Fig. 5

The mechanism of our two-parameter prognostic model using collagen structural information. a ATC CFD⁽⁺⁾ indicates the presence of a strong layer of collagen fibers around the tumor nests, and DTC CFL⁽⁺⁾ indicates longer collagen fibers. Only a few cancer cells escape; the strong layer of collagen fibers and the longer collagen fibers help the immune cells deal with the malignant cells. b Although cancer cells are less able to escape from the tumor nest in this condition, DTC CFL⁽⁻⁾ status suggests that the fiber is relatively short and makes it more difficult for the immune cells to respond to potential malignant cell invasion. c ATC CFD⁽⁻⁾ indicates a weaker protective collagen layer. In this case, cancer cells may easily escape the tumor nest. Although the collagen fibers are shorter in this condition, i.e., DTC CFL⁽⁻⁾, the larger number of cancer cells escaping may cause a higher chance of metastasis. d These tumors have a weaker protective collagen layer around the tumor nests and have long DTC collagen fibers. Cancer cells may both escape with relative ease and use the longer DTC collagen fiber to migrate more efficiently overwhelming the immune cell response; hence, the stromal collagen fiber length plays a bipartite role—being beneficial to the immune cells as long as the ATC CFD stays high, or conversely becoming beneficial to malignant cells when this protective layer of collagen weakens. This resulted in the worst survival among the four groups