Randomized, multicenter, phase IIb study of preoperative chemoradiotherapy in T3 mid-distal rectal cancer: raltitrexed + oxaliplatin + radiotherapy versus cisplatin + 5-fluorouracil + radiotherapy.
OBJECTIVE
To prospectively compare the rates of pathologic response, acute toxicity, and sphincter preservation with two different schedules of preoperative chemoradiotherapy in patients with cT3 mid-distal rectal cancer.


METHODS
Patients with cT3 and/or N+ resectable rectal carcinoma were randomized to receive one of the two following chemoradiotherapy regimens: cisplatin, 5-fluorouracil, and radiotherapy (PLAFUR) or raltitrexed, oxaliplatin, and radiotherapy (TOMOX-RT). For PLAFUR, cisplatin (60 mg/m(2)) was given on Days 1 and 29, with a prolonged infusion of 5-fluorouracil (1,000 mg/m(2)) on Days 1-4 and 29-32, plus concurrent radiotherapy (50.4 Gy in 1.8-Gy fractions daily). For TOMOX-RT, raltitrexed (3 mg/m(2)) and oxaliplatin (130 mg/m(2)) was given on Days 1, 19, and 38 with the same radiotherapy regimen as used for PLAFUR. Surgery was performed 6-8 weeks after completion of chemoradiotherapy. All pathologic specimens were reviewed by a designated expert pathologist. The primary endpoint of this study was pathologic tumor downstaging (defined as tumor regression grade 1-2). Secondary endpoints included the incidence of ypT0, clinical tumor downstaging, sphincter-saving surgery, and acute treatment-related toxicity.


RESULTS
Between 2002 and 2005, 164 patients were accrued in 10 Italian centers, 83 patients in the PLAFUR arm and 81 in the TOMOX-RT arm. Overall, tumor regression grade 1-2 was observed in 76 patients (46.4%) and ypT0 in 49 (29.9%). The tumor regression grade 1-2 rate was 41.0% vs. 51.9% (p = 0.162) and the ypT0 rate was 24.1% vs. 35.8% (p = 0.102) for the PLAFUR vs. TOMOX-RT arm, respectively. The overall rate of tumor regression grade 1 and ypN+ was 4.6%. The occurrence of ypT downstaging was significantly greater in the TOMOX-RT arm (p = 0.035). Grade 3-4 acute toxicity occurred in 19 patients (11.6%): 7.1% in the PLAFUR arm vs. 16.4% in the TOMOX-RT arm. Sphincter-saving surgery was performed in 143 patients (87.2%) overall: 87.9% in the PLAFUR arm and 86.4% in the TOMOX-RT arm.


CONCLUSIONS
Compared with the PLAFUR regimen, TOMOX-RT achieved a greater incidence of downstaging but was associated with a correspondingly greater rate of acute Grade 3+ toxicity. With longer follow-up, the local control and survival rates might offer additional guidance as to the choice of regimen.
Valentini
Vincenzo
V
Department of Radiation Therapy, Università Cattolica Sacro Cuore, Rome, Italy. vvalentini@rm.unicatt.it
Coco
Claudio
C
Minsky
Bruce D
BD
Gambacorta
Maria Antonietta
MA
Cosimelli
Maurizio
M
Bellavita
Rita
R
Morganti
Alessio G
AG
La Torre
Giuseppe
G
Trodella
Lucio
L
Genovesi
Domenico
D
Portaluri
Maurizio
M
Maurizi-Enrici
Riccardo
R
Barbera
Fernando
F
Maranzano
Ernesto
E
Lupattelli
Marco
M
D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D002945:Cisplatin / Q000008:administration & dosage / Q000009:adverse effects; D003131:Combined Modality Therapy / Q000379:methods; D004334:Drug Administration Schedule; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009944:Organoplatinum Compounds / Q000008:administration & dosage / Q000009:adverse effects; D000077150:Oxaliplatin; D011446:Prospective Studies; D011799:Quinazolines / Q000008:administration & dosage / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D013876:Thiophenes / Q000008:administration & dosage / Q000009:adverse effects
D009944:Organoplatinum Compounds; D011799:Quinazolines; D013876:Thiophenes; D000077150:Oxaliplatin; C068874:raltitrexed; D002945:Cisplatin; D005472:Fluorouracil