Location, morphology and invasiveness of lateral spreading tumors in the colorectum differ between two large cohorts from an eastern and western country / La localización, morfología y la infiltración de las lesiones de extensión lateral en colon y recto difieren en dos cohortes extensas de un país oriental y occidental

Background and study aims: Data from Japanese series show that surface morphology of laterally spreading tumors (LST) in the colon identifies lesions with different incidence and pattern of submucosal invasion. Such data from western countries are scarce. We compared clinical and histological features of LST in a western country and an eastern country, with special interest on mucosal invasiveness of LST, and investigated the effect of clinical factors on invasiveness in both countries. Patients and methods: Patients with LST lesions ≥20mm were included from a multicenter prospective registry in Spain and from a retrospective registry from the National Cancer Center Hospital East, Japan. The primary outcome was the presence of submucosal invasion in LST. The secondary outcome was the presence of high-risk histology, defined as high-grade dysplasia or submucosal invasion. Results: We evaluated 1102 patients in Spain and 663 in Japan. Morphological and histological characteristics differed. The prevalence of submucosal invasion in Japan was six-fold the prevalence in Spain (Prevalence Ratio PR=5.66; 95%CI: 3.96, 8.08), and the prevalence of high-risk histology was 1.5 higher (PR=1.44; 95%CI: 1.31, 1.58). Compared to the granular homogeneous type and adjusted by clinical features, granular mixed, flat elevated, and pseudo-depressed types were associated with higher odds of submucosal invasion in Japan, whereas only the pseudo-depressed type showed higher risk in Spain. Regarding high-risk histology, both granular mixed and pseudo-depressed were associated with higher odds in Japan, compared with only the granular mixed type in Spain. Conclusion: This study reveals differences in location, morphology and invasiveness of LST in an eastern and a western cohort.(AU)

Antecedentes y objetivos del estudio: Los datos de series japonesas muestran que la morfología de los tumores de extensión lateral (LST) en el colon identifica lesiones con diferente incidencia y patrón de invasión submucosa. Esta información es escasa en series de países occidentales. Comparamos las características clínicas e histológicas de LST en un país occidental y un país del este, con especial interés en la infiltración de la lesión, e investigamos el efecto de los factores clínicos sobre esta infiltración en ambos países. Pacientes y métodos: Se incluyeron pacientes con lesiones LST ≥20mm de un registro prospectivo multicéntrico en España y de un registro retrospectivo del National Cancer Center Hospital East, Japón. El objetivo primario fue la presencia de invasión submucosa en los LST. El objetivo secundario fue la presencia de histología de alto riesgo, definida como displasia de alto grado o invasión submucosa. Resultados: Evaluamos 1.102 pacientes en España y 663 en Japón. Las características morfológicas e histológicas difirieron. La prevalencia de invasión submucosa en Japón fue 6 veces mayor que la prevalencia en España (razón de prevalencia PR=5,66; IC 95%: 3,96, 8,08), y la prevalencia de histología de alto riesgo fue 1,5 mayor (PR=1,44; IC 95%: 1,31, 1,58). En comparación con el tipo granular homogéneo y ajustado por las características clínicas, los tipos granular mixto, plano elevado y pseudodeprimido se asociaron con mayores probabilidades de invasión submucosa en Japón, mientras que solo el tipo pseudodeprimido mostró mayor riesgo en España. Con respecto a la histología de alto riesgo, tanto el granular mixto como el pseudodeprimido se asociaron con mayores probabilidades en Japón, en comparación con solo el tipo granular mixto en España. Conclusión: Este estudio revela diferencias en la localización, morfología e invasividad de LST en una cohorte oriental y occidental.(AU)

Location, morphology and invasiveness of lateral spreading tumors in the colorectum differ between two large cohorts from an eastern and western country.

BACKGROUND AND STUDY AIMS: Data from Japanese series show that surface morphology of laterally spreading tumors (LST) in the colon identifies lesions with different incidence and pattern of submucosal invasion. Such data from western countries are scarce. We compared clinical and histological features of LST in a western country and an eastern country, with special interest on mucosal invasiveness of LST, and investigated the effect of clinical factors on invasiveness in both countries. PATIENTS AND METHODS: Patients with LST lesions ≥20mm were included from a multicenter prospective registry in Spain and from a retrospective registry from the National Cancer Center Hospital East, Japan. The primary outcome was the presence of submucosal invasion in LST. The secondary outcome was the presence of high-risk histology, defined as high-grade dysplasia or submucosal invasion. RESULTS: We evaluated 1102 patients in Spain and 663 in Japan. Morphological and histological characteristics differed. The prevalence of submucosal invasion in Japan was six-fold the prevalence in Spain (Prevalence Ratio PR=5.66; 95%CI: 3.96, 8.08), and the prevalence of high-risk histology was 1.5 higher (PR=1.44; 95%CI: 1.31, 1.58). Compared to the granular homogeneous type and adjusted by clinical features, granular mixed, flat elevated, and pseudo-depressed types were associated with higher odds of submucosal invasion in Japan, whereas only the pseudo-depressed type showed higher risk in Spain. Regarding high-risk histology, both granular mixed and pseudo-depressed were associated with higher odds in Japan, compared with only the granular mixed type in Spain. CONCLUSION: This study reveals differences in location, morphology and invasiveness of LST in an eastern and a western cohort.