Table 1. Patients’ characteristics and progressions recorded in the test and validation cohorts (pooled data).
| Childhood cutaneous mastocytosis | Adulthood cutaneous mastocytosis | Mastocytosis in the skin | Indolent systemic mastocytosis | Smouldering systemic mastocytosis | Aggressive systemic mastocytosis | Mast cell leukaemia | Mast cell sarcoma | Systemic mastocytosis with an associated haematological neoplasm | All patients | |
|---|---|---|---|---|---|---|---|---|---|---|
|
| ||||||||||
| Test cohort | ||||||||||
|
| ||||||||||
| Patients (n) | 153 | 127 | 194 | 1006 | 53 | 62 | 23 | 2 | 174 | 1794 |
| Age at diagnosis (years) | 1 (0·15–16) | 37 (18–76) | 43 (18–87) | 47 (17–83) | 52 (25–79) | 58 (17–83) | 54 (27–90) | 19 (8–30) | 64 (22–83) | 46 (0·15–90) |
| Female:male ratio | 1:1·2 | 1:0·5 | 1:0·5 | 1:0·7 | 1:0·7 | 1:1 | 1:1·3 | 1:0 | 1:2·5 | 1:0·8 |
| Tryptase (ng/mL) | 6 (1–98) | 9 (1–126) | 12 (1–141) | 31 (3–885) | 200 (60–819) | 175 (9–1432) | 397 (114–4530) | 3 (1–6) | 150 (2–1022) | 29 (1–4530) |
| Alkaline phosphatase (U/L) | 212 (79–1729) | 68 (33–212) | 66 (36–290) | 74 (22–317) | 114 (36–345) | 161 (63–1696) | 194 (55–1121) | 100* 201 (39–1407) | 80 (22–1729) | |
| KIT Asp816Val positive | 0/2 (0%) | 23/98 (23%) | 7/15 (47%) | 680/799 (85%) | 34/38 (89%) | 38/45 (84%) | 12/19 (63%) | 0/2 (0%) | 125/144 (87%) | 919/1162 (79%) |
| Progression† | 1/153 (1%) | 5/127 (4%) | ·· | 39/1006 (4%) | 5/53 (9%) | 11/62 (18%) | ·· | 0/2 (0%) | 27/174 (16%) | 88/1577 (6%) |
| Progression to AdvSM† | 0/153 (0%) | 0/127 (0%) | ·· | 27/1006 (3%) | 5/53 (9%) | ·· | ·· | ·· | ·· | ·· |
|
| ||||||||||
| Validation cohort | ||||||||||
|
| ||||||||||
| Patients (n) | 0 | 18 | 0 | 384 | 11 | 19 | 5 | 0 | 25 | 462 |
| Age at diagnosis (years) | ·· | 33 (17–62) | ·· | 46 (17–79) | 52 (21–72) | 61 (25–77) | 65 (27–73) | ·· | 61 (24–73) | 47 (17–79) |
| Female:male ratio | ·· | 1:0·2 | ·· | 1:0·9 | 1:1·8 | 1:1·4 | 1:1·5 | ·· | 1:3·2 | 1:1 |
| Tryptase (ng/mL) | ·· | 5 (2–19) | ·· | 29 (6–664) | 267 (161–380) | 279 (72–2036) | 196 (91–660) | ·· | 82 (6–390) | 31 (2–2036) |
| Alkaline phosphatase (U/L) | ·· | 62 (44–125) | ·· | 68 (17–332) | 133 (49–553) | 211 (68–1972) | 82 (46–365) | ·· | 124 (51–1310) | 71 (17–1972) |
| KIT Asp816Val positive | ·· | 0/11 (0%) | ·· | 333/356 (94%) | 10/11 (91%) | 17/18 (94%) | 1/5 (20%) | ·· | 18/24 (75%) | 379/425 (89%) |
| Progression† | ·· | 0/18 (0%) | ·· | 6/384 (2%) | 1/11 (9%) | 3/62 (5%) | ·· | ·· | 6/25 (24%) | 15/462 (3%) |
| Progression to AdvSM† | ·· | 0/18 (0%) | ·· | 4/384 (1%) | 1/11 (9%) | ·· | ·· | ·· | ·· | ·· |
Data are median (range) or n/N (%), unless otherwise stated. AdvSM=advanced systemic mastocytosis.
*
Only one of the two patients had data for alkaline phosphatase available.
†
Disease progression was examined by analysing progression-related events defined by a shift from a known disease category in a higher graded (more advanced) form of mastocytosis or advanced haematological malignancy during follow-up.