JMIR Publications

ABSTRACT

Background:

The amount of stroma in the primary tumor is an important prognostic parameter. The tumor-stroma ratio (TSR) was previously validated by international research groups and showed to be a robust prognostic parameter for disease prognosis with good interobserver agreements.

Objective:

The UNITED study (Uniform Noting for International Application of the Tumor-stroma ratio as Easy Diagnostic tool) is developed to bring the TSR to clinical implementation. As part of the study, an E-learning module was developed to confirm the reproducibility of scoring TSR after proper instruction.

Methods:

The E-learning module consisted of an auto-instruction for TSR determination (instruction video or written protocol) and three sets of 40 cases (training-, test- and repetition set). Scoring the TSR is performed on haematoxylin and eosin stained sections and takes only 1-2 minutes per case. Cases are considered stroma-low if the amount of stroma is ≤50%, stroma-high is defined as >50% stroma. In the present study, inter- and intra-observer agreements were determined after each set to evaluate the reproducibility.

Results:

Pathologists and pathology residents (n=63) with special interest in colorectal cancer participated in the E-learning. Forty-nine participants started the E-learning, thirty-one (63%) finished the whole cycle (3 sets). A significant improvement was seen from training set to test set; median kappa improved from K=.72 to K=.77 (p=.002).

Conclusions:

E-learning is an effective method to instruct pathologists and pathology residents for scoring TSR. The reliability of scoring improved from the training to the test set and did not fall back with the repetition set, confirming the reproducibility of the TSR scoring method. Clinical Trial: The UNITED study is registered in the Netherlands Trial Registry (NTR 7270). http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=7270