Clinicopathologic and molecular features
| Variable . | African Americans,* n = 137 (%) . | Caucasians,† n= 236 (%) . | χ2 P . | |||
|---|---|---|---|---|---|---|
| Age group (y) | ||||||
| <65 | 56 (41) | 102 (43) | 0.66 | |||
| ≥65 | 81 (59) | 134 (57) | ||||
| Gender | ||||||
| Female | 60 (44) | 86 (36) | 0.16 | |||
| Male | 77 (56) | 150 (64) | ||||
| Tumor location | ||||||
| Proximal colon | 80 (58) | 101 (43) | 0.005 | |||
| Distal colon | 41 (30) | 79 (34) | ||||
| Rectum | 16 (12) | 55 (23) | ||||
| Depth of tumor invasion | ||||||
| pTx | 0 | 1 (<1) | 0.79 | |||
| pT1 | 4 (2) | 6 (3) | ||||
| pT2 | 20 (15) | 42 (18) | ||||
| pT3 | 86 (63) | 135 (58) | ||||
| pT4 | 27 (20) | 50 (21) | ||||
| Nodal status | ||||||
| Nx | 0 | 1 (<1) | 0.64 | |||
| N0 | 73 (53) | 131 (56) | ||||
| N1-3 | 64 (47) | 102 (44) | ||||
| Distant metastasis | ||||||
| M0 | 118 (86) | 203 (87) | 0.86 | |||
| M1 | 19 (14) | 31 (13) | ||||
| Tumor stage | ||||||
| I | 17 (12) | 33 (14) | 0.96 | |||
| II | 53 (39) | 92 (39) | ||||
| III | 48 (35) | 78 (34) | ||||
| IV | 19 (14) | 31 (13) | ||||
| Tumor grade | ||||||
| Low | 103 (76) | 179 (78) | 0.65 | |||
| High | 33 (24) | 51 (22) | ||||
| Tumor size (cm) | ||||||
| ≤5 | 73 (53) | 132 (59) | 0.48 | |||
| >5 | 62 (47) | 96 (41) | ||||
| p53 status | ||||||
| Wild-type | 69 (50) | 109 (46) | 0.44 | |||
| Mutated | 68 (50) | 127 (54) | ||||
| p53 mutation type‡ | ||||||
| Disruptive | 31 (46) | 51 (40) | 0.46 | |||
| Nondisruptive | 37 (54) | 76 (60) | ||||
| p53 codon 72 phenotypes | ||||||
| Arg/Arg | 26 (19) | 85 (36) | 0.002 | |||
| Arg/Pro | 87 (64) | 134 (57) | ||||
| Pro/Pro | 24 (17) | 17 (7) | ||||
| Vital status at the end of follow-up§ | ||||||
| Alive | 36 (28) | 64 (29) | 0.98 | |||
| Died due to CRC | 61 (48) | 104 (47) | ||||
| Died due to other causes | 31 (24) | 52 (24) | ||||
| Variable . | African Americans,* n = 137 (%) . | Caucasians,† n= 236 (%) . | χ2 P . | |||
|---|---|---|---|---|---|---|
| Age group (y) | ||||||
| <65 | 56 (41) | 102 (43) | 0.66 | |||
| ≥65 | 81 (59) | 134 (57) | ||||
| Gender | ||||||
| Female | 60 (44) | 86 (36) | 0.16 | |||
| Male | 77 (56) | 150 (64) | ||||
| Tumor location | ||||||
| Proximal colon | 80 (58) | 101 (43) | 0.005 | |||
| Distal colon | 41 (30) | 79 (34) | ||||
| Rectum | 16 (12) | 55 (23) | ||||
| Depth of tumor invasion | ||||||
| pTx | 0 | 1 (<1) | 0.79 | |||
| pT1 | 4 (2) | 6 (3) | ||||
| pT2 | 20 (15) | 42 (18) | ||||
| pT3 | 86 (63) | 135 (58) | ||||
| pT4 | 27 (20) | 50 (21) | ||||
| Nodal status | ||||||
| Nx | 0 | 1 (<1) | 0.64 | |||
| N0 | 73 (53) | 131 (56) | ||||
| N1-3 | 64 (47) | 102 (44) | ||||
| Distant metastasis | ||||||
| M0 | 118 (86) | 203 (87) | 0.86 | |||
| M1 | 19 (14) | 31 (13) | ||||
| Tumor stage | ||||||
| I | 17 (12) | 33 (14) | 0.96 | |||
| II | 53 (39) | 92 (39) | ||||
| III | 48 (35) | 78 (34) | ||||
| IV | 19 (14) | 31 (13) | ||||
| Tumor grade | ||||||
| Low | 103 (76) | 179 (78) | 0.65 | |||
| High | 33 (24) | 51 (22) | ||||
| Tumor size (cm) | ||||||
| ≤5 | 73 (53) | 132 (59) | 0.48 | |||
| >5 | 62 (47) | 96 (41) | ||||
| p53 status | ||||||
| Wild-type | 69 (50) | 109 (46) | 0.44 | |||
| Mutated | 68 (50) | 127 (54) | ||||
| p53 mutation type‡ | ||||||
| Disruptive | 31 (46) | 51 (40) | 0.46 | |||
| Nondisruptive | 37 (54) | 76 (60) | ||||
| p53 codon 72 phenotypes | ||||||
| Arg/Arg | 26 (19) | 85 (36) | 0.002 | |||
| Arg/Pro | 87 (64) | 134 (57) | ||||
| Pro/Pro | 24 (17) | 17 (7) | ||||
| Vital status at the end of follow-up§ | ||||||
| Alive | 36 (28) | 64 (29) | 0.98 | |||
| Died due to CRC | 61 (48) | 104 (47) | ||||
| Died due to other causes | 31 (24) | 52 (24) | ||||
Abbreviations: n, total number of cases; CRC, colorectal cancer.
Information on tumor grade for one case and tumor size for two cases was not available for African Americans.
Information on tumor location for one case; pT, pN and M for two cases; tumor stage for two cases; tumor grade for six cases; and tumor size for eight cases was not available for Caucasians.
p53 mutation that introduces an amino acid that disrupts functional domains of p53.
As described in Materials & Methods, 9 African American and 16 Caucasian patients were lost to follow-up.