Chemotherapy used after surgery or radiotherapy for cancer is termed as:

Combination chemotherapy is the use of multiple drugs together at the same time rather than a single agent. Use of multiple drugs together has advantage of low toxicity, drugs acting on different phases of cell cycle and reduction in drug resistance.Adjuvant chemotherapy refers to chemotherapy used after operation or completion of course of radiotherapy.Neoadjuvant chemotherapy is use of chemotherapy before surgery or radiotherapy in the hope to shrink the size of tumour to permit better efficacy of radiation or reduce the size of surgical resection. Also it is expected to eradicate micrometastases.NeoadjuvantConcomitantAdjuvantChemotherapyChemotherapyChemotherapyBefore surgeryAt the same timeAfter surgeryor radiotherapyas radiotherapyor radiotherapyConcomitant chemotherapy refers to simultaneous use of chemotherapy with radiotherapy. It is superior to radiotherapy alone in unresectable tumors and the resectable tumors where surgery is refused.