Should I be concerned about penile cancer? Brother had it.

May be. There are no clear cut genetic patterns in penile cancer. However, given that you share half your genes and probably similar environment with your brother, it would be prudent to be on the look out for any changes in the penile skin, especially the glans penis.
Not to worry but. We do not know about familial penile cancer. Let us say that the incidence of being familial is 5.0%. Risk factors include human papilloma virus (hpv), smoking, poor hygiene..It rare with an incidence of one in 1400 cases. Early circumcision my be preventive. I would not worry about it. Lead a normal life. Have annual medical exam. In men, the most common cancer are lung and prostate.