Melphalan and Stem Cell Transplant Before Total-Body Irradiation and Donor Stem Cell Transplant in Treating Patients With Stage I-III Multiple Myeloma

Inclusion Criteria:

* Meet Salmon and Durie criteria for initial diagnosis of multiple myeloma; transplant will be offered to patients with stage II or III multiple myeloma (MM) at diagnosis or have received chemotherapy and/or radiation therapy for progressive MM after initial diagnosis of stage I disease
* The patient must have the capacity to give informed consent
* Have received at least 4 cycles of conventional dose chemotherapy for MM
* DONOR: HLA genotypically identical sibling
* DONOR: Donor must consent to filgrastim (G-CSF) administration and leukapheresis for both peripheral blood stem cell (PBSC) allograft and subsequent DLI
* DONOR: Donor must have adequate veins for leukapheresis or agree to placement of central venous catheter (femoral, subclavian)
* DONOR: Age \< 75, older donors may be considered after consultation by Psychological Consultation Center (PCC)

Exclusion Criteria:

* Karnofsky score less than 60, unless due solely to myeloma
* Left ventricular ejection fraction less than 40%
* Bilirubin greater than 2 X the upper limit of normal
* Serum glutamic pyruvic transaminase (SGPT) and serum glutamic oxaloacetic transaminase (SGOT) \> 2 X the upper limit of normal
* Diffusion lung capacity of carbon monoxide (DLCO) \< 50% (corrected) or receiving continuous supplemental oxygen
* Patients with poorly controlled hypertension
* Pregnancy
* Seropositive for the human immunodeficiency virus
* Fertile men or women unwilling to use contraceptive techniques during and for 12 months following treatment
* Creatinine clearance \< 40 cc/min at the time of initial autografting evaluation
* Prior autograft (can be treated on alternative protocol)
* DONOR: Identical twin
* DONOR: Age less than 12 years
* DONOR: Pregnancy
* DONOR: Infection with human immunodeficiency virus (HIV)
* DONOR: Inability to achieve adequate venous access
* DONOR: Known allergy to G-CSF
* DONOR: Current serious systemic illness
* DONOR: Failure to meet Fred Hutchinson Cancer Research Center (FHCRC) criteria for stem cell donation as described in the standard practice guidelines of the institution