Predicting the response to preoperative radiation or chemoradiation by a microarray analysis of the gene expression profiles in rectal cancer.
Preoperative radiotherapy or chemoradiotherapy (CRT) has become a standard treatment for patients with locally advanced rectal cancer. However, there is a wide spectrum of responses to preoperative CRT, ranging from none to complete. There has been intense interest in the identification of molecular biomarkers to predict the response to preoperative CRT, in order to spare potentially non-responsive patients from unnecessary treatment. However, no specific molecular biomarkers have yet been definitively proven to be predictive of the response to CRT. Instead of focusing on specific factors, microarray-based gene expression profiling technology enables the simultaneous analysis of large numbers of genes, and might therefore have immense potential for predicting the response to preoperative CRT. We herein review published studies using a microarray-based analysis to identify gene expression profiles associated with the response of rectal cancer to radiation or CRT. Although some studies have reported gene expression signatures capable of high predictive accuracy, the compositions of these signatures have differed considerably, with little gene overlap. However, considering the promising data regarding gene profiling in breast cancer, the microarray analysis could still have potential to improve the management of locally advanced rectal cancer. Increasing the number of patients analyzed for more accurate prediction and the extensive validation of predictive classifiers in prospective clinical trials are necessary before such profiling can be incorporated into future clinical practice.
Gastroenterological Center, Department of Gastroenterological Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
Takashi
T
Akiyoshi
Takashi
T
Kobunai
Toshiaki
T
Watanabe
D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D059186:Chemoradiotherapy, Adjuvant; D003661:Decision Support Techniques; D020869:Gene Expression Profiling; D005819:Genetic Markers; D006801:Humans; D020360:Neoadjuvant Therapy; D020411:Oligonucleotide Array Sequence Analysis; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000235:genetics / Q000628:therapy*; D016896:Treatment Outcome
D014408:Biomarkers, Tumor; D005819:Genetic Markers