Demographic and clinical characteristics of the study participants
| Patient characteristics . | Entire cohort, N = 298 . | Non-Hispanic whites, n = 159 . | Asian Americans, n = 71 . | African Americans, n = 68 . | P* . |
|---|---|---|---|---|---|
| Age, median (range), y | |||||
| Age at diagnosis | 5.0 (1-19) | 5.0 (1-19) | 4.0 (1-18) | 6.0 (1-15) | .1 |
| Age at study participation | 6.0 (2-20) | 6.0 (2-20) | 6.0 (2-20) | 7.0 (3-16) | .1 |
| Gender, n (%) | |||||
| Male | 198/298 (66.4) | 104/159 (65.4) | 46/71 (64.8) | 48/68 (70.6) | .7 |
| Disease characteristics, n (%) | |||||
| High-risk disease (NCI criteria) | 127/297 (42.8)† | 64/159 (40.3) | 33/71 (46.5) | 30/67 (44.8)† | .6 |
| Unfavorable cytogenetics‡ | 16/285 (5.6)† | 9/151 (6.0)† | 3/70 (4.3)† | 4/64 (6.3)† | .9 |
| Favorable cytogenetics‡ | 146/285 (51.2)† | 78/151 (51.7)† | 33/70 (47.1)† | 35/64 (54.7)† | |
| T-cell ALL | 35/ 297 (11.8)† | 15/159 (9.4) | 8/71 (11.3) | 12/67 (17.9)† | .2 |
| Indices of 6MP metabolism | |||||
| Daily 6MP dose intensity, mean ± SD§ | 80.4% ± 25.8% | 80.7% ± 21.4% | 75.4% ± 24.7% | 84.8% ± 34.4% | .07 |
| TPMT wild-type genotype n (%) | 282/298 (94.6) | 149/159 (93.7) | 69/71 (97.2) | 64/68 (94.1) | .5 |
| Average TGN, median (range), pmol/8 × 108 RBC | 146.8 (2.1-714.1) | 150.7 (42.9-714.1) | 145.4 (2.1-459.1) | 126.3 (38.9-414.5) | .2 |
| Sociodemographic characteristics | |||||
| Annual household income <$50K, n (%) | 130/282 (46.1)† | 68/154 (44.2)† | 21/64 (32.8)† | 41/64 (64.1)† | .001 |
| No. of people in household, median (range) | 3 (1-10) | 3 (1-9) | 3 (1-10) | 3 (1-7) | .9 |
| Stay-at-home mother, n (%) | 113/289 (39.1)† | 60/157 (38.2)† | 36/69 (52.2)† | 17/63 (27.0)† | .01 |
| Paternal education, n (%) | |||||
| Less than college degree/vocational training | 139/291 (47.8)† | 76/159 (47.8) | 21/68 (30.9)† | 42/64 (65.6)† | .0009 |
| College degree/vocational training | 103/291 (35.4)† | 58/159 (36.5) | 28/68 (41.2)† | 17/64 (26.6)† | |
| Postgraduate degree | 49/291 (16.8)† | 25/159 (15.7) | 19/68 (27.9)† | 5/64 (7.8)† | |
| Maternal education, n (%) | |||||
| Less than college degree/vocational training | 135/293 (46.1)† | 73/159 (45.9) | 22/68 (32.4)† | 40/66 (60.6)† | .03 |
| College degree/vocational training | 110/293 (37.5)† | 61/159 (38.4) | 31/68 (45.6)† | 18/66 (27.3)† | |
| Postgraduate degree | 48/293 (16.4)† | 25/159 (15.7) | 15/68 (22.1)† | 8/66 (12.1)† | |
| Household structure, n (%) | |||||
| Nuclear family | 254/296 (85.8)† | 145/159 (91.2) | 67/70 (95.7)† | 42/67 (62.7)† | <.0001 |
| Single-parent/single-child | 18/296 (6.1)† | 6/159 (3.8) | 3/70 (4.3)† | 9/67 (13.4)† | |
