SUPPLEMENTARY MATERIAL
Supplementary Table 1. The difference in survival outcome according to several different cut-offs of PD-L1 and SUV
Characteristics PFS LRFS DMFS
No. HR (95% CI) HR (95% CI) HR (95% CI)
PD-L1 (continuous) 1.02 (1.00-1.03) 1.02 (1.00-1.03) 1.02 (1.00-1.03) PD-L1 (+) vs. (-) 97 vs. 20 6.66 (1.24-53.86) 5.27 (0.71-39.10) 5.97 (0.81-44.10) PD-L1 ≤ 80% vs. >80% 99 vs. 18 4.05 (1.86-8.83) 4.74 (2.03-11.03) 4.52 (2.04-10.01) PD-L1 ≤ 70% vs. >70% 80 vs. 37 2.76 (1.31-5.80) 2.61 (1.15-5.93) 3.24 (1.49-7.06) PD-L1 ≤ 60% vs. >60% 60 vs. 57 1.72 (0.81-3.68) 1.74 (0.75-4.02) 2.10 (0.94-4.71) PD-L1 ≤ 50% vs. >50% 48 vs. 69 2.26 (0.96-5.31) 2.13 (0.84-5.41) 2.04 (0.86-4.86) PD-L1 ≤ 40% vs. >40% 41 vs. 76 2.08 (0.84-5.14) 2.04 (0.76-5.51) 1.89 (0.76-4.71) PD-L1 ≤ 30% vs. >30% 34 vs. 83 1.97 (0.75-5.19) 2.03 (0.69-5.98) 1.80 (0.68-4.78)
SUVmax (continuous) 1.02 (0.97-1.08) 1.03 (0.98-1.09) 1.02 (0.96-1.08) SUVmax <4 vs. ≥4 23 vs. 122 1.25 (0.49-3.23) 1.04 (0.40-2.72) 1.13 (0.44-2.94) SUVmax <5 vs. ≥5 32 vs. 113 1.94 (0.75-5.00) 1.61 (0.62-4.21) 1.74 (0.67-4.53) SUVmax <6 vs. ≥6 39 vs. 106 2.52 (1.01-6.50) 2.09 (0.80-5.47) 2.27 (0.88-5.91) SUVmax <7 vs. ≥7 52 vs. 93 0.95 (0.48-1.89) 1.12 (0.52-2.39) 0.83 (0.41-1.67) SUVmax <8 vs. ≥8 60 vs. 85 0.94 (0.48-1.83) 1.21 (0.57-2.54) 0.80 (0.40-1.61) SUVmax <9 vs. ≥9 69 vs. 76 0.84 (0.43-1.64) 1.01 (0.49-2.07) 0.70 (0.35-1.40) Bold text: statistically significant cut-offs
Abbreviations: PD-L1, programmed death ligand-1; SUV, standardized uptake value; PFS, progression-free survival; LRFS, Locoregional recurrence-free survival; DMFS, distant metastasis-free survival; HR, hazard ratio; CI, confidence interval
Supplementary Table 2. Detail of patients who experienced locoregional failures
N o. Sta
ge Ag
e Lateral ity Patholo
gy HG N
G Neoadjuvant
CTx Surgery PD-L1
(%) PD-L1
>70% SUV
max
SUVmax
≥6 Adjuvant
RT RT dose
(cGy) RT
field Recurrence
pattern Recurrence site
for LRF LRF
field PFS
(mo) OS
(mo) Dea th
1 T1
N0 62 L IDC 2 3 N Mastecto
my 80 Y 2.39 N N Local +
systemic Lt. chest wall Infield* 48 124 Y
2 T2
N3 50 R IDC 3 2 Y BCS Unknow
n 6.35 Y Y WB 5940/
SCL5040 Rt.
WB, SCL
Regional +
systemic Rt. neck lymph
node Infield 12 13 Y
3 T2
N3 30 R IDC 2 2 Y Mastecto
my 70 N 8.55 Y Y 5040
Rt.
