Clinical outcome and prognostic factors for central neurocytoma: twenty year institutional experience

Central neurocytomas are uncommon intraventricular neoplasms whose optimal management remains controversial due to their rarity. We assessed outcomes for a historical cohort of neurocytoma patients and evaluated effects of tumor atypia, size, resection extent, and adjuvant radiotherapy. Progression-free survival (PFS) was measured by Kaplan-Meier and Cox proportional hazards methods. A total of 28 patients (15 males, 13 females) were treated between 1995 and 2014, with a median age at diagnosis of 26 years (range 5-61). Median follow-up was 62.2 months and 3 patients were lost to follow-up postoperatively. Thirteen patients experienced recurrent/progressive disease and 2-year PFS was 75% (95% CI 53-88%). Two-year PFS was 48% for MIB-1 labeling >4% versus 90% for ≤4% (HR 5.4, CI 2.2-27.8, p = 0.0026). Nine patients (32%) had gross total resections (GTR) and 19 (68%) had subtotal resections (STR). PFS for >80% resection was 83 versus 67% for ≤80% resection (HR 0.67, CI 0.23-2.0, p = 0.47). Three STR patients (16%) received adjuvant radiation which significantly improved overall PFS (p = 0.049). Estimated 5-year PFS was 67% for STR with radiotherapy versus 53% for STR without radiotherapy. Salvage therapy regimens were diverse and resulted in stable disease for 54% of patients and additional progression for 38 %. Two patients with neuropathology-confirmed atypical neurocytomas died at 4.3 and 113.4 months after initial surgery. For central neurocytomas, MIB-1 labeling index >4% is predictive of poorer outcome and our data suggest that adjuvant radiotherapy after STR may improve PFS. Most patients requiring salvage therapy will be stabilized and multiple modalities can be effectively utilized.

Long-term disease-specific and cognitive quality of life after intensity-modulated radiation therapy: a cross-sectional survey of nasopharyngeal carcinoma survivors

Background

There is a lack of data on quality of life in long-term survivors of nasopharyngeal carcinoma (NPC) who have been treated with intensity-modulated radiation therapy (IMRT). We characterized long-term disease-specific and cognitive QoL in NPC survivors after IMRT.

Methods

We conducted a cross-sectional study of surviving patients diagnosed and treated for NPC at our center with curative-intent IMRT, with or without chemotherapy. Patients who were deceased, still undergoing treatment, with known recurrent disease, or treated with RT modality other than IMRT were excluded. QoL was measured by FACT-NP and FACT-Cog.

Results

Between May and November 2013, 44 patients completed cognitive (FACT-Cog), general (FACT-G), and NPC-specific (NPCS) QoL assessments. Patients were categorized into 4 cohorts based on duration since IMRT (≤2.5, >2.5–6, >6–10, and >10–16 years). There was no significant difference in age (p = 0.20) or stage ((I/II vs III/IV: p = 0.78) among the cohorts. The 4 cohorts differed overall for all QoL measures (ANOVA: p < 0.02 for each), due to improved scores >2.5–6 years post-IMRT compared with ≤2.5 years post-IMRT (post hoc tests: p ≤ 0.04 for each). No differences were observed between >2.5–6 and >6–10 years post-IMRT, but lower mean FACT-Cog and NPCS scores were observed for >10 years compared to >2.5–6 years post-IMRT (post hoc: p < 0.05 for each).

Conclusions

All QoL measures were low during the initial recovery period (≤2.5 years) and were higher by 6 years post-IMRT. At >10 years post-IMRT, lower scores were observed in the domains of NPC-specific and cognitive QoL. Survivors of NPC, even if treated with IMRT, are at risk for detriment in domain-specific QoL measures at very long-term follow-up.

Evaluation of Heart Dose for Left-Sided Breast Cancer Patients Over an 11-Year Period Spanning the Transition From 2-Dimensional to 3-Dimensional Planning

INTRODUCTION/BACKGROUND

We evaluated heart dose from left breast radiotherapy with 2-dimensional (2D) versus 3-dimensional (3D) plans.

PATIENTS AND METHODS

Treatment plans from patients treated with standard fractionation for left breast cancer from 2003 to 2013 were reviewed, with patients grouped into 3 cohorts: 2003 to 2004 ("2D", with computed tomography scans for dose calculation but fields defined using simulation films; n = 29), 2005 to 2006 ("2D-post," after several influential articles on heart dose were published; n = 31), and 2007 to 2013 ("3D"; n = 256). All patients were treated with free-breathing technique. Heart volumes were retrospectively contoured for the earlier 2 cohorts. Mean heart dose (MHD) and percentage of structure receiving at least 25 Gy (V25 Gy) and percentage of structure receiving at least 5 Gy for the whole heart, left ventricle (LV), right ventricle (RV), and both ventricles were recorded and compared among cohorts.

RESULTS

MHD was 345 cGy (2D), 213 cGy (2D-post) and 213 cGy (3D). LV V25 Gy was 6.3%, 1.5%, and 1.1%, respectively. Lower doses were seen over time for all indices (analysis of variance, P < .0001). Post hoc tests indicated significantly higher doses for 2D versus 2D-post or 3D cohorts (P ≤ .001) for all parameters except RV V25 Gy (P = .24).

CONCLUSION

Heart doses were higher with 2D versus 3D plans. Cardiac doses and resulting toxicity with modern 3D planning might be lower than those in previous reports.

A multicenter phase I study of cabazitaxel, mitoxantrone, and prednisone for chemotherapy-naïve patients with metastatic castration-resistant prostate cancer

202

Background: Cabazitaxel and prednisone (Cbz/pred) extend survival in mCRPC patients (pts) following docetaxel and first-line studies comparing Cbz to docetaxel are ongoing. Mito/pred also has anti-tumor activity in mCRPC and a non-overlapping mechanism of action and toxicity profile with Cbz. A multicenter phase 1 trial was initiated to establish the maximally tolerated dose (MTD) and recommended phase 2 dose (RP2D) of the combination of Cbz, Mito, and Pred(CAMP). Methods: Chemotherapy (chemo)-naive pts with mCRPC were enrolled in an accelerated titration design. The primary objective was to determine the MTD and RP2D of CAMP; secondary objectives included PSA response rate and duration of response. Cbz 20 and 25 mg/m2 were evaluated in combination with escalating doses of Mito (starting dose 4 mg/m2), both administered on day 1 of a 21-day cycle. Pred 5 mg BID and pegfilgrastim were given with each cycle. Results: 23 pts were enrolled. The median age was 66 (range 51-78) and the median baseline PSA was 62.5 (range 3-791.2). There were 2 DLTs (sepsis and febrile neutropenia) observed at the dose level of Cbz 25 mg/m2 + Mito 10 mg/m2 (n = 4). There was 1 DLT (febrile neutropenia) observed with Cbz 20 mg/m2 (N = 12), establishing Cbz 20 mg/m2 + Mito 12 mg/m2 as the MTD and RP2D. The most common grade ³ 3 related adverse events were hematologic (neutropenia, n = 9; thrombocytopenia, n = 3; febrile neutropenia, n = 3). The median number of treatment cycles was 7.5 (range 2-16), and 2 pts remain on study. Greater than or equal to 50% maximal PSA declines from baseline were observed in 12 of 19 evaluable pts(63%). The median duration of response has not been reached (range 4.9-10.0+ months). Conclusions: The approved single-agent dose of Mito (12 mg/m2) was safely combined with Cbz 20 mg/m2, a dose with demonstrated activity in mCRPC and potentially less hematologic toxicity than 25 mg/m2. Preliminary efficacy data are encouraging with durable control of disease observed in a subset of pts. Further study of the treatment combination is warranted. Clinical trial information: NCT01594918.

Sentinel lymph node imaging guided IMRT for prostate cancer: Individualized pelvic radiation therapy versus RTOG guidelines

Purpose/Objectives

Current Radiation Therapy Oncology Group (RTOG) guidelines for pelvic radiation therapy are based on general anatomic boundaries. Sentinel lymph node (SLN) imaging can identify potential sites of lymph node involvement. We sought to determine how tailored radiation therapy fields for prostate cancer would compare to standard RTOG-based fields. Such individualized radiation therapy could prioritize the most important areas to irradiate while potentially avoiding coverage in areas where critical structures would be overdosed. Individualized radiation therapy could therefore increase the therapeutic index of pelvic radiation therapy.

Methods and materials

Ten intermediate or high-risk prostate cancer patients received androgen deprivation therapy with definitive radiation therapy, including an SLN imaging–tailored elective nodal volume (ENV). For dosimetric analyses, the ENV was recontoured using RTOG guidelines (RTOG_ENV) and on SLNs alone (SLN_ENV). Separate intensity modulated radiation therapy (IMRT) plans were optimized using RTOG_ENV and SLN_ENV for each patient. Dosimetric comparisons for these IMRT plans were performed for each patient. Dose differences to targets and critical structures among the different IMRT plans were calculated. Distributions of dose parameters were analyzed using non-parametric methods.

Results

Sixty percent of patients had SLNs outside of the RTOG_ENV. The larger volume IMRT plans covering SLN imaging–tailored elective nodal volume exhibited no significant dose differences versus plans covering RTOG_ENV. IMRT plans covering only the SLNs had significantly lower doses to bowel and femoral heads.

Conclusions

SLN-guided pelvic radiation therapy can be used to either treat the most critical nodes only or as an addition to RTOG guided pelvic radiation therapy to ensure that the most important nodes are included.

