Neoadjuvant chemotherapy is a term originally used to describe the administration of chemotherapy preoperatively before surgery.
Neoadjuvant chemotherapy is induced chemotherapy to shrink or downstage a locally advanced tumor.
It thereby facilitates more effective local treatment with surgery or radiotherapy.
The method has been extended with more effective combinations of chemotherapy to reduce the risks of metastatic disease.
It seems logical that survival could be lengthened, or organ preservation rates increased in resectable tumors by neoadjuvant chemotherapy.
In rectal cancer neoadjuvant chemotherapy is being increasingly used in locally advanced and nonmetastatic unresectable tumors.
Randomized studies in advanced colorectal cancer show high response rates to combination cytotoxic therapy.
This evidence of efficacy coupled with the introduction of novel molecular targeted therapies have rekindled an interest in neoadjuvant chemotherapy.
Long waiting times for radiotherapy have also increased interest in delivering neoadjuvant chemotherapy in locally advanced rectal cancer.
In contrast, this enthusiasm is waning for sites such as head and neck, and nasopharynx cancer where traditionally neoadjuvant chemotherapy has been used.
The question arises whether neoadjuvant chemotherapy in rectal cancer a real advance or just history repeating itself.
Dr Glynne-Jones and colleagues from England explored the advantages and disadvantages of the separate approaches of chemotherapy.
The research team undertook a review of neoadjuvant, concurrent and consolidation chemotherapy in locally advanced rectal cancer.
The researchers drew on theoretical principles, preclinical studies and clinical experience both in rectal cancer and other disease sites.
The team found that neoadjuvant chemotherapy may improve outcome in terms of disease-free or overall survival in selected groups in some disease sites.
However, the researchers noted that this strategy has not been shown to be associated with better outcomes than postoperative adjuvant chemotherapy.
|Neoadjuvant chemotherapy does not appear to enhance local control|
|British Journal of Cancer|
In particular, the team highlighted that there is insufficient data in rectal cancer.
The evidence for benefit is strongest when neoadjuvant chemotherapy is administered before surgical resection.
In contrast, the data in favour of neoadjuvant chemotherapy before radiation or chemoradiation is inconclusive.
The team noted these findings despite the suggestion that response to induction chemotherapy can predict response to subsequent radiotherapy.
The observation that spectacular responses to chemotherapy before radical radiotherapy did not result in improved survival, was noted 25 years ago.
Multiple trials in head and neck cancer, nasopharyngeal cancer, and non-small-cell lung cancer, do no support the routine use of neoadjuvant chemotherapy.
The researchers also found that trials in small-cell lung cancer and cervical cancer do not support the routine use of neoadjuvant chemotherapy.
The trials identified did not advocate the use of neoadjuvant chemotherapy either as an alternative, or as additional benefit to chemoradiation.
The addition of neoadjuvant chemotherapy does not appear to enhance local control over concurrent chemoradiation or radiotherapy alone.
Dr Glynne-Jones' team concluded, “Neoadjuvant chemotherapy before chemoradiation or radiation should be used with caution, and only in the context of clinical trials.”
“The evidence base suggests that concurrent chemoradiation with early positioning of radiotherapy appears the best option for patients with locally advanced rectal cancer and in all disease sites where radiation is the primary local therapy.”