What Causes Swollen Legs And Arms After Breast Removal Surgery?

my sister age 53 got operated for breast cancer, breast fully removed 2 yrs back, followed by chemotherapy 6 cycles, now after 2 years her ESR raised to 105 and CA 15.3 marker having value 60ul. having swelling on legs and right arm the side where breast removed. I have other test reports also if required.