Prognostic significance of stroma tumorinfiltrating lymphocytes according to molecular subtypes of breast cancer Hee Jung Kwon, Nuri Jang, Min Hui Park, Young Kyung Bae Department of Pathology, Yeungnam University College of Medicine
The authors declare that there is no conflict of interest.
Backgroud Tumor infiltrating lymphocytes (TILs) Indicator of immune microenvironment in cancer tissues Prognostic factor and predictor of therapeutic efficacy
Aim of this study 1. To investigate whether stromal TILs (stils) which is measured in routine clinical practice is prognostic in breast cancer 2. To find valid cutoffs for TILs that represent clinical significance
Material & Methods Invasive breast carcinoma samples (n=1489) Patients who underwent surgical resection between 1995-2007 postoperative follow-up: 0-238 months (median, 117 months) Adjuvant chemotherapy Chemotherapy type Regimen Number of cases None 208 208 Anthracyclines FEC 620 1024 AC 274 FAC 130 Others 5-FU 133 257 CMF 94 Taxol, taxotere, furtulon, xeloda 30 Total 1489 1489
Material & Methods Measurement of TILs one representative whole section H&E slide Inside the borders of invasive tumor Only stromal TILs (lymphocytes and plasma cells) Percentage of stromal TILs over the analyzed stromal area (1%, 5%, 10%, 20%, 30%...) Average TILs (not hotspots) International TILs Working Group 2014 (Ann Oncol 2014; 26: 259) + Average
Material & Methods Molecular subtypes St. Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2013 Ann. Oncol. 2013; 24: 2206-2223 Subtype Definition No. of cases Luminal A ER+/PR+/HER2 /Ki-67 20% 424 Luminal B, HER2-negative Luminal B, HER2-positive ER+/HER2 /Ki-67>20% or ER+/HER2 /PR or low ER+/HER2+/any Ki-67/any PR 467 123 HER2-positive ER /PR /HER2+ 155 Triple-negative ER /PR /HER2 308 Unknown 12 Total 1489 278
Results Representative cases showing variable density of TILs 1% 10% 40% 70%
Results Distribution of cases according to % stromal TILs TILs high (n=427, 28.7%) Mean: 9.85% Median: 5% ROC curve: 5% (AUC=0.598; 95% CI, 0.570-0.625; p<0.001)
Results Correlations between TILs and clinicopathological parameters Parameter Total cases TILs (n=1489) (%) Low (%) (n = 1062) High (%) (n = 427) P-value Age 0.847 <50 975 (65.5) 697 (65.6) 278 (65.1) 50 514 (34.5) 365 (34.4) 149 (34.9) Tumor size 0.001 2 cm 787 (52.9) 591 (55.6) 196 (45.9) >2 cm 702 (47.1) 471 (44.4) 231 (54.1) LN metastasis 0.524 Absent 809 (54.4) 571 (53.9) 238 (55.7) Present 677 (45.6) 488 (46.1) 189 (44.3) LVI 0.182 Absent 737 (49.5) 514 (48.4) 223 (52.2) Present 752 (50.5) 548 (51.6) 204 (47.8) Histological grade <0.001 1 and 2 703 (47.2) 613 (57.7) 90 (21.1) 3 786 (52.8) 449 (42.3) 337 (78.9) Estrogen receptor <0.001 Negative 476 (32.0) 219 (20.6) 257 (60.2) Positive 1013 (68.0) 843 (79.4) 170 (39.8) Progesterone receptor <0.001 Negative 615 (41.3) 330 (31.1) 285 (66.7) Positive 874 (58.7) 732 (68.9) 142 (33.3) HER2 <0.001 Negative 1207 (81.1) 908 (85.5) 299 (70.0) Positive 282 (18.9) 154 (14.5) 128 (30.0) Ki-67 labeling index <0.001 20% 621 (41.7) 540 (50.9) 81 (19.0) >20% 867 (58.3) 521 (49.1) 346 (81.0)
Results TILs according to molecular subtypes Comparison of TILs between two different molecular subtypes Lum A Lum B (HER2-) HER2+ TNBC Lum A Lum B (HER2-) p=0.147* HER2+ p<0.001* p<0.001* TNBC p<0.001* p<0.001* p<0.001* *P value by one-way ANOVA
Results TILs according to adjuvant chemotherapy Comparison of TILs between two different treatment groups No CTx Anthracycline Nonanthracycli ne No CTx p<0.001* Anthracycline Nonanthracycli ne p=0.024 p=0.270 *P value by one-way ANOVA
Results: Survival analysis in all patients (n=1489) High TILs (n=427) High TILs (n=427) Low TILs (n=1062) Low TILs (n=1062) p=0.09 p<0.001
Results: Survival analysis in all patients (n=1489) Multivariate analysis for DFS TILs, 10% p<0.001 Tumor size, >2 cm p=0.016 LN metastasis LVI p=0.001 p<0.001 Histologic grade, 3 ER positivity PR positivity HER2 positivity Ki-67, >20% Adjuvant CTx -anthracyclines Adjuvant CTx -non-anthracyclines * * * * * p=0.001 * favorable unfavorable Hazard ratio (range, 95% confidence interval) for recurrence/metastasis * p>0.05
Results: Survival analysis according to adjuvant chemotherapy in all patients (n=1489) Low TILs group (n=1062) High TILs group (n=427) No chemotherapy (n=175) Non-anthracycline (n=191) Anthracycline (n=696) Anthracycline (n=328) Non-anthracycline (n=66) No chemotherapy (n=33) p<0.001 p=0.222
Results: subgroup analysis No chemotherapy (n=208) Anthracyclines (n=1024) Non-anthracyclines (n=257) Low TILs (n=175) High TILs (n=33) High TILs (n=328) Low TILs (n=696) Low TILs (n=191) High TILs (n=66) p=0.293 p=0.012 p=0.873 Low TILs (n=175) High TILs (n=328) High TILs (n=66) High TILs (n=33) Low TILs (n=696) Low TILs (n=191) p=0.02 p<0.001 p=0.158
Results: Survival analysis in anthracycline group (n=1014) Luminal A Luminal B (HER2-) HER2+ Triple-negative High TILs (n=22) High TILs (n=59) High TILs (n=106) High TILs (n=137) Low TILs (n=220) Low TILs (n=254) Low TILs (n=122) Low TILs (n=94) p=0.519 p=0.012 p=0.064 p=0.063 p=0.394 p=0.002 p=0.007 p=0.031
Multivariate analysis for DFS Luminal B (HER2-) subtype TILs, 10% p=0.003 Tumor size, >2 cm Histologic grade, 3 p=0.009 p=0.002 HER2+ subtype TILs, 10% p=0.011 LVI p=0.045 Triple-negative subtype TILs, 10% p=0.034 LVI p<0.001 Hazard ratio (range, 95% confidence interval) for recurrence/metastasis
Conclusion High TILs ( 10%) was significantly associated with large tumor size (>2cm), histologic grade 3, negative hormone receptors, positive HER2 status and high Ki-67 (>20%) Prognostic significance of TILs was associated with adjuvant treatment and molecular subtypes High TILs was predictive of better OS and DFS in patients who received adjuvant anthracyclines in univariate and multivariate analyses High TILs was an independent marker for favorable DFS in patients with luminal B (HER2-), HER2+, and TNBC in univariate and multivariate analyses High TILs could be a useful marker to predict therapeutic effect of anthracyclines in luminal B, as well as HER2-positive and triple-negative subtypes of breast cancer