Penis cancer It is a rare form of cancer a disease in which cancer cells malignant can occur anywhere along the shaft of the penis but most are on the foreskin or head of the penis glans

What is the correctly punctuated version of this sentence?
Penis cancer - It is a rare form of cancer, a disease in which cancer cells (malignant) can occur anywhere along the shaft of the penis, but most are on the foreskin or head of the penis (glans).