Optimizing cancer treatments to induce an acute immune response: radiation Abscopal effects, PAMPs, and DAMPs.

Clinical results indicate improved survival in poorly differentiated prostate cancer patients following a treatment schedule that maximizes hormone therapy prior to radiation. This may be because of a systemic immune response, called an abscopal effect. A literature review showed an association between acute infection and abscopal cancer remission. This led to the theory that, in the presence of endogenous cancer-specific antigens exposed by cancer necrosis, an innate immune response can adapt to respond to those antigens via a cross-talk mechanism. This theory was validated in an animal model. An acute innate immune T-cell response was stimulated using cluster vaccination with Poly(I:C). In the presence of exogenous cancer-specific antigens, this immune response became adaptive, creating an abscopal effect that resulted in cancer resolution. These concepts may be of clinical value, improving outcomes by inducing systemic abscopal effects.

Extreme-risk prostate adenocarcinoma presenting with prostate-specific antigen (PSA)>40 ng/ml: prognostic significance of the preradiation PSA nadir.

PURPOSE: To examine the impact of patient, disease, and treatment characteristics on survival outcomes in patients treated with neoadjuvant androgen deprivation therapy (ADT) and radical external-beam radiotherapy (RT) for clinically localized, extreme-risk prostate adenocarcinoma with a presenting prostate-specific antigen (PSA) concentration of >40 ng/ml. METHODS AND MATERIALS: A retrospective chart review was conducted of 64 patients treated at a single institution between 1991 and 2000 with ADT and RT for prostate cancer with a presenting PSA level of >40 ng/ml. The effects of patient age, tumor (presenting PSA level, Gleason score, and T stage), and treatment (total ADT duration and pre-RT PSA level) characteristics on rates of biochemical disease-free survival (bDFS), prostate cancer-specific survival (PCSS), and overall survival (OS) were examined. RESULTS: Median follow-up time was 6.45 years (range, 0.09-15.19 years). Actuarial bDFS, PCSS, and OS rates at 5 years were 39%, 87%, and 78%, respectively, and 17%, 64%, and 45%, respectively, at 10 years. On multivariate analysis, the pre-RT PSA level (≤0.1 versus >0.1 ng/ml) was the single most significant prognostic factor for bDFS (p=0.033) and OS (p=0.018) rates, whereas age, T stage, Gleason score, and ADT duration (≤6 versus >6 months) were not predictive of outcomes. CONCLUSION: In prostate cancer patients with high presenting PSA levels, >40 ng/ml, treated with combined modality, neoadjuvant ADT, and RT, the pre-RT PSA nadir, rather than ADT duration, was significantly associated with improved survival. This observation supports the use of neoadjuvant ADT to drive PSA levels to below 0.1 ng/ml before initiation of RT, to optimize outcomes for patients with extreme-risk disease.

Prospective evaluation of the prevalence and severity of fatigue in patients with prostate cancer undergoing radical external beam radiotherapy and neoadjuvant hormone therapy.

OBJECTIVE: To prospectively evaluate the prevalence and severity of fatigue and its impact on quality of life (QOL) during and after radical external beam radiotherapy (RT) for prostate cancer. METHOD AND MATERIALS: Twenty-eight men with prostate cancer undergoing RT over 6-8 consecutive weeks were prospectively accrued. The Brief Fatigue Inventory (BFI), a validated fatigue assessment tool, was administered at five time points: baseline (week 1), middle of RT (week 3-4), end of RT (last week of RT), and follow-up (median 6.5 weeks after RT). The BFI contained nine questions, each using 0-10 ratings to quantify fatigue severity and interference with six QOL domains. The prevalence of moderate-severe fatigue was plotted as a function of time. Mean sum and subscale scores at each time point were compared to baseline scores using Wilcoxon tests. Linear regression analyses were performed to assess associations between fatigue scores and age, tumor and treatment characteristics. RESULTS: The median age was 69 years (range 57-84), Gleason score 7 (range 6-10), and presenting PSA 9.0 ng/mL (range 2.5 ng/mL-103.0 ng/mL). Patients were treated once daily to a median dose of 74 Gy (range 60 Gy-78 Gy) over a median of 37 fractions (range 30-39). Hormone therapy was used in all patients (median duration 12.2 months). The prevalence of moderate-severe present fatigue increased from 7% at baseline to 8% at mid-RT and 32% at RT completion. Compared to baseline (mean score 11.5), fatigue increased significantly mid-RT (mean score 14.6, p = 0.03) and peaked at the end of RT (mean score 23.5, p = 0.001). Fatigue significantly interfered with walking ability, normal work, daily chores, and enjoyment of life only at the end of RT. After RT completion, fatigue improved but remained higher compared to baseline at 6.5 weeks of follow-up (mean score 15.0, p = 0.02). On linear regression analysis, age, Gleason score, PSA, T-stage, hormone therapy duration, RT dose and fractions were not significantly associated with mean fatigue scores. CONCLUSION: Patients undergoing 6-8 weeks of RT experienced significant fatigue adversely affecting QOL persisting after therapy completion. Since walking ability was not affected until the end of RT, a walking exercise intervention to combat fatigue is likely feasible and is being investigated.

Neoadjuvant hormone therapy and external-beam radiation for localized high-risk prostate cancer: the importance of PSA nadir before radiation.

PURPOSE: To examine the impact of various patient, disease, and treatment characteristics on outcome in patients treated with neoadjuvant hormone therapy (NAHT) and external-beam radiation therapy (EBRT) for clinically localized, high-risk prostate adenocarcinoma (initial prostate-specific antigen [PSA] level >20, Gleason score 8-10 or Stage > or = T3). METHODS AND MATERIALS: A retrospective chart review was conducted on 407 patients treated between 1991 and 2001 with NAHT and EBRT for high-risk prostate cancer. The effect of tumor (PSA level, Gleason score, and T stage) and treatment (NAHT duration, total-hormone duration, preradiation PSA) characteristics on rates of biochemical disease-free survival (bDFS), prostate cancer-specific survival, and overall survival were examined. RESULTS: Median follow-up time was 78 months (range: 5-140 months). Actuarial bDFS at 5 years was 52% (95% confidence interval [CI], 46% to 57%) for the entire group. On multivariate analysis, initial PSA level (p = 0.004), Gleason score (p = 0.005), and preradiation PSA level (p < 0.001) were predictive of bDFS, whereas age, T stage, duration of NAHT, and duration of total hormone therapy were not predictive of outcomes. Gleason score and preradiation PSA level were also predictive of prostate cancer-specific survival rates. CONCLUSION: Improved bDFS in patients with high-risk prostate cancer was associated with lower initial PSA level, lower Gleason score, and lower preradiation PSA level. The duration of NAHT did not have an impact on outcomes, but the preradiation PSA was an important predictor of bDFS in high-risk patients.