Author

N

Method

Treatment

Endpoint

Comment

Terrazino

125

PCR/DNA

45-50.4 Gy 5-FU or 5-FU+LV or 5-FU+Oxa or 5-FU+ carboplatin

TRG

No correlation

Bertolini

91

IHC

50 Gy 5-FU

TRG; TNM downstaging; OS/DFS

No correlation

Spindler

60

PCR/DNA

65 Gy UFT+LV

TRG

TS 2R/2R associated with tumor regression

Jakob

22

PCR/RNA

50.4 Gy 5-FU

TRG

Low TS expression associated with tumor regression

Stoehlmacher

40

PCR/DNA; PCR/RNA

50.4 Gy 5-FU

TRG

TS 3-UTR 6 bp deletion slightly associated with tumor response

Negri

57

IHC

40-45 Gy +/- 5-FU + oxa

pCR

High TS expression associated with higher rate of response

Kikuchi

60

IHC

45 Gy Irinotecan

TRG

Higher TS expression associated with better response

Carlomagno

46

IHC

45 Gy Capecitabine + Oxa

TRG

Low TS expression assocoated with low response

Hur

44

IHC; PCR/DNA

45 Gy 5-FU

TRG; TNM downstaging

Low-expression genotypes associated with TNM downstaging; no correlation with TRG

Paez

51

PCR/DNA

45 Gy 5-FU

TRG; TNM downstaging

Genotipe 3R/3R associated with tumor response

TS: Thymidylate synthase; PCR: polymerase chain reaction; IHC:inmunohistochemistry; 5-FU:5-fluoruracil; LV:leucovorin; Oxa:oxaliplatin; UFT:Uftotal; TRG: tumor regression grade; OS: overall survival; DFS: disease-free survival; TNM tumor node metastasis staging; pCR: pathological complete response

Table 3: TS expression and prediction of response to preoperative radio-chemotherapy in rectal cancer patients.