Validation and reliability of current guidelines for the treatment of essential thrombocythemia under real-world clinical settings in Japan

Figures & data

Table 1. Patient characteristics according to different treatment groups.

	All (n = 199, 100%)	Observation (n = 40, 20.1%)	APT^a alone (n = 39, 19.6%)	CRT^b alone (n = 43, 21.6%)	Combination (n = 77, 38.7%)	P value
Age, median (range), year	60 (8–87)	49 (18–81)	48 (25–81)	65 (8–87)	65 (15–86)	<0.001
Male, n	82 (41.2%)	17 (42.5%)	9 (23.1%)	21 (48.8%)	35 (45.5%)	0.068
Female, n	117 (58.8%)	23 (57.5%)	30 (76.9%)	22 (51.2%)	42 (54.5%)	–
WBC, median (range), ×10^9/L	8.8 (3.2–29.5)	7.9 (4.1–13.8)	8.0 (3.2–15.4)	8.8 (4.3–19.3)	9.0 (4.0–29.5)	0.055
RBC median (range), ×10^4/μL	464 (297–638)	459 (380–521)	456 (368–631)	467 (345–587)	470 (297–638)	0.170
Hb, median (range), ×g/dL	13.6 (9.1–16.9)	13.4 (10.4–15.7)	13.3 (10.8–16.1)	13.8 (9.6–16.9)	13.8 (9.1–16.7)	<0.05
PLT, median (range), ×10^9/L	814 (370–4691)	742 (475–2337)	725 (418–1234)	903 (370–4691)	931 (439–1824)	<0.001
JAK2V617F, n	113 (56.8%)	17 (42.5%)	20 (51.3%)	24 (55.8%)	52 (67.5%)	0.058
CALR exon 9, n	41 (20.6%)	7 (17.5%)	9 (23.1%)	10 (23.3%)	15 (19.5%)	0.817
MPL exon 10, n	12 (6.0%)	3 (7.5%)	2 (5.1%)	4 (9.3%)	3 (3.9%)	0.333
Triple-negative, n	33 (16.6%)	13 (32.5%)	8 (20.5%)	5 (11.6%)	7 (9.1%)	<0.05
History of thrombosis, n	25 (12.6%)	0 (0.0%)	5 (12.8%)	4 (9.3%)	16 (20.8%)	<0.05
Cardiovascular risk factors, n	100 (50.3%)	16 (40.0%)	18 (46.2%)	26 (60.5%)	40 (51.9%)	0.276

Note: APT^a, antiplatelet therapy; CRT^b, cytoreductive therapy.

Table 2. Details of thrombotic events occurring in different treatment groups during the follow-up period.

	All (n = 199)	Observation (n = 40)	APT^a alone (n = 39)	CRT^b alone (n = 43)	Combination (n = 77)
Total thrombotic events, n	26 (13.1%)	5 (12.5%)	5 (12.8%)	13 (30.2%)	3 (3.9%)
Major thrombosis, n	11 (5.5%)	2 (5.0%)	2 (5.1%)	6 (14.0%)	1 (1.3%)
Stroke, n	9 (4.5%)	1 (2.5%)	2 (5.1%)	5 (11.6%)	1 (1.3%)
Pulmonary embolism, n	1 (0.5%)	1 (2.5%)	0 (0.0%)	0 (0.0%)	0 (0.0%)
Peripheral arterial thrombosis, n	1 (0.5%)	0 (0.0%)	0 (0.0%)	1 (2.3%)	0 (0.0%)
Minor thrombosis, n	15 (7.5%)	3 (7.5%)	3 (7.7%)	7 (16.3%)	2 (2.6%)
Erythromelalgia, n	7 (3.5%)	2 (5.0%)	1 (2.6%)	3 (7.0%)	1 (1.3%)
Angina pectoris, n	5 (2.5%)	1 (2.5%)	1 (2.6%)	3 (7.0%)	0 (0.0%)
Transient ischemic attack, n	3 (1.5%)	0 (0.0%)	1 (2.6%)	1 (2.3%)	1 (1.3%)

Please revise "combination (n=77)" as the others. (The two-level notation)

Note: APT^a, antiplatelet therapy; CRT^b, cytoreductive therapy.

Table 3. Frequency of thrombotic events in ET patients in different risk groups according to treatment approaches.

Risk stratification model	Risk category	All	Observation	APT^a alone	CRT^b alone	Combination
Unstratified	N/A^c	26/199 (13.1%)	5/40 (12.5%)	5/39 (12.8%)	13/43 (30.2%)	3/77 (3.9%)
Conventional	Low	4/82 (4.9%)	0/27 (0%)	2/26 (7.7%)	2/12 (16.7%)	0/17 (0%)
	High	22/117 (18.8%)	5/13 (38.5%)	3/13 (23.1%)	11/31 (35.5%)	3/60 (5.0%)
IPSET-thrombosis	Low	4/60 (6.7%)	1/20 (5.0%)	1/15 (6.7%)	1/11 (9.1%)	1/14 (7.1%)
	Intermediate	4/46 (8.7%)	0/10 (0%)	1/10 (10.0%)	3/10 (30.0%)	0/16 (0%)
	High	18/93 (19.4%)	4/10 (40.0%)	3/14 (21.4%)	9/22 (40.9%)	2/47 (4.3%)
Revised IPSET-thrombosis	Very low	2/50 (4.0%)	1/20 (5.0%)	1/14 (7.1%)	0/7 (0%)	0/9 (0%)
	Low	3/34 (8.8%)	0/8 (0%)	1/13 (7.7%)	2/5 (40%)	0/8 (0%)
	Intermediate	4/33 (12.1%)	0/4 (0%)	0/3 (0%)	3/12 (25%)	1/14 (7.1%)
	High	17/82 (20.7%)	4/8 (50%)	3/9 (33.3%)	8/19 (42.1%)	2/46 (4.3%)

Note: APT^a, antiplatelet therapy; CRT^b, cytoreductive therapy; N/A^c, Not applicable.

Figure 1. Impact of different treatment approaches on thrombosis-free survival (TFS) in patients stratified by the conventional risk model. Low- (a) and high-risk patients (b) are shown. Treatment groups consisted of observation (Obs), antiplatelet monotherapy (APT alone), cytoreductive monotherapy (CRT alone), and combination therapy (Com).

Figure 2. Impact of different treatment approaches on thrombosis-free survival (TFS) in patients stratified by the IPSET-thrombosis risk model. Low- (a), intermediate- (b), and high-risk patients (c) are shown. Treatment groups consisted of observation (Obs), antiplatelet monotherapy (APT alone), cytoreductive monotherapy (CRT alone), and combination therapy (Com).

Figure 3. Impact of different treatment approaches on thrombosis-free survival (TFS) in patients stratified by the revised IPSET-thrombosis risk model. Very low- (a), low- (b), intermediate- (c), and high-risk patients (d) are shown. Treatment groups consisted of observation (Obs), antiplatelet monotherapy (APT alone), cytoreductive monotherapy (CRT alone), and combination therapy (Com).