The RACOX phase I study: radiation (RA), capecitabine (C) and oxaliplatin (OX) as adjuvant treatment of stage II and III rectal cancer.
OBJECTIVE
The aim of this phase I trial was to deter- mine the maximum tolerated dose (MTD) of adjuvant che- motherapy (CT) with oxaliplatin in combination with capecitabine during concomitant pelvic radiotherapy (RT) in patients with rectal cancer.


METHODS
Eligible patients had pathological stage II (T3-4N0M0) or III (any T N1-2M0) rectal adenocarcinoma, and no prior treatment other than curative resection. Fixed capecitabine dose (825 mg/m(2) bid on days 1-14 and 22-35) was given and external beam RT was delivered to the pelvis (50.4 Gy in 27 fractions in 5.5 weeks, with field reduction after 45 Gy in linear accelerator, 18Mev). Oxaliplatin was tested at 4 dose levels: 100, 110, 120 and 130 mg/m(2). The dose of oxaliplatin was escalated when all 3 entered patients at each level had been monitored for at least 8 weeks after the CT/RT course without dose limiting toxicities (DLTs). In the presence of a DLT at any dose level, a further 3 patients were enrolled. If only 1 of the 6 patients experienced a DLT, escalation could proceed. The MTD was defined as the level at which >/= 2 of 3 to 6 patients experienced DLTs. Fifteen patients (10 males and 5 females, median age 62 years) were enrolled at oxaliplatin dose levels of 100 (n=3), 110 (n=3), 120 (n=3) and 130 mg/m(2) (n=6).


RESULTS
All patients completed the planned CT/RT course. Dose reduction or delay of the 2nd CT cycle was not required. No DLTs were observed at all dose levels. Overall, gastrointestinal and neurological toxicities were mild and transient. Toxicities included non-dose-limiting nausea / vomiting, diarrhea, dysesthesias in 2 level III and in 1 level IV patients. Grade II myelotoxicity, mainly neutropenia, was seen in 6 patients. With a median follow-up of 4 months (range 2-12) after the completion of CT/RT, late toxicities were restricted to grade II radiation colitis and dermatitis in 2 and 2 patients, respectively.


CONCLUSIONS
The combination of pelvic RT, capecitabine and 3-weekly oxaliplatin is feasible and well tolerated. The MTD was not reached up to the dose of 130 mg/m(2) of oxaliplatin, which is the recommended dose.
Bountouroglou
N
N
Department of Radiation Oncology-A, Metaxa Cancer Hospital, Piraeus, Greece.
Ziras
N
N
Sarris
G
G
Petrides
A
A
Potamianou
A
A
Synodinou
M
M
Karvounis
N
N
Angelides
A
A
Chrysanthou
K
K
Athanassiou
A E
AE