Vitamin D Receptor Antagonist MeTC7 Inhibits PD-L1

Small-molecule inhibitors of PD-L1 are postulated to control immune evasion in tumors similar to antibodies that target the PD-L1/PD-1 immune checkpoint axis. However, the identity of targetable PD-L1 inducers is required to develop small-molecule PD-L1 inhibitors. In this study, using chromatin immunoprecipitation (ChIP) assay and siRNA, we demonstrate that vitamin D/VDR regulates PD-L1 expression in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) cells. We have examined whether a VDR antagonist, MeTC7, can inhibit PD-L1. To ensure that MeTC7 inhibits VDR/PD-L1 without off-target effects, we examined competitive inhibition of VDR by MeTC7, utilizing ligand-dependent dimerization of VDR-RXR, RXR-RXR, and VDR-coactivators in a mammalian 2-hybrid (M2H) assay. MeTC7 inhibits VDR selectively, suppresses PD-L1 expression sparing PD-L2, and inhibits the cell viability, clonogenicity, and xenograft growth of AML cells. MeTC7 blocks AML/mesenchymal stem cells (MSCs) adhesion and increases the efferocytotic efficiency of THP-1 AML cells. Additionally, utilizing a syngeneic colorectal cancer model in which VDR/PD-L1 co-upregulation occurs in vivo under radiation therapy (RT), MeTC7 inhibits PD-L1 and enhances intra-tumoral CD8+T cells expressing lymphoid activation antigen-CD69. Taken together, MeTC7 is a promising small-molecule inhibitor of PD-L1 with clinical potential.

TRAIL-coated leukocytes to kill circulating tumor cells in the flowing blood from prostate cancer patients

Background

Radical surgery is the first line treatment for localized prostate cancer (PC), however, several studies have demonstrated that surgical procedures induce tumor cell mobilization from the primary tumor into the bloodstream.

Methods

The number and temporal fluctuations of circulating tumor cells (CTC), cancer associated fibroblasts (CAF) and CTC cluster present in each blood sample was determined.

Results

The results show that both CTC and CTC cluster levels significantly increased immediately following primary tumor resection, but returned to baseline within 2 weeks post-surgery. In contrast, the CAF level decreased over time. In patients who experienced PC recurrence within months after resection, CTC, CAF, and cluster levels all increased over time. Based on this observation, we tested the efficacy of an experimental TNF-related apoptosis-inducing ligand (TRAIL)-based liposomal therapy ex-vivo to induce apoptosis in CTC in blood. The TRAIL-based therapy killed approximately 75% of single CTCs and CTC in cluster form.

Conclusion

Collectively, these data indicate that CTC cluster and CAF levels can be used as a predictive biomarker for cancer recurrence. Moreover, for the first time, we demonstrate the efficacy of our TRAIL-based liposomal therapy to target and kill prostate CTC in primary patient blood samples, suggesting a potential new adjuvant therapy to use in combination with surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08589-8.

Next generation sequencing of sarcomas: Response to crizotinib in two cases with MET amplification

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Background: Sarcoma subtypes are often defined by recurrent molecular alterations. The purpose of this study is to review the utility of next generation sequencing (NGS) in sarcoma patients and report clinical outcomes to matched therapies. Methods: The records of all patients seen at the University of Rochester Medical Center (URMC) with sarcoma and NGS profiling between 8/2013 and 3/2020 were reviewed. Responses to agents targeting reported alterations were analyzed. In patients with fluorescent-in-situ hybridization (FISH) testing, fusion events by NGS were compared with FISH results. All highlighted pathogenic alterations on the NGS profile report as well as variants of uncertain significance (VUS) were recorded. Results: Seventy-five patients met inclusion criteria. Of these, 25 received a treatment based on identified alterations; 1 had a complete response (CR), 4 had partial responses (PR), and 4 experienced disease stabilization (SD). We identified two patients with MET amplified sarcoma that responded to treatment with crizotinib. One other patient with a diagnosis of leiomyosarcoma was found to have an unusually high total mutational burden (TMB) and experienced complete pathologic response to dual checkpoint blockade. In 4 cases, testing resulted in a change in subtype diagnosis. Several rare and novel fusions were identified; a sarcoma with TPM4-NTRK3 fusion responded to larotrectinib, while a sarcoma with PML-JAK1 fusion did not respond to ruxolitinib, and a sarcoma with IL7R-BCL2 fusion progressed on venetoclax. Table summarizes matched therapies in responders. Conclusions: NGS profiling led to a targeted therapy with a clinical benefit rate of 12% in this cohort. NGS profiling led to a change in diagnosis in 5% of this cohort. Multi-institutional collaborations to track outcomes of matched therapy would help determine the utility of therapies in rare cancers and unusual alterations.[Table: see text]

Efficacy and toxicities of immune checkpoint inhibitors (ICIs) in advanced melanoma: A single institution experience

