Supplementary Table S1 Matching Quality Assessed by Standardized Difference

Supplementary Table S1 Matching quality assessed by standardized difference

Variable / Black patients / All whites / Standardized Difference / demographics match / Standardized Difference / presentation match / Standardized Difference / presentation
+HGB match / Standardized Difference / treatment match / Standardized Difference
mean / STD / mean / STD / mean / STD / mean / STD / mean / STD / mean / STD
age / 57.26 / 13.99 / 60.05 / 13.43 / -0.20 / 57.95 / 13.27 / -0.05 / 58.13 / 13.39 / -0.06 / 57.86 / 14.21 / -0.04 / 57.23 / 13.02 / 0.00
Year of diagnosis / 2004.90 / 3.83 / 2003.50 / 3.86 / 0.36 / 2004.89 / 3.82 / 0.00 / 2004.61 / 3.84 / 0.08 / 2004.60 / 3.89 / 0.08 / 2004.65 / 3.91 / 0.06
smoking / 0.65 / 0.70 / 0.64 / 0.71 / 0.02 / 0.66 / 0.70 / -0.02 / 0.64 / 0.69 / 0.02 / 0.63 / 0.70 / 0.04 / 0.65 / 0.68 / 0.01
drinking / 0.67 / 0.76 / 0.79 / 0.72 / -0.16 / 0.67 / 0.76 / 0.00 / 0.64 / 0.74 / 0.04 / 0.63 / 0.73 / 0.06 / 0.65 / 0.73 / 0.02
stage / 2.02 / 1.08 / 1.72 / 1.07 / 0.28 / 1.81 / 1.13 / 0.19 / 2.00 / 1.06 / 0.02 / 1.97 / 1.07 / 0.05 / 1.99 / 1.09 / 0.03
grade / 1.67 / 0.82 / 1.47 / 0.89 / 0.23 / 1.48 / 0.91 / 0.22 / 1.69 / 0.77 / -0.02 / 1.63 / 0.79 / 0.05 / 1.68 / 0.78 / -0.01
ER / 0.78 / 0.59 / 0.98 / 0.54 / -0.36 / 0.94 / 0.55 / -0.28 / 0.79 / 0.55 / -0.02 / 0.81 / 0.54 / -0.04 / 0.82 / 0.57 / -0.07
PR / 0.71 / 0.62 / 0.90 / 0.62 / -0.30 / 0.87 / 0.61 / -0.25 / 0.72 / 0.59 / 0.00 / 0.74 / 0.58 / -0.04 / 0.74 / 0.61 / -0.05
surgery / 0.93 / 0.26 / 0.96 / 0.19 / -0.16 / 0.95 / 0.21 / -0.12 / 0.93 / 0.25 / -0.04 / 0.93 / 0.26 / -0.01 / 0.94 / 0.23 / -0.07
chemotherapy / 0.56 / 0.55 / 0.32 / 0.53 / 0.45 / 0.39 / 0.57 / 0.31 / 0.47 / 0.56 / 0.18 / 0.44 / 0.57 / 0.22 / 0.54 / 0.53 / 0.05
radiation / 0.53 / 0.60 / 0.45 / 0.57 / 0.14 / 0.49 / 0.60 / 0.06 / 0.46 / 0.59 / 0.12 / 0.41 / 0.54 / 0.21 / 0.53 / 0.57 / 0.01
hormone / 0.42 / 0.60 / 0.49 / 0.66 / -0.11 / 0.53 / 0.67 / -0.18 / 0.47 / 0.67 / -0.09 / 0.51 / 0.68 / -0.15 / 0.41 / 0.58 / 0.01
hemoglobin / 12.06 / 1.43 / 12.90 / 1.31 / -0.61 / 12.93 / 1.28 / -0.64 / 12.80 / 1.40 / -0.52 / 12.19 / 1.37 / -0.09 / 12.89 / 1.37 / -0.59

STD: standard deviation; ER: estrogen receptor; PR: progesterone receptor.

Bolded values of standardized differences indicated those of the matched variables.