Comparison of stereotactic body radiotherapy and conventional external beam radiotherapy in renal cell carcinoma

434

Background: Renal cell carcinoma (RCC) is considered a radiation-resistant histology, often with poor response to conventionally fractionated external beam radiotherapy (EBRT). We compared outcomes for patients treated with EBRT versus stereotactic body radiotherapy (SBRT) for RCC. Methods: From 2004 and 2012, a total of 89 patients were treated with either EBRT or SBRT and retrospectively reviewed. Patients with locally recurrent RCC, bone or soft tissue RCC metastases, or primary RCC in a solitary kidney were included. 51 patients received EBRT, while 38 patients received SBRT. The median biologically effective dose (BED), assuming an α/β ratio of 10, was 32.6 Gy10 for the EBRT group and 48.0 Gy10 for the SBRT group. Local failure (LC) was defined pathologically or by imaging according to RECIST 1.1 and toxicity reported according to CTCAE v4.0 guidelines. Univariable and multivariable analyses using Cox’s regression model was performed to determine predictors of local control. Results: Median follow up from RT was 9.8 mo (range: <1-73 mo) with EBRT and 19.7 mo (range: <1-61 mo) with SBRT (p=0.26). EBRT patients were younger (p=0.02) and more were M1 (p=0.04), yet other baseline features did not differ significantly. Total RT dose, dose/fraction, and BED10 were significantly higher in the SBRT group (p≤0.002 for each), while number of fractions was significantly fewer (p<0.001). The 1-year LC estimate was 88% (95% CI, 72-96%) with SBRT and 50% (95% CI, 32-65%) with EBRT (p=0.001), with no significant difference in rate of distant recurrences (p=0.37). The 1-year progression free survival (PFS) and overall survival (OS) between the EBRT and SBRT groups were 17% (95% CI, 8-29%) vs. 39% (95% CI, 24-54%) (p=0.06) and 39% (95% CI, 25-52%) vs. 82% (95% CI, 65-91%) (p=0.002), respectively. The use of SBRT was the most important independent factor significantly predictive of local control on multivariable analysis (p=0.001, LLR test; HR=0.29, 95% CI, 0.13-0.61), while neither age nor metastasis at diagnosis was predictive. No drade 3-4 toxicity was observed in either RT group. Conclusions: The data support that SBRT improves local control over standard fractionation schemes. Higher dose per fraction, with a BED in the range of 48 Gy10, is a safe and effective local treatment modality for RCC.

A multicenter phase I study of cabazitaxel (Cbz), mitoxantrone (Mito), and prednisone (Pred) (CAMP) for chemotherapy-naïve patients with metastatic castration-resistant prostate cancer (mCRPC)

238

Background: Cbz/pred extends survival in mCRPC patients (pts) following docetaxel and first-line studies comparing Cbz to docetaxel are ongoing. Mito/pred also has anti-tumor activity in mCRPC and a non-overlapping mechanism of action and toxicity profile with Cbz. A multicenter phase 1 trial was initiated through the DOD PCCTC to establish the maximally tolerated dose (MTD) and recommended phase 2 dose (RP2D) of the combination of Cbz, Mito, and Pred (CAMP). Methods: Chemotherapy (chemo)-naïve pts with mCRPC were enrolled in an accelerated titration design. The primary objective was to determine the MTD and RP2D of CAMP; secondary objectives included PSA response rate and duration of response. Cbz 20 and 25 mg/m2 were each evaluated in combination with escalating doses of Mito (starting dose 4 mg/m2), both administered on day 1 of a 21-day cycle. Pred 5 mg BID and pegfilgrastim were given with each cycle. Results: 20 pts were enrolled. The median age was 66 (range 51-78) and the median baseline PSA was 62.5 (range 3.0-791.2). There were 2 DLTs observed at the dose level of Cbz 25 mg/m2 + Mito 10 mg/m2 (sepsis and febrile neutropenia). No DLTs were observed with Cbz 20 mg/m2 (N = 10), establishing Cbz 20 mg/m2 + Mito 12 mg/m2 as the MTD and RP2D. The most common grade ≥ 3 related adverse events were hematologic (neutropenia, n = 8; thrombocytopenia, n = 3; febrile neutropenia, n = 2). No cardiac adverse events were observed. The median number of treatment cycles was 9 (range 2-16), and 5 pts remain on study. Greater than 50% maximal PSA declines from baseline were observed in 8 of 18 evaluable pts (44%). Objective tumor responses have been observed in 2 of 4 pts (50%) with measurable disease, with evaluation ongoing. The median duration of response has not been reached (range 4.9-10.0+ months). Conclusions: The approved single-agent dose of Mito (12 mg/m2) was safely combined with Cbz 20 mg/m2, a dose with demonstrated activity in mCRPC and potentially less hematologic toxicity than 25 mg/m2. Preliminary efficacy data are encouraging with durable responses observed in a subset of pts. Further study of the treatment combination is warranted. Clinical trial information: NCT01594918.

Intermittent Chemotherapy as a Platform for Testing Novel Agents in Patients With Metastatic Castration-Resistant Prostate Cancer: A Department of Defense Prostate Cancer Clinical Trials Consortium Randomized Phase II Trial of Intermittent Docetaxel With Prednisone With or Without Maintenance GM-CSF

BACKGROUND

Immunotherapy with granulocyte-macrophage colony-stimulating factor (GM-CSF), an agent that previously demonstrated antitumor activity, was evaluated within an intermittent chemotherapy framework of docetaxel with prednisone (D+P) in metastatic castration-resistant prostate cancer (mCRPC).

PATIENTS AND METHODS

mCRPC patients with ≥ 50% prostate-specific antigen (PSA) decline after 6 cycles of D+P were randomized to either GM-CSF or observation (Obs). At disease progression (PD), D+P was reinitiated for 6 cycles followed by the same "off chemotherapy" regimen in patients eligible for chemotherapy interruption. The sequence was repeated until PD during chemotherapy, lack of PSA response to chemotherapy, or unacceptable toxicity. The primary end point was time to chemotherapy resistance (TTCR).

RESULTS

Of 125 patients enrolled, 52 (42%) experienced ≥ 50% PSA decline on induction D+P and were randomized to GM-CSF (n = 27) or Obs (n = 25). The median time to PD was 3.3 months (95% confidence interval [CI], 2.4-3.5) and 1.5 months (95% CI, 1.5-2.4) during the initial course of GM-CSF and Obs, respectively. Twelve of 26 (46%) patients responded to a second course of D+P. Eleven randomized patients (21%) experienced PD during chemotherapy, precluding accurate assessment of TTCR. The remaining 41 randomized patients discontinued study for lack of PSA response to chemotherapy (n = 8), patient choice to not restart chemotherapy with PSA PD (n = 13), toxicity (n = 7), or study withdrawal (n = 13).

CONCLUSION

Conducting a prospective study in mCRPC with maintenance immunotherapy within the framework of intermittent chemotherapy was feasible. The use of PSA instead of radiographic end points limited the number of evaluable patients. This study provides important insight into designing contemporary intermittent chemotherapy trials with maintenance immunotherapy in patients with advanced prostate cancer.

Metabolic imaging of patients with prostate cancer using hyperpolarized [1-¹³C]pyruvate

This first-in-man imaging study evaluated the safety and feasibility of hyperpolarized [1-¹³C]pyruvate as an agent for noninvasively characterizing alterations in tumor metabolism for patients with prostate cancer. Imaging living systems with hyperpolarized agents can result in more than 10,000-fold enhancement in signal relative to conventional magnetic resonance (MR) imaging. When combined with the rapid acquisition of in vivo ¹³C MR data, it is possible to evaluate the distribution of agents such as [1-¹³C]pyruvate and its metabolic products lactate, alanine, and bicarbonate in a matter of seconds. Preclinical studies in cancer models have detected elevated levels of hyperpolarized [1-¹³C]lactate in tumor, with the ratio of [1-¹³C]lactate/[1-¹³C]pyruvate being increased in high-grade tumors and decreased after successful treatment. Translation of this technology into humans was achieved by modifying the instrument that generates the hyperpolarized agent, constructing specialized radio frequency coils to detect ¹³C nuclei, and developing new pulse sequences to efficiently capture the signal. The study population comprised patients with biopsy-proven prostate cancer, with 31 subjects being injected with hyperpolarized [1-¹³C]pyruvate. The median time to deliver the agent was 66 s, and uptake was observed about 20 s after injection. No dose-limiting toxicities were observed, and the highest dose (0.43 ml/kg of 230 mM agent) gave the best signal-to-noise ratio for hyperpolarized [1-¹³C]pyruvate. The results were extremely promising in not only confirming the safety of the agent but also showing elevated [1-¹³C]lactate/[1-¹³C]pyruvate in regions of biopsy-proven cancer. These findings will be valuable for noninvasive cancer diagnosis and treatment monitoring in future clinical trials.

Activity of abiraterone acetate in metastatic patients with castration-resistant prostate cancer (mCRPC) previously treated with ketoconazole: A prospective phase II study from the prostate cancer clinical trials consortium

53

Background: Abiraterone acetate (AA), like ketoconazole (keto), inhibits CYP17, the rate-limiting enzyme in androgen biosynthesis. Since patients (pts) with prior keto treatment were excluded from the pivotal phase III AA trials, the utility of AA after keto is not well understood. This prospective study evaluated the efficacy of AA in pts who had received prior keto. Methods: Pts with progressive castration-resistant prostate cancer (mCRPC), prior keto therapy 28 days or more, and normal baseline organ function (including ACTH stimulation) tests were treated with AA 1,000 mg PO daily and prednisone 5 mg PO BID. Pts with prior chemotherapy were excluded. Serum androgen levels, including dehydroepiandrosterone (DHEA), were measured by liquid chromatography/mass spectroscopy (LC/MS) at baseline and during treatment for exploratory analyses. Radiographic progression-free survival (rPFS) was defined as freedom from: death, radiographic progression, or unequivocal clinical progression. Results: Forty two pts were enrolled. Median age was 71. Median prostate-specific antigen (PSA) was 47.5ng/dL. Median duration of prior keto was 38 weeks (range 5 to 207). Treatment with AA resulted in 30% or greater decline in PSA at 12 weeks in 20 pts (48%, 95% CI, 32-63%), and 50% or greater decline in PSA at 12 weeks in 16 pts (38%, 95% CI 24-54%). Median time to PSA progression (TTPP) was 16 weeks (range 4 to 64). Median rPFS was 24 weeks (range 1 to 88). Baseline serum DHEA levels were measured in 40 pts. Nine pts had DHEA less than the limit of quantitation (LOQ, 0.250ng/mL), and 31 pts had DHEA greater than or equal to LOQ. One pt with DHEA less than LOQ (1 out of 9, 11%, 95% CI 0.6-49%) had PSA decline 30% or more at 12 weeks, compared to 17 pts (17 out of 31, 55%, 95% CI 36-72%) with DHEA greater than or equal to LOQ (p=0.028). Median time to pain progression (TTPP) was 8 weeks (range 4 to 32) for pts with DHEA less than LOQ, compared to 18 weeks (range 4 to 64) for pts with DHEA greater than or equal to LOQ (p=0.012). Median rPFS was 12 weeks (range 4 to 24) for pts with DHEA less than LOQ, compared to 36 weeks (range 1 to 88) for pts with DHEA greater tha or equal to LOQ (p = 0.0006). Six pts remain on AA. Conclusions: A significant proportion of pts with prior keto exposure demonstrate clinical response to AA. DHEA levels via LC/MS merits further study as a predictive biomarker in pts treated with androgen synthesis inhibitors. Clinical trial information: NCT01199146.

