Study in Patients With Primary Breast Diffuse Large B-cell Lymphoma

Inclusion Criteria:

* Histologically confirmed CD20 positive primary breast DLBCL
* age ≤ 70
* No prior chemotherapy or radiotherapy for DLBCL
* Performance status (ECOG) ≤ 2
* Cardiac ejection fraction ≥ 50 % as measured by MUGA or 2D ECHO without clinically significant abnormalities
* Adequate renal function: serum creatinine level \< 2 mg/dL (177 μmol/L)
* Adequate liver functions: Transaminase (AST/ALT) \< 3 X upper normal value, Bilirubin \< 2 X upper normal value
* Adequate BM functions: hemoglobin ≥ 9 g/dL absolute neutrophil count (ANC) ≥ 1,500/μL and platelet count ≥ 75,000/μL
* A negative serum or urine pregnancy test prior to treatment must be available both for pre menopausal women and for women who are \< 1 years after the onset of menopause
* Life expectancy more than 6 months
* Informed consent

Exclusion Criteria:

* other subtype primary breast non-Hodgkin's lymphoma than DLBCL
* secondary breast DLBCL
* Patients with a known history of HIV seropositivity or HCV (+). Patients who have HBV (+) are eligible. However, primary prophylaxis using antiviral agents (i.e. lamivudine) is recommended for HBV carrier to prevent HBV reactivation during whole treatment period.
* Any other malignancies within the past 5 years except curatively treated non-melanoma skin cancer or in situ carcinoma of cervix uteri
* Pregnant or lactating women, women of childbearing potential not employing adequate contraception
* Other serious illness or medical conditions

  * Unstable cardiac disease despite treatment, myocardial infarction within 6 months prior to study entry
  * History of significant neurologic or psychiatric disorders including dementia or seizures
  * Active uncontrolled infection (viral, bacterial or fungal infection)
  * Other serious medical illnesses
* Known hypersensitivity to any of the study drugs or its ingredients (i.e., hypersensitivity to Polysorbate 20, CHO cell products, or recombinant human antibodies)
* Concomitant administration of any other experimental drug under investigation, or concomitant chemotherapy, hormonal therapy, or immunotherapy