Adjuvant therapy is treatment that is administered in addition to a primary or initial treatment. In the case of cancer, adjuvant therapy often refers to the follow-up treatment given to patients after they have undergone surgery to remove any detectable disease.

The main purpose of adjuvant therapy is to prevent the recurrence of the cancer and therefore reduce patient mortality and prolong survival.

Cancer recurrence often occurs because cancer cells still remain after the primary treatment has been performed or administered. Adjuvant therapy is therefore given in cases where all obvious disease appears to have been removed, to help reduce the likelihood of this occurring. Therapy given in cases where disease is known to be remaining is not technically adjuvant therapy.

The primary treatment in cases of stage I, II and III renal cell carcinoma is either partial or complete surgical removal of the kidney. This procedure is referred to as nephrectomy. For stage III cancer, this may also include removal of any lymph nodes the cancer has spread to. At present, no adjuvant therapies are known to improve patient outcome in renal cell carcinoma. The administration of adjuvant therapies after surgery such as chemotherapy, target therapy, radiotherapy or immunotherapy has so far not been shown to have beneficial effects after the cancer has been surgically removed. However, clinical trials exploring adjuvant therapies for kidney cancer are ongoing.

In the case of stage IV renal cell carcinoma that has spread or metastasized to other parts of the body, patients may still benefit from surgical removal of the tumor. Nephrectomy in these patients is often combined with an immunotherapy called interferon-alfa (IFN-alfa). Other therapies that may be used to treat these cancers include embolisation, targeted therapy, radiotherapy and immunotherapy. However, as the disease is known to still exist, these therapies are not considered adjuvant therapies.