The KM OS analysis for each dose level is shown in Figure 1. Figure 1 Kaplan Meier overall survival curves by dose level. In the UV survival
analysis, several different adjuvant treatment parameters were associated with Dasatinib purchase higher risk of death including RT dose below the median, RT dose <30 Gy, and RT dose ≥30 to <40 Gy, and shorter radiation duration. Factors significantly associated with lower risk of death included, smaller tumor size, lower grade, and younger age. The results of the complete UV can be found in Table 2. Table 2 Univariate survival analysis The UV associated between categorized radiation dose and all other covariates Inhibitors,research,lifescience,medical are summarized in Table 3. Factors found to be significantly correlated with the different dose level categories of RT included facility type, tumor size, and Inhibitors,research,lifescience,medical grade. It can be seen that the RT dose was independent of stage. Table
3 Variable association with RT dose levels In the MV Inhibitors,research,lifescience,medical survival analysis, RT dose <30 Gy [HR, 2.38 (95% CI, 1.85-3.07); P≤0.001] and RT dose ≥30 Gy and <40 Gy [HR, 1.41 (95% CI, 1.04-1.91); P=0.026] vs. RT dose ≥55 Gy; were significantly associated with worse OS. In addition to radiation dose, age was also found to be significant on MV analysis. The complete MV survival analysis can be seen in Table 4. As the results of the MV survival analysis were not significantly different with and without the propensity score weighting, we present the unweighted results only. Table 4 Multivariate survival analysis The duration of time over which each Inhibitors,research,lifescience,medical of the respective RT doses was delivered is summarized in Table 5. It can be seen that the vast majority of patients for which
the RT duration was known received conventionally fractionated RT. Table 5 Duration of radiation therapy administration Discussion The purpose of this analysis of the NCDB Inhibitors,research,lifescience,medical was to examine the effect of RT dose escalation in a large cohort of patients with unresectable PAC. This series presents a heterogeneous group of patients, ALOX15 treated in a variety of facility types, with a wide range of RT doses. There was no measureable benefit or detriment to OS in patients treated with conventionally delivered, escalating RT doses greater than 40 Gy. There exists a historical precedent for RT dose escalation in unresectable PAC. An early prospective study examining RT dose escalation was the Gastrointestinal Tumor Study Group’s (GITSG) locally advanced dose escalation trial (5). Published in 1981, this prospective trial randomized 194 patients to 60 Gy of RT alone or concurrent chemo-RT with dose escalated RT consisting of 40 vs. 60 Gy.