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Background: Historically, the prognosis of advanced melanoma has been poor. Recent landmark studies (KEYNOTE-006, CheckMate 066, CheckMate 037 and CheckMate 067) have shown significant improvement in outcomes of patients with advanced melanoma treated with ICIs. In a single institution retrospective study, we evaluated the efficacy and toxicities of ICIs in patients with advanced melanoma treated in real-world clinical practice. Methods: We included patients who received pembrolizumab (PEMBRO), nivolumab (NIVO), or ipilimumab plus nivolumab (IPI/NIVO) at the University of Rochester Medical Center from June 2015 to December 2018. Patient- and cancer-related characteristics were collected and compared between treatment groups. Outcomes including duration of treatment, response rates, and adverse events (AEs) were captured. Progression free survival (PFS) and overall survival (OS) were summarized using the Kaplan-Meier method. Results: We included 89 patients (55 received PEMBRO, 20 received NIVO, and 14 received IPI/NIVO); median age at ICI initiation was 68 years (range, 28-92) and 29% had Eastern Cooperative Oncology Group Performance Status (ECOG PS) of ≥2. Forty-five patients (51%) had ≥2 co-morbidities. Nine patients (10%) had autoimmune diseases prior to initiating ICIs and 34 patients (38%) had brain metastasis. ICIs were given as first line in 71 patients (80%). Compared to those who received PEMBRO or NIVO, patients who received IPI/NIVO were younger (median age was 61 vs.71 vs. 70, p=0.003) and had better ECOG PS (ECOG PS ≥2 was 0% vs. 40% vs. 33%, p=0.007). Table shows the outcomes for the three groups. Conclusions: Patients with advanced melanoma treated with ICIs derived similar response rates to those seen in published landmark studies. However, median OS was shorter (range was 38 months to not reached in published studies). [Table: see text]

Impact of cisplatin-related adverse health outcomes (AHOs) on employment outcomes and self-reported health (SRH) among testicular cancer survivors (TCS)

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Background: We aim to provide new information on cisplatin-related AHOs and employment status in TCS and evaluate impact on SRH. Methods: 1,815 TCS ³1 year post-chemotherapy underwent physical exam, audiometry, renal function evaluation, and completed questionnaires. Therapy data were obtained from medical records. A cumulative burden of morbidity score (CBMPt) assessed the number and severity of platinum-related AHOs (peripheral sensory neuropathy (PSN), hearing loss, tinnitus, and renal function) with grading per CTCAE v4.03. Multivariable regression assessed relations between CBMPt score, individual AHOs and employment status as well as SRH, adjusting for sociodemographic/clinical factors. Unemployment in TCS was compared with subjects in the Behavioral Risk Factor Surveillance System (BRFSS) of similar age/race/ethnicity. Results: Almost 1 in 10 TCS were either on disability leave (2.4%) or unemployed (6.8%) at a median age of 37 yr (median follow-up: 4 yr). TCS with tinnitus (OR = 3.1, grade 3 vs. 0, P = 0.04), renal dysfunction (OR = 13.5, grade 3 vs. 0, P = 0.01), or pain (OR = 7.2 and 40.9, grade 2 or 3 vs. 0, respectively; P < 0.001 each) had significantly greater odds of disability leave vs. full-time employment after adjusting for sociodemographic/clinical factors; pain was strongly correlated with PSN (Pearson r2= 0.40; P < 0.001). CBMPt score was associated with disability leave (OR = 1.5, P = 0.04), but not with unemployment. A significantly higher percentage of TCS were unemployed vs. BRFSS norms (e.g. 3.6% of TCS age 35-39 vs. 2.0% in BRFSS). PSN (OR = 2.2, grade 3 vs. 0, P = 0.02), self-reported hearing loss (OR = 1.8, grade 2/3 vs. 0, P = 0.04), and pain (OR = 2.8 and 8.5, grade 2 or 3 vs. 0, respectively; P < 0.01 each) were each associated with increased odds of unemployment vs. full-time employment. Cisplatin-related AHOs and pain were associated with significantly worse SRH (P < 0.05). Conclusions: Our findings have new, important implications regarding productivity loss and socioeconomic costs in TCS. Survivorship care strategies should include inquiries about employment status, and every effort made to assist affected TCS in returning to the work force.

A phase II study of enzalutamide (Enz) with dutasteride (Dut) or finasteride (Fin) in men ≥ 65 years with hormone-naive systemic prostate cancer (HNSPCa): Tolerability and geriatric asssessment (GA) results