A multicenter phase I study of cabazitaxel (Cbz), mitoxantrone (Mito), and prednisone (Pred) (CAMP) for chemotherapy-naive patients with metastatic castration-resistant prostate cancer (mCRPC)

243

Background: Cbz/pred extends survival in mCRPC patients (pts) following docetaxel and first-line studies comparing Cbz to docetaxel are ongoing. Mito/pred also has anti-tumor activity in mCRPC and a non-overlapping mechanism of action and toxicity profile with Cbz. A multicenter phase I trial was initiated through the DOD PCCTC to establish the maximally tolerated dose (MTD) of the combination of Cbz, Mito, and Pred. Methods: Chemotherapy (chemo)-naive pts with mCRPC were enrolled in an accelerated titration design. The primary objective was to determine the MTD of CAMP; secondary objectives included assessing PSA and objective response rates and duration of response. Starting dose of Cbz was 25 mg/m2 (the currently approved single-agent dose) and Mito 4 mg/m2, administered on day 1 of a 21-day cycle. Mito was escalated by 2 mg/m2 per dose level. Pred 5 mg BID and pegfilgrastim were administered with each cycle. Results: 9 pts were enrolled (dose level I, N = 1; dose level II, N = 1; dose level III, N = 3; dose level IV N = 4). The median age was 67 (range 55-81) and the median baseline PSA was 82.3 (range 20.4-791.2). There were 2 DLTs observed at dose level IV (Cbz 25 mg/m2 + mito 10 mg/m2), both grade 4 sepsis. The most common grade 3 adverse events were hematologic (neutropenia, n = 5; febrile neutropenia, n = 2, thrombocytopenia, n = 2). 6 of 9 pts remain on study (range 2.2 - 10.5+ months). Maximal PSA declines from baseline > 50% have been observed in 4/7 (57%) evaluable pts to date. 2 of 4 pts with measurable disease have experienced partial responses and a third has had a minor response after 4 cycles of chemo. The median progression-free survival and duration of response have not been reached. Conclusions: The approved single-agent dosage of Mito (12 mg/m2) could not be safely reached in combination with Cbz 25 mg/m2. Pre-planned evaluation of an alternate dosing strategy combining Mito with Cbz 20 mg/m2, which has demonstrated activity in mCRPC and potentially less hematologic toxicity, is underway. Preliminary efficacy data are encouraging but additional follow-up and further study of the treatment combination is required. Clinical trial information: NCT01594918.

Association of TP53 mutational status and gender with survival after adjuvant treatment for stage III colon cancer: results of CALGB 89803

PURPOSE

The TP53 tumor suppressor is frequently mutated in colon cancer, but the influence of such mutations on survival remains controversial. We investigated whether mutations in the DNA-binding domain of TP53 are associated with survival in stage III colon cancer.

EXPERIMENTAL DESIGN

The impact of TP53 genotype was prospectively evaluated in Cancer and Leukemia Group B 89803, a trial that randomized stage III colon cancer patients to receive adjuvant 5-fluorouracil/leucovorin (5FU/LV) or 5FU/LV with irinotecan (IFL).

RESULTS

TP53 mutations were identified in 274 of 607 cases. The presence of any TP53 mutation did not predict disease-free survival (DFS) or overall survival with either adjuvant regimen when men and women were considered together or as separate groups. However, outcome differences among women became apparent when tumor TP53 genotype was stratified as wild-type versus zinc- or non-zinc-binding mutations in the TP53 DNA-binding domain. DFS at 5 years was 0.59, 0.52, and 0.78 for women with TP53 wild-type tumors, and tumors with zinc- or non-zinc-binding mutations, respectively. Survival at 5 years for these same women was 0.72, 0.59, and 0.90, respectively. No differences in survival by TP53 genotype were observed in men.

CONCLUSIONS

The presence of any TP53 mutation within the DNA-binding domain did not predict survival in stage III colon cancer. However, TP53 genotype was predictive of survival in women following adjuvant therapy. Future colon cancer therapeutic trials, with inclusion of correlative molecular markers, should be designed to permit evaluation of survival and/or response to treatment in women separately from men.

Metabolic imaging of patients with prostate cancer using hyperpolarized [1-¹³C]pyruvate

This first-in-man imaging study evaluated the safety and feasibility of hyperpolarized [1-¹³C]pyruvate as an agent for noninvasively characterizing alterations in tumor metabolism for patients with prostate cancer. Imaging living systems with hyperpolarized agents can result in more than 10,000-fold enhancement in signal relative to conventional magnetic resonance (MR) imaging. When combined with the rapid acquisition of in vivo ¹³C MR data, it is possible to evaluate the distribution of agents such as [1-¹³C]pyruvate and its metabolic products lactate, alanine, and bicarbonate in a matter of seconds. Preclinical studies in cancer models have detected elevated levels of hyperpolarized [1-¹³C]lactate in tumor, with the ratio of [1-¹³C]lactate/[1-¹³C]pyruvate being increased in high-grade tumors and decreased after successful treatment. Translation of this technology into humans was achieved by modifying the instrument that generates the hyperpolarized agent, constructing specialized radio frequency coils to detect ¹³C nuclei, and developing new pulse sequences to efficiently capture the signal. The study population comprised patients with biopsy-proven prostate cancer, with 31 subjects being injected with hyperpolarized [1-¹³C]pyruvate. The median time to deliver the agent was 66 s, and uptake was observed about 20 s after injection. No dose-limiting toxicities were observed, and the highest dose (0.43 ml/kg of 230 mM agent) gave the best signal-to-noise ratio for hyperpolarized [1-¹³C]pyruvate. The results were extremely promising in not only confirming the safety of the agent but also showing elevated [1-¹³C]lactate/[1-¹³C]pyruvate in regions of biopsy-proven cancer. These findings will be valuable for noninvasive cancer diagnosis and treatment monitoring in future clinical trials.

Detection and genomic interrogation of invasive circulating tumor cells (iCTCs) derived from men with metastatic castration resistant prostate cancer (mCRPC)

11048

Background: Isolation, enumeration, and genomic profiling of CRPC CTCs offers the potential to discover genetic changes that occur in advanced disease. The Vitatex VitaCap platform captures CTCs based on their ability to invade a collagenous matrix (CAM), allows for capture of invasive CTCs (iCTCs) independent of EpCAM status, and yields viable cells suitable for comprehensive genomic study. Here we sought to compare CTC yields between the CAM and CellSearch platforms, to determine the utility of prostate-specific membrane antigen (PSMA) as an iCTC biomarker, to identify iCTC clusters and iCTCs expressing stem-like markers, and to explore the feasibility of iCTC epigenomic analysis. Methods: CTCs were isolated and enumerated simultaneously using the CellSearch and CAM platforms in 23 men with mCRPC. CAM-isolated iCTCs were defined as EpCAM+PSMA+ and were enumerated immunocytochemically (ICC) and by flow cytometry. iCTC clusters were enumerated by ICC. The Illumina Infinium HumanMethylation27 BeadChip was used to determine whole genome methylation status for CAM isolated cells. Results: 35 samples were collected for CAM analysis. A median of 27 (range 0-800) and 23 (range 2-390) iCTCs/ml were detected by ICC and flow respectively. In a subset of 20 samples, a median of 7 CTCs/ml (range 0-85) were detected by the CellSearch platform. CTCs were detectable by either CAM or CellSearch in >95% of samples. iCTC clusters were observed in 23% of samples with a median 7 clusters/ml (range 1-200). iCTCs expressing stem-like markers CD44 and Seprase were detected in 70% and 97% of samples by ICC and flow respectively, with a median of 9/ml (range 1-264) by flow. The iCTC methylation profile highly resembled mCRPC. Conclusions: The CAM and CellSearch platforms yield comparable CTC counts. iCTC clusters and iCTCs expressing stem-like markers are detectable using the CAM platform, and the iCTC methylome closely resembles that of mCRPC. Correlation with clinical data may yield further insight into the functional significance of these findings.

