Loading
Bowel cancer needed its own rule for calling a tumour HER2-positive, because the rules written for breast and stomach cancer did not transfer. The HERACLES criteria are that rule: intense membrane staining in more than half the cells, confirmed by gene amplification, which finds about one in twenty RAS wild-type bowel cancers.
Why a separate rule. HER2-directed drugs work in colorectal cancer only in a small, well-defined group, and enrolling the wrong patients would have buried the effect. A consensus panel of pathologists adapted the breast and gastric protocols for colorectal tissue on an archival cohort of 256 tumours, then applied the result prospectively to screen 830 KRAS wild-type tumours for the HERACLES phase 2 trial of trastuzumab and lapatinib (Valtorta 2015).
What the criteria say. A positive tumour shows intense membranous HER2 protein expression, corresponding to homogeneous gene amplification, in more than 50 percent of cells. No tumour scoring 0 or 1+ by immunohistochemistry was amplified, and concordance between silver and fluorescence in situ hybridisation was complete. In both the archival and the clinical cohorts about 5 percent of KRAS wild-type colorectal cancers met the definition.
Why it matters beyond pathology. In a population resistant to cetuximab, HER2 positivity defined this way predicted response to HER2-directed therapy, which is how a scoring rule became a predictive biomarker. The criteria are why the reported prevalence of HER2 amplification in colorectal cancer clusters around 3 to 5 percent rather than the higher figures quoted when breast cancer rules are applied, and they are the reason the parent record's HER2 rows and the HER2-amplified colorectal page test RAS wild-type tumours specifically.
In plain words · A growth-signal receptor. Some cancers make far too much of it, and drugs that block it or use it as a docking site have transformed those cancers.
Showing the target this term concerns: HER2.
Shares Extended RAS testing, Sidedness (left vs right colon), Colon cancer (adenocarcinoma of the colon), Rectal cancer and the tags gi, colorectal.
Shares Comprehensive genomic profiling, Colon cancer (adenocarcinoma of the colon), Rectal cancer, Colorectal cancer and the tags gi, colorectal.
Shares Grade, Histopathology & immunohistochemistry, Colon cancer (adenocarcinoma of the colon), Rectal cancer and the tags gi, colorectal.
Shares Sidedness (left vs right colon), Colon cancer (adenocarcinoma of the colon), Rectal cancer, Colorectal cancer and the tags gi, colorectal.
Shares Sidedness (left vs right colon), Colon cancer (adenocarcinoma of the colon), Rectal cancer, Colorectal cancer and the tags gi, colorectal.
Shares Histopathology & immunohistochemistry, Colon cancer (adenocarcinoma of the colon), Rectal cancer, Colorectal cancer and the tags gi, colorectal.
Shares Sidedness (left vs right colon), Histopathology & immunohistochemistry, Colon cancer (adenocarcinoma of the colon), Colorectal cancer and the tags gi, colorectal.
Shares Histopathology & immunohistochemistry, Colon cancer (adenocarcinoma of the colon), Rectal cancer, Colorectal cancer and the tags gi, colorectal.