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Background: Older men are at a high risk for adverse events (AEs) from androgen deprivation therapy (ADT). In this phase II study, we evaluated Enz and Dut/Fin in lieu of ADT for at-risk older patients with HNSPCa. Methods: Eligible patients were ≥65 years (y); at high risk of AEs from ADT by GA or treating physicians; metastatic (M1) or non-metastatic (M0) HNSPCa with a PSA doubling time ≤ 9 months and testosterone > 50ng/dl. They received Enz 160 mg/day and Dut 0.5 mg/day or Fin 5 mg/day until disease progression. GA was performed at baseline and week (wk) 61 and/or at the time of progression. GA included validated tests: Instrumental Activities of Daily Living (IADL), fall history, Short Physical Performance Battery (SPPB), Geriatric Depression Scale (GDS), and Montreal Cognitive Assessment (MOCA). The prevalence of impairment for each assessment was calculated; change in prevalence from baseline to wk 61 was analyzed using paired sample t-test. Results: 43 patients were enrolled in the study. Median age at enrollment was 78 y (range 66-94) and 93% were ECOG 0-1; 37% (n = 16) had M0 and 63% (n = 27) had M1 HNSPCa, with the majority (67%) having Gleason 6 or 7 disease. At baseline, 18.6% met the cutoff for impairment for IADLs, 53.7% for SPPB, 7.9% for GDS and 64.3% for MOCA; 9.8% had a recent fall. Median baseline PSA was 11.38 ng/ml (range: 2-145). At the time of analysis, 29 men (67.4%) remain on study treatment. 95.3%, 74.4% and 46.5% of patients reported at least one Grade 1, 2 or 3 AE respectively. No patient had a Grade 4 AE and one Grade 5 AE was reported but was an unrelated event. The most common Grade 3 AEs were hypertension (27.8%), GI (19.4%), and cardiac (8.3%); all Grade 3 GI AEs reported were deemed unrelated to the study drugs. Only impairment in ≥ 1 IADL showed a statistically significant increase in prevalence at wk 61 of treatment (40.6%) compared to baseline (18.6%, p = 0.036). Conclusions: For older men with HNSPCa, Enz with Dut/Fin demonstrated efficacy with reasonable toxicity profile, and no significant impact on the majority of GA domains. Clinical trial information: NCT02213107.

Genetic testing patterns for homologous recombination repair (HRR) alterations in patients with metastatic prostate cancer (mPC): An assessment at the University of Rochester (UR)

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Background: Germline and somatic HRR alterations are present in 12% and 20% of patients with mPC, respectively, and can have treatment implications. NCCN guidelines recommend offering genetic testing for patients with mPC. This study examines genetic testing patterns in patients with mPC at UR. Methods: We conducted a retrospective study of all patients (n = 240) with mPC who saw medical oncology at UR from 10/1/2017 to 4/1/2018. We abstracted the following data from medical records: patient demographics, mPC characteristics, types of genetic testing, and clinically significant (CS) HRR alterations as defined by Myriad, Ambry, and Foundation One. To compare characteristics of patients who had genetic testing to those who did not, we used non-parametric Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categorical variables. Results: The median age at mPC diagnosis was 71 years (range: 42-93 years), 86.3% were white, and 35% had mPC at initial diagnosis. 64 patients (26.7%) were offered genetic testing and 40 patients (16.7%) completed germline (n = 12), somatic (n = 21), or both germline and somatic genetic testing (n = 7). Median time from diagnosis of mPC to germline and somatic genetic testing were 9 months and 35 months, respectively. Among the 24 patients who were offered, but did not have testing, the reasons were: patients’ refusal (n = 10), death/hospice care (n = 7), insurance issue (n = 3), patient’s preference to have somatic testing at disease progression (n = 3), and missed genetic counseling visit (n = 1). Compared to patients who did not have genetic testing, those who had testing were younger at the time of mPC diagnosis (63.5 vs 73.0 years; p < 0.0001). CS HRR alterations were identified in 8 of 40 patients tested (20%): somatic HRR alterations include BRCA2 (n = 2), ATM (n = 1), CDK 12 (n = 1), and C HEK2 (n = 1); germline HRR alterations include BRCA2 (n = 2) and CHEK2 (n = 1). Conclusions: We report that approximately one-fourth of patients with mPC at UR had genetic testing offered, with a 20% prevalence of HRR alterations in those tested. Future research should develop strategies to address barriers to genetic testing.

Effect of Intravesical Instillation of Gemcitabine vs Saline Immediately Following Resection of Suspected Low-Grade Non-Muscle-Invasive Bladder Cancer on Tumor Recurrence: SWOG S0337 Randomized Clinical Trial

Importance

Low-grade non-muscle-invasive urothelial cancer frequently recurs after excision by transurethral resection of bladder tumor (TURBT).

Objective

To determine whether immediate post-TURBT intravesical instillation of gemcitabine reduces recurrence of suspected low-grade non-muscle-invasive urothelial cancer compared with saline.

Design, Setting, and Participants

Randomized double-blind clinical trial conducted at 23 US centers. Patients with suspected low-grade non-muscle-invasive urothelial cancer based on cystoscopic appearance without any high-grade or without more than 2 low-grade urothelial cancer episodes within 18 months before index TURBT were enrolled between January 23, 2008, and August 14, 2012, and followed up every 3 months with cystoscopy and cytology for 2 years and then semiannually for 2 years. Patients were monitored for tumor recurrence, progression to muscle invasion, survival, and toxic effects. The final date of follow-up was August 14, 2016.