Evaluating the hypothalamic-pituitary-adrenal axis (HPAA) in men receiving ketoconazole for castrate resistant prostate cancer (CRPC)

5077

Background: Serum adrenal androgen (AA) levels may be prognostic for survival in men with CRPC treated with androgen synthesis inhibitors (ASIs) including ketoconazole (keto) and abiraterone. We hypothesize that up-regulation of the HPAA and adrenocorticotropic hormone (ACTH) may contribute to therapeutic resistance on ASIs. The current study explores the relationship between ACTH, AA, testosterone (T) and estradiol (E) among CRPC patients (pts) treated with ASI + corticosteroids. Methods: Phase II study of keto (400 mg TID) + hydrocortisone (HC) (30 mg/day) in pts with CRPC. Pts who achieved ≥ 30% PSA decline from baseline at week 12 continued keto/HC until progression, at which point HC was replaced by dexamethasone (dex). Serum hormone (H) levels were measured (in AM) at baseline and every 4 weeks using standard assays. Statistical tests include Spearman’s rank test for correlation between baseline H levels; Wilcoxon matched pairs for baseline vs. week 4 distribution; and Fisher’s exact test for associations between H levels (dichotomized at median) with PSA decline. Results: Of 30 pts enrolled and 24 evaluable for PSA response, 13 pts (54%) achieved ≥ 30% PSA decline at 12 weeks. Baseline ACTH was positively correlated with DHEA (r = 0.40; p = 0.04) and cortisol (r = 0.52; p = 0.007). Change from baseline to week 4 in H levels is shown in table. There was a significant increase in pts achieving a PSA decline of > 30% if there was a decrease in E at week 4 vs. no decrease (83% vs. 18%; p = 0.003). Baseline and changes in other H levels were not associated with PSA outcome at week 12. Conclusions: ACTH is positively correlated with DHEA and cortisol in CRPC pts. Declines in E may serve as an additional predictive marker of benefit for ASI therapy. These observations require prospective validation. Analyses exploring changes in ACTH at disease progression and impact of substituting dex for HC are ongoing. Clinical trial information: NCT01036594. [Table: see text]

Comparison of PSA slope and nadir between hypofractionated SBRT and conventionally fractionated EBRT

112

Background: Patients with early stage prostate cancer have a challenge in selecting from a variety of curative radiotherapy options, including external beam radiotherapy (EBRT) and hypofractionated stereotactic body radiotherapy (SBRT). Rapid post-treatment PSA decline and low PSA nadir have been associated with improved clinical outcomes. The purpose of this study was to compare the PSA measurements over time between conventionally fractionated EBRT and SBRT in newly diagnosed localized prostate cancer. Methods: 104 patients with low to low-intermediate risk prostate cancer (GS 3+3, PSA < 20 or 3+4, PSA < 15) treated with standard fractionated EBRT (> 70.2 Gy, < 76 Gy) without hormones to the prostate only were identified from a prospectively collected cohort of patients treated at the University of California, San Francisco (1997-2012). Patients were excluded if they failed therapy by the Phoenix definition. All included patients had at least 1 year of follow up and 3 serial PSAs. 35 patients that were treated with SBRT to the prostate to 38 Gy in 4 daily fractions also met the same criteria. Of these, 47 and 19 patients treated with EBRT and SBRT, respectively, had a yearly increase in PSA follow-up over 3 years. PSA nadir and rate of change in PSA over time (e.g. slope) were calculated from the completion of RT to 1, 2 and 3 years post RT. Results: The median PSA nadir and slope for patients treated with EBRT was 0.80, 0.50, 0.40 ng and ‑0.07, ‑0.02, ‑0.01 ng/ml/month, respectively, for durations of 1, 2 and 3 years post RT. Similarly, for SBRT, the median PSA nadir and slope were 0.73, 0.50, 0.24 ng and ‑0.09, ‑0.06, ‑0.05 ng/ml/month. The PSA slope for SBRT was greater than EBRT (p = 0.001) at 2 and 3 years following RT, although similar during the first year. These results were consistent when limited to patients with more complete PSA follow-up each year, with PSA nadir significantly lower 3 years after treatment with SBRT compared with EBRT (p = 0.03). Conclusions: Patients treated with SBRT experienced a more rapid decline in PSA 2 and 3 years following completion of RT than with EBRT, and for those with continuous long term followup, a lower PSA nadir, consistent with delivery of a higher bioequivalent dose.

Evaluating the hypothalamic-pituitary-adrenal axis (HPAA) in men receiving ketoconazole for castrate-resistant prostate cancer (CRPC)

64

Background: Serum adrenal androgen (AA) levels may be prognostic for survival in men with CRPC treated with androgen synthesis inhibitors (ASIs) including ketoconazole (keto) and abiraterone. We hypothesize that up-regulation of the HPAA and adrenocorticotropic hormone (ACTH) may contribute to therapeutic resistance on ASIs. The current study explores the relationship between ACTH, AA, testosterone (T) and estradiol (E) among CRPC patients (pts) treated with ASI + corticosteroids. Methods: Phase 2 study of keto (400 mg TID) + hydrocortisone (HC) (30 mg/day) in pts with CRPC. Pts who achieved ≥ 30% PSA decline from baseline at week 12 continued keto/HC until progression, at which point HC was replaced by dexamethasone (dex). Serum hormone (H) levels were measured (in AM) at baseline and every 4 weeks using standard assays. Statistical tests include Spearman’s rank test for correlation between baseline H levels; Wilcoxon matched pairs for baseline vs. week 4 distribution; and Fisher’s exact test for associations between H levels (dichotomized at median) with PSA decline. Results: Of 30 pts enrolled and 24 evaluable for PSA response, 13 pts (54%) achieved ≥ 30% PSA decline at 12 weeks. Baseline ACTH was positively correlated with DHEA (r = 0.40; p = 0.04) and cortisol (r = 0.52; p = 0.007). Change from baseline to week 4 in H levels is shown in table. There was a significant increase in pts achieving a PSA decline of ≥ 30% if there was a decrease in E at week 4 vs. no decrease (83% vs. 18%; p = 0.003). Baseline and changes in other H levels were not associated with PSA outcome at week 12. Conclusions: ACTH is positively correlated with DHEA and cortisol in CRPC pts. Declines in E may serve as an additional predictive marker of benefit for ASI therapy. These observations require prospective validation. Analyses exploring changes in ACTH at disease progression and impact of substituting dex for HC are ongoing. Clinical trial information: NCT01036594. [Table: see text]

Neoadjuvant sipuleucel-T in localized prostate cancer: Effects on immune cells within the prostate tumor microenvironment

2564

Background: Sipuleucel-T is an FDA-approved autologous cellular immunotherapy for patients with asymptomatic or minimally symptomatic metastatic castrate resistant prostate cancer (mCRPC). To date, studies of sipuleucel-T in patients with mCRPC have studied immune response in peripheral blood. The effects of sipuleucel-T on prostate tumors are unknown. Methods: NeoACT (P07-1; NCT00715104) is an open-label, phase 2 study of patients with localized prostate cancer who received sipuleucel-T prior to radical prostatectomy (RP) to examine the immunologic effects of treatment on prostate tissue. Patients received 3 infusions of sipuleucel-T at approximately 2-week intervals, beginning 6-7 weeks prior to RP. The primary endpoint was the change in the frequency of lymphocytes between prostate biopsies (pre-treatment) and RP tissue (post-treatment), as assessed by immunohistochemistry (IHC). Results: The median age of the 42 enrolled patients was 61 years, and all had an ECOG performance status of 0. Thirty-eight patients received all 3 pre-RP sipuleucel-T infusions. To date, tissue IHC analysis has been completed on 32 patients. Treatment-related AEs were manageable and transient. Sipuleucel-T did not appear to impact surgery, as judged by operative complications, procedure time, and estimated blood loss. Frequent events that occurred ≤1 day after infusion (>10% of patients) were fatigue, headache, and myalgia. Significant increases (≥3 fold) in CD3+ and CD4+ T cell populations were observed at the tumor interface (where benign and malignant glands interface), compared with the pre-treatment biopsy, benign RP tissue, and tumor RP tissue (ANOVA post hoc Newman-Keuls test: p<0.0001 for each comparison). FoxP3+ CD4+ T cells were also increased (p=0.0005) at the tumor interface, but represented a small fraction of the observed CD4+ T cells. Conclusions: Neoadjuvant sipuleucel-T treatment is associated with an increased frequency of T cells in prostate cancer tissue at the interface of the benign and malignant glands. These data suggest that sipuleucel-T can modulate the presence of lymphocytes at the prostate tumor site. Work is ongoing to more fully characterize the immune response.

A first-in-human phase I imaging study using hyperpolarized 1c-13 pyruvate (h-Py) in patients (pts) with localized prostate cancer (l-PCa)

4660

Background: Preclinical studies demonstrated that the conversion of h-Py to hyperpolarized 13C lactate (h-lac) is detectable on MRI-spectroscopy and is a useful marker of differentiation in PCa. H-Py MRI provides more than 10,000-fold enhancement in signal to noise ratio (SNR), allowing for rapid detection of metabolic alterations in vivo. Hyperpolarized compounds have not been previously studied in man. Methods: Pts with biopsy-proven untreated l-PCa were enrolled in a phase I study of h-Py MRI. Following a modified 3+3 design, 6 pts were enrolled at each dose level (0.14, 0.28 and 0.43 mL/Kg): 3 to monitor kinetics of h-Py, and 3 to evaluate the spatial distribution of metabolism in PCa and normal prostate (nl-P). An expansion cohort of 15 pts explored the biological variability of metabolism. A dynamic nuclear polarization (DNP) system, the first human system anywhere, generated and delivered 230 mM sterile h-Py. IV injection of h-Py was followed by imaging with a 3T MR scanner with custom transmit and receive coils. Monitoring included EKG, vital signs, and laboratory testing. Results: 31 pts were imaged. 23 pts had Gleason (G) 6, 6 pts G7, and 2 pts G8 PCa. Median age was 63 years (range 45-75); median PSA was 5.9 ng/mL (1.88-20.2). No dose limiting toxicities or >grade (gr) 2 toxicity was observed. Toxicity included: gr 1dysgeusia (6 pts), gr 1 hypokalemia, gr 1 hypocalcemia, gr 1 dizziness, and gr 2 diarrhea (1 pt each). Median time from dissolution of the agent to delivery into patients was 66 seconds (43-88). Signals from h-Py and h-Lac were seen in PCa and nl-P at all doses; 0.43 mL/Kg showed the best SNR and discrimination between PCa and nl-P and was therefore established as the phase II dose. There appeared to be an association between h-Lac levels and PCa grade. Conclusions: H-py metabolic imaging has minimal toxicity and provides the ability to discriminate Ca from nl-P based on increased levels of h-lac. The correlation with grade and changes with therapy require further study.

