In the German language the word Schmuck means jewelry, adornment. The etymology of the pejorative meaning is a matter of some disagreement. The lexicographer Michael Wex, author of How to Be a Mentsh (And Not a Shmuck), writes that the Yiddish term and the German term are completely unrelated.
A fundamental philosophy of medical oncology, including combination chemotherapy, is that different drugs work through different mechanisms, and that the results of using multiple drugs will be synergistic to some extent.
Doctors call this adjuvant chemotherapy because it's given in addition to surgery, which is considered the primary treatment. In some cases, chemotherapy is given before surgery to shrink the cancer so less tissue has to be removed. When chemotherapy is given before surgery, it's called neoadjuvant chemotherapy.