Interventions

Participants were randomly assigned to receive intravesical instillation of gemcitabine (2 g in 100 mL of saline) (n = 201) or saline (100 mL) (n = 205) for 1 hour immediately following TURBT.

Main Outcomes and Measures

The primary outcome was time to recurrence of cancer. Secondary end points were time to muscle invasion and death due to any cause.

Results

Among 406 randomized eligible patients (median age, 66 years; 84.7% men), 383 completed the trial. In the intention-to-treat analysis, 67 of 201 patients (4-year estimate, 35%) in the gemcitabine group and 91 of 205 patients (4-year estimate, 47%) in the saline group had cancer recurrence within 4.0 years (hazard ratio, 0.66; 95% CI, 0.48-0.90; P<.001 by 1-sided log-rank test for time to recurrence). Among the 215 patients with low-grade non-muscle-invasive urothelial cancer who underwent TURBT and drug instillation, 34 of 102 patients (4-year estimate, 34%) in the gemcitabine group and 59 of 113 patients (4-year estimate, 54%) in the saline group had cancer recurrence (hazard ratio, 0.53; 95% CI, 0.35-0.81; P = .001 by 1-sided log-rank test for time to recurrence). Fifteen patients had tumors that progressed to muscle invasion (5 in the gemcitabine group and 10 in the saline group; P = .22 by 1-sided log-rank test) and 42 died of any cause (17 in the gemcitabine group and 25 in the saline group; P = .12 by 1-sided log-rank test). There were no grade 4 or 5 adverse events and no significant differences in adverse events of grade 3 or lower.

Conclusions and Relevance

Among patients with suspected low-grade non-muscle-invasive urothelial cancer, immediate postresection intravesical instillation of gemcitabine, compared with instillation of saline, significantly reduced the risk of recurrence over a median of 4.0 years. These findings support using this therapy, but further research is needed to compare gemcitabine with other intravesical agents.

Trial Registration

clinicaltrials.gov Identifier: NCT00445601.

Cumulative Burden of Morbidity Among Testicular Cancer Survivors After Standard Cisplatin-Based Chemotherapy: A Multi-Institutional Study

Purpose In this multicenter study, we evaluated the cumulative burden of morbidity (CBM) among > 1,200 testicular cancer survivors and applied factor analysis to determine the co-occurrence of adverse health outcomes (AHOs). Patients and Methods Participants were ≤ 55 years of age at diagnosis, finished first-line chemotherapy ≥ 1 year previously, completed a comprehensive questionnaire, and underwent physical examination. Treatment data were abstracted from medical records. A CBM score encompassed the number and severity of AHOs, with ordinal logistic regression used to assess associations with exposures. Nonlinear factor analysis and the nonparametric dimensionality evaluation to enumerate contributing traits procedure determined which AHOs co-occurred. Results Among 1,214 participants, approximately 20% had a high (15%) or very high/severe (4.1%) CBM score, whereas approximately 80% scored medium (30%) or low/very low (47%). Increased risks of higher scores were associated with four cycles of either ifosfamide, etoposide, and cisplatin (odds ratio [OR], 1.96; 95% CI, 1.04 to 3.71) or bleomycin, etoposide, and cisplatin (OR, 1.44; 95% CI, 1.04 to 1.98), older attained age (OR, 1.18; 95% CI, 1.10 to 1.26), current disability leave (OR, 3.53; 95% CI, 1.57 to 7.95), less than a college education (OR, 1.44; 95% CI, 1.11 to 1.87), and current or former smoking (OR, 1.28; 95% CI, 1.02 to 1.63). CBM score did not differ after either chemotherapy regimen ( P = .36). Asian race (OR, 0.41; 95% CI, 0.23 to 0.72) and vigorous exercise (OR, 0.68; 95% CI, 0.52 to 0.89) were protective. Variable clustering analyses identified six significant AHO clusters (χ² P < .001): hearing loss/damage, tinnitus (OR, 16.3); hyperlipidemia, hypertension, diabetes (OR, 9.8); neuropathy, pain, Raynaud phenomenon (OR, 5.5); cardiovascular and related conditions (OR, 5.0); thyroid disease, erectile dysfunction (OR, 4.2); and depression/anxiety, hypogonadism (OR, 2.8). Conclusion Factors associated with higher CBM may identify testicular cancer survivors in need of closer monitoring. If confirmed, identified AHO clusters could guide the development of survivorship care strategies.

