Figures (5)  Tables (4)

    • Figure 1. 

      Flow diagram of eligible patients diagnosed with T1 stage CRC.

    • Figure 2. 

      Proportion of different treatments between 2000-2018.

    • Figure 3. 

      Kaplan–Meier curves of overall and cancer-specific survival according to treatment methods (a), (b) before PSM, and (c), (d) after PSM.

    • Figure 4. 

      Cox regression model of multivariable analyses in (a) OS, and (b) CSS.

    • Figure 5. 

      Subgroup analysis divided by (a) age, (b) sex, or (c) histological grade of the CSS rate by the two treatment options.

    • Variables Surgery
      (n = 4,116)      		 ET
      (n = 718)      		 p-value
      Age (years) 20−59 970 (83.8) 188 (16.2) 0.175
      60−79 2,374 (86.0) 388 (14.0)
      ≥ 80 772 (84.5) 142 (15.5)
      Marital status Unmarried 1,532 (84.8) 274 (15.2) 0.646
      Married 2,584 (85.3) 444 (14.7)
      Sex Male 2,089 (84.8) 373 (15.2) 0.571
      Female 2,027 (85.5) 345 (14.5)
      Race Non-API 3,840 (85.0) 675 (15.5) 0.515
      API 276 (86.5) 43 (13.5)
      Tumor size ≤ 3 cm 2,413 (81.2) 557 (18.8) < 0.001
      > 3 cm 1,703 (91.4) 161 (8.6)
      Histological
      grade      		 Grade I 984 (81.4) 225 (18.6) < 0.001
      Grade II 2,813 (86.3) 446 (13.7)
      Grade III−IV 319 (87.2) 47 (12.8)
      LNM Negative 3,888 (84.4) 716 (15.6) < 0.001
      Positive 288 (99.1) 2 (0.9)
      Tumor location Colon 2,927 (90.4) 311 (9.6) < 0.001
      Rectum 1,189 (74.5) 407 (25.5)
      Stage 0 269 (72.9) 100 (27.1) < 0.001
      1 3,407 (85.0) 602 (15.0)
      2 217 (93.9) 14 (6.1)
      3 223 (99.1) 2 (0.9)
      T stage Tis 277 (73.5) 100 (26.5) < 0.001
      T1 3,839 (86.1) 618 (13.9)

      Table 1. 

      Baseline characteristics of patients treated with surgery and ET for T1 stage colorectal cancer before PSM.

    • Variables Univariate analysis Multivariate analysis
      CSS OS CSS OS
      HR (95% CI) p-value HR (95% CI) p-value HR (95% CI) p-value HR (95% CI) p-value
      Age (years) 20–59 Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      60–79 1.818 (1.448–2.283) < 0.001 3.409 (3.004–3.867) < 0.001 1.857 (1.477–2.335) < 0.001 3.363 (2.963–3.816) < 0.001
      ≥ 80 3.818 (2.934–4.968) < 0.001 10.286 (8.963–11.805) < 0.001 3.757 (2.866–4.926) < 0.001 9.797 (8.513–11.273) < 0.001
      Sex Female Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Male 1.075 (0.914–1.265) 0.384 1.073 (0.998–1.155) 0.058 1.270 (1.069–1.508) 0.007 1.302 (1.205–1.407) < 0.001
      Race Non–API Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      API 1.181 (0.874–1.596) 0.278 0.774 (0.658–0.910) 0.002 1.327 (0.980–1.796) 0.068 0.918 (0.780–1.080) 0.302
      Marital status Unmarried Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Married 0.685 (0.581–0.807) < 0.001 0.660 (0.612–0.710) < 0.001 0.751 (0.628–0.897) 0.002 0.780 (0.720–0.846) < 0.001
      Tumor size ≤ 3 cm Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      > 3 cm 1.404 (1.193–1.652) < 0.001 1.182 (1.097–1.273) < 0.001 1.362 (1.153–1.610) < 0.001 1.101 (1.021–1.188) 0.013
      Histological
      grade      		 Grade I Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Grade II 1.177 (0.962–1.439) 0.113 1.025 (0.941–1.117) 0.569 1.156 (0.942–1.418) 0.166 1.014 (0.930–1.106) 0.753
      Grade III–IV 1.725 (1.270–2.343) < 0.001 1.097 (0.942–1.276) 0.234 1.627 (1.193–2.219) 0.002 1.085 (0.931–1.265) 0.295
      LNM Negative Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Positive 1.864 (1.383–2.511) < 0.001 1.004 (0.841–1.198) 0.966 0.595 (0.053–6.709) 0.674 0.248 (0.059–1.047) 0.058
      T stage Tis Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      T1 0.726 (0.552–0.954) 0.022 0.836 (0.733–0.953) 0.007 0.165 (0.023–1.194) 0.074 0.123 (0.039–0.385) < 0.001
      Stage 0 Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      1 0.732 (0.552–0.970) 0.030 0.858 (0.750–0.980) 0.024 4.779 (0.646–35.344) 0.125 7.463 (2.362–23.580) 0.001
      2 0.669 (0.377–1.189) 0.171 0.825 (0.621–1.095) 0.183 4.965 (0.630–39.152) 0.128 7.942 (2.443–25.822) 0.001
      3 1.359 (0.915–2.019) 0.129 0.849 (0.683–1.055) 0.140 16.551 (0.252–1087.739) 0.189 32.986 (2.877–387.235) 0.005
      Location Colon Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Rectum 1.246 (1.056–1.472) 0.009 0.851 (0.787–0.921) < 0.001 1.238 (1.041–1.473) 0.016 0.934 (0.861–1.014) 0.101
      Treatment
      option      		 Surgery Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      ET 1.375 (1.120–1.687) 0.002 0.992 (0.896–1.098) 0.878 1.474 (1.184–1.834) 0.001 1.080 (0.970–1.203) 0.159
      CI, confidence interval; CSS, cancer–specific survival; OS, overall survival; HR, hazard ratio; API, Asian Pacific Islander.

