Abstract 2845

Background:

The MPNs are a family of chronic hematologic malignancies that typically affect pts ages 60–70s. However, there is growing awareness of hematologic malignancies developing in young pts, particularly a unique subset of pts known as AYAs. Little is known about incidence and outcomes of AYA pts with MPNs.

Objectives:

To determine the incidence and outcomes of MPN AYA pts.

Results:

We retrospectively reviewed charts of 1,616 MPN pts evaluated at our institution from 1986–2011. A total of 171 MPN pts (11%) were identified whose ages were 16–39, defined as AYA pts (per NCCN guideline recommendations on AYA cancers). Breakdown by MPN subtype: Essential Thrombocytosis, ET (n=78, 46% of AYA MPNs), Polycythemia Vera, PV (n=25, 15%), Myelofibrosis, MF(n=24, 14%), [3 post-ET, 1 post-PV, 20 primary MF], Hypereosinophilic syndrome, HES (n=22, 13%), and Systemic Mastocytosis, SM (n=22, 13%). Baseline characteristics of AYA MPN pts detailed in Table 1. Only significant difference among AYA and non-AYA pts in terms of baseline CBC parameters was WBC: 6.4 (0.4–108.4) in AYA MF vs 10.1 (0.6–361) in non-AYA MF, p=0.0049. Analysis of median overall survival (OS), by Kaplan-Meier method, compared by age group (AYA vs non-AYA pts) and broken down by MPN subtype, shown in Table 2.

Table 1.

Baseline Pt Characteristics in MPN AYA pts (n=171)

MPN# AYA# female (%)# JAK2 mutated# Received SCT# TransformationBaseline Median lab values (range)
WBC (K/uL)Hb (g/dL)Plt (K/uL)PB blasts%BM blasts%
ET 78 56 (72) 19 0 1 8.3 (3.4–21.9) 13.4 (10.4–16.8) 801 (163–6512) 0 1 
PV 25 13 (52) 13 1 0 9.5 (3.8–29.1) 15.3 (11.8–18.8) 546 (126–1420) 0 1 
MF 24 12 (50) 3 6 0 6.4 (0.4–108.4) 11.8 (7.2–16.4) 278.5 (12–1283) 0 1 
HES 22 5 (23) 0 0 0 12.7 (3.3–80.1) 13.2 (7.1–16.9) 220 (88–412) 0 1 
SM 22 14 (67) 0 2 0 7.0 (4.4–26.7) 13.9 (8.5–15.3) 246 (105–519) 0 1 
MPN# AYA# female (%)# JAK2 mutated# Received SCT# TransformationBaseline Median lab values (range)
WBC (K/uL)Hb (g/dL)Plt (K/uL)PB blasts%BM blasts%
ET 78 56 (72) 19 0 1 8.3 (3.4–21.9) 13.4 (10.4–16.8) 801 (163–6512) 0 1 
PV 25 13 (52) 13 1 0 9.5 (3.8–29.1) 15.3 (11.8–18.8) 546 (126–1420) 0 1 
MF 24 12 (50) 3 6 0 6.4 (0.4–108.4) 11.8 (7.2–16.4) 278.5 (12–1283) 0 1 
HES 22 5 (23) 0 0 0 12.7 (3.3–80.1) 13.2 (7.1–16.9) 220 (88–412) 0 1 
SM 22 14 (67) 0 2 0 7.0 (4.4–26.7) 13.9 (8.5–15.3) 246 (105–519) 0 1 
View Large
Table 2.

Overall Survival (OS) at 5-yrs and 10-yrs by Age Comparison (n=1,616 MPN pts)

ET# of pts5-yr med OS %10-yr med OS %p-value
    AYA 78 98 92 0.026 
    Non-AYA 203 84 69  
PV     
    AYA 25 100 100 0.016 
    Non-AYA 182 82 55  
MF     
    AYA 24 73 73 0.004 
    Non-AYA 898 37 18  
HES     
    AYA 22 64 64 NS 
    Non-AYA 60 N/A N/A  
SM     
    AYA 22 90 90 NS 
    Non-AYA 102 64 N/A  
ET# of pts5-yr med OS %10-yr med OS %p-value
    AYA 78 98 92 0.026 
    Non-AYA 203 84 69  
PV     
    AYA 25 100 100 0.016 
    Non-AYA 182 82 55  
MF     
    AYA 24 73 73 0.004 
    Non-AYA 898 37 18  
HES     
    AYA 22 64 64 NS 
    Non-AYA 60 N/A N/A  
SM     
    AYA 22 90 90 NS 
    Non-AYA 102 64 N/A  
View Large
Conclusion:

MPN AYA pts constitute 11% of MPN pts at our institution. Overall, their 5- and 10- yr OS were significantly better than their older counterparts in the 3 major MPN subtypes (ET, PV, MF) and trended towards better survival but not statistically significant in HES and SM. Among AYA MPN pts, female predominance was noted among ET and SM pts and only 1 transformation event was noted among all MPN AYA pts in this analysis.

Disclosures:

No relevant conflicts of interest to declare.

Topics:
adolescent, brachial plexus neuritis, cancer, complete blood count, disseminated eosinophilic collagen disease, hematologic neoplasms, kaplan-meier survival curve, mastocytosis, systemic, myelofibrosis, myeloproliferative disease

Author notes

*

Asterisk with author names denotes non-ASH members.

© 2012 by The American Society of Hematology
2012
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