RESUMEN
Background: Adding carboplatin to weekly paclitaxel as part of neoadjuvant chemotherapy (NACT) for stage II-III triple negative breast cancer (TNBC) has been shown to significantly increase the pathologic complete response (pCR) rate. Hematologic toxicities associated with every 3-week dosing of carboplatin have led some oncologists to explore weekly dosing as an alternative, but there are little published data comparing the two dosing schedules. Methods: We performed a retrospective analysis of patients who received paclitaxel and carboplatin, usually followed by AC, as initial NACT for TNBC at two academic cancer centers between 2008 and 2018 for whom pathologic results and post-operative follow-up were available. We recorded pCR, defined as ypT0/isN0, treatment delivery and disease-free survival, censored as of the patient's last follow-up visit. Results: A total of 76 patients were identified (median age 49 years). A total of 47 received weekly carboplatin, of whom 83% received at least 11 of 12 planned doses, and 29 received every 3-week carboplatin, of whom 90% received all 4 planned doses. pCR rates were similar, 53% with weekly and 55% with every 3-week carboplatin dosing. At median follow-up of 18 months (range <1-118), 93% of patients who achieved pCR were alive and free from recurrence, compared to 74% of those who did not. Conclusion: pCR rates were similar between patients receiving weekly or every 3-week carboplatin and were similar to those reported in prior trials with carboplatin. These data suggest that providers can choose either weekly or every 3-week carboplatin dosing without compromising the likelihood of achieving pCR.
RESUMEN
Endospore formation by Bacillus subtilis involves three differentiating cell types, the predivisional cell, the mother cell, and the forespore. Here we report the program of gene expression in the forespore, which is governed by the RNA polymerase sigma factors sigma(F) and sigma(G) and the DNA-binding proteins RsfA and SpoVT. The sigma(F) factor turns on about 48 genes, including the gene for RsfA, which represses a gene in the sigma(F) regulon, and the gene for sigma(G). The sigma(G) factor newly activates 81 genes, including the gene for SpoVT, which turns on (in nine cases) or stimulates (in 11 cases) the expression of 20 genes that had been turned on by sigma(G) and represses the expression of 27 others. The forespore line of gene expression consists of many genes that contribute to morphogenesis and to the resistance and germination properties of the spore but few that have metabolic functions. Comparative genomics reveals a core of genes in the sigma(F) and sigma(G) regulons that are widely conserved among endospore-forming species but are absent from closely related, but non-spore-forming Listeria spp. Two such partially conserved genes (ykoU and ykoV), which are members of the sigma(G) regulon, are shown to confer dry-heat resistance to dormant spores. The ykoV gene product, a homolog of the non-homologous end-joining protein Ku, is shown to associate with the nucleoid during germination. Extending earlier work on gene expression in the predivisional cell and the mother cell, we present an integrated overview of the entire program of sporulation gene expression.