| Single-parent/multiple children | 24/296 (8.1)† | 8/159 (5.0) | 0/70 (0.0) | 16/67 (23.9)† | |
| Length of follow-up, median (range), y | |||||
| Time from start of maintenance to study entry | 0.8 (0.2-2.3) | 0.8 (0.2-2.1) | 0.8 (0.2-2.3) | 0.8 (0.2-2.2) | 1.0 |
| Time from diagnosis to study entry | 1.6 (0.9-2.9) | 1.6 (0.9-2.9) | 1.6 (1.0-2.8) | 1.6 (0.9-2.7) | .5 |
| Time from diagnosis to date of last contact | 6.4 (1.3-10.6) | 7.1 (1.3-10.6) | 5.4 (2.5-9.6) | 5.3 (1.8-10.1) | <.0001 |
| Time from study entry to date of last contact | 5.0 (0.07-9.1) | 6.4 (0.07-9.1) | 3.8 (0.07-7.7) | 3.7 (0.4-8.7) | <.0001 |
| Time from study exit to date of last contact | 4.6 (0-9.0) | 6.0 (0-9.0) | 3.6 (0-7.6) | 3.3 (0.04-8.6) | <.0001 |
| Adherence | |||||
| Person-days of adherence monitoring | 39 803 | 21 258 | 9375 | 9170 | __ |
| Adherence ≥85%, n (%) | 253/298 (84.9) | 148/159 (93.1) | 62/71 (87.3) | 43/68 (63.2) | <.0001 |
| Adherence ≥90%, n (%) | 237/298 (79.5) | 139/159 (87.4) | 60/71 (84.5) | 38/68 (55.9) | <.0001 |
| Patient characteristics . | Entire cohort, N = 298 . | Non-Hispanic whites, n = 159 . | Asian Americans, n = 71 . | African Americans, n = 68 . | P* . |
|---|---|---|---|---|---|
| Age, median (range), y | |||||
| Age at diagnosis | 5.0 (1-19) | 5.0 (1-19) | 4.0 (1-18) | 6.0 (1-15) | .1 |
| Age at study participation | 6.0 (2-20) | 6.0 (2-20) | 6.0 (2-20) | 7.0 (3-16) | .1 |
| Gender, n (%) | |||||
| Male | 198/298 (66.4) | 104/159 (65.4) | 46/71 (64.8) | 48/68 (70.6) | .7 |
| Disease characteristics, n (%) | |||||
| High-risk disease (NCI criteria) | 127/297 (42.8)† | 64/159 (40.3) | 33/71 (46.5) | 30/67 (44.8)† | .6 |
| Unfavorable cytogenetics‡ | 16/285 (5.6)† | 9/151 (6.0)† | 3/70 (4.3)† | 4/64 (6.3)† | .9 |
| Favorable cytogenetics‡ | 146/285 (51.2)† | 78/151 (51.7)† | 33/70 (47.1)† | 35/64 (54.7)† | |
| T-cell ALL | 35/ 297 (11.8)† | 15/159 (9.4) | 8/71 (11.3) | 12/67 (17.9)† | .2 |
| Indices of 6MP metabolism | |||||
| Daily 6MP dose intensity, mean ± SD§ | 80.4% ± 25.8% | 80.7% ± 21.4% | 75.4% ± 24.7% | 84.8% ± 34.4% | .07 |
| TPMT wild-type genotype n (%) | 282/298 (94.6) | 149/159 (93.7) | 69/71 (97.2) | 64/68 (94.1) | .5 |
| Average TGN, median (range), pmol/8 × 108 RBC | 146.8 (2.1-714.1) | 150.7 (42.9-714.1) | 145.4 (2.1-459.1) | 126.3 (38.9-414.5) | .2 |
| Sociodemographic characteristics | |||||
| Annual household income <$50K, n (%) | 130/282 (46.1)† | 68/154 (44.2)† | 21/64 (32.8)† | 41/64 (64.1)† | .001 |
| No. of people in household, median (range) | 3 (1-10) | 3 (1-9) | 3 (1-10) | 3 (1-7) | .9 |
| Stay-at-home mother, n (%) | 113/289 (39.1)† | 60/157 (38.2)† | 36/69 (52.2)† | 17/63 (27.0)† | .01 |
