11.25 years, depending on risk level.3

Cancer 5-Year Overall Survival Rates4a
shows chart of percentage of cancer 5 year survival rate by type of cancer
aFive-year overall survival rates were estimated using SEER data obtained from population-based cancer registries of the US population and SEER Stat Software version 8.3.2. The analysis included patients with initial/primary site diagnosis between years 2007–2011. Overall survival is defined as the time from diagnosis until death from any cause.4,5
Causes of Mortality in PMF
shows pie chart of the percentage of mortality in primary myelofibrosis
CI, confidence interval; PMF, primary myelofibrosis. A study of 1,054 patients with PMF examined the causes of mortality in patients with myelofibrosis. The results are shown in the graph above. The most common cause of death was transformation to acute leukemia.3
References

1. Barbui T, Barosi G, Birgegard G, et al. J Clin Oncol. 2011;29(6):761-770. 2. Passamonti F, Cervantes F, Vannucchi AM, et al. Blood. 2010;115(9):1703-1708. 3. Cervantes F, Dupriez B, Pereira A, et al. Blood. 2009;113(13):2895-2901. 4. Surveillance, Epidemiology, and End Results (SEER) Program (www.seer.cancer.gov) SEER*Stat Database: Incidence - SEER 18 Regs Research Data + Hurricane Katrina Impacted Louisiana Cases, November 2015 Submission (1973-2013 varying) - Linked To County Attributes - Total U.S., 1969-2014 Counties. Accessed January 4, 2017. 5. Howlader N, Noone AM, Krapcho M, et al (eds). SEER Cancer Statistics Review, 1975-2012, National Cancer Institute. Bethesda, MD. Available at: http://seer.cancer.gov/csr/1975_2012/, based on November 2014 SEER data submission, posted to the SEER web site, April 2015. Accessed November 7, 2016.

 
Resources
By: World Health Organization (WHO)
A diagnostic worksheet from the WHO for primary MF, PV, and ET.
By: International Working Group for Myeloproliferative Neoplasms Research and Treatment (IWG-MRT)
Diagnostic criteria from the IWG-MRT.