Feasibility of utilizing a novel mhealth platform to deliver an evidence-based exercise intervention among testicular cancer survivors (TCS)

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Background: Cardiovascular disease results in significant morbidity among TCS. Exercise for Cancer Patients (EXCAP) is a self-directed, individually tailored intervention that improves cardiovascular fitness in cancer patients, yet this has not been tested in TCS. We conducted a randomized phase II feasibility study of a novel exercise intervention using a mHealth delivery platform for EXCAP. Methods: We developed mHealth-EXCAP, which integrates data from a wearable digital activity tracker (DAT) into a patient’s electronic medical record (EMR), allowing providers to monitor and adjust EXCAP prescriptions via a patient-centered virtual portal. We randomized TCS ( < 69 yr at diagnosis, any treatments, not in active or maintenance stage of exercise behavior) into 3 study arms: Arm 1 (mHealth-EXCAP), Arm 2 (EXCAP) and Arm 3 (usual care). TCS in both Arm 1 and 2 completed a 12 week EXCAP program with the goal of 12,000 daily steps and daily resistance exercises but Arm 1 used the mHealth platform. Arm 3 used a TCS care plan that promotes exercises. Results: 74 TCS were screened (32 ineligible; 23 declined), 19 consented and 14 (74%) completed study (3 withdrew; 2 lost to follow up) as of 1/31/17. Median age (yr) was 35 (Arm 1; n = 6), 48 (Arm 2; n = 4), and 48 (Arm 3; n = 4). In Arm 1, 83% TCS wore DAT and synced daily step data to EMR > 90% of days. EXCAP prescriptions were adjusted via EMR portal on average 5 times over 12 weeks for each TCS and their weekly daily step goals were met 73% of the time. The number of daily steps recorded by DAT and those synced from DAT to EMR differed by a mean of 1.5% steps (±1.8). Median baseline number of daily steps were 5,525 (Arm 1), 6,795 (Arm 2), and 5,904 (Arm 3) and increased by 5,236, 1,160, and 1,544 respective steps at 12 weeks, with only Arm 1 (50% TCS) achieving > 12,000 daily steps. At 3 months after intervention, 33% TCS in Arm 1 maintained > 12,000 daily steps. On average, TCS in Arm 1 performed resistance exercises 26 minutes a day/5 times a week vs. 28 minutes a day/4 times a week in Arm 2. Conclusions: mHealth-EXCAP is feasible to implement among TCS and may decrease sedentary behavior. Ongoing research will examine its effects on cardiovascular fitness and risk factors.

Clinical, sociodemographic, and behavioral factors associated with cumulative burden of morbidity (CBM) among testicular cancer survivors (TCS) in the Platinum study

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Background: TCS are an important group in which to characterize late effects of cancer and its therapy given their young age at diagnosis and high cure rate. We comprehensively evaluated CBM and identified associated clinical, sociodemographic, and behavioral risk factors among TCS given cisplatin based chemotherapy in a multicenter study. Methods: TCS completed a comprehensive health questionnaire. Responses were grouped into 22 adverse health outcomes (AHO) and graded by severity. A CBM score was calculated based on AHO number and severity, following Geenen et al (JAMA 2007). Multivariable ordinal logistic regression examined the association of clinical, sociodemographic, and behavioral factors with CBM. Variable-based hierarchical clustering identified individual AHOs that co-occurred. Results: Among 1,215 TCS (median age at evaluation 38 y, range 19-68 y; time since chemotherapy 4.6 y), over 20% had a CBM score of high (17%), very high (4%) or severe (0.4%). Most TCS, however, had CBM scores of low (37%), medium (28%), very low (9%) or none (5%). In a multivariable model controlling for time since chemotherapy, older attained age (OR 1.2; 95% CI 1.1 - 1.3), being widowed/divorced/separated (OR 1.8; 95% CI 1.1 - 3.1), having less than college-level education (OR 1.7; 95% CI 1.3 - 2.2), being retired/on disability (OR 2.5; 95% CI 1.2 - 5.3), and receipt of 4 cycles of BEP vs. 4 cycles of EP or 3 cycles of BEP (OR 1.3; 95% CI 1.01 - 1.8) were associated with increased odds of a worse CBM score; vigorous exercise (OR 0.7; 95% CI 0.5 - 0.9) and non-white race (OR 0.6; 95% CI 0.4 - 0.9) were associated with decreased odds. A separate cluster analysis revealed five groups of AHOs: those known to be cisplatin-related (e.g. neuropathy, ototoxicity); metabolic abnormalities (e.g. hypercholesterolemia, diabetes); vascular damage (e.g. stroke); testicular cancer-related (e.g. hypogonadism); and other (e.g. thyroid disease). Conclusions: TCS with factors associated with worse CBM may be candidates for closer monitoring. If confirmed, our cluster analysis showing that groups of conditions tend to co-occur in TCS could provide guidance for survivorship care plans.

