This study will provide follow-up evaluations of breast cancer or multiple myeloma patients who received gene therapy (gene transfer) as part of their participation in an NIH protocol. Gene therapy is a new technology, which may involve a permanent change in the patient s genetic code. Therefore, although the risk of long-term harmful effects of this therapy is very small, the Food and Drug Administration requires prolonged monitoring of patients health status.

Patients previously enrolled in NIH protocols 96-C-0007, 93-C-0208, 92-C-0161, or 92-H-0057 will be followed under the current protocol. No further gene therapy will be provided in this study.

Patients health status will be evaluated for an indefinite period of time, or as long as they are willing to be monitored. They will provide a blood sample once a year and will be interviewed about their health status twice a year for the first 5 years after gene therapy and once a year thereafter. These procedures are done to look for the development of any diseases such as cancer, neurological disorders, autoimmune or blood disorders that may be related to side effects of the gene transfer.

This Protocol aims to provide long-term follow-up of breast cancer and multiple myeloma subjects previously receiving autologous primitive marrow and blood hematopoietic cells exposed to gene transfer retroviral vectors on the following protocols: MB 294 (92-C-0161; T-92-0018), MB 310 (93-C-0208; T-92-0192), MB 361 (96-C-0007; T-95-0096) or (92-H-0057; T-92-0139) at the National Cancer Institute and the National Heart, Lung, and Blood Institute. Subjects will undergo an annual health history and annual complete blood counts will be performed. Blood samples will also be collected annually (either locally or off-site by the subjects' personal physicians) for testing for presence of the gene transfer vector and vector integration sites.

• INCLUSION CRITERIA:

Subjects who received gene transfer products on the following protocols: MB 361, 96-C-0007, T-95-0096; MB 294, 92-C-0161, T-92-0018; MB 310, 93-C 0208, T-92-0192; or 92-H-0057, T-92-0139.

EXCLUSION CRITERIA:

Patients unwilling to participate.