CW, IMN, AXL, SCL
Local+systemic Lt. chest wall Infield 8 34 Y
4 T2
N2 39 R IDC Unkno
wn 0 Y BCS Unknow
n 9.19 Y Y WB 5940/
SCL5040 Rt.
WB,
SCL Local Rt. breast Infield 42 51 N
5 T1
N1 38 R IDC 3 3 N Mastecto
my 90 Y 7.32 Y N Regional +
systemic Rt. IMN Infield* 19 53 Y
6 T2
N3 47 R IDC 3 2 Y Mastecto
my 100 Y 11.64 Y Y
SCL5940/
Others 5040
Rt.
CW, IMN, AXL, SCL
Regional +systemic
Bilateral SCL
lymph node Infield 18 33 Y
7 T2
N0 69 L IDC 3 2 N Mastecto
my 30 N 12.76 Y N Regional +
systemic Bilateral SCL
lymph node Infield* 19 37 Y
8 T2
N0 77 L IDC 3 3 N Mastecto
my 60 N 12.62 Y N Local +
systemic
Lt. IMN, axilla,
SCL lymph node Infield* 14 29 Y
9 T2
N0 31 R IDC 3 3 N Mastecto
my 60 N 17.49 Y N Local Rt. chest wall Infield* 36 53 N
10 T2
N3 43 L IDC 3 2 Y Mastecto
my 20 N 13.50 Y N Regional Lt. IMN, axilla,
SCL lymph node Infield* 2 22 Y
11 T2
N0 62 L IDC 3 3 N BCS 60 N 11.68 Y Y 1260 Lt.
WB Local Lt. breast Infield 5 48 N
* would be infield-failures if post-mastectomy RT was done.
Abbreviations: IDC, invasive ductal carcinoma; HG, histologic grade; NG, nuclear grade; BCS, breast-conserving surgery; PD-L1, programmed death ligand-1; SUV, standardized uptake value; RT, radiotherapy; WB, whole breast; SCL, supraclavicular lymph node;
IMN, internal mammary node; AXL, axillary lymph node; LRF, locoregional failure; PFS, progression-free survival; OS, overall survival
Supplementary Figure 1. Scatter plots with Spearman’ correlation coefficient (rho) and linear regression tests. Correlation of PD-L1 (%) with SUVmax
Supplementary Figure 2. Differences in pattern of failure according to SUVmax uptake (High SUVmax group: SUVmax ≥6, low SUVmax group: SUVmax <6)
Supplementary Text 1.
Four-micrometer-thick sections of formalin-fixed, paraffin-embedded tissues were
deparaffinized, rehydrated, and washed twice with buffer. To reduce endogenous peroxidase activity, slides were incubated in Hydrogen Peroxide Block for 10 minutes and washed four times with buffer. Slides were stained with anti-PD1 (1:100 dilution; Abcam, Cambridge, UK), anti-PD-L1 (1:2000; EMD Millipore, Temecula, CA, USA), and Ki-67 antibodies (1:200; Lab Vision Corp., Fremont, CA) according to the manufacturers’ recommendations, washed four times with buffer, incubated with Primary Antibody Enhancer for 20 minutes at room temperature, and washed four times with buffer. Slides were then treated with HRP Polymer for 30 minutes at room temperature, washed four times with buffer, incubated with hematoxylin for chromogen development, washed four times with deionized water, and counterstained.
Supplementary Text 2.
Locoregional recurrences were seen in 11 patients (8%); 6 local failures (breast 2, chest wall 4) and 5 regional failures (all within axillary, internal mammary, or supraclavicular fossa lymph node areas). Six failures occurred after radiotherapy (3 after breast-conserving surgery
+ radiotherapy and 3 after mastectomy + radiotherapy), and the remaining 5 patients were all those who did not receive radiotherapy after mastectomy even with intermediate-stage tumors.
Regardless of whether the patient received radiotherapy actually or not, all locoregional failures corresponded to the common infield of post-mastectomy radiotherapy.
