Introduction: neoadjuvant and adjuvant therapy for rectal cancer
The aim of neoadjuvant and adjuvant therapy for rectal cancer is to reduce the risk of local and distant recurrence (metastatic disease). Locally recurrent rectal cancer is often incurable and is associated with high morbidity and deterioration in quality of life. Distant recurrence, if unresectable, is virtually always fatal.
Adjuvant therapy is any treatment that is given in addition to a standard curative cancer treatment such as surgery. By convention, the term ‘adjuvant’ is reserved for postoperative treatment, while ‘neoadjuvant’ refers to treatment given prior to the definitive treatment.
Radiation treatment[edit source]
Radiation treatment uses ionising radiation to kill cancer cells. Only tissues within the treatment portals are affected. Radiation treatment prevents or reduces the incidence of recurrent rectal cancer within the pelvis.
The value of radiation treatment (preferably given preoperatively) in the management of rectal cancer is well established. Several meta-analyses that included multiple trials have demonstrated a significant improvement in local disease control.
Chemotherapy is cytotoxic drug treatment. Systemic chemotherapy affects the entire body, and is given with the intent of killing circulating cancer cells that may lodge and grow in distant organs such as the liver and lungs.
The addition of fluoropyrimidine-based chemotherapy to radiation treatment in the treatment of rectal cancer is primarily for its effect as a radiosensitiser, enhancing the effect of radiation. Adjuvant chemotherapy cycles are given with the aim of eradicating systemic micro-metastatic disease.
Chapter subsections[edit source]
- Barton, M. Oncology for Medical Students: Principles of radiotherapy. [homepage on the internet] Cancer Council Australia 2014; [cited 2016 Dec 28]. Available from: http://wiki.cancer.org.au/oncologyformedicalstudents_mw/index.php?oldid=1680.
- Colorectal Cancer Collaborative Group.. Adjuvant radiotherapy for rectal cancer: a systematic overview of 8,507 patients from 22 randomised trials. Lancet 2001 Oct 20;358(9290):1291-304 Available from: http://www.ncbi.nlm.nih.gov/pubmed/11684209.
- George, M; Schwarz, M; McKinnon, R. Clinical Oncology for Medical Students: Principles of medical therapy. [homepage on the internet] Cancer Council Australia 2014; [cited 2016 Dec 26]. Available from: http://wiki.cancer.org.au/oncologyformedicalstudents_mw/index.php?oldid=1683.