Progression-free survival and quality of life in metastatic breast cancer: The patient perspective.

INTRODUCTION: Treatment advances for metastatic breast cancer (mBC) have improved overall survival (OS) in some mBC subtypes; however, there remains no cure for mBC. Considering the use of progression-free survival (PFS) and other surrogate endpoints in clinical trials, we must understand patient perspectives on measures used to assess treatment efficacy. OBJECTIVE: To explore global patient perceptions of the concept of PFS and its potential relation to quality of life (QoL). MATERIALS AND METHODS: Virtual roundtables in Europe and the United States and interviews in Japan with breast cancer patients, patient advocates, and thought leaders. Discussions were recorded, transcribed, and analyzed thematically. RESULTS: Lengthened OS combined with no worsening or improvement in QoL remain the most important endpoints for mBC patients. Time when the disease is not progressing is meaningful to patients when coupled with improvements in QoL and no added treatment toxicity. Clinical terminology such as "PFS" is not well understood, and participants underscored the need for patient-friendly terminology to better illustrate the concept. Facets of care that patients with mBC value and that may be related to PFS include relief from cancer-related symptoms and treatment-related toxicities as well as the ability to pursue personal goals. Improved communication between patients and providers on managing treatment-related toxicities and addressing psychosocial challenges to maintain desired QoL is needed. CONCLUSION: While OS and QoL are considered the most relevant endpoints, patients also value periods of time without disease progression. Incorporation of these considerations into the design and conduct of future clinical trials in mBC, as well as HTA and reimbursement decision-making, is needed to better capture the potential value of a therapeutic innovation.

Ongoing somatic hypermutation of the rearranged VH but not of the V-lambda gene in EBV-transformed rheumatoid factor-producing lymphoblastoid cell line.

Epstein-Barr virus (EBV) transforms human peripheral B cells into lymphoblastoid cell lines (LCLs) that secrete specific antibodies. In contrast to peripheral blood B cells, LCLs express the activation-induced cytidine deaminase (AID) gene, a key enzyme in the generation of somatic hypermutation (SHM) in immunoglobulin variable genes. We have previously studied an LCL that secretes a rheumatoid factor (RF: an IgM(lambda) anti-IgG antibody) and identified the accumulation of SHM at a frequency of 1.5 x 10(-3)mut/bp in the rearranged variable region heavy chain gene (VH) of its RF sub-culture (i.e., RF-2004). The aim of the present work was to find out whether SHM was initiated as an early event following EBV transformation. Our results show that already the earliest RF-culture (RF-1983) mutates its VH at a somewhat higher frequency of 1.9 x 10(-3). Overall, we detected 17 point mutations in the RF-2004 culture and in 26 cellular clones derived from the RF-1983 and RF-2004 cultures. Most of the mutations were due to C to T or G to A transitions, with preferential targeting to WRCH/DGYW hotspot motifs, indicating that they were due to the initial phase of AID-directed mutations. A genealogical tree demonstrates that mutations were accumulated in a stepwise manner with 1-2 mutations per cell division. However, no mutations were found in the rearranged V-lambda (Vlambda) gene in the same RF-cultures and their subclones (i.e., <1.2 x 10(-4)mut/bp). To our knowledge this is the first reported clonal cell line that generates SHM in the VH, but not in the Vlambda. It may be due to abrogation of a cis-regulatory element(s) in the Vlambda or to a lack of a specific trans-acting factor which differentially direct the SHM machinery to this gene. Out of the 17 point mutations detected in both cell lines there were, 1 stop codon, 3 mutations which obliterated the binding of the RF antibody to its IgG antigen and 1 or 2 mutations which enhanced antigen-binding affinity. These results show that the evolutionary developed germline encoded antibody combining site is highly sensitive to amino acid replacements. Our combined findings that the RF cells accumulate in a stepwise manner up to 1-2 point mutations/sequence per cell division and the generation of high percentage of functionally deleterious mutations, are in accord with the 'multiphase-recycling model' of SHM, which states that B cells in the germinal center are subjected to multiple rounds of somatic mutations interchanged with periods of antigenic selection.