Cancer invasion into musculature: Mechanics, molecules and implications

•Basement membrane coated muscle cells are embedded within linear ECM-rich mysia.•Tumor cell migration is guided by linear confinement present in muscle tissue.•Experimental tumor cell invasion occurs along linear ECM-coated mysial structures.•Biophysical properties of muscle tissue favor tumor cell invasion and survival.•Neoplastic muscle invasion is often associated with negative patient prognosis.