Justice Ginsburg and "precautionary chemotherapy"

One of the recent things we've been reading is that Justice Ginsburg had been diagnosed with pancreatic cancer, which incidentally is a tough-to-diagnose and consequently deadly form of cancer as it presents few symptoms until very late in disease progression. After her surgery, she is reported to be undergoing "precautionary chemotherapy". From the sound of it, this is simply another way to say adjuvant chemotherapy confusing everyone. As is the case with many surgical resection of cancerous masses, even though the disease is not detectable by examination alone, cancer cells can still circulate the body or remain undiscovered in small pockets of tissue. The purpose of adjuvant chemotherapy is to eradicate these last remaining cancer cells.
Apparently ex-justice O'Connor also battled cancer, as did Ginsburg herself many years ago.