Neoadjuvant and adjuvant chemotherapy

Neoadjuvant chemotherapy is given before the main treatment — usually surgery or radiotherapy — to shrink the tumour and make that treatment feasible or less extensive. Adjuvant chemotherapy is given afterwards, to destroy cancer cells that may remain in the body and to reduce the risk of recurrence. Both terms describe the timing and purpose of treatment, not particular drugs.

How it works

In the neoadjuvant setting, drugs travel through the bloodstream and shrink the tumour before an operation or irradiation. This can make the procedure less extensive, and it also lets doctors see directly how the cancer responds to the chosen drugs, which may inform later treatment decisions. Adjuvant treatment rests on a different premise: even when a tumour has been removed completely, single cancer cells too few to detect with tests may already be present elsewhere in the body. Chemotherapy given after surgery or radiotherapy aims to destroy these cells before they can grow into a recurrence or metastases. Whether such treatment is proposed depends, among other things, on the cancer type, its stage, and the estimated risk of relapse.