Study of the Efficacy and Safety of Epoetin Alfa Administered Weekly in Patients With Gastric or Rectal Cancers Undergoing a Treatment Plan of Preoperative Chemotherapy and Radiation Therapy, Followed by Surgery

Inclusion Criteria:

* Patients must have a confirmed diagnosis of gastric cancer or rectal cancer for whom the treatment plan is preoperative chemotherapy and radiation therapy, followed by surgery
* have a life expectancy of greater than 6 months
* have a baseline hemoglobin value of \>= 10 g/dL and \< 15 g/dL and adequate hematologic function
* have adequate liver and kidney function
* if female, must be postmenopausal, surgically sterile, or practicing an effective method of birth control.

Exclusion Criteria:

* Rectal cancer patients who have received chemotherapy or gastric cancer patients who have received more than two cycles of chemotherapy
* anemia due to factors other than cancer or chemotherapy (e.g., iron, vitamin B12 or folate deficiencies, hemolysis or gastrointestinal bleeding)
* history of any other major medical condition or uncontrolled disease
* had a transfusion of white blood cells or packed red blood cells within one month prior to study entry or administration of androgen (male sex hormone) therapy within 2 months of study entry
* have received prior treatment with epoetin alfa or any investigational forms of erythropoietin within the previous six months.