Supplementary Table S2 Quality of matches on presentation plus baseline level of hematologic variables

Variable / Black patients
N=443, (%) / Matched white patients
Presentation+
HCT match
N=443, (%) / Presentation+
MCHC match
N=443, (%) / Presentation+
MCV match
N=443, (%) / Presentation+
RDW match
N=443, (%) / Presentation+
RBC match
N=443, (%) / Presentation+
WBC match
N=443, (%) / Presentation+
Platelet match
N=443, (%)
Age, years (mean (SD)) / 57.26(13.99) / 58.12(14.11) / 58.15(13.07) / 58.21(13.41) / 58.08(13.07) / 57.95(12.95) / 57.59(12.98) / 58.14(12.96)
Year of diagnosis (mean (SD)) / 2004.90(3.83) / 2004.55(3.85) / 2004.66(3.68) / 2004.84(3.85) / 2004.50(3.85) / 2004.60(3.84) / 2004.79(3.85) / 2004.70(3.83)
Smoking status
Never / 211(47.63) / 225(50.79) / 217(48.98) / 222(50.11) / 216(48.76) / 215(48.53) / 220(49.66) / 216(48.76)
Ever / 175(39.5) / 168(37.92) / 176(39.73) / 172(38.83) / 174(39.28) / 179(40.41) / 172(38.83) / 171(38.6)
Unknown / 57(12.87) / 50(11.29) / 50(11.29) / 49(11.06) / 53(11.96) / 49(11.06) / 51(11.51) / 56(12.64)
Drinking status
Never / 224(50.56) / 231(52.14) / 217(48.98) / 226(51.02) / 232(52.37) / 230(51.92) / 229(51.69) / 226(51.02)
Ever / 141(31.83) / 143(32.28) / 157(35.44) / 149(33.63) / 141(31.83) / 149(33.63) / 147(33.18) / 147(33.18)
Unknown / 78(17.61) / 69(15.58) / 69(15.58) / 68(15.35) / 70(15.8) / 64(14.45) / 67(15.12) / 70(15.8)
Tumor stages
I / 166(37.47) / 166(37.47) / 177(39.95) / 171(38.6) / 172(38.83) / 164(37.02) / 170(38.37) / 165(37.25)
II / 172(38.83) / 188(42.44) / 171(38.6) / 178(40.18) / 174(39.28) / 184(41.53) / 189(42.66) / 185(41.76)
III / 53(11.96) / 43(9.71) / 49(11.06) / 49(11.06) / 42(9.48) / 47(10.61) / 41(9.26) / 48(10.84)
IV / 34(7.67) / 30(6.77) / 29(6.55) / 33(7.45) / 37(8.35) / 34(7.67) / 25(5.64) / 30(6.77)
Unknown / 18(4.06) / 16(3.61) / 17(3.84) / 12(2.71) / 18(4.06) / 14(3.16) / 18(4.06) / 15(3.39)
Tumor grades
Well differentiated / 32(7.22) / 22(4.97) / 33(7.45) / 30(6.77) / 31(7) / 21(4.74) / 24(5.42) / 24(5.42)
Moderately differentiated / 148(33.41) / 163(36.79) / 159(35.89) / 170(38.37) / 160(36.12) / 163(36.79) / 158(35.67) / 156(35.21)
Poorly differentiated / 196(44.24) / 197(44.47) / 196(44.24) / 189(42.66) / 202(45.6) / 202(45.6) / 199(44.92) / 208(46.95)
Cell type not determined / 67(15.12) / 61(13.77) / 55(12.42) / 54(12.19) / 50(11.29) / 57(12.87) / 62(14) / 55(12.42)
Estrogen receptor
Negative / 137(30.93) / 120(27.09) / 116(26.19) / 111(25.06) / 120(27.09) / 121(27.31) / 117(26.41) / 121(27.31)
Positive / 266(60.05) / 291(65.69) / 296(66.82) / 298(67.27) / 287(64.79) / 293(66.14) / 291(65.69) / 289(65.24)
Unknown / 40(9.03) / 32(7.22) / 31(7) / 34(7.67) / 36(8.13) / 29(6.55) / 35(7.9) / 33(7.45)
Progesterone receptor