Activity of intravesical CG0070 in Rb-inactive superficial bladder cancer after BCG failure: Updated results of a phase I/II trial

4593

Background: Loss of retinoblastoma (Rb) tumor suppressor activity occurs commonly in bladder cancer and leads to upregulation of the E2F-1 transcription factor. CG0070 is a replication-competent oncolytic adenovirus genetically modified to express GMCSF under control of the human E2F-1 promoter. Updated results from a phase I study of CG0070 in patients with recurrent superficial bladder cancer (T1, Ta, Tcis) after BCG treatment are presented here. Methods: The V-0046 phase I/II study previously reported the safety and evidence of efficacy of single and multiple doses of intravesical CG0070. Efficacy was determined using quarterly cystoscopy, biopsy, and/or urine cytology. Tumor Rb status was assessed immunohistochemically in 18 tumors. Results: 35 patients were treated with either a single dose (n=13) of CG0070 ranging from 1x1012 to 3x1013 viral particles (vp) or with weekly x 6 (n=9) or every 4 week x 3-6 doses (n=13) ranging from 1x1012 to 1x1013 vp per dose. The most common adverse events regardless of schedule were flu-like illness, dysuria, hematuria, bladder spasm, and nocturia. No maximum tolerated dose was reached. Urine GMCSF and CG0070 levels were detectable in almost all patients suggesting in-vivo viral replication. The CR rate in the single dose cohort was 23% (3/13), and 64% (14/22) in the multi-dose cohorts. The CR rate for patients with either CIS or Ta tumors was 65% (15/23). Of all responders, 11 recurred with a remission duration ranging from 3.0 - 33.4 months and 6 patients, all in the multiple dose cohorts, remain in remission as of last follow-up with a remission duration ranging from 3.3 – 38.2 months. Phosphorylated (inactive) Rb was detected in 13 of the 18 (72%) patients evaluated. Nine of these 13 patients (70%) had a complete response. All patients (5/5, 100%) with known phosphorylated Rb treated in the weekly cohort experienced a CR. Conclusions: CG0070 was well tolerated with minimal toxicities. Complete responses were more frequently observed in the multiple-dose cohorts, including durable CRs in patients with inactive Rb and in patients with CIS. Further study in Rb-inactive superficial tumors is warranted.

Effects of 6 months of abiraterone acetate (AA) on muscle and adipose mass in men with metastatic castration-resistant prostate cancer (mCRPC)

e15137

Background: AA, an inhibitor of androgen biosynthesis, has been shown to prolong overall survival in patients with mCRPC who have previously been treated with chemotherapy. ADT has been shown to result in muscle wasting in prostate cancer patients. The effects of AA on progression of muscle and fat wasting have not been characterized. We evaluated whether 6 months of AA therapy altered total skeletal muscle mass or adipose mass. Methods: 10 sequential patients who responded to AA therapy for at least 6 months and had available computed tomography (CT) scans were retrospectively selected from the phase I-II COU-AA-002 study. CT image analysis was used to quantify change from baseline in total skeletal muscle and adipose tissue after 6 months of AA treatment. Skeletal muscle and adipose tissue cross-sectional area were calculated at the L3 level using Slice-O-Matic software V4.3. Previously published regression models were used to estimate fat-free mass, fat mass and skeletal muscle mass. Paired t-tests were performed to determine the change in measurements. Results: At baseline, 7 of 10 patients were overweight or obese (body mass index [BMI] > 25 kg/m2), and none were underweight. Advanced muscle wasting (sarcopenia, previously defined as the ratio of skeletal muscle cross-sectional area at L3 level to height < 52.4 cm2/m2) was present at baseline and 6 months in 9 of 10 pts. Over 6 months of AA treatment, patients lost an average of 1.9 kg ± 3.6 kg (p = 0.13). Mean changes (kg) (±standard deviation) in total skeletal muscle mass (-0.80 ± 1.71, p = 0.18) and total non-adipose mass (-1.44 ± 3.09, p = 0.17) were not significant. A significant decrease in total adipose mass (-0.61 ± 0.84, p = 0.048) was observed. Conclusions: Sarcopenia is prevalent in patients with mCRPC. AA was not related to significantly worsening sarcopenia or overall weight loss during the first 6 months of treatment; however, this may reflect a relatively short duration of therapy and/or small sample size. A significant loss of adipose tissue was observed, which is unexpected given the known effects of ADT, which increases adipose mass. Evaluation of additional AA treated patients is ongoing.

A novel interaction of genotype, gender, and adjuvant treatment in survival after resection of stage III colon cancer: Results of CALGB 89803

3517

Background: The p53 tumor suppressor is frequently mutated in colon cancer, but the influence of such mutations on survival is remains undefined. We investigated whether domain-specific mutations in p53 are predictive of survival in stage III colon cancer. Methods: p53 was evaluated in an intergroup trial (CALGB 89803) of patients with stage III colon cancer who were randomized to receive adjuvant 5-fluorouracil/leucovorin (5FU/LV) or 5FU/LV with irinotecan (IFL) Tissue was collected to allow correlation of molecular markers with outcomes. p53 was genotyped in 607 patient tumors. Results: p53 mutations were identified in 274 tumors, divided ~ equally between zinc binding and non-zinc binding regions of the DNA binding domain. Overall, p53 status was not predictive of benefit from either adjuvant regimen. Unexpectedly, the 5 year overall survival (OS) of women with tumors harboring non-zinc binding mutations treated with 5FU/LV was 97% compared to OS of 72% for women with p53 wild-type (wt) tumors (p =0.004). Adding irinotecan to 5FU/LV negated this survival benefit (5 year OS of 81% vs. 72%). Conversely, 5 year OS of women harboring tumors with zinc binding mutations who received 5FU/LV was 50% compared to 72% for women with p53 wt tumors (p=0.04). Adding irinotecan to 5FU/LV reversed the poor survival of women with tumors harboring zinc binding mutations and improved 5 year OS (50% vs. 73%; p=0.1). No difference in OS was observed for men on either treatment arm or when genotype was considered. Conclusions: CALGB 89803 demonstrated a lack of survival benefit for stage III colon cancer patients when irinotecan was added to 5FU/LV (IFL). We now show that in the setting of a large clinical trial, refined stratification of women, based upon domain- specific mutations of p53 identifies subsets of patients likely to benefit from, or respond poorly to, adjuvant 5FU/LV. The interaction of p53 genotype, gender, and adjuvant therapy regimen has the potential to be paradigm changing in the treatment of colon cancer, and possibly other malignancies. These data, if validated, suggest that evaluation of p53 genotype and gender may guide clinicians to make rational choices of adjuvant therapy.

A prospective randomized phase II trial evaluating maintenance GM-CSF in an intermittent chemotherapy (chemo) regimen for metastatic castration-resistant prostate cancer (mCRPC): A DoD prostate cancer clinical trials consortium trial

35

Background: The optimal number of cycles of docetaxel for patients (pts) with mCRPC is not known, and in practice, treatment breaks are common. The current study was designed to test the safety and efficacy of utilizing 6 cycles of standard docetaxel with chemo free intervals in patients who achieve and maintain a response to docetaxel.

Methods: Pts with mCRPC, no prior chemo, and KPS > 60% were eligible. Pts were treated with “induction” docetaxel 75 mg/m2 q 3 weeks, and prednisone 5 mg po bid. PSAWG1 criteria were used to define response and progression. After 6 cycles, responding pts stopped chemo and were randomized to observation (Obs) or to GM-CSF, 250 mcg/m2 daily for 14 days out of every 28-day cycle. Pts were followed with monthly PSA and imaging every 2 cycles until progression, at which point docetaxel was reinitiated for another 6 cycles, followed by the same “off chemo” regimen. The primary endpoint was the time to progression while on chemo (time to chemo resistance).

Results: 114 pts have been enrolled: 3 are undergoing induction, and 111 are therefore evaluable. Of these pts, 82 completed induction, (10 did not due to PD, 9 due to adverse events (AE), 10 due to pt or MD choice). Of 111 evaluable pts, 48 (43%) had a response to chemo and were eligible for randomization. 22 were randomized to Obs and 26 to GM-CSF. Of 48 randomized pts, 25 restarted chemo, all for PSA PD. (23 pts did not re-start chemo because of AE, other therapy being started, or pt choice; 1 pt is still on GM-CSF.) 6/25 (24%) pts experienced a response to the 2nd series of chemo, and 1/6 (17%) to the 3rd. The time to chemo re-initiation (n=25) was 3.1 mos in Obs pts and 4.2 mos in GM-CSF pts.

Conclusions: 43% of patients met criteria for undergoing intermittent chemo. The response proportion to the 1st, 2nd, and 3rd series of docetaxel was 43%, 24% and 17%, respectively. GM-CSF may modestly delay the time to chemo re-initiation, but the sample size is small and insufficient to assess the impact of GM-CSF on time to chemo resistance.

Updated results of a phase I/II trial of intravesical CG0070 in patients with superficial bladder cancer after BCG failure

271

Background: Loss of retinoblastoma (Rb) tumor suppressor activity occurs commonly in bladder cancer and leads to upregulation of the E2F-1 transcription factor. CG0070 is a replication competent oncolytic adenovirus genetically modified to express GMCSF under control of the human E2F-1 promoter. Updated results from a phase I/II study of CG0070 in patients with recurrent superficial bladder cancer (T1, Ta, Tcis) after BCG treatment are presented here.

Methods: The V-0046 phase I/II study previously reported the safety and evidence of efficacy of single and multiple doses of intravesical CG0070. Efficacy was determined using quarterly cystoscopy, biopsy, and/or urine cytology. Tumor Rb status was assessed immunohistochemically in 18 tumors.