A phase II study of enzalutamide (Enz) with dutasteride (Dut) or finasteride (Fin) in men ≥ 65 years with hormone-naive systemic prostate cancer (HNSPCa)

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Background: Older men are at a high risk for adverse events (AEs) from androgen deprivation therapy (ADT). In prior studies, peripheral androgen blockade with bicalutamide and Fin was better tolerated but less efficacious than ADT in HNSPCa. The potential syngerism of Enz (a potent antiandrogen) and Dut/Fin (5-a reductase inhibitors for conversion of testosterone [T] to dihydrotestosterone [DHT]) provided the rationale for this Phase II study that examined the clinical efficacy and safety of Enz with Dut/Fin in men > 65 years with HNSPCa. Methods: Eligible patients were > 65 years (y) ; at a high risk of AE from ADT by comprehensive geriatric assessment or treating physicians; had metastatic (M1) or biochemical recurrent (M0) HNSPCa with a PSA doubling time < 9 months; and had T > 50ng/dl. They received Enz (160mg daily) and Dut (0.5mg daily) or Fin (5mg daily) until disease progression according to the Prostate Cancer Working Group 2 guidelines. The primary study endpoint is time to PSA progression. The secondary endpoints are time to PSA nadir and treatment-related AEs. Results: As of July 31, 2016, 24 patients were screened (3 ineligible) and 21 were enrolled with a median follow-up of 31 weeks (7-79). Median age at enrollment was 79.5 y (66-94) and 14 %, 72% and 14% had ECOG performance status of 0, 1, and 2, respectively. 57% (n = 12) had M0 and 43% (n = 9) had M1 HNSPCa, with 18%, 62%, 5%, and 10% having Gleason 6, 7, 8, and 9 disease, respectively (5% with unkown Gleason sum). The median PSA at enrollment was 12 ng/ml (2-102). The median time to 90% PSA decline after treatment initiation was 7 weeks (7-20) and 92% achieved 80% DHT decline in 9 months. At the time of analysis, all patients had ongoing PSA decline of > 90% without radiographic evidence of disease progression. Common Grade 1 AEs included gynecomastia (28%), fatigue (28%), hot flashes (19%) and paresthesias (15%). One patient withdrew from the study due to Grade 2 paresthesia. None had Grade 3 or 4 treatment-related AEs. One patient died due to colitis unrelated to study treatments. Conclusions: Enz with Dut/Fin appears to have clinical activity for older patients with M0 and M1 HNSPCa with acceptable side effects. Clinical trial information: NCT02213107.

Feasibility of an electronic implementation method of an evidence-based exercise intervention among testicular cancer survivors (TCS)

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Background: Cardiovascular (CV) disease results in significant morbidity among TCS. The effects of exercise on mitigating these late effects remain unknown in this population. Exercise for Cancer Patients (EXCAP) is a self-directed, individually tailored intervention that has been shown to improve CV fitness in cancer patients. We conducted a randomized phase II feasibility study of a novel electronic implementation method (mHealth) of EXCAP. Methods: We developed mHealth-EXCAP that integrates data from a wearable digital activity tracker (DAT) into a patient’s electronic medical record (EMR), allowing providers to monitor and adjust EXCAP prescriptions via a patient-centered virtual portal. We randomized TCS ( < 69 yr at diagnosis, any treatments, not in active or maintenance stage of exercise behavior) into 3 study arms: Arm 1 (mHealth-EXCAP), Arm 2 (EXCAP) and Arm 3 (usual care). Both Arm 1 and 2 completed a 12 week EXCAP program with the goal of 12,000 daily steps and daily resistance exercises and Arm 1 has integration of mHealth. Arm 3 received a TCS care plan that encourages exercises. Results: 52 TCS were screened (23 ineligible; 12 declined), 17 consented and 13 (80.9%) completed study (3 withdrew; 1 lost to follow up) as of May 31, 2016. Median age (yr) was 34 (Arm 1; n = 6), 52 (Arm 2; n = 3), and 48 (Arm 3; n = 4). In Arm 1, 83% TCS wore DAT and synced daily step data to EMR > 90% of days. Further, EXCAP prescriptions were adjusted via EMR portal on average 5 times over 12 weeks for each TCS and their weekly daily step goals were met 73% of the time. The number of daily steps recorded by DAT and those synced from DAT to EMR differed by a mean of 1.5% steps (±1.8). Median baseline number of daily steps were 5,432 (Arm 1), 6,737 (Arm 2), and 5,875 (Arm 3) and increased by 6,161, 1,742, and 1,921 respective steps, with only Arm 1 (50% TCS) achieving > 12,000 daily steps at study completion. On average, TCS in Arm 1 and 2 performed resistance exercises 15 minutes a day/2 times a week and 34 minutes a day/3 times a week, respectively. Conclusions: mHealth-EXCAP is feasible to implement among TCS and may decrease sedentary behavior. Ongoing research will examine its effects on CV risk factors and cardiopulmonary function.