      Table 2. 

      Univariate and multivariate analyses of OS and CSS in patients with T1 stage colorectal cancer treated with surgery and endoscopy before propensity score matching.

    • Variables Surgery
      (n = 663) n (%)      		 Endoscopy
      (n = 663) n (%)      		 p-value
      Age (years) 20−59 170 (50) 170 (50) 0.991
      60−79 367 (49.9) 369 (50.1)
      ≥ 80 126 (50.4) 124 (49.6)
      Marital status Unmarried 248 (49.8) 250 (50.2) 0.955
      Married 415 (50.1) 413 (49.9)
      Sex Male 341 (49.8) 344 (50.2) 0.912
      Female 322 (50.2) 319 (49.8)
      Race Non-API 632 (50.0) 633 (50.0) 1.000
      API 31 (50.8) 30 (49.2)
      Tumor size ≤ 3 cm 511 (50.0) 511 (50.0) 1.000
      > 3 cm 152 (50.0) 152 (50.0)
      Histological
      grade      		 Grade I 198 (50.0) 198 (50.0) 1.000
      Grade II 430 (50.1) 429 (49.9)
      Grade III-IV 35 (49.3) 36 (50.7)
      LNM Negative 662 (50.0) 662 (50.0) 1.000
      Positive 1 (50.0) 1 (50.0)
      Location Colon 301 (50) 301 (50) 1.000
      Rectum 362 (50) 362 (50)
      Stage 0 69 (49.6) 70 (50.4) 0.988
      1 583 (50.1) 581 (49.9)
      2 10 (47.6) 11 (52.4)
      3 1 (50) 1 (50)
      T stage Tis 69 (49.6) 70 (50.4) 1.000
      T1 594 (50) 593 (50.0)

      Table 3. 

      Baseline characteristics of patients treated with surgery and ET for T1 stage colorectal cancer after PSM.

    • Variables Univariate analysis Multivariate analysis
      CSS OS CSS OS
      HR (95% CI) p-value HR (95% CI) p-value HR (95% CI) p-value HR (95% CI) p-value
      Age (years) 20–59 Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      60–79 1.811 (1.216–2.699) 0.003 3.698 (2.912–4.696) < 0.001 1.898 (1.269–2.838) 0.002 3.677 (2.892–4.675) < 0.001
      ≥ 80 4.070 (2.557–6.476) < 0.001 12.375 (9.527–16.075) < 0.001 4.286 (2.625–6.999) <0.001 11.638 (8.883–11.248) < 0.001
      Sex Female Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Male 1.120 (0.834–1.505) 0.452 0.915 (0.975–1.051) 0.209 1.480 (1.072–2.044) 0.017 1.257 (1.079–1.465) 0.003
      Race Non–API Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      API 1.531 (0.870–2.692) 0.139 0.720 (0.497–1.043) 0.083 2.004 (1.126–3.569) 0.018 0.937 (0.644–1.362) 0.733
      Marital status Unmarried Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Married 0.667 (0.495–0.899) 0.008 0.599 (0.486–0.644) < 0.001 0.733 (0.524–1.024) 0.068 0.762 (0.650–0.894) 0.001
      Tumor size ≤ 3 cm Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      > 3 cm 1.242 (0.890–1.733) 0.203 1.042 (0.883–1.229) 0.627 1.164 (0.827–1.640) 0.384 1.027 (0.868–1.217) 0.754
      Histological
      grade      		 Grade I Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Grade II 1.534 (1.067–2.204) 0.021 1.043 (0.893–1.218) 0.598 1.560 (1.070–2.275) 0.021 1.145 (0.973–1.348) 0.102
      Grade III–IV 2.042 (1.088–3.834) 0.026 1.084 (0.780–1.506) 0.632 2.170 (1.143–4.120) 0.018 1.121 (0.803–1.565) 0.503
      Nodal status Negative Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Positive NA NA 0.050 (0.001–44.849) 0.387 NA NA NA NA
      T stage Tis Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      T1 1.083 (0.657–1.786) 0.754 0.910 (0.729–1.136) 0.403 1.957 (0.563–6.809) 0.291 0.641 (0.202–2.037) 0.451
      Stage 0 Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      1 1.077 (0.653–1.776) 0.773 0.916 (0.734–1.143) 0.436 0.473 (0.149–1.507) 0.205 1.445 (0.463–4.511) 0.526
      2 1.937 (0.565–6.641) 0.293 0.472 (0.149–1.494) 0.201 NA NA NA NA
      3 NA NA NA NA NA NA NA NA
      Location Colon Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      Rectum 1.150 (0.853–1.550) 0.360 0.860 (0.748–0.989) 0.034 1.103 (0.808–1.505) 0.536 0.879 (0.760–1.017) 0.082
      Treatment
      option      		 Surgery Ref 1.0 Ref 1.0 Ref 1.0 Ref 1.0
      ET 1.246 (0.927–1.673) 0.145 1.044 (0.908–1.201) 0.541 1.273 (0.947–1.710) 0.110 1.074 (0.934–1.235) 0.316
      CI, confidence interval; CSS, cancer–specific survival; OS, overall survival; HR, hazard ratio; API, Asian Pacific Islander.

      Table 4. 

      Univariate and multivariate analyses of OS and CSS in patients with T1 stage colorectal cancer treated with surgery and ET after PSM.