Impact of stromal maturity and proportion on prognosis and immune landscape in colorectal cancer

Abstract

The tissue surrounding a tumor — called stroma — is not passive filler; its composition and abundance can shape how aggressively a cancer behaves and how well the immune system can fight it. Researchers combined two established ways of evaluating tumor stroma into a new scoring system called SMAPS, and tested it across nearly 1,900 colorectal cancer patients. Tumors with high SMAPS scores — meaning stroma that was both abundant and immature — were twice as likely to result in cancer-related death, and outperformed each individual measure used alone. These high-stroma tumors also harbored fewer cancer-fighting immune cells, suggesting that an abnormal stromal environment suppresses the body’s natural defenses and may represent an important target for improving patient outcomes.