RESUMEN
Purpose: Uterine leiomyosarcoma is a rare and aggressive tumor known for its drug resistance and metastatic potential. The standard first-line treatment typically involves anthracycline-based chemotherapy or a combination of gemcitabine and docetaxel; however, there is currently no established second-line treatment. Therefore, the aim of this study was to evaluate the efficacy and toxicity of doxorubicin plus ifosfamide as a potential second-line treatment for uterine leiomyosarcoma. Materials and methods: This is a retrospective, single-center, single-arm study. We reviewed the tumor registry data from January 2010 to December 2022 and identified patients with uterine leiomyosarcoma who had previously received first-line salvage or adjuvant treatment involving gemcitabine and taxotere, and later experienced tumor recurrence. Patients who met these criteria were included in the study. The primary endpoint was the efficacy of doxorubicin and ifosfamide as a second-line treatment for uterine leiomyosarcoma, as measured by progression-free survival, 1-year overall survival, and response rate. The secondary endpoint was the adverse events associated with this regimen. Results: Fifty-two patients were diagnosed with uterine leiomyosarcoma during the study period, nine of whom were included in the data analysis. All patients had previously received gemcitabine-docetaxel as first-line adjuvant therapy, with a median progression-free survival period of 8.4 months. Doxorubicin-ifosfamide was administered as second-line treatment, with a median progression-free survival of 6.0 months (range: 2.7-79.9 months). The clinical benefit rate of the second-line treatment was 66.7%, with a median overall survival of 33.0 months, and a 1-year overall survival rate of 83.3%. Previous reports have shown that the median progression-free survival for second-line treatments using other regimens ranged from 1.4-5.6 months. The most common adverse event was myelosuppression, with five patients requiring granulocyte colony-stimulating factor and one patient requiring a blood transfusion. No patient discontinued treatment due to unmanageable adverse events. Conclusion: Use of doxorubicin with ifosfamide may be a promising and reasonable second-line treatment with manageable adverse events for patients with uterine leiomyosarcoma.
RESUMEN
Enteropathogenic Escherichia coli (EPEC), an important paediatric diarrhoeal pathogen, employs multiple adhesins to colonize the small bowel and produces characteristic 'attaching and effacing' (A/E) lesions on small intestinal enterocytes. EPEC adhesins that have been associated with A/E adhesion and intestinal colonization include bundle-forming pili (BFP), EspA filaments and intimin. BFP are involved in bacteria-bacteria interaction and microcolony formation but their role in cell adhesion remains unclear; EspA filaments are components of the EPEC type III secretion system but since they interact directly with host cells they may also function as adhesins; intimin is the well characterized intimate EPEC adhesin which binds the translocated intimin receptor, Tir. However, other uncharacterized host cell receptors have been implicated in intimin-mediated adhesion. In this study, the role of BFP, EspA filaments and intimin in EPEC adhesion to intestinal brush border cells was assessed by observing adhesion of wild-type EPEC strain E2348/69 and a set of isogenic single, double and triple mutants in bfpA, espA and eae (intimin gene) to differentiated human intestinal Caco-2 cells. E2348/69 (bfpA(+) espA(+) eae(+)) adhered rapidly (<10 min) to the brush border of Caco-2 cells and subsequently produced microcolonies and typical A/E lesions. Non-intimate brush border adhesion of double mutant strain UMD880 (bfpA(+) espA(-) eae(-)) also occurred rapidly, whereas adhesion of strain UMD886 (bfpA(-) espA(+) eae(-)) occurred later in the infection (>1 h) and with much lower efficiency; confocal microscopy indicated BFP and EspA-mediated adhesion, respectively. Strain UMD883 (bfpA(-) espA(-) eae(+)), which is unable to translocate Tir, was non-adherent although this strain was able to form intimate attachment and A/E lesions when co-cultured with strain CVD206 (bfpA(+) espA(+) eae(-)) which supplied Tir to the membrane. Single mutant strains CVD206 (bfpA(+) espA(+) eae(-)) and UMD872 (bfpA(+) espA(-) eae(+)) showed adherence characteristics of strain UMD880 (bfpA(+) espA(-) eae(-)), whilst triple mutant strain UMD888 (bfpA(-) espA(-) eae(-)) was totally non-adherent. These results support an adhesive role for BFP and EspA in initial brush border cell attachment, and in typical EPEC which express both BFP and EspA filaments suggest a predominant role for BFP; EspA filaments, however, could serve as initial attachment factors in atypical EPEC which lacks BFP. The study found no evidence for an independent host cell intimin receptor or for other adhesive factors able to support bacterial adherence.