Negative / 168(37.92) / 152(34.31) / 150(33.86) / 144(32.51) / 153(34.54) / 157(35.44) / 153(34.54) / 153(34.54)
Positive / 234(52.82) / 257(58.01) / 260(58.69) / 265(59.82) / 252(56.88) / 256(57.79) / 254(57.34) / 257(58.01)
Unknown / 41(9.26) / 34(7.67) / 33(7.45) / 34(7.67) / 38(8.58) / 30(6.77) / 36(8.13) / 33(7.45)
Surgery
No / 33(7.45) / 30(6.77) / 23(5.19) / 27(6.09) / 32(7.22) / 28(6.32) / 19(4.29)a / 25(5.64)
Yes / 410(92.55) / 413(93.23) / 420(94.81) / 416(93.91) / 411(92.78) / 415(93.68) / 424(95.71) / 418(94.36)
Chemotherapy
No / 206(46.5) / 266(60.05)c / 253(57.11)b / 254(57.34)b / 249(56.21)b / 248(55.98)b / 254(57.34)b / 243(54.85)a
Yes / 224(50.56) / 165(37.25) / 170(38.37) / 171(38.6) / 173(39.05) / 177(39.95) / 170(38.37) / 183(41.31)
Unknown / 13(2.93) / 12(2.71) / 20(4.51) / 18(4.06) / 21(4.74) / 18(4.06) / 19(4.29) / 17(3.84)
Radiation therapy
No / 232(52.37) / 267(60.27)a / 249(56.21) / 266(60.05) / 263(59.37) / 255(57.56) / 269(60.72)a / 258(58.24)
Yes / 187(42.21) / 160(36.12) / 168(37.92) / 152(34.31) / 159(35.89) / 166(37.47) / 151(34.09) / 163(36.79)
Unknown / 24(5.42) / 16(3.61) / 26(5.87) / 25(5.64) / 21(4.74) / 22(4.97) / 23(5.19) / 22(4.97)
Hormone therapy
No / 283(63.88) / 261(58.92) / 250(56.43)b / 267(60.27) / 267(60.27)a / 263(59.37)a / 262(59.14)a / 271(61.17)a
Yes / 135(30.47) / 140(31.6) / 143(32.28) / 132(29.8) / 126(28.44) / 130(29.35) / 132(29.8) / 125(28.22)
Unknown / 25(5.64) / 42(9.48) / 50(11.29) / 44(9.93) / 50(11.29) / 50(11.29) / 49(11.06) / 47(10.61)
HGB, g/dL (mean (SD))e / 12.06(1.43) / 12.41(1.35)c / 12.70(1.41)d / 12.72(1.44)d / 12.65(1.45)d / 12.83(1.33)d / 12.92(1.29)d / 12.91(1.29)d
HCT, % (mean (SD))e / 36.84(4.01) / 37.09(3.90) / 38.58(4.02)d / 38.19(4.07)d / 38.04(4.23)d / 38.39(3.91)d / 38.6(3.79)d / 38.63(3.8)d
MCH, pg (mean (SD))e / 28.30(2.79) / 29.92(2.67)d / 29.42(2.63)d / 29.08(2.64)d / 29.55(2.67)d / 30.10(2.38)d / 30.13(2.24)d / 30.15(2.25)d
MCHC, g/dL (mean (SD))e / 32.72(1.22) / 33.45(1.21)d / 32.91(1.09) / 33.31(1.18)d / 33.27(1.18)d / 33.43(1.17)d / 33.47(1.14)d / 33.42(1.11)d
MCV, fL (mean (SD))e / 86.42(7.10) / 89.38(6.65)d / 89.37(6.91)d / 87.23(6.61) / 88.79(6.83)d / 90.01(5.91)d / 90.01(5.57)d / 90.22(5.76)d
RDW, % (mean (SD))e / 14.43(1.97) / 13.68(1.82)d / 13.83(2.04)d / 13.90(2.09)c / 14.20(1.94) / 13.55(1.89)d / 13.44(1.63)d / 13.48(1.51)d
RBC, T/L (mean (SD))e / 4.28(0.49) / 4.17(0.48)c / 4.34(0.46) / 4.40(0.48)c / 4.31(0.51) / 4.28(0.45) / 4.31(0.42) / 4.30(0.46)
WBC, B/L (mean (SD))e / 6.77(2.39) / 7.65(2.66)d / 7.66(2.59)d / 7.68(2.57)d / 7.79(2.61)d / 7.55(2.27)d / 6.79(1.94) / 7.55(2.24)d
Platelet, B/L (mean (SD))e / 275.08(72.66) / 266.76(76.84) / 281.00(77.65) / 277.89(78.91) / 276.90(83.19) / 270.71(70.41) / 266.02(68.37) / 272.55(64.77)