Results: 35 patients were treated with either a single dose (n=13) of CG0070 ranging from 1x1012 to 3x1013 viral particles (vp) or with weekly x 6 (n=9) or every 4 week x 3 doses (n=13) ranging from 1x1012 to 1x1013 vp per dose. Only one dose limiting toxicity, grade 3 lymphopenia in an every 4 week patient, was observed. The most common adverse events regardless of schedule were flu-like illness, dysuria, hematuria, bladder spasm, and nocturia. Urine GMCSF was detectable in 94% of patients and 58% of patients in the single dose cohort had an increase in CG0070 levels suggesting in-vivo viral replication. The CR rate in the single dose cohort was 23% (3/13), and 64% (14/22) in the multi-dose cohorts. Median follow up for all responders is 9.1 months. Of all responders, 11 recurred with a remission duration ranging from 3.0 - 33.4 months and 6 patients, all in the multiple dose cohorts, remain in remission as of last follow-up with a remission duration ranging from 3.3 – 38.2 months. Phosphorylated (inactive) Rb was detected in 13 of the 18 (72%) patients evaluated. Nine of these 13 patients (70%) had a CR. All patients (5/5, 100%) with known phosphorylated Rb treated in the weekly cohort experienced a CR.

Conclusions: CG0070 was well tolerated with minimal local and systemic toxicities. Complete responses were more frequently observed in the multiple-dose cohorts, including durable CRs in patients with phosphorylated Rb. Further study in Rb inactivated tumors is warranted.

Immune responses in prostate tumor tissue following neoadjuvant sipuleucel-T in patients with localized prostate cancer

181

Background: Sipuleucel-T is an FDA-approved autologous cellular therapy that has been demonstrated to prolong overall survival in patients with asymptomatic or minimally symptomatic metastatic castrate resistant prostate cancer (mCRPC). To better understand the immunologic effects of sipuleucel-T, an open-label Phase 2 study (P07‐1; NCT00715104 ) of sipuleucel-T prior to radical prostatectomy (RP) was undertaken in patients with localized prostate cancer.

Methods: Patients received 3 infusions of sipuleucel-T at approximately 2-week intervals, beginning 6–7 weeks prior to RP. Prostate biopsies (pre-treatment) and tissue from RP (post-treatment) were assessed for the presence of lymphocytes by immunohistochemistry (IHC).

Results: The median age of the 42 enrolled patients was 61 years, and all had an ECOG performance status of 0. Thirty-eight patients received all 3 pre-RP infusions of sipuleucel-T. To date, tissue IHC analysis has been completed in 19 patients. Treatment-related AEs were manageable and reversible. Sipuleucel-T did not appear to impact surgery, as judged by operative complications, procedure time, and estimated blood loss. Frequent events that occurred ≤1 day after infusion (>10% of patients) were fatigue, headache, and myalgia. Significant increases (>2‐fold) in CD3+ and CD4+ T cells populations were observed at the tumor rim (where benign and malignant glands interface), compared with the pre-treatment biopsy (ANOVA post hoc Newman-Keuls test: p=0.0002, 0.0002, respectively). CD8+ T cells or CD56+ cells were not significantly increased at the tumor rim compared with benign biopsy regions.

Conclusions: Neoadjuvant sipuleucel-T treatment appears to result in an increased frequency of T cells in prostate cancer tissue at the rim between the benign and malignant glands. These data suggest that sipuleucel-T may modulate the presence of lymphocytes at the prostate tumor site. Work is ongoing to more fully characterize the immune response within the prostate tumor tissue and in the peripheral blood.

Effects of 6 months of abiraterone acetate (AA) on muscle and adipose mass in men with metastatic castration-resistant prostate cancer (mCRPC)

222

Background: AA, an inhibitor of androgen biosynthesis, has been shown to prolong overall survival in patients with mCRPC who have previously been treated with chemotherapy. Androgen deprivation therapy (ADT) has been shown to result in muscle wasting in prostate cancer pts. The effects of AA on progression of muscle and fat wasting have not been characterized. We evaluated whether 6 months of AA therapy altered total skeletal muscle mass or adipose mass.

Methods: 10 sequential pts who responded to AA therapy for at least 6 months and had available computed tomography (CT) scans were retrospectively selected from the phase I-II COU-AA-002 study. CT image analysis was used to quantify change from baseline in total skeletal muscle and adipose tissue after 6 months of AA treatment. Skeletal muscle and adipose tissue cross-sectional area were calculated at the L3 level using Slice-O-Matic software V4.3. Previously published regression models were used to estimate fat-free mass, fat mass and skeletal muscle mass. Paired t-tests were performed to determine the change in measurements.

Results: At baseline, 7 of 10 pts were overweight or obese (body mass index [BMI] > 25 kg/m2), and none were underweight. Advanced muscle wasting (sarcopenia, previously defined as the ratio of skeletal muscle cross-sectional area at L3 level to height < 52.4 cm2/m2) was present at baseline and 6 months in 9 of 10 pts. Over 6 months of AA treatment, pts lost an average of 1.9 kg ± 1.9 kg (p = 0.13). Mean changes (kg) (±standard deviation) in total skeletal muscle mass (−0.80 ± 1.71, p = 0.18) and total non-adipose mass (−1.44 ± 3.09, p = 0.17) were not significant. A significant decrease in total adipose mass (−0.61 ± 0.84, p = 0.048) was observed.

Conclusions: Sarcopenia is prevalent in pts with mCRPC. AA was not related to significantly worsening sarcopenia or overall weight loss during the first 6 months of treatment; however, this may reflect a relatively short duration of therapy and/or small sample size. A significant loss of adipose tissue was observed, which is unexpected given the known effects of ADT, which increases adipose mass. Evaluation of additional AA treated patients is ongoing.

Genetic variants in antioxidant genes, Gleason grade, and prostate cancer recurrence after radical prostatectomy

33

Background: Laboratory and genomic data suggest that the antioxidant defense system is important in prostate carcinogenesis, and that this relation may vary by plasma antioxidant status.

Methods: Among 567 radical prostatectomy (RP) patients with non-metastatic prostate cancer (CaP), we examined genetic variants in SOD1(5 SNPs), SOD2(6), SOD3(6), TXRND1(5), TXRND2(21), GPX1(3), GPX3(8), GPX4(5), CAT(9), XRCC1(2), SELENBP1(5), SEP15(4), SEPP1(4), SEC14L2(8), and TTPA(4) and risk of high pathologic Gleason sum (8+ or 7 with primary 4+) using logistic regression, and CaP recurrence (PSA rise, second treatment, metastasis) using Cox proportional hazards regression. We also examined whether the genetic variants interacted with plasma selenium, alpha-tocopherol, or gamma-tocopherol in relation to risk of high grade CaP.

Results: 21% (n = 117) of men had high grade CaP, and 47 recurrences occurred (median follow-up of all participants = 3 y). Men with 1+ of the less common allele (CT or TT) in rs4880 (SOD2) had a 49% reduced rate of recurrence (hazard ratio (HR): 0.51; 95% confidence interval (CI): 0.28, 0.92), independent of grade, stage, and PSA. In contrast, men with 1+ of the less common allele in 3 of the TXRND1, 4 of the TXRND2, and 1 of the SEP15 SNPs had 2-fold increased rate of recurrence (HRs: 1.93-2.95; p-values: 0.002-0.04), and men with 2 of the less common allele in 2 of the GPX3 SNPs had 3-fold increased rate of recurrence (p-values from additive models: <0.01). For high grade CaP, men with 1+ of the less common allele in 1 of the SOD3 SNPs or 2 of the less common alleles in 2 of the TXRND2 SNPs had 2-fold increased risk (p-values = 0.007-0.02), while men with 1+ of the less common allele in 1 of the GPX1 SNPs had 37% reduced risk (p-value = 0.04). Among men with certain genotypes in 3 TXRND2, 1 GPX3, or 2 CAT SNPs, high plasma selenium reduced risk of high grade CaP by 50-76%. Among men with certain genotypes in 1 SOD1 or 1 SOD2 SNP, high plasma alpha-tocopherol reduced risk of high grade CaP by 65-68%.

Conclusions: Genetic variants in antioxidant genes may be associated with CaP recurrence after RP, and may interact with plasma selenium and alpha-tocopherol in relation to risk of high grade CaP.

A novel interaction of genotype, gender, and adjuvant treatment in survival after resection of stage III colon cancer: Results of CALGB 89803

452

Background: The p53 tumor suppressor gene is frequently mutated in colorectal cancer, but reports on the effect of p53 mutations on response to adjuvant chemotherapy and survival are inconclusive. This study investigates whether p53 mutational status (wild-type, zinc or non-zinc binding mutations) impacts survival following adjuvant therapy containing fluorouracil/leucovorin with or without irinotecan (5FU/LV or IFL) in women and men with stage III colon cancer.

Methods: As part of a retrospective analysis of prospectively accrued data, p53 mutational status was determined for 609 patients with stage III colon cancer who were randomized on CALGB 89803, a phase III adjuvant chemotherapy trial. p53 exons 5-8 were analyzed by direct sequencing or sequencing by hybridization. p53 mutations were identified in 276 tumors (45%), of which 134 were in the zinc binding and 142 were in the non-zinc binding regions of the core domain. Cox regression was used to study the impact of p53 mutational status, sex, and adjuvant chemotherapy on disease-free (DFS) and overall survival (OS).

Results: p53 mutational status did not predict differential survival or response to adjuvant therapy among the 609 patients assessed. However, a significant sex by treatment interaction was observed for both DFS (Pinteraction=0.008) and OS (Pinteraction=0.002). Significant differences in DFS by p53 mutational status were observed among women (logrank P = 0.009). No such differences were observed among men (logrank P = 0.33). Similar results were observed for OS. There was marginal evidence of a treatment-related impact on the interaction between sex and p53 mutational status for both DFS and OS (DFS Pinteraction = 0.07; OS Pinteraction = 0.11). There was a trend toward improved OS when women with zinc binding mutations received IFL versus 5FU/LV (P = 0.08) and toward worse DFS when women with non-zinc binding mutations were treated with IFL versus 5FU/LV (P =0.08).

