Age Variance in the Survival of United States Pediatric Leukemia Patients (1973–2006)
Table 1
(a) Risk (hazard) of dying in leukemia patients (1973–2006 SEER dataset) by age at diagnosis
Age at diagnosis (yrs)
Alive No. (%)
Dead No. (%)
Incidence rate of dying per 1000 person-month
0
375 (48.6)
396 (51.4)
9.86
1
834 (71.0)
340 (29.0)
3.33
2
1468 (81.1)
341 (18.9)
1.77
3
1430 (82.7)
300 (17.3)
1.60
4
1099 (81.5)
249 (18.5)
1.87
5
762 (78.4)
210 (21.6)
2.04
6
544 (74.7)
184 (25.3)
2.44
7
477 (72.9)
177 (27.1)
2.94
8
406 (72.4)
155 (27.6)
2.86
10
349 (69.0)
157 (31.0)
3.61
10
320 (65.7)
167 (34.3)
4.05
11
312 (64.9)
169 (35.1)
4.92
12
325 (62.6)
194 (37.4)
5.12
13
299 (57.9)
217 (42.1)
5.70
14
330 (61.0)
211 (39.0)
5.82
15
268 (51.6)
251 (48.4)
7.20
16
293 (55.6)
234 (44.4)
6.20
17
230 (48.7)
242 (51.3)
8.81
18
196 (42.2)
269 (57.8)
10.22
19
187 (43.0)
248 (57.0)
10.77
Abbreviation. SEER: Surveillance Epidemiology and End Results.
(b) Demographics and other study variables characterization by age group at diagnosis of pediatric patients with leukemia, SEER registry 1973–2006
Covariates
Age group at diagnosis (yrs)
χ
2 (df)
value
>1
1–4
5–9
10–14
15–19
Sex
49.7 (4)
<0.0001
Male
386 (50.1)
3411 (56.3)
1871 (54.7)
1450 (57.0)
1504 (62.2)
Female
385 (49.9)
2649 (43.7)
1550 (45.3)
1094 (43.0)
914 (37.8)
Race
52.2 (12)
<0.0001
White
623 (80.8)
5000 (82.5)
2776 (81.1)
2048 (80.5)
1988 (82.2)
Black
71 (9.2)
389 (6.4)
283 (8.3)
261 (10.3)
208 (8.6)
Others
75 (9.7)
651 (10.7)
345 (10.1)
223 (8.8)
212 (8.8)
Unknown
2 (0.3)
21 (0.3)
17 (0.5)
12 (0.5)
10 (0.4)
No. of primaries
57.9 (4)
<0.0001
1.0
769 (99.7)
6004 (99.1)
3361 (98.2)
2494 (98.0)
2346 (97.0)
≥ 2.0
2 (0.3)
57 (0.9)
60 (1.8)
50 (2.0)
72 (3.0)
Cell type
321.3 (4)
<0.0001
T-cell
13 (7.3)
168 (6.5)
293 (19.6)
244 (25.5)
199 (25.3)
B-cell, B-precursor
166 (92.7)
2407 (93.5)
1199 (80.4)
711 (74.5)
588 (74.7)
Radiation
190.5 (4)
<0.0001
Yes
90 (11.7)
846 (14.0)
581 (17.0)
631 (24.8)
517 (21.4)
No
681 (88.3)
5215 (86.0)
2840 (83.0)
1913 (75.2)
1901 (78.6)
Year of diagnosis
61.8 (24)
<0.0001
1973–77
47 (6.1)
442 (7.3)
268 (7.8)
201 (7.9)
213 (8.8)
1978–82
61 (7.9)
430 (7.1)
248 (7.2)
206 (8.1)
212 (8.8)
1983–87
68 (8.8)
506 (8.3)
271 (7.9)
223 (8.8)
193 (8.0)
1988–92
71 (9.2)
649 (10.7)
382 (11.2)
213 (8.4)
211 (8.7)
1993–97
109 (14.1)
994 (16.4)
519 (15.2)
357 (14.0)
316 (13.1)
1998–02
203 (23.3)
1501 (24.8)
903 (26.4)
657 (25.8)
623 (25.8)
2003–06
212 (27.5)
1539 (25.4)
830 (24.3)
687 (27.0)
650 (26.9)
Survival time (months)
<0.0001
Median
33.0
—
398.0
307.0
44.0
Mean (Sd)
160.6 (7.8)
308.0 (2.6)
279.9 (3.7)
224.9 (4.7)
167.3 (4.5)
Mortality status
1043.3 (4)
<0.0001
Alive
375 (48.6)
4831 (79.7)
2538 (74.2)
1586 (62.3)
1174 (48.6)
Dead
396 (51.4)
1230 (20.3)
883 (25.8)
958 (37.7)
1244 (51.4)
Notes and Abbreviations. The significance level is 0.01, CI: confidence interval, df: degrees of freedom. The median survival time for age group 1–4 years was not estimated as 50% of patients did not die in this group at any point of time (that is the KM estimator for 1–4 age group never reaches a probability of dying greater than 0.5).
(c) Five-year interval survival percentage of pediatric leukemia patients overall and by age group at diagnosis
Survival time interval (months)
Overall survival (%)
Survival percentage by age group (years) at diagnosis
