[The relationship between symptom burden and hematologic responses after treatment with interferon/hydroxyurea in...

Objective: To explore the relationship between symptom burden and hematologic responses after treatment with interferon and/or hydroxyurea in patients with polycythemia vera (PV) . Methods: Hematologic responses after continuous treatment with interferon and/or hydroxyurea for six months were evaluated in 190 patients with PV using the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-10 score) . In all patients, the PV diagnosis was based on the 2016 World Health Organization diagnostic definitions. Results: The study cohort comprised 93 (48.9% ) male and 97 (51.1% ) female patients. The median age at the time of MPN-10 assessment was 60 (32-82) years. The median MPN-10 score of the entire cohort was 9 (range, 0-67) . The median MPN-10 score of patients treated with interferon plus hydroxyurea (n=27) was 11 (0-67) , which was significantly higher than those of patients treated with interferon only (n=64) (6[0-56], P=0.019) or hydroxyurea only (n=99) (9[0-64], P=0.047) , whereas the median MPN-10 score was not significantly different between those treated with interferon only and hydroxyurea only (P=0.421) . The rate of severe symptom burden (i.e., any single symptom burden score ≥ 7 and/or total score ≥ 44) was 28.9% (55/190) in the entire cohort, whereas the rate of severe symptom burden was not significantly different among the interferon only (23.4% ) , hydroxyurea only (29.3% ) , and interferon plus hydroxyurea (40.7% ) groups (P>0.05 for all two-group comparisons) . When evaluating MPN-10 score, 37.4% (71/190) of the patients achieved complete hematologic remission (CHR) . Only 28.9% (55/190) patients had adequate disease control, defined as CHR without severe symptom burden. Reasons for inadequate disease control were evaluating blood counts alone, severe symptom burden alone, and evaluating blood counts accompanied with severe symptom burden in 42.1% (80/190) , 8.4% (16/190) , and 20.5% (39/190) of the patients, respectively. Compared to the patients with a platelet count ≤ 400×10(9)/L, those with a platelet count > 400×10(9)/L had a significantly higher rate of severe symptom burden (40.8% [20/49] vs 24.8% [35/141], P=0.044) and a higher median MPN-10 score (14[0-67] vs 7[0-56], P=0.038) . Platelet count > 400×10(9)/L was associated with an increased risk of severe symptom burden (hazard ratio, 2.089; 95% confidence interval, 1.052-4.147, P=0.035) . Conclusions: Symptoms related to disease after treatment with interferon and/or hydroxyurea were rather universal in patients with PV. Some patients still experienced severe symptom burden despite achieving CHR. Platelet count > 400×10(9)/L was associated with an increased risk of severe symptom burden in patients with PV treated with interferon and/or hydroxyurea.