Conclusions: This exploratory subset analysis suggests that p53 mutational status may be used to predict prognosis in a sex- and potentially chemotherapeutic regimen-specific manner.

A phase II study of insulin-like growth factor receptor inhibition with nordihydroguaiaretic acid in men with non-metastatic hormone-sensitive prostate cancer

Insulin-like growth factor (IGF)-mediated signaling is a newly recognized clinical target in prostate cancer, and it is hypothesized that blockade of the IGF receptor (IGF1R) will impair downstream signaling and slow tumor growth. In this study the efficacy of nordihydroguaiaretic acid (NDGA), a small molecule inhibitor of the IGF-1R, was prospectively evaluated in patients with non-metastatic hormone-sensitive prostate cancer (HSPC). Eligible patients had non-metastatic HSPC with a rising prostate-specific antigen (PSA) and a normal testosterone level. NDGA 2000 mg was given orally daily in 28 day cycles and treatment continued until PSA progression or toxicity. Accrual was stopped early after a pre-planned interim analysis showed no significant PSA declines after 3 cycles of treatment among the first 12 patients enrolled. Median time on treatment was 9 cycles (range 2-19) for 11 patients now off study; 1 patient continues to receive therapy and has been on study for 29 months. Seven patients experienced non-sustained declines in PSA ranging from 1.9 to 15.8% of baseline. PSADT lengthened by a median of 1.4 months for all evaluable patients when compared to pretreatment PSADT (range -6.1 to +19.8 months). Grade 3 events were rare and included nausea/vomiting, syncope due to dehydration, and elevated liver function tests in 1 patient, and cognitive disturbance in another patient. NDGA therapy lengthens median PSADT but does not induce significant PSA declines. Further study may require a placebo-control to determine if changes in PSADT are drug related.

A phase 1 study of everolimus and sorafenib for metastatic clear cell renal cell carcinoma

BACKGROUND

The current study was conducted to assess the maximum tolerated dose (MTD), safety, pharmacokinetics, and preliminary antitumor effect of everolimus, a mammalian target of rapamycin inhibitor, in combination with sorafenib, a tyrosine kinase inhibitor, in patients with metastatic clear cell renal cell carcinoma.

METHODS

Sequential cohorts of patients received escalating doses of everolimus and sorafenib in 28-day cycles in the absence of a dose-limiting toxicity (DLT) or disease progression were examined.

RESULTS

Twenty patients with a median age of 65 years received therapy in 3 cohorts. Dose level 1 was comprised of everolimus at a dose of 2.5 mg daily and sorafenib at a dose of 400 mg twice daily (6 patients), dose level 2 was comprised of everolimus at a dose of 5 mg daily and sorafenib at a dose of 400 mg twice daily (8 patients), and dose level 3 was comprised of everolimus at a dose of 10 mg daily and sorafenib at a dose of 200 mg twice daily (6 patients). DLTs included grade 4 (according to National Cancer Institute Common Terminology Criteria for Adverse Events [version 3.0]) hyperuricemia with grade 2 gout and grade 3 lipase associated with grade 2 pancreatitis at dose level 2, and grade 3 rash in 2 patients at dose level 3. Dose level 2 (everolimus at a dose of 5 mg daily and sorafenib at a dose of 400 mg twice daily) was established as the maximum tolerated dose. Treatment-related adverse events occurring in >20% of patients included diarrhea, hand-foot syndrome, hypertension, hypophosphatemia, hypothyroidism, and rash. Five of 20 patients achieved Response Evaluation Criteria In Solid Tumors (RECIST)-defined partial responses, all of which occurred in patients without a history of prior systemic therapy. Seven of 8 patients treated at dose level 2 experienced a partial response or stable disease. Pharmacokinetic analysis revealed no interaction between everolimus and sorafenib.

CONCLUSIONS

The combination of everolimus and sorafenib was associated with acceptable toxicity and evidence of antitumor activity in previously untreated patients with metastatic renal cell carcinoma.

Stereotactic body radiotherapy as monotherapy or post-external beam radiotherapy boost for prostate cancer: technique, early toxicity, and PSA response

PURPOSE

High dose rate (HDR) brachytherapy has been established as an excellent monotherapy or after external-beam radiotherapy (EBRT) boost treatment for prostate cancer (PCa). Recently, dosimetric studies have demonstrated the potential for achieving similar dosimetry with stereotactic body radiotherapy (SBRT) compared with HDR brachytherapy. Here, we report our technique, PSA nadir, and acute and late toxicity with SBRT as monotherapy and post-EBRT boost for PCa using HDR brachytherapy fractionation.

PATIENTS AND METHODS

To date, 38 patients have been treated with SBRT at the University of California-San Francisco with a minimum follow-up of 12 months. Twenty of 38 patients were treated with SBRT monotherapy (9.5 Gy × 4 fractions), and 18 were treated with SBRT boost (9.5 Gy × 2 fractions) post-EBRT and androgen deprivation therapy. PSA nadir to date for 44 HDR brachytherapy boost patients with disease characteristics similar to the SBRT boost cohort was also analyzed as a descriptive comparison.

RESULTS

SBRT was well tolerated. With a median follow-up of 18.3 months (range, 12.6-43.5), 42% and 11% of patients had acute Grade 2 gastrourinary and gastrointestinal toxicity, respectively, with no Grade 3 or higher acute toxicity to date. Two patients experienced late Grade 3 GU toxicity. All patients are without evidence of biochemical or clinical progression to date, and favorably low PSA nadirs have been observed with a current median PSA nadir of 0.35 ng/mL (range, <0.01-2.1) for all patients (0.47 ng/mL, range, 0.2-2.1 for the monotherapy cohort; 0.10 ng/mL, range, 0.01-0.5 for the boost cohort). With a median follow-up of 48.6 months (range, 16.4-87.8), the comparable HDR brachytherapy boost cohort has achieved a median PSA nadir of 0.09 ng/mL (range, 0.0-3.3).

CONCLUSIONS

Early results with SBRT monotherapy and post-EBRT boost for PCa demonstrate acceptable PSA response and minimal toxicity. PSA nadir with SBRT boost appears comparable to those achieved with HDR brachytherapy boost.

Chemoprevention of colonic polyps with balsalazide: an exploratory, double-blind, placebo-controlled study

BACKGROUND

A number of agents, including aspirin, nonsteroidal antiinflammatory drugs, cyclooxygenase-2 inhibitors, folic acid, calcium, and vitamins, have been evaluated for their potential in chemoprevention of sporadic colorectal adenomas or cancer. Preclinical data suggest that 5-aminosalicylates also may have a chemopreventive effect.

AIM

To investigate chemoprevention of colonic polyps with balsalazide, a 5-aminosalicylate prodrug.

METHODS

In this randomized, double-blind, placebo-controlled study, adults diagnosed with small polyps in the rectosigmoid colon were treated with either balsalazide 3 g/d or placebo for 6 months. Follow-up lower endoscopy was performed, and all polyps were measured and analyzed histologically. The primary endpoint was reduction in mean size of the largest polyp per subject.

RESULTS

Among 241 participants screened, 86 were randomized to treatment, with 75 subjects evaluable. Balsalazide 3 g/d (n = 38) did not significantly reduce the mean size of the largest colonic polyp or the number of polyps compared with placebo (n = 37). Although not significant, post-hoc analysis revealed that total adenoma burden per subject, calculated as the sum of the volumes of all adenomas in mm3, increased by 55% in the balsalazide group compared with 95% in the placebo group.

CONCLUSIONS

Although balsalazide did not have significant chemopreventive effects on established colonic polyps, these results can aid in designing future prospective studies.

Phase I study of ixabepilone, mitoxantrone, and prednisone in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel-based therapy: a study of the department of defense prostate cancer clinical trials consortium

PURPOSE

Mitoxantrone plus prednisone and ixabepilone each have modest activity as second-line chemotherapy in docetaxel-refractory castration-resistant prostate cancer (CRPC) patients. Clinical noncrossresistance was previously observed.

PATIENTS AND METHODS

Metastatic CRPC patients progressing during or after taxane-based chemotherapy enrolled in a phase I multicenter study of ixabepilone and mitoxantrone administered every 21 days along with prednisone. Ixabepilone and mitoxantrone doses were alternately escalated in a standard 3 + 3 design. Patients were evaluated for toxicity and disease response. Dose-limiting toxicities (DLTs) were defined as treatment related, occurring during cycle 1, and included grade 4 prolonged or febrile neutropenia, thrombocytopenia (grade 4 or grade 3 with bleeding), or > or = grade 3 nonhematologic toxicity.

RESULTS

Thirty-six patients were treated; 59% of patients experienced grade 3/4 neutropenia. DLTs included grade 3 diarrhea (n = 1), prolonged grade 4 neutropenia (n = 4), and grade 5 neutropenic infection (n = 1). Due to prolonged neutropenia, the highest dose levels were repeated with pegfilgrastim on day 2 of each cycle. The maximum tolerated dose in combination with pegfilgrastim was not exceeded. The recommended phase II dose is mitoxantrone 12 mg/m2 and ixabepilone 35 mg/m2 every 21 days, pegfilgrastim 6 mg subcutaneously day 2, and continuous prednisone 5 mg twice per day. Thirty-one percent of patients have experienced > or = 50% prostate-specific antigen (PSA) declines, and two experienced objective responses. Of 21 patients treated with mitoxantrone 12 mg/m2 plus ixabepilone > or = 30 mg/m2, nine (43%) experienced > or = 50% PSA declines (95% CI, 22% to 66%).

CONCLUSION

These results suggest that the combination of ixabepilone and mitoxantrone is feasible and active in CRPC and requires dosing with pegfilgrastim.

Activity of second-line chemotherapy in docetaxel-refractory hormone-refractory prostate cancer patients

BACKGROUND

This randomized, noncomparative, multicenter, clinical trial evaluated ixabepilone or mitoxantrone/prednisone (MP) as second-line chemotherapy for taxane-refractory, hormone-refractory, prostate cancer (HRPC).

