Combination of Oxaliplatin, Capecitabine, and Celecoxib With Concurrent Radiation for Rectal Cancer

Inclusion Criteria:

* All patients 18 years of age or older, with biopsy proven T3-4N0-2M0 rectal cancer are eligible.
* Life expectancy of at least 2 years.
* Zubrod performance status of 0-2.
* Patients must be able to sign an informed consent.
* Adequate bone marrow function: peripheral granulocyte count of \> 1,500 cells/mm3 and platelet count \>100,000/mm3, hemoglobin \> 10 gm/dl and absence of a regular red blood cell transfusion requirement.
* Adequate hepatic function with a total serum bilirubin \< 1.5 x ULN; alkaline phosphatase, alanine aminotransferase (ALAT), and aspartate aminotransferase (ASAT) \< 2.5 x the upper limit of normal (ULN); and adequate renal function as defined by a calculated creatinine clearance \> 50 ml/min \[Cockroft-Gault\].
* Other initial cancer diagnosis more than five years ago without evidence of residual or recurrent disease
* Prior diagnosis of squamous or basal cell carcinoma of skin,no active disease at the time of enrollment.

Exclusion Criteria:

* Known metastases
* Pregnant or lactating women. Women/men of childbearing potential not using a reliable and appropriate contraceptive method.
* May receive no other concurrent chemotherapy or radiation therapy during this trial.
* Severe medical problems such as uncontrolled diabetes mellitus or cardiovascular disease or active infections
* Prior pelvic radiation
* Known active inflammatory bowel disease, Crohn's disease or ulcerative colitis.
* Medical conditions that would preclude the patient from definitive surgery at the end of concurrent chemoradiation
* Serious, uncontrolled, concurrent infection(s).
* Prior severe reaction to fluoropyrimidine therapy, or known hyper-sensitivity to 5-fluorouracil or known dihydropyrimidine dehydrogenase (DPD) deficiency.
* Treatment for other carcinomas within the last five years, except cured non-melanoma skin and treated in-situ cervical cancer.
* Participation in any investigational drug study within 4 weeks preceding the start of study treatment.
* Clinically significant cardiac disease or myocardial infarction within the last 12 months.
* History of uncontrolled seizures, central nervous system disorders or psychiatric disability judged by the investigator to be clinically significant, precluding informed consent, or interfering with compliance of oral drug intake.
* Other serious uncontrolled medical conditions that the investigator feels might compromise study participation.
* Major surgery \<4 weeks of the start of study treatment, without complete recovery.
* Lack of physical integrity of the upper gastrointestinal tract or malabsorption syndrome.
* Known, existing uncontrolled coagulopathy
* Any of the following laboratory values:

  * Abnormal hematologic values (neutrophils \< 1.5 x 10\^9/L, platelet count \< 100 x 10\^9/L, hemoglobin \< 10 gm/dl)
  * Impaired renal function (estimated creatinine clearance \<50 ml/min as calculated with Cockroft-Gault equation.
  * Serum total bilirubin \> 1.5 x upper normal limit.
  * ALAT, ASAT \> 2.5 x upper normal limit (or \> 5 x upper normal limit in the case of liver metastases).
  * Alkaline phosphatase \> 2.5 x upper normal limit (or \> 5 x upper normal limit in the case of liver metastases or \> 10 x upper normal limit in the case of bone disease).
* Unwillingness to give written informed consent.
* Unwillingness to participate or inability to comply with the protocol for the duration of the study.
* History of allergic reactions, hypersensitivity reactions to aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or sulfonamides