We have reported that Escherichia coli K-12 colonizes hypoxic and necrotic tumor regions after intravenous injection into tumor-bearing mice. In this study, we established a novel strategy for cancer therapy using engineered bacteria to enhance the therapeutic effects of radiation. E. coli strain K-12 was engineered to produce cytolysin A (ClyA), and its effects on tumor growth in primary and metastatic tumor models were evaluated. A single treatment with E. coli-expressing ClyA significantly decreased tumor growth rates initially (9 days after treatment); however, the tumors tended to grow thereafter. With only radiotherapy (RT; 21 Gy), the tumor growth rates were retarded, but not the tumor sizes. A combination of therapy with E. coli-expressing ClyA and radiation [a total of 5 x 10(7) colony-forming units (CFU) and 21 Gy] resulted in significant tumor shrinkage and even complete disappearance of tumors in mice with tumors derived from murine CT26 colon cancer. Furthermore, treatment with E. coli-expressing ClyA markedly suppressed metastatic tumor growth and prolonged the survival time in mice. The results described here indicate that therapy with engineered E. coli could significantly improve the results of RT, and could exert a striking inhibitory effect on the development of lung metastasis.
How best to manage advanced esophageal cancer remains unresolved, especially in palliative care. Here, in a pilot study, we evaluated the efficacy and safety of concurrent chemoradiotherapy with S-1 and cisplatin in advanced esophageal cancer. Patients with locally advanced or metastatic squamous cell carcinoma of the esophagus received S-1 and cisplatin at doses of 70 mg/m(2)/day for 14 days and 70 mg/m(2) on day 1, respectively, every 3 weeks. Concurrently, radiotherapy was started at a dose of 200 cGy/day, up to a total of 5400 cGy. After concurrent chemoradiotherapy, additive chemotherapy was repeated up to six cycles. Thirty patients were enrolled in this study; of the 27 in whom efficacy could be evaluated, an objective response rate was seen in 20 (74.1%), including five (18.5%) complete pathologic responses in primary lesions. Improvement of dysphagia was seen in 21 (76%) patients. In patients with stage II or III esophageal cancer, the median progression-free survival and overall survival were 10.6 +/- 0.6 months (95% CI: 9.4-11.8) and 23.0 +/- 5.1 months (95% CI: 13.0-32.9), respectively. In patients with stage IV esophageal cancer, the median progression-free survival and overall survival were 5.4 +/- 1.6 months (95% CI: 2.2-8.6) and 11.6 +/- 1.6 months (95% CI: 8.4-14.8), respectively. The main hematological toxicity was neutropenia, but no neutropenic fever was observed. The major non-hematological toxicities were asthenia and vomiting, mostly of grades 1 and 2. Thus, concurrent chemoradiotherapy with S-1 and cisplatin may be a promising nonsurgical treatment in advanced esophageal cancer.
The prognostic relevance of tumor human papillomavirus (HPV) status in anal squamous cell carcinoma (SCC) had not been previously investigated, although its relevance to cervical, head and neck SCC is known. We retrospectively evaluated outcomes in 47 patients with anal SCC treated with combined chemoradiotherapy (CCRT) and determined tumor HPV status by HPV DNA chip method and p16 expression by immunohistochemistry (IHC) from paraffin-embedded tumor tissues. The median age was 65 years (range, 44-90 years). Sixteen (34%) patients were diagnosed with T stage 3 to 4, and 18 (38%) patients had regional nodal disease (N-positive). Thirty-five (75%) patients were HPV positive, and 31 (66%) patients were genotype 16 (HPV16-positive). Thirty-nine (83.0%) patients were positive for p16. After median follow-up of 51.7 months (range, 5.1-136.0 months), HPV16-positive group had significantly better 4-year progression-free survival (PFS, 63.1% vs. 15.6%, p < 0.001) and overall survival (84.6% vs. 39.8%, p 5 0.008) than HPV genotype 16 negative (HPV16-negative) group. Patients with p16-positive tumor also had a better 4-year PFS (52.5% vs. 25.0%, p 5 0.014) than those with p16-negative tumor. In multivariate analysis for PFS, N-positive and HPV16-negative were independent prognostic factors for shorter PFS. Comparing patterns of failure, time to loco-regional failure was statistically superior in HPV16-positive over HPV16-negative groups (p 5 0.006), but time to systemic failure was not different (p 5 0.098). Tumor HPV genotype 16 status is a prognostic and predictive factor in anal SCC treated with CCRT, and p16 expression determined by IHC might be advocated as a surrogate biomarker of HPV integration in anal SCC. Further studies are warranted.Anal squamous cell carcinoma (SCC) is an uncommon malignancy of the anal canal and perianal skin area. The clinical biology of anal SCC is distinct from other gastrointestinal tract cancers. It is mostly a loco-regional disease at diagnosis, with metastasis in only 15% of patients.1 Therefore, in managing anal cancer, the concerns of treatment strategies include improving loco-regional control and preserving sphincter function. Combined chemoradiotherapy (CCRT)
We investigated the patterns of pretreatment expression of the epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) by immunohistochemical staining and determined their correlation with treatment response and survival in 44 patients with esophageal squamous cell carcinoma (ESCC) treated with definitive concurrent chemoradiotherapy (CCRT). The definitive CCRT consisted of a median dose of 54 Gy (range: 40.0-68.4 Gy) and two cycles of concurrent administration of mostly 5-fluorouracil + cisplatinum. High expression of EGFR, VEGF, and COX-2 was found in 79.5%, 31.8%, and 38.6%, respectively. The Cox regression analysis for overall survival (OS) showed that both the treatment response and COX-2 expression were significant. The 3-yr OS rates of patients that achieved a complete response and those that did not were 46.7% and 5.3%, respectively (P = 0.006). The logistic regression analysis for treatment response with various parameters showed that only a high expression of VEGF was significantly associated with a complete response. Unlike other well-known studies, higher expression of VEGF was significantly correlated with a complete response to CCRT in this study. However, higher expression of COX-2 was significantly associated with shorter survival. These results suggest that VEGF might be a predictive factor for treatment response and COX-2 a prognostic factor for OS in patients with ESCC after definitive CCRT.
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