Biopsychosocial distress assessment among testicular cancer survivors (TCS) using electronic patient reported outcomes (PROs)

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Background: Distressis a frequently endorsed experience by cancer patients.Many organizations advocate formal distress screening as part of clinical care in order to better meet the “psychological, social, and/or spiritual needs of patients that may interfere with the ability to cope effectively with cancer, its physical symptoms, and its treatments.” The primary objective of this study is to characterize distress levels among TCS using electronic PROs via a modified version of the National Comprehensive Cancer Network Distress Thermometer (DT) and Patient Reported Outcomes Measurement System (PROMIS). Methods: Eligible TCS ( < 69 years at diagnosis, any treatments, not in active or maintenance stage of exercise behavior) enrolled onto a pilot study of an electronic, self-directed, individually tailored “EXercise for CAncer Patients” (EXCAP) program were offered iPad-based distress screening during routine medical oncology clinic visits. Screening consisted of a modified DT, where patients self-report distress on a scale of 1-10, wherein scores of greater than 4 refer to increased distress, as well as PROMIS domains for anxiety and depression, where scores range from 0-100, 50 is the average for the United States (US) general population, and higher values indicate more anxiety or depression. Results: A total of 18 TCS (median age 44) enrolled in the EXCAP study as of May 31, 2016. Among participants, 56%, 28% and 17% had stage I, II, and III testicular cancer, respectively. Treatment modality and median time from treatment to enrollment were: 78% orchiectomy, 23.5 months (range 1-204); 33% retroperitoneal lymph node dissection, 8 months (range 1-48); and 72% chemotherapy, 22 months (range 3-587). TCS completed a median of 2 distress screenings (range 1-8). The median DT score was 3 (range 1-8). Median PROMIS anxiety and depression scores were 52.88 (32.87-69.36) and 51.02 (34.17-6.65). Conclusions: TCS self-report low levels of distress on the DT and PROMIS scores for anxiety and depression that are comparable to the US general population. Future research will explore associations between patient- and disease-specific factors and distress in TCS.

TGFβ Superfamily Members Mediate Androgen Deprivation Therapy-Induced Obese Frailty in Male Mice

First line treatment for recurrent and metastatic prostate cancer is androgen deprivation therapy (ADT). Use of ADT has been increasing in frequency and duration, such that side effects increasingly impact patient quality of life. One of the most significant side effects of ADT is sarcopenia, which leads to a loss of skeletal muscle mass and function, resulting in a clinical disability syndrome known as obese frailty. Using aged mice, we developed a mouse model of ADT-induced sarcopenia that closely resembles the phenotype seen in patients, including loss of skeletal muscle strength, reduced lean muscle mass, and increased adipose tissue. Sarcopenia onset occurred about 6 weeks after castration and was blocked by a soluble receptor (ActRIIB-Fc) that binds multiple TGFβ superfamily members, including myostatin, growth differentiation factor 11, activin A, activin B, and activin AB. Analysis of ligand expression in both gastrocnemius and triceps brachii muscles demonstrates that each of these proteins is induced in response to ADT, in 1 of 3 temporal patterns. Specifically, activin A and activin AB levels increase and decline before onset of strength loss at 6 weeks after castration, and myostatin levels increase coincident with the onset of strength loss and then decline. In contrast, activin B and growth differentiation factor 11 levels increase after the onset of strength loss, 8-10 weeks after castration. The observed patterns of ligand induction may represent differential contributions to the development and/or maintenance of sarcopenia. We hypothesize that some or all of these ligands are targets for therapy to ameliorate ADT-induced sarcopenia in prostate cancer patients.

Cardiovascular Disease Mortality After Chemotherapy or Surgery for Testicular Nonseminoma: A Population-Based Study

PURPOSE

Increased risks of incident cardiovascular disease (CVD) in patients with testicular cancer (TC) given chemotherapy in European studies were largely restricted to long-term survivors and included patients from the 1960s. Few population-based investigations have quantified CVD mortality during, shortly after, and for two decades after TC diagnosis in the era of cisplatin-based chemotherapy.

PATIENTS AND METHODS

Standardized mortality ratios (SMRs) for CVD and absolute excess risks (AERs; number of excess deaths per 10,000 person-years) were calculated for 15,006 patients with testicular nonseminoma reported to the population-based Surveillance, Epidemiology, and End Results program (1980 to 2010) who initially received chemotherapy (n=6,909) or surgery (n=8,097) without radiotherapy and accrued 60,065 and 81,227 person-years of follow-up, respectively. Multivariable modeling evaluated effects of age, treatment, extent of disease, and other factors on CVD mortality.

RESULTS

Significantly increased CVD mortality occurred after chemotherapy (SMR, 1.36; 95% CI, 1.03 to 1.78; n=54) but not surgery (SMR, 0.81; 95% CI, 0.60 to 1.07; n=50). Significant excess deaths after chemotherapy were restricted to the first year after TC diagnosis (SMR, 5.31; AER, 13.90; n=11) and included cerebrovascular disease (SMR, 21.72; AER, 7.43; n=5) and heart disease (SMR, 3.45; AER, 6.64; n=6). In multivariable analyses, increased CVD mortality after chemotherapy was confined to the first year after TC diagnosis (hazard ratio, 4.86; 95% CI, 1.25 to 32.08); distant disease (P<.05) and older age at diagnosis (P<.01) were independent risk factors.

CONCLUSION

This is the first population-based study, to our knowledge, to quantify short- and long-term CVD mortality after TC diagnosis. The increased short-term risk of CVD deaths should be further explored in analytic studies that enumerate incident events and can serve to develop comprehensive evidence-based approaches for risk stratification and application of preventive and interventional efforts.

