Table 3.

Quality assessment of studies on transcriptomic analyses to identify distinct subtypes of EAC.

Author	Retrospective or Prospective	Number Independent EAC Cases	Quality Assessment of RNA	Tumor Percentage	Independent Cohort Validation	Overall Recommendation Level (+, +/−, −)
TCGA, Australia, Brazil, Canada, Germany, South-Korea, Moldova, Netherlands, Poland, Russia, Ukraine United Kingdom, United States of America, Vietnam [31]	Retrospective	72	RNA Integrity ≥ 7.0	≥60% tumor nuclei	No	−
Bornschein, United Kingdom, Germany [33]	Retrospective	84	RNA integrity number (RIN) > 7.0	≥70% tumor cellularity	Yes	+/−
Kim, United States of America [34]	Retrospective	64	RNA quality index (>7)	NA	Only for sub-selection of genes	−