| Paternal education, n (%) | |||||
| Less than college degree/vocational training | 139/291 (47.8)† | 76/159 (47.8) | 21/68 (30.9)† | 42/64 (65.6)† | .0009 |
| College degree/vocational training | 103/291 (35.4)† | 58/159 (36.5) | 28/68 (41.2)† | 17/64 (26.6)† | |
| Postgraduate degree | 49/291 (16.8)† | 25/159 (15.7) | 19/68 (27.9)† | 5/64 (7.8)† | |
| Maternal education, n (%) | |||||
| Less than college degree/vocational training | 135/293 (46.1)† | 73/159 (45.9) | 22/68 (32.4)† | 40/66 (60.6)† | .03 |
| College degree/vocational training | 110/293 (37.5)† | 61/159 (38.4) | 31/68 (45.6)† | 18/66 (27.3)† | |
| Postgraduate degree | 48/293 (16.4)† | 25/159 (15.7) | 15/68 (22.1)† | 8/66 (12.1)† | |
| Household structure, n (%) | |||||
| Nuclear family | 254/296 (85.8)† | 145/159 (91.2) | 67/70 (95.7)† | 42/67 (62.7)† | <.0001 |
| Single-parent/single-child | 18/296 (6.1)† | 6/159 (3.8) | 3/70 (4.3)† | 9/67 (13.4)† | |
| Single-parent/multiple children | 24/296 (8.1)† | 8/159 (5.0) | 0/70 (0.0) | 16/67 (23.9)† | |
| Length of follow-up, median (range), y | |||||
| Time from start of maintenance to study entry | 0.8 (0.2-2.3) | 0.8 (0.2-2.1) | 0.8 (0.2-2.3) | 0.8 (0.2-2.2) | 1.0 |
| Time from diagnosis to study entry | 1.6 (0.9-2.9) | 1.6 (0.9-2.9) | 1.6 (1.0-2.8) | 1.6 (0.9-2.7) | .5 |
| Time from diagnosis to date of last contact | 6.4 (1.3-10.6) | 7.1 (1.3-10.6) | 5.4 (2.5-9.6) | 5.3 (1.8-10.1) | <.0001 |
| Time from study entry to date of last contact | 5.0 (0.07-9.1) | 6.4 (0.07-9.1) | 3.8 (0.07-7.7) | 3.7 (0.4-8.7) | <.0001 |
| Time from study exit to date of last contact | 4.6 (0-9.0) | 6.0 (0-9.0) | 3.6 (0-7.6) | 3.3 (0.04-8.6) | <.0001 |
| Adherence | |||||
| Person-days of adherence monitoring | 39 803 | 21 258 | 9375 | 9170 | __ |
| Adherence ≥85%, n (%) | 253/298 (84.9) | 148/159 (93.1) | 62/71 (87.3) | 43/68 (63.2) | <.0001 |
| Adherence ≥90%, n (%) | 237/298 (79.5) | 139/159 (87.4) | 60/71 (84.5) | 38/68 (55.9) | <.0001 |
TGN, erythrocyte thioguanine nucleotide concentrations; RBC, erythrocyte. — indicates not applicable.
The P value describes statistical significance of difference in the various characteristics of patients in the 3 racial groups.
Statistics were calculated for this table by excluding patients with missing values for the characteristics.
Unfavorable chromosomal abnormalities included t(9;22), t(4;11), hypodiploidy, or extreme hypodiploidy. Favorable cytogenetics included 1 or more of the following: t(12;21); hyperdiploidy; trisomy 4 and 10; or trisomy 4, 10, and 17.
6MP dose intensity: ratio of 6MP dose actually prescribed (mg/m2 body surface area), to the planned protocol dose (75 mg/m2 per day).