Abstract 4041: IQGAP1 in human acutae myelogenous leukemia

Background: AML is phenotypically diverse. However, genome-wide sequencing studies indicate that median number of non-synonymous mutations in AML is 8 (B Vogelstein Science 2013) and that the same pathways are affected in tumors with distinct genetic alterations. These insights provided the impetus to confirm and extend the previously published observation that immunization with normal human white blood cells (WBC) whose surface charge had been modified in vitro by incubation with fluorodinitrobenzene (FDNB) elicited an antibody response that cross-reacted against a broad range of leukemias (Nature 232:197-198,1971).

Specific Aims: 1) Isolation and molecular characterization of a shared antigenic moiety from human AML, 2) Examine the prevalence- and role in AML of IQGAP1, which was identified as a shared antigenic moiety.

Methods: WBCs from healthy donors were incubated with FDNB at 104 molecules/cell for 12-15 minutes in PBS. Three rabbits were immunized with FDNB-treated cells (experimental rabbits). A control rabbit was immunized with sham-treated cells. After complement inactivation, immune sera were absorbed against WBCs from healthy donors. Absorbed immune sera were tested for their ability to stain AML cell lines by flow cytometry and clinical AML samples by Western blotting. Immunoprecipitation of antigens from whole cell lysates of clinical AML samples was done using IgG adsorbed on protein A/G Agarose beads. Liquid chromatography and mass spectrometry of the immuneprecipitated material was performed. Fold change in IQGAP1 expression in normal vs AML bone marrow was determined from raw data from Gene Expression Omnibus at the NCBI using Partek Genomic Suite. IQGAP1 expression was knocked down by shRNA and the effect on proliferation and colony formation was measured.

Results: Sera from experimental rabbits stained AML cell lines with greater intensity by flow cytometry compared to serum from the control rabbit. Western blotting of whole cell lysates of clinical AML samples revealed bands that were recognized by immune serum from experimental rabbits but not the control rabbit. Immunoprecipitation of antigens from whole cell lysates of clinical AML samples revealed IQGAP1 as being differentially recognized in independent experiments. Western blots of human AML samples probed with anti-IQGAP1 antibody revealed the predicted 190 kDa band. The fold change in IQGAP1 expression in normal bone marrow versus AML was -3.22636, p-value 2.62 × 10e-7. Knocking down expression of IQGAP1 in K562, MV4-11 and THP1 cell lines resulted in significant decrease in proliferation and colony formation.

Conclusion and Future Directions: IQGAP1 was identified as a shared antigenic moiety in. IQGAP1 is over-expressed in AML compared to normal bone marrow. Knocking down IQGAP1 expression in AML cell lines decreased proliferation and colony formation. Experiments to determine the mechanistic basis of the effect of FDNB on cells and if IQGAP1 is “druggable” are underway.

Citation Format: Deepak M. Sahasrabudhe, Jeremy Bechelli, Fred P. Hagen, Mark Paris, Marlene Balys, Mohammad Minhajuddin, Jane Liesveld. IQGAP1 in human acutae myelogenous leukemia. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4041. doi:10.1158/1538-7445.AM2015-4041

Cardiovascular disease (CVD) risk factors among cisplatin-treated testicular cancer survivors (TCS): A multicenter clinical study of U.S. and Canadian patients

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Background: The remarkable success of cisplatin-based chemotherapy in curing metastatic TC has been accompanied by potential life-threatening sequelae, including CVD. Most prior studies, however, have been conducted in Europe and included older chemotherapy regimens. We examined CVD risk factors in an ongoing multi-center clinical study of TCS given modern cisplatin-based chemotherapy (CHEM) at centers in North America (NCI 1R01 CA157823-02). Methods: TCS aged ≤49 years at time of first-line CHEM were eligible to undergo clinical examination and complete a questionnaire regarding co-morbidities, lifestyle behaviors, and prescription drug use. Results: We evaluated the first 443 consecutively enrolled TCS (23% seminoma; 77% nonseminoma) with most having stage II (52%) or III (28%) disease. The median age at time of TC diagnosis was 32 years (range 15-49 years) and median time since completion of chemotherapy was 59 months (range 1-24 years). Patients were largely white (90%), married (62%), and had full-time employment (82%) and health insurance (88%). 8% of TCS were current smokers. 48% of TCS had gained >10 lbs after CHEM with 29% having a ≥102 cm (40 inch) waist circumference, and 43% and 31% having a body mass index of 25 to <30 kg/m2 (overweight) and ≥ 30 kg/m2 (obese), respectively. A sizable proportion of men had abnormal systolic (21% with 130-139 mm Hg and 17% with ≥140 mm Hg) and diastolic (35% with 80-89 mm Hg and 13% with ≥90 mm Hg) blood pressure. 14%, 11%, and 5% TCS indicated that they currently used medications for hypertension, cholesterol and diabetes, respectively. Cardiac conditions were reported by 32 TCