Blood test could catch colon cancer years earlier than current screening
Researchers identified a set of proteins in circulating blood particles that reliably distinguish colon cancer patients from healthy people, with 76% cancer-specific accuracy. The discovery could transform colorectal cancer screening—currently missing 30% of early-stage cases—into a simple, non-invasive blood test that rivals or beats colonoscopy and existing biomarkers.
Originaltitel: Proteomic Profiling of Human Extracellular Vesicles Reveals Diagnostic Biomarkers for Colon Adenocarcinoma
Extracellulära vesiklar (EVs) i blod kan ersätta dagens bristfälliga screening för tjocktarmscancer — en 10-proteinpanel uppnådde över 90 procents känslighet för att skilja sjuka från friska. Detta öppnar en marknad för blodbaserad tidig diagnostik som löser problemet att befintliga tester missar 30 procent av stadium I-tumörer. Forskarna analyserade EV-proteomer från 233 patienter med hjälp av LC-MS/MS och identifierade 166 proteiner berikade i cancer-cirkulerande vesiklar — däribland SRPK1 och THBS2 från tumörer. En jämförelse med pancreas- och lungcancer visade att 76 procent av tumör-EV-proteinerna var specifika för tjocktarmscancer, vilket styrker diagnostisk precision. Sex veckor efter kirurgisk borttagning minskade cancer-associerade EV-proteiner med över 70 procent, vilket demonstrerar klinisk responsivitet. Linköpings universitet bidrog till studien. Aktörer inom diagnostik och in-vitro-testutveckling bör utvärdera kommersialisering av EV-proteinpaneler innan konkurrenter etablerar marknadsposition.
<p>Early detection of colon adenocarcinoma (COAD) remains suboptimal. Fecal tests fail to diagnose 30% of stage I cancer, and serum CEA lacks sensitivity (&lt; 40%). Extracellular vesicles (EVs) circulate systemically and package tumor-related cargo, making them attractive non-invasive biomarkers for cancer diagnosis. We profiled the EV proteome from 233 human patients using LC-MS/MS, including stage I-IV tumors with matched non-tumor colon tissues (n = 50 each; n = 100), paired pre-/post-operative plasma (n = 90) and healthy plasma (n = 43). Circulating EVs contained both tumor-specific and stromal/immune cell-derived proteins, reflecting the systemic nature of EV biology in the cancer setting. Proteomic analysis identified 745 proteins enriched in tumor-derived EVs (e.g., SRPK1, THBS2) and 127 proteins enriched in adjacent tissues. Plasma EVs revealed 166 proteins enriched in COAD (e.g., UBA1, FCN1) and 233 enriched in healthy controls. Pathway analysis linked tumor EV cargo to angiogenesis, mRNA splicing, TGF-beta signalling and RNA translation. Notably, a cross-cancer comparison (pancreatic = 10, lung = 14 cases) revealed that 76% of tumor EV proteins were COAD-specific, highlighting tissue of origin specificity. We further developed a 10-protein EV panel comprising seven tumor-associated and three healthy-enriched EV proteins, which effectively distinguished COAD patients from healthy controls in the two validation cohorts (n = 104 and n = 215), achieving &gt; 90% sensitivity for differentiating COAD from healthy and non-COAD colorectal conditions. Six weeks after curative resection, tumor-associated EV proteins decreased by &gt; 70%, whereas healthy-associated proteins rebounded to baseline, indicating surgical responsiveness. Collectively, EV protein signatures provide a sensitive and tissue-specific window into tumor-host communication, further supporting blood-based early detection of COAD.</p>