Background

The significance of combination of docetaxel (DTX) with estramustine phosphate (EMP) in castration-resistant prostate cancer (CRPC) patients remains unclear. In this study, we aimed to retrospectively evaluate the efficacy and toxicity of DTX with or without EMP and to elucidate the significance of DTX and EMP combination therapy in Japanese EMP-refractory CRPC patients.

Methods

To compare the efficacy and toxicity of DTX and EMP, we divided CRPC patients, who were confirmed to be resistant to EMP, into the following two groups: group D (n = 28), which included patients treated with DTX (60 mg/m2, once in every four weeks) alone, and group DE (n = 33), which included patients treated with a combination of DTX (60 mg/m2, once in every four weeks) and EMP (twice daily oral administration at 280 mg).

Results

Prostate specific antigen (PSA) response (> 50% decline in PSA) was observed in six patients (21%) in group D and eight patients (24%) in group DE. The median time to progression (TTP) was 12.0 months and 6.2 months and the median overall survival (OS) was 26.4 months and 24.3 months in group D and DE, respectively. There was no statistical difference between the two groups in terms of PSA response, TTP, and OS. The incidence of adverse events of grade 3/4 was low in both the groups, and there was no statistical difference between the two groups.

Conclusions

Although treatment with DTX at 60 mg/m2 was effective and highly tolerated in EMP-refractory Japanese CRPC patients, the DTX and EMP combination therapy might not exhibit any survival benefit for CRPC patients.

Background

Radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) is a thermoablative technique to kill tumor tissue by generating areas of coagulative necrosis. Recent reports have raised concern that RFA may lead to a local recurrence of HCC with an aggressive phenotype and unfavorable prognosis, suggesting that RFA may induce further malignant transformation of HCC. However, the biological effects of RFA on HCC cells have not been directly analyzed. The aim of this study was to determine whether heat stress of the type associated with RFA induces malignant transformation of HCC.

Methods

We assessed the sensitivity of three HCC cell lines (HepG2, Alexander, and Huh7) to heat treatment for 10 min. We then determined the temperature at which a heat-resistant subline can be generated. We established and expanded sublines that survived heat treatment. And their proliferation rates, heat sensitivities, and invasive capacities were further examined.

Results

All HepG2 died after 48°C treatment, whereas 49°C treatment was required to kill all Alexander and HuH7. We generated 20 sublines for each parental cell line. A HepG2 subline, HepG2#18, proliferated 100% faster than parental HepG2. Moreover, HepG2#18 survived after 50°C treatment, whereas all parental HepG2 died after heat treatments at 48°C or higher.

Conclusion

Our results showed that even a single heat treatment could induce further transformation of an HCC cell line. Our results suggest that an insufficient treatment of HCC by RFA that enables survival of some cells might induce further malignant transformation in vivo.