We should remember riskfactors for PAS: radiotherapy for breast cancer, Stewart-Treves syndrome, infectionsuch as filariasis, toxins including arsenic, anabolic steroids, vinyl chloride, andthorium dioxide, neurofibromatosis type 1, Maffucci syndrome,Klippel-Trénaunay syndrome, and some genetic mutations(e.g., BRCA1 and BRCA2)[14]. Here, BRCA2 is linked to filariasis.