Complications during or after the endoscopic procedures.

<p>Complications during or after the endoscopic procedures.</p

Factors related to non-recurrence in the univariate or multivariate analysis.

<p>Factors related to non-recurrence in the univariate or multivariate analysis.</p

Patients’ characteristics and details of the endoscopic procedures.

<p>Patients’ characteristics and details of the endoscopic procedures.</p

Clinical course after the endoscopic procedures.

<p>Clinical course after the endoscopic procedures.</p

Schematic diagram of the patients enrollment in this study.

<p>Schematic diagram of the patients enrollment in this study.</p

Malignant Potential of Gastrointestinal Cancers Assessed by Structural Equation Modeling

<div><p>Background</p><p>Parameters reported in pathologic reviews have been failing to assess exactly the malignant potential of gastrointestinal cancers. We hypothesized that malignant potential could be defined by common latent variables (hypothesis I), but there are substantial differences in the associations between malignant potential and pathologic parameters according to the origin of gastrointestinal cancers (hypothesis II). We shed light on these issues by structural equation modeling.</p><p>Materials and Methods</p><p>We conducted a cross-sectional survey of 217 esophageal, 192 gastric, and 175 colorectal cancer patients who consecutively underwent curative surgery for their pathologic stage I cancers at Keiyukai Sapporo Hospital. Latent variables identified by factor analysis and seven conventional pathologic parameters were introduced in the structural equation modeling analysis.</p><p>Results</p><p>Because latent variables were disparate except for their number, 'three' in the examined gastrointestinal cancers, the first hypothesis was rejected. Because configural invariance across gastrointestinal cancers was not approved, the second hypothesis was verified. We could trace the three significant paths on the causal graph from latent variables to lymph node metastasis, which were mediated through depth, lymphatic invasion, and matrilysin expression in esophageal cancer, whereas only one significant path could be traced in both gastric and colorectal cancer. Two of the three latent variables were exogenous in esophageal cancer, whereas one factor was exogenous in the other gastrointestinal cancers. Cancer stemness promoted viability in esophageal cancer, but it was suppressed in others.</p><p>Conclusion</p><p>These results reflect the malignant potential of esophageal cancer is higher than that of the other gastrointestinal cancers. Such information might contribute to refining clinical treatments for gastrointestinal cancers.</p></div

Malignant potential of each GI cancer type.

<p>Malignant potential of each GI cancer type.</p

SEM of gastric cancer.

<p>Circles indicate unobserved latent variables, while rectangles represent observed variables. Yellow indicates a dependent endogenous variable and grey indicates an independent exogenous variable. Significant paths with their estimated parameter are shown by solid lines, while insignificant paths are shown by broken lines (Fig 2). Rred arrows represent either a negative causal effect or measurement errors within the model. The blue triangle in the center suggests that the malignant potential includes three latent variables. Coefficient of determination is written as R². Abbreviations: v, vascular invasion; ly, lymphatic invasion; n, lymph node metastasis; hist, histological grade.</p

SEM of colorectal cancer.

<p>Circles indicate unobserved latent variables, while rectangles represent observed variables. Yellow indicates a dependent endogenous variable and grey indicates an independent exogenous variable. Significant paths with their estimated parameter are shown by solid lines, while insignificant paths are shown by broken lines (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149327#pone.0149327.g002" target="_blank">Fig 2</a>). Red arrows represent either a negative causal effect or measurement errors within the model. The blue triangle in the center suggests that the malignant potential includes three latent variables. Coefficient of determination is written as R². Abbreviations: v, vascular invasion; ly, lymphatic invasion; n, lymph node metastasis; hist, histological grade.</p

Characteristics of the study population.

<p>Characteristics of the study population.</p