The time from they the start of any treatment to the end of the TRT was not a significant factor for OS when SER was analyzed as a continuous variable or as a categorical variable based on the median value. There were no significant differences in OS based on sex, lactate dehydrogenase, ipsilateral supracla Inhibitors,Modulators,Libraries vicular nodes, daily fraction, TRT technique, chemother apy cycles Inhibitors,Modulators,Libraries or ORT. Multivariate analysis demonstrated that age 65 years, high KPS, weight loss 5% and high BED remained sig nificantly correlated with improved OS, while PCI was borderline associated with OS. Figure 3 showed the median OS as a function of BED, a positive correlation was found although the slope of the BED response seems relatively flat in the low BED region.

Discussion This retrospective study showed that patients treated with BED 57 Gy had significantly better LC, PFS and OS in LS SCLC, indicating that patients could achieve benefits Inhibitors,Modulators,Libraries from high BED. This result is consistent with previous findings that TRT dose intensification improved LC, resulting in better outcomes in LS SCLC. Specifically, all patients in our study received TRT dose 50 Gy, which is high compared to doses adopted by pre vious studies. Our results supported the hypoth esis that a biologically dose response relationship still existed even in a relatively high radiation dose range for LS SCLC. The radiation dose 50 Gy determined as the inclu sion criteria for this retrospective analysis was based on our assumption that 50 Gy might be a conservative radiation dose for our LS SCLC population with cura tive intent when sequential chemoradiotherapy was given, according to our previous study.

In the cur rent analysis with a large sample size, patients who received BED 57 Gy had significantly better LC rate, with a trend toward better DMFS. It was suggestive that further improving Inhibitors,Modulators,Libraries LC of the primary tumor with high BED may play a major role in reducing the risk of sub sequent metastasis Inhibitors,Modulators,Libraries and that combination of improved LC and decreased distant metastasis would finally con tribute to better OS in patients treated with high BED. In addition, our results showed that high BED was sig nificantly associated with improved OS in patients with LS SCLC, which is comparable to the findings of Schild et al, of which a strong positive correlation between BED and 5 year OS was shown with a reported Pearson correlation coefficient of 0. 81 based on randomized trials that included various TRT programs for LS SCLC. Results from these studies suggested that for LS SCLC, high DAPT secretase Notch BED which integrated the factors of TRT dose and ORT is important to achieve a better outcome. Accelerated proliferation of tumor clonogens during radiotherapy has been shown to affect outcomes in many malignant solid tumors.