Table 1.

Clinical, pathologic, and molecular features according to tumor PDCD1LG2 (PD-L2) expression in 823 colorectal cancer cases

Fraction of PDCD1LG2-expressing tumor cells (quartile)a
CharacteristicbTotal (n = 823)0%–20%, quartile 1 (n = 210)21%–50%, quartile 2 (n = 187)51%–80%, quartile 3 (n = 247)81%–100%, quartile 4 (n = 179)Pc
Mean age ± SD (y)68.7 ± 9.068.1 ± 9.168.8 ± 10.169.3 ± 8.768.5 ± 8.10.60
Sex0.0001
 Men364 (44%)98 (47%)96 (51%)117 (47%)53 (30%)
 Women459 (56%)112 (53%)91 (49%)130 (53%)126 (70%)
Year of diagnosis0.66
 Prior to 1996272 (33%)76 (36%)59 (32%)77 (31%)60 (34%)
 1996–2000284 (35%)62 (30%)72 (39%)88 (36%)62 (35%)
 2001–2008267 (32%)72 (34%)56 (30%)82 (33%)57 (32%)
Family history of colorectal cancer in a first-degree relative0.58
 Absent642 (79%)164 (80%)138 (75%)196 (80%)144 (80%)
 Present170 (21%)42 (20%)45 (25%)48 (20%)35 (20%)
Tumor location0.040
 Cecum146 (18%)45 (22%)40 (22%)39 (16%)22 (12%)
 Ascending to transverse colon260 (32%)68 (33%)58 (31%)67 (27%)67 (38%)
 Splenic flexure to sigmoid249 (30%)56 (27%)46 (25%)90 (36%)57 (32%)
 Rectosigmoid and rectum164 (20%)40 (19%)42 (23%)51 (21%)31 (18%)
Disease stage0.39
 I171 (23%)39 (21%)42 (24%)50 (22%)40 (24%)
 II250 (33%)61 (33%)63 (37%)78 (34%)48 (29%)
 III216 (29%)54 (29%)44 (26%)74 (32%)44 (26%)
 IV120 (16%)33 (18%)23 (13%)29 (13%)35 (21%)
Tumor differentiation0.001
 Well to moderate746 (91%)177 (84%)171 (92%)234 (95%)164 (92%)
 Poor75 (9%)33 (16%)14 (8%)13 (5%)15 (8%)
MSI status0.86
 Non–MSI-high663 (83%)167 (82%)149 (82%)203 (84%)144 (85%)
 MSI-high136 (17%)37 (18%)33 (18%)40 (16%)26 (15%)
CIMP status0.047
 Low/negative627 (83%)154 (79%)141 (82%)183 (81%)149 (90%)
 High131 (17%)40 (21%)30 (18%)44 (19%)17 (10%)
BRAF mutation0.52
 Wild type686 (85%)171 (83%)161 (88%)208 (84%)146 (85%)
 Mutant119 (15%)34 (17%)21 (12%)39 (16%)25 (15%)
KRAS mutation0.27
 Wild type474 (59%)111 (55%)117 (65%)145 (59%)101 (59%)
 Mutant327 (41%)92 (45%)64 (35%)100 (41%)71 (41%)
PIK3CA mutation0.43
 Wild type639 (85%)150 (83%)154 (88%)204 (86%)131 (82%)
 Mutant113 (15%)31 (17%)22 (13%)32 (14%)28 (18%)
Mean LINE-1 methylation level ± SD (%)62.2 ± 9.763.5 ± 9.961.9 ± 9.761.7 ± 9.961.6 ± 8.90.15
Fusobacterium nucleatum DNA0.44
 Negative574 (87%)139 (85%)129 (85%)183 (89%)123 (89%)
 Low42 (6%)15 (9%)8 (5%)12 (6%)7 (5%)
 High42 (6%)10 (6%)14 (9%)10 (5%)8 (6%)
Tumor CD274 (PD-L1) expression level0.001
 Low296 (38%)84 (44%)80 (45%)86 (36%)46 (27%)
 High478 (62%)106 (56%)98 (55%)150 (64%)124 (73%)
  • Abbreviation: CIMP, CpG island methylator phenotype.

  • aTumors were categorized into quartiles according to the percentage of PDCD1LG2-expressing carcinoma cells (quartile 1, 0%–20%; quartile 2, 21%–50%; quartile 3, 51%–80%; quartile 4, 81%–100%).

  • bPercentage indicates the proportion of cases with a specific clinical, pathologic, or molecular feature in colorectal cancer cases with each quartile category of tumor PDCD1LG2 expression.

  • cTo assess associations between the quartile categories of tumor PDCD1LG2 expression and categorical data, the χ2 test was performed. To compare mean age and mean LINE-1 methylation, an ANOVA was performed. We adjusted two-sided α level to 0.003 (≈0.05/15) by simple Bonferroni correction for multiple hypothesis testing.