Adjuvant chemotherapy with doxorubicin and cyclophosphamide in women with rapidly proliferating node-negative breast cancer.

This prospective clinical trial was designed to assess the impact of adjuvant chemotherapy in women with rapidly proliferating node-negative breast cancer. This group has been predicted to have a 5-year disease-free survival (DFS) of 70% without adjuvant chemotherapy. In this study, 449 women with rapidly proliferating breast cancer (91% measured by S-phase fraction and 9% by histochemistry) received adjuvant chemotherapy with doxorubicin/cyclophosphamide (AC) plus tamoxifen for estrogen receptor-positive or progesterone receptor-positive cancer. The 5-year DFS was 90% (+/- 2%) and the 5-year overall survival was 94% (+/- 1%). At a median follow-up of 62 months, the strategy of administering 6 cycles of AC to women with T2 N0 cancer and 3 cycles in those with smaller T1 N0 cancers appeared to eliminate tumor size as a potential prognostic factor. Adjuvant chemotherapy with AC appears effective in reducing recurrence rates for women with rapidly proliferating node-negative breast cancer.

Synthetic Escherichia coli consortia engineered for syntrophy demonstrate enhanced biomass productivity.

Synthetic Escherichia coli consortia engineered for syntrophy demonstrated enhanced biomass productivity relative to monocultures. Binary consortia were designed to mimic a ubiquitous, naturally occurring ecological template of primary productivity supported by secondary consumption. The synthetic consortia replicated this evolution-proven strategy by combining a glucose positive E. coli strain, which served as the system's primary producer, with a glucose negative E. coli strain which consumed metabolic byproducts from the primary producer. The engineered consortia utilized strategic division of labor to simultaneously optimize multiple tasks enhancing overall culture performance. Consortial interactions resulted in the emergent property of enhanced system biomass productivity which was demonstrated with three distinct culturing systems: batch, chemostat and biofilm growth. Glucose-based biomass productivity increased by ∼15, 20 and 50% compared to appropriate monoculture controls for these three culturing systems, respectively. Interestingly, the consortial interactions also produced biofilms with predictable, self-assembling, laminated microstructures. This study establishes a metabolic engineering paradigm which can be easily adapted to existing E. coli based bioprocesses to improve productivity based on a robust ecological theme.