The UNITED study
The UNITED study (Uniform Noting for International application of the Tumour-stroma ratio as Easy Diagnostic tool) is an international multicentre study to validate the TSR in a prospective study. This research study focuses on the implementation of the TSR in the clinic for colon carcinoma.
At the start of the study 17 hospitals from 14 countries are participating. About 1500 patients will be included, all pStage II and III colon carcinoma.
TSR in epithelial carcinoma
The prognostic value of the TSR reaches further than colon cancer; it is also observed in a range of different other solid epithelial tumours. Like in colon cancer, also in other carcinomas stroma-high tumours were associated with worse overall survival and disease-free survival. TSR is prognostic in colon cancer, breast cancer, ovarian cancer, non-small cell lung cancer, nasopharyngeal cancer, oesophageal cancer and hepatocellular cancer.
Similar to colon cancer, the TSR method also has a high inter-observer agreement in a variety of studies of other epithelial cancer types. The use of the TSR across tumour types emphasizes the robustness of the method.
The tumour-stroma ratio (TSR) is based on the amount of stroma within the primary tumour. Several studies have shown promising results of the TSR to predict disease free and overall survival for patients with colon carcinoma stage II and III. The TSR, combined with current routine histological data, might open a way to improve personalized treatment of patients with colon carcinoma.
The tumour stroma is a biomarker which can be easily determined in daily routine pathology. Scoring TSR only costs 1-2 minutes extra time and is scored on Haematoxylin & Eosin stained sections. There are no additional costs.
The parameter distinguishes tumours with a high stroma percentage and low stroma percentage in two categories. Stroma-low tumours are tumours with a stroma percentage of 50% or less (≤50%). Tumours containing more than 50% stroma are stroma-high. Patients with a stroma-high tumour have a worse overall and disease free survival.
When determining the TSR a number of aspects must be taken into account:
Mucinous tumours can be difficult. An area containing mucus may be used. However, mucus should be excluded when determining the tumour-stroma ratio.
Score an area with as little necrosis or muscle tissue as possible, or preferably even none at all.
Tumour cells should be present on all sides of the view.
See Research page.
Step 1: Select
Choose a section from the most invasive part of the tumour for microscopic analysis.
Step 2: Magnify
View with a 2.5x or 5x magnification and find the part with the most stroma visible.
Step 3: Zoom in
Zoom in and view that with a 10x magnification. Ensure that tumour cells are visible on all four sides of the area. Preferably with as much stroma as possible in between.
Step 4: Estimate percentage
Estimate a percentage for the amount of stroma, in increments of 10%.
Step 5: Determine and note
If there is more than one area, then note the area with the highest percentage of stroma in the pathological report.