Figures (2)  Tables (5)

    • Figure 1. 

      Representative immunohistochemical staining in gastric adenocarcinoma. (a) ERBB2 amplification (HER-2 positive); (b) ERBB2 amplification was not obvious (HER-2 negative); (c) expression of MLH1 protein; (d) deletion of MLH1 protein; (e) expression of MSH2 protein; (f) deletion of MSH2 protein; (g) expression of MSH6 protein; (h) deletion of MSH6 protein; (i) expression of PMS2 protein; (j) deletion of PMS2 protein; (k) positive PD-L1 (CPS ≥ 5); (l) PD-L1 negative (CPS < 5). Scale = 200 μm.

    • Figure 2. 

      The relationship between ERBB2, microsatellite status, PD-L1 expression, and prognosis of patients. (a) Survival curve of ERBB2 expression and prognosis; (b) survival curve of microsatellite status and prognosis; (c) survival curve of PD-L1 expression and prognosis.

    • Target protein Company Product name Item No. Batch No. Clone No. Antibody type
      PMS2 Beijing Zhongshan Jinqiao Biotechnology PMS2 protein ZM-0407 24090414 OTI4B2 Mouse monoclonal
      MSH2 Beijing Zhongshan Jinqiao Biotechnology MSH2 protein ZA-0702 25012033 OTIR1B12 Rabbit monoclonal
      MSH6 Beijing Zhongshan Jinqiao Biotechnology MSH6 protein ZM-0367 24111703 UMAB258 Mouse monoclonal
      MLH1 Beijing Zhongshan Jinqiao Biotechnology MLH1 protein ZM-0152 24112706 OTI4H4 Mouse monoclonal
      HER-2 Roche Diagnostics GmbH HER-2/NEU antibody reagent (IHC method) − (10) M22565 − −
      PD-L1 Dako Monoclonal Mouse Anti-PD-L1, Clone 22C3 − 11756940 22C3 Mouse monoclonal

      Table 1. 

      Antibodies and reagents used in the study.

    • Clinicopathological features ERBB2(−)
      (n = 150)      		 ERBB2(+)
      (n = 26)      		 χ2 p-value
      Gender 1.997 0.158
      Male 107 (71.33%) 22 (84.62%)
      Female 43 (28.67%) 4 (15.38%)
      Age 0.798 0.372
      < 65 66 (44.00%) 9 (34.62%)
      ≥ 65 84 (56.00%) 17 (65.38%)
      Differentiation degree 8.935 0.047
      High differentiated 3 (2.00%) 0 (0%)
      Moderately differentiated 54 (36.00%) 13 (50.00%)
      Poorly differentiated 73 (48.67%) 6 (23.08%)
      Signet ring cell 4 (2.67%) 0 (0%)
      NA 16 (10.67%) 7 (26.92%)
      Surgery 2.618 0.270
      Initial surgery 135 (90.00%) 21 (80.77%)
      Neoadjuvant post-surgery 5 (3.33%) 2 (7.69%)
      None 10 (6.67%) 3 (11.54%)
      T stage 1.719 0.622
      T1 14 (9.33%) 1 (3.85%)
      T2 39 (26.00%) 8 (30.77%)
      T3 81 (54.00%) 16 (61.54%)
      T4 16 (10.67%) 1 (3.85%)
      N stage 1.881 0.610
      N0 52 (34.67%) 7 (26.92)
      N1 24 (16.00%) 6 (23.08%)
      N2 36 (24.00%) 8 (30.77%)
      N3 38 (25.33%) 5 (19.23%)
      M stage 0.151*
      M0 137 (91.33%) 21 (80.77%)
      M1 13 (8.67%) 5 (19.23%)
      * Fisher's exact test was used for M stage analysis.

      Table 2. 

      Relationship between ERBB2 gene amplification and clinicopathological features.

    • Clinicopathological features pMMR
      (n = 154)      		 dMMR
      (n = 22)      		 χ2 p-value
      Gender 13.473 <0.001
      Male 120 (77.92%) 9 (40.91%)
      Female 34 (22.08%) 13 (59.09%)
      Age 0.083 0.773
      < 65 65 (42.21%) 10 (45.45%)
      ≥ 65 89 (57.79%) 12 (54.55%)
      Differentiation degree 11.385 0.011
      High differentiated 2 (1.30%) 1 (4.55%)
      Moderately differentiated 53 (34.42%) 14 (63.64%)
      Poorly differentiated 75 (48.70%) 4 (18.18%)
      Signet ring cell 3 (1.95%) 1 (4.55%)
      NA 21 (13.64%) 2 (9.09%)
      Surgery 0.535 0.861
      Initial surgery 135 (87.66%) 21 (95.45%)
      Neoadjuvant post-surgery 7 (4.55%) 0 (0%)
      None 12 (7.79%) 1 (4.55%)
      T stage 6.253 0.069
      T1 11 (7.14%) 4 (18.18%)
      T2 39 (25.32%) 8 (36.36%)
      T3 87 (56.49%) 10 (45.45%)
      T4 17 (11.04%) 0 (0%)
      N stage 4.507 0.208
      N0 47 (30.52%) 12 (54.54%)
      N1 27 (17.53%) 3 (13.64%)
      N2 40 (25.97%) 4 (18.18%)
      N3 40 (25.97%) 3 (13.64%)
      M stage 1.000*
      M0 138 (89.61%) 20 (90.91%)
      M1 16 (10.39%) 2 (9.09%)
      * Fisher's exact test was used for M stage analysis.

      Table 3. 

      Relationship between mismatch repair (MMR) gene status and clinicopathological features.

    • Clinicopathological
      features      		 ERBB2(−)
      (n = 150)      		 ERBB2(+)
      (n = 26)      		 χ2 p-value
      Mismatch repair status 0.206*
      pMMR 129 (86.00%) 25 (96.15%)
      dMMR 21 (14.00%) 1 (3.85%)
      * Fisher's exact test was used for statistical analysis.

      Table 4. 

      Association between ERBB2 expression and mismatch repair status.

    • Clinicopathological features Events
      (n)      		 Mean DFS
      (months) ± SD      		 χ2 p-value
      ERBB2 status 0.057 0.812
      Negative (−) 48 40.312 ± 17.40
      Positive (+) 9 38.003 ± 13.73
      MMR status 0.009 0.926
      pMMR 50 40.67 ± 14.36
      dMMR 7 40.18 ± 14.49
      PD-L1 expression 5.898 0.015*
      Negative (−) 32 41.08 ± 17.27
      Positive (+) 25 40.31 ± 17.40
      * p < 0.05 indicates statistical significance.

      Table 5. 

      Association of ERBB2, MMR, and PD-L1 expression with patient prognosis.