METHODS

Patients with HRPC that progressed during or within 60 days of cessation of taxane chemotherapy were randomly selected with equal probability to ixabepilone 35 mg/m(2) intravenously every 3 weeks, or mitoxantrone 14 mg/m(2) intravenously every 3 weeks and prednisone 5 mg orally twice daily. Treatment continued until progression or toxicity; crossover was allowed.

RESULTS

Forty-one patients were accrued to each arm of the study. The median number of cycles administered for each arm was 3. Median survival from protocol entry was 10.4 months with ixabepilone and 9.8 months with MP. Prostate-specific antigen (PSA) declines of >or=50% were observed in 17% of ixabepilone (95% CI, 7-32) and 20% of second-line MP patients (95% CI, 9-35). Partial responses were observed in 1 of 24 ixabepilone and in 2 of 21 MP patients with evaluable measurable disease. Median duration of second-line ixabepilone and MP treatment was 2.2 months and 2.3 months, respectively. For third-line crossover treatment, PSA declines of >or=50% were observed in 3 of 27 ixabepilone-treated and 4 of 15 MP-treated patients. Prior taxane response was associated with an increased likelihood of second-line ixabepilone or MP response. Low baseline lactate dehydrogenase and absence of visceral metastases independently predicted improved survival. The most common grade 3/4 toxicity associated with second-line treatment was neutropenia (54% of ixabepilone patients and 63% of MP patients).

CONCLUSIONS

Ixabepilone and MP had modest activity as second-line chemotherapy for docetaxel-refractory HRPC. The median survival for the entire cohort treated in this study was 9.8 months.

Survival after recurrence of osteosarcoma: a 20-year experience at a single institution

BACKGROUND

Approximately one-third of patients with osteosarcoma who have a complete response to their initial treatment can be expected to relapse. It is important to define what host, tumor, or treatment characteristics determine outcome after relapse. We present findings in 59 patients treated at our institution from 1974 to 1996 who have relapsed one or more times after their initial response.

METHODS

Host and tumor characteristics at diagnosis and relapse, therapeutic interventions and survival outcomes were determined from examination of medical records and a follow-up questionnaire.

RESULTS

Of the 59 patients, 37 initially presented with localized disease of the extremity, 11 with localized non-extremity disease, and 11 with metastatic disease. This report focuses on those with localized disease of the extremity. For these patients, median time from original diagnosis to first recurrence was 14 months. Median survival after first recurrence was 31 months. The median post initial relapse survival was the same for patients whose first relapse occurred before or after 14 months from original diagnosis. Seventeen of 29 patients with systemic metastasis at first recurrence had complete removal of their disease and had a median post-op survival of 2.5 years, while the remaining 12 patients with no surgery, had a median survival of 2 years. Of the 37 patients who presented with primary disease only in the extremities and relapsed: 31 died (2 more than 6 years from first recurrence) and 6 are alive from 6 to 24 years from first recurrence (5 without disease and 1 with disease). Three of the five disease-free survivors had three or more relapses.

CONCLUSION

With a long follow-up time, we found 15% of patients with relapsed osteosarcoma who originally presented with localized disease in the extremity are alive with no evidence of disease at 10 years from first recurrence (Kaplan-Meier estimate). Even patients with multiple relapses may have long-term disease-free survival after salvage therapy. Chemotherapy and time to first recurrence were unrelated to survival after relapse in this study. Complete surgical removal of metastatic disease may be important for long-term survival.

A retrospective evaluation of second-line chemotherapy response in hormone-refractory prostate carcinoma

BACKGROUND

Epothilones and taxanes interfere with microtubule function. Ixabepilone, which is an epothilone-B analog, has activity against taxane-resistant cell lines and as first-line therapy for men with hormone-refractory prostate carcinoma (HRPC). Clinical cross-resistance of ixabepilone and taxanes in HRPC is unknown.

METHODS

Records were evaluated retrospectively from patients with HRPC who were treated on a randomized Phase II trial of ixabepilone with or without estramustine and who subsequently received taxane chemotherapy. Posttherapy declines in prostate-specific antigen (PSA) levels and time to PSA progression were defined by consensus criteria. The median survival was evaluated by using the Kaplan-Meier method.

RESULTS

Forty-nine patients who received ixabepilone with estramustine (28 patients) or without estramustine (21 patients) subsequently received second-line taxane therapy. Second-line PSA declines > or = 50% were achieved by 51% of patients (95% confidence interval [95% CI], 33-66%). Second-line PSA declines > or = 50% were achieved by 61% of patients (95% CI, 42-78%) who achieved a first-line PSA decline > or = 50% with ixabepilone, compared with 33% of patients (95% CI, 13-59%) who did not (P = 0.08). Patients who discontinued first-line ixabepilone treatment for disease progression were less likely to achieve a PSA decline > or = 50% in response to second-line, taxane-based therapy compared with patients who discontinued for toxicity or patient preference (36% vs. 71%; P = 0.01).

CONCLUSIONS

Second-line taxane chemotherapy after ixabepilone resulted in a substantial frequency of PSA declines. Although patients with ixabepilone-refractory disease were less likely to respond to second-line taxane chemotherapy, 36% did achieve a PSA response. These findings were consistent with incomplete clinical cross-resistance between the taxanes and the epothilones.

3D inverse treatment planning for the tandem and ovoid applicator in cervical cancer

PURPOSE

Three-dimensional treatment planning systems and inverse planning optimization for brachytherapy are becoming commercially available. Guidelines for target delineation and dose constrictions have not been established using this new software. In this study we describe a method of target delineation for the tandem and ovoids applicator. We then compare inverse planning dose distributions with the traditional methods of prescribing dose.

METHODS AND MATERIALS

Target and organ-at-risk volumes were defined using systematic guidelines on 15 patients treated in our department with high-dose-rate brachytherapy for cervical cancer using tandem and ovoids. High-dose-rate distributions were created according to three different dose optimization protocols: inverse planning simulated annealing (IPSA), point A, and point A with a normalization of 2 cc of the bladder receiving 80% of the dose (bladder-sparing method). An uniform cost function for dose constraints was applied to all IPSA generated plans, and no manual optimization was allowed for any planning method.

RESULTS

Guidelines for target and structure-at-risk volumes, as well as dose constraint cost functions, were established. Dose-volume histogram analysis showed that the IPSA algorithm indicated no difference in tumor coverage compared with point A optimization while decreasing dose to the bladder and rectum. The IPSA algorithm provided better target volume coverage compared with bladder-sparing method with equivalent doses to the bladder and rectum.

CONCLUSION

This study uses a systematic approach for delineating target and organ-at-risk volumes and a uniform cost function for generating IPSA plans for cervical cancer using tandem and ovoids. Compared with conventional dose prescription methods, IPSA provides a consistent method of optimization that maintains or improves target coverage while decreasing dose to normal structures. Image-guided brachytherapy and inverse planning improve brachytherapy dosimetry.

Integration of high-resolution array comparative genomic hybridization analysis of chromosome 16q with expression array data refines common regions of loss at 16q23–qter and identifies underlying candidate tumor suppressor genes in prostate cancer

We have constructed a high-resolution genomic microarray of human chromosome 16q, and used it for comparative genomic hybridization analysis of 16 prostate tumors. We demarcated 10 regions of genomic loss between 16q23.1 and 16qter that occurred in five or more samples. Mining expression array data from four independent studies allowed us to identify 11 genes that were frequently underexpressed in prostate cancer and that co-localized with a region of genomic loss. Quantitative expression analyses of these genes in matched tumor and benign tissue from 13 patients showed that six of these 11 (WWOX, WFDC1, MAF, FOXF1, MVD and the predicted novel transcript Q9H0B8 (NM_031476)) had significant and consistent downregulation in the tumors relative to normal prostate tissue expression making them candidate tumor suppressor genes.

Is anastomotic biopsy necessary before radiotherapy after radical prostatectomy?

PURPOSE

External beam radiotherapy may be given after radical prostatectomy as adjuvant (immediate) or therapeutic (delayed) treatment, the latter in response to evidence of disease recurrence. In patients receiving delayed radiotherapy the necessity of a positive anastomotic biopsy before treatment remains unclear. We determined whether a positive anastomotic biopsy predicted the response to radiation in this setting.

MATERIALS AND METHODS

We reviewed the records of 67 patients who received radiotherapy for biochemical or biopsy proved recurrent prostate cancer after radical prostatectomy. Patients underwent surgery at our institution or its affiliated hospitals, or were referred to our institution for radiotherapy. All patients had a negative metastatic evaluation before receiving radiotherapy. Biochemical failure after radiotherapy was defined as serum prostate specific antigen (PSA) 0.2 ng./dl. or greater on 2 or more consecutive occasions. Biochemical recurrence-free survival was calculated using the Kaplan-Meier method. Independent predictors of PSA failure after radiotherapy were identified using the multivariate Cox proportional hazards model.

RESULTS

Of the 67 patients evaluated 33 and 34 received radiotherapy for biochemical failure and biopsy proved local recurrence, respectively. The 3-year recurrence-free survival rate was 49% in patients treated for biochemical failure and 39% in those with biopsy proved local recurrence. There was no significant difference in PSA-free survival in these 2 groups. Only pre-radiotherapy PSA 1 ng./dl. or greater (p = 0.02) and seminal vesicle invasion (p = 0.02) were significant independent predictors of biochemical failure.

CONCLUSIONS

A positive anastomotic biopsy did not predict an improved outcome after radiotherapy following radical prostatectomy. Anastomotic biopsy was associated with a longer time to salvage radiotherapy. However, this delay did not translate into worse disease-free outcomes in patients who underwent anastomotic biopsy. High pre-radiotherapy PSA greater than 1 ng./ml. was the most significant predictor of biochemical failure after therapeutic radiotherapy. Decisions regarding local radiation therapy after radical prostatectomy may be made without documenting recurrent local disease.