Table 1.
Studies showing DNA microarray gene expression profile predictive of response to CRT in LARC.
| Study | Specimen | N patients | Validation group |
Radiotherapy dose
Chemotherapy |
Response assessment | Identified genes: more relevant genes | Outcome |
|---|---|---|---|---|---|---|---|
| Ghadimi et al. 2005 [9] | Tumor tissue biopsy | 30 | No |
50.4 Gy/28 fractions
5FU |
Downsizing | 54 genes: SMC1, CLMN, CDC42BPA, and FLNB | Group prediction 83% |
|
| |||||||
| Watanabe et al. 2006 [10] | Tumor tissue biopsy | 52 | 17 |
50.4 Gy
— |
Japanese Classification of Colorectal Carcinoma | 33 genes (i) Overexpressed: LUM, THBS2, and LGALS1 (ii) Downregulated: CYP40 and GPX2 |
Class prediction 82.4%, sensitivity 50%, specificity 100%, PPV 100%, NPV 76.6% |
|
| |||||||
| Kim et al. 2007 [11] | Tumor tissue biopsy | 31 | 15 |
50.4 Gy/28 fractions
5FU + LV/capecitabine/ capecitabine + irinotecan |
Dworak regression grade | 95 genes: TYMS and RAD23B | Precision 87%, sensitivity 100%, specificity 82% |
|
| |||||||
| Rimkus et al. 2008 [12] | Tumor tissue biopsy | 43 | No |
45 Gy
5FU |
Becker regression grade | 42 genes (i) Overexpressed: CASP1, SLC35E1, CCNK, STAT2, and ETS2 (ii) Downregulated: TDE1, USP42, M-RIP, and FREM1 |
Accuracy 81%, sensitivity 71%, specificity 86%, PPV 71%, NPV 86% |
|
| |||||||
| Nishioka et al. 2011 [13] | Tumor tissue biopsy | 17 | 3 |
40 Gy/20 fractions
S1 |
Japanese Classification of Colorectal Carcinoma | 17 genes: MMP7, MMP14, MMP9, MMP1, MMP16, and RRM1 | |
|
| |||||||
| Casado et al. 2011 [14] | Tumor tissue biopsy formalin-fixed paraffin-embedded biopsies |
25 94 |
50.4 Gy/28 fractions
25 oxaliplatin + raltitrexed 94 different treatment |
Dworak regression grade | 24 genes: genetic profile of 13: (i) 6 overexpressed: ALDH1A1, CDKN1 1, FOS, RELB, STAT3, and TFF3 (ii) 7 downregulated: BAK, MLH1, TYMS, CKB, GPX2, HIG2, and PH-4 |
Nonresponders: accuracy 86%, sensitivity 87%, specificity 82% |
|
|
| |||||||
| Palma et al. 2013 [8] | Blood sample | 27 | 8 |
50.4 Gy/28 fractions
Capecitabine/capecitabine + oxaliplatin |
Mandard regression grade | 8 genes: FALZ | |
|
| |||||||
| Palma et al. 2014 [7] | Tumor tissue biopsy | 26 | 8 |
50.4 Gy/28 fractions
Capecitabine/capecitabine + oxaliplatin |
Mandard regression grade | 257 genes: c-MYC, GNG4, POLA, and RRM1 | Accuracy 85%, sensitivity 60%, specificity 100%, PPV 100%, NPV 80% |
|
| |||||||
| Gantt et al. 2014 [15] | Tumor tissue biopsy | 36 | 10 |
50.4 Gy/30 fractions
5FU |
American Joint Committee on Cancer | 183 genes up- and downregulated: RAD50 | No response: sensitivity 33%, specificity 100% |
|
| |||||||
| Watanabe et al. 2014 [16] | Tumor tissue biopsy | 46 | 16 |
50.4 Gy/28 fractions
Tegafur-uracil + leucovorin |
Japanese Classification of Colorectal Carcinoma | 22 probes (18 genes): signature LRRIQ3, FRMD3, SAMD5, and TMC7 | Accuracy 81.3%, sensitivity 100%, specificity 62.5%, PPV 72.7%, NPV 100% |