Recent advances in biomedical engineering require the development of new types of blood-compatible polymers that also allow non-blood cell attachment for the isolation of stem cells and circulating tumor cells (CTCs) from blood and for the development of artificial organs for use under blood-contact conditions. Poly(2-methoxyethyl acrylate) (PMEA) and poly(tetrafurfuryl acrylate) (PTHFA) were previously identified as blood-compatible polymers. Here, it is demonstrated that cancer cells can attach to the PMEA and PTHFA substrates, and the differences in the attachment mechanisms to the PMEA and PTHFA substrates between cancer cells and platelets are investigated. It is also found that the adsorption-induced deformation of fibrinogen, which is required for the attachment and activation of platelets, does not occur on the PMEA and PTHFA substrates. In contrast, fibronectin is deformed on the PMEA and PTHFA substrates. Therefore, it is concluded that cancer cells and not platelets can attach to the PMEA and PTHFA substrates based on this protein-deformation difference between these substrates. Moreover, it is observed that cancer cells attach to the PMEA substrate via both integrin-dependent and -independent mechanisms and attach to the PTHFA substrate only through an integrin-dependent mechanism. It is expected that PMEA and PTHFA will prove useful for blood-contact biomedical applications.