Table. Characteristics of the Study Population at Baseline.
| Characteristics | Stromal TIL percentage | |||
|---|---|---|---|---|
| <30 (n = 1300) | 30-49 (n = 249) | 50-74 (n = 249) | ≥75 (n = 168) | |
| Age, median (IQR), y | 59 (41-72) | 57 (43-70) | 48 (37-68) | 38 (35-55) |
| Age <50 y, No. (%) | 467 (36) | 84 (34) | 130 (52) | 119 (71) |
| Premenopausal, No./total No. (%) | 198/929 (21) | 51/192 (27) | 39/139 (28) | 20/55 (36) |
| Tumor size, cm | ||||
| Median (IQR) | 2.0 (1.2-2.5) | 2 (1.2-2.8) | 2 (1.3-3.0) | 1.8 (1.3-2.3) |
| Mean (SD) | 2.1 (1.6) | 2.2 (1.4) | 2.4 (1.6) | 1.9 (1.1) |
| Pathologic tumor size, No./total No. (%)a | ||||
| <2 cm (pT1) | 782/1278 (61) | 142/249 (57) | 126/247 (51) | 109/166 (66) |
| 2-5 cm (pT2) | 448/1278 (35) | 97/249 (39) | 105/247 (43) | 55/166 (33) |
| >5 cm (pT3) or any size with chest wall or skin extension (pT4)b | 48/1278 (4) | 10/249 (4) | 16/247 (7) | 2/166 (1) |
| ALN metastases, No./total No. (%)c | ||||
| None (pN0) | 1075/1252 (86) | 205/243 (84) | 211/244 (87) | 160/167 (96) |
| 1-3 ALN (pN1) | 117/1252 (9) | 24/243 (10) | 22/244 (9) | 3/167 (2) |
| 4-9 ALN (pN2) | 41/1252 (3) | 7/243 (3) | 10/244 (4) | 4/167 (2) |
| ≥10 ALN (pN3) | 19/1252 (2) | 7/243 (3) | 1/244 (0.4) | 0/167 (0) |
| AJCC anatomic stage, No./total No. (%)d | ||||
| I | 689/1230 (56) | 124/243 (51) | 114/242 (47) | 107/165 (65) |
| II | 470/1230 (38) | 105/243 (43) | 114/242 (47) | 54/165 (33) |
| III | 71/1230 (6) | 14/243 (6) | 14/242 (6) | 4/165 (2) |
| pT1 N0 subgroups, No./total No. (% of stage I) | ||||
| pT1mi N0 tumor, ≤0.1 cm | 21/675 (3) | 3/122 (3) | 9/108 (8) | 0/102 (0) |
| pT1a N0 tumor, 0.2-0.5 cm | 66/675 (10) | 16/122 (13) | 17/108 (16) | 12/102 (12) |
| pT1b N0 tumor, 0.6-1.0 cm | 146/675 (22) | 31/122 (25) | 19/108 (18) | 18/102 (18) |
| pT1c N0 tumor, 1.1-2.0 cm | 442/675 (65) | 72/122 (59) | 63/108 (58) | 72/102 (71) |
| Histological subtype, No./total No. (%) | ||||
| Invasive breast carcinomae | 937/1225 (77) | 186/239 (78) | 186/240 (78) | 118/166 (71) |
| Medullary | 32/1225 (3) | 21/239 (9) | 30/240 (13) | 37/166 (22) |
| Lobular carcinomaf | 35/1225 (3) | 2/239 (1) | 2/240 (1) | 2/166 (1) |
| Metaplastic carcinomaf | 45/1225 (4) | 3/239 (1) | 10/240 (4) | 4/166 (2) |
| Mucinous adenocarcinoma | 8/1225 (0.7) | 0/239 | 1/240 (0.4) | 0/166 |
| Tubular carcinoma | 2/1225 (0.2) | 1/239 (0.4) | 0/240 | 0/166 |
| Otherg | 166/1225 (14) | 26/239 (11) | 11/240 (5) | 5/166 (3) |
| Histological grade, No./total No. (%)h | ||||
| Low | 85/1285 (7) | 7/242 (3) | 2/245 (1) | 1/165 (1) |
| Intermediate | 384/1285 (30) | 44/242 (18) | 30/245 (12) | 15/165 (9) |
| High | 816/1285 (64) | 191/242 (79) | 213/245 (87) | 149/165 (90) |
| Stromal TIL levels, %i | ||||
| TIL level, median (IQR), % | 5 (4-15) | 35 (30-40) | 60 (55-70) | 85 (80-90) |
| TIL level, mean (SD), % | 9 (7) | 36 (6) | 61 (7) | 85 (7) |
| Primary surgery, No./total No. (%) | ||||
| Breast conservation | 789/1297 (61) | 147/249 (59) | 141/248 (57) | 124/165 (75) |
| Mastectomy | 508/1297 (39) | 102/249 (41) | 107/248 (43) | 41/165 (25) |
| Adjuvant radiotherapy | 793/1292 (61) | 146/248 (59) | 148/246 (60) | 124/168 (74) |
Abbreviations: AJCC, American Joint Committee on Cancer; ALN, axillary lymph node; TIL, tumor-infiltrating lymphocyte.
Refers to tumor size on surgical specimen.
Data for pT3 and pT4 were combined into a single category given that only tumor size information was available. Information on characteristics defining T4 tumors (extension to chest wall, ulceration, skin nodules, inflammatory changes) was not available.
Pathologic nodal stage refers to the number of lymph nodes affected by metastases.
Categories indicate AJCC 8th edition anatomic stages: I, less advanced disease with a pT1 tumor and no lymph node involvement (pN0) or microscopic lymph node involvement only; II, more advanced disease with either macroscopic lymph node involvement in 1 to 3 lymph nodes (pN1) or a larger tumor (pT2-3 without nodal involvement); and III, more extensive nodal involvement (N2-3) or a T4 tumor regardless of extent of nodal involvement.
Indicates no special type of invasive breast carcinoma.
Indicates subtype category was not otherwise specified.
Other histologic subtypes included apocrine carcinoma, papillary carcinoma, anaplastic carcinoma, neuroendocrine carcinoma, secretory carcinoma, and mixed ductal and lobular carcinoma.
Histological grade describes the degree of tumor differentiation, with grade 1 tumors being well-differentiated, grade 2 tumors being moderately differentiated, and grade 3 tumors being poorly differentiated. In general, the higher the grade, the more aggressive the biology of the tumor.
Stromal TIL levels refer to the percentage of the tumor stromal area occupied by mononuclear inflammatory cells in breast tumor tissue (reported as 0%-100%), as assessed using hematoxylin and eosin–stained tissue sections according to the International Immuno-Oncology Biomarker Working Group Guidelines.