SD: standard deviation; HGB: hemoglobin; HCT: hematocrit; MCH: mean corpuscular hemoglobin; MCHC: MCH concentration; MCV: mean corpuscular volume; RDW: red blood cell distribution width; RBC: red blood cell; WBC: white blood cell.

P value: a <0.05; b <0.01; c <0.001; d <0.0001.

e Based on the average value measured from one year before the diagnosis of breast cancer till any kind of treatment.

Supplementary Table S3 Associations between the levels of hematologic variables and breast cancer survival

All (Alive/Dead=1417/399) / Blacks (Alive/Dead=331/112) / Whites (Alive/Dead=1086/287)
HR (95% CI) / P / HR (95% CI)* / P* / HR (95% CI) / P / HR (95% CI)# / P# / HR (95% CI) / P / HR (95% CI)# / P#
HGB / 0.77 (0.73-0.83) / <0.0001 / 0.82 (0.76-0.87) / <0.0001 / 0.84 (0.74-0.95) / 0.0048 / 0.96 (0.91-1.00) / 0.0719 / 0.76 (0.70-0.83) / <0.0001 / 0.79 (0.73-0.86) / <0.0001
HCT / 0.92 (0.90-0.94) / <0.0001 / 0.93 (0.91-0.95) / <0.0001 / 0.94 (0.90-0.98) / 0.0039 / 0.89 (0.77-1.02) / 0.1043 / 0.92 (0.89-0.95) / <0.0001 / 0.92 (0.90-0.95) / <0.0001
MCH / 0.95 (0.91-0.98) / 0.0055 / 0.98 (0.93-1.02) / 0.2778 / 0.97 (0.90-1.03) / 0.3182 / 0.97 (0.90-1.04) / 0.3681 / 0.97 (0.92-1.02) / 0.2728 / 0.98 (0.93-1.04) / 0.4857
MCHC / 0.82 (0.75-0.90) / <0.0001 / 0.95 (0.85-1.06) / 0.3527 / 0.93 (0.79-1.10) / 0.3970 / 0.98 (0.82-1.17) / 0.8342 / 0.82 (0.73-0.92) / 0.0006 / 0.93 (0.81-1.07) / 0.3284
MCV / 0.99 (0.97-1.01) / 0.1740 / 0.99 (0.97-1.01) / 0.3150 / 0.99 (0.96-1.01) / 0.3443 / 0.98 (0.96-1.01) / 0.2562 / 1.00 (0.98-1.03) / 0.7486 / 1.00 (0.97-1.02) / 0.6678
RDW / 1.14 (1.10-1.17) / <0.0001 / 1.09 (1.05-1.14) / <0.0001 / 1.14 (1.04-1.23) / 0.0030 / 1.13 (1.04-1.23) / 0.0028 / 1.13 (1.09-1.17) / <0.0001 / 1.09 (1.04-1.15) / 0.0004
RBC / 0.55 (0.44-0.67) / <0.0001 / 0.61 (0.50-0.75) / <0.0001 / 0.69 (0.47-1.01) / 0.0562 / 0.85 (0.57-1.28) / 0.4434 / 0.49 (0.38-0.63) / <0.0001 / 0.54 (0.42-0.69) / <0.0001
WBC / 1.06 (1.04-1.09) / <0.0001 / 1.05 (1.02-1.09) / 0.0005 / 1.10 (1.04-1.16) / 0.0008 / 1.05 (0.99-1.12) / 0.1268 / 1.06 (1.03-1.09) / <0.0001 / 1.05 (1.02-1.09) / 0.0031
Platelet / 1.00 (0.99-1.00) / 0.0625 / 1.00 (0.99-1.00) / 0.5805 / 1.00 (0.99-1.00) / 0.8182 / 1.00 (0.99-1.00) / 0.2746 / 0.99 (0.98-0.99) / 0.0133 / 1.00 (0.99-1.00) / 0.1632

HR: hazard ratio; CI: confidence interval; HGB: hemoglobin; HCT: hematocrit; MCH: mean corpuscular hemoglobin; MCHC: MCH concentration; MCV: mean corpuscular volume; RDW: red blood cell distribution width; RBC: red blood cell; WBC: white blood cell.

* Adjusted for age, year of diagnosis, ethnicity, smoking status, drinking status, stage, grade, estrogen receptor status, and progesterone receptor status.

# Adjusted for age, year of diagnosis, smoking status, drinking status, stage, grade, estrogen receptor status, and progesterone receptor status.

Supplementary Table S4 Associations between the levels of HGB/RDW and 5-year survival of breast cancer

All / Blacks / Whites
Alive/Dead / HR(95% CI) / P / HR(95% CI)* / P* / Alive/Dead / HR(95% CI) / P / HR(95% CI)# / P# / Alive/Dead / HR(95% CI) / P / HR(95% CI)# / P#
HGB
≥12 g/dL / 1216/139 / 1.00 / 1.00 / 221/38 / 1.00 / 1.00 / 995/101 / 1.00 / 1.00
<12g/dL / 340/121 / 2.93(2.30-3.74) / <0.0001 / 2.22(1.71-2.86) / <0.0001 / 138/46 / 1.91(1.24-2.94) / 0.0032 / 1.37(0.87-2.18) / 0.1771 / 202/75 / 3.28(2.43-4.42) / <0.0001 / 2.64(1.94-3.59) / <0.0001
RDW
≤14.5% / 1323/177 / 1.00 / 1.00 / 242/51 / 1.00 / 1.00 / 1081/126 / 1.00 / 1.00
>14.5% / 233/83 / 2.74(2.11-3.56) / <0.0001 / 1.76(1.33-2.32) / <0.0001 / 117/33 / 1.47(0.95-2.28) / 0.0842 / 1.53(0.96-2.45) / 0.0734 / 116/50 / 3.53(2.54-4.89) / <0.0001 / 2.13(1.50-3.01) / <0.0001

HR: hazard ratio; CI: confidence interval; HGB: hemoglobin; RDW: red blood cell distribution width.

* Adjusted for age, year of diagnosis, ethnicity, smoking status, drinking status, stage, grade, estrogen receptor status, and progesterone receptor status.

# Adjusted for age, year of diagnosis, smoking status, drinking status, stage, grade, estrogen receptor status, and progesterone receptor status.

Supplementary Table S5 Survival disparity in different matching groups stratified by tumor stage

Black patients (stage I & II) / White patients Presentation match / White patients Presentation+ HGB match / White patients Treatment match / Black patients (stage III & IV) / White patients Presentation match / White patients Presentation+ HGB match / White patients Treatment match
Alive/Dead / 282/56 / 297/41 / 289/49 / 295/43 / 35/52 / 45/42 / 43/44 / 44/43
HR(95% CI) / 1.00 / 0.66 (0.44-0.99) / 0.78 (0.53-1.15) / 0.72 (0.48-1.07) / 1.00 / 0.67 (0.44-1.00) / 0.76 (0.51-1.13) / 0.65 (0.43-0.97)
P values / 0.0420 / 0.2077 / 0.1047 / 0.0503 / 0.1763 / 0.0352

HR: hazard ratio; CI: confidence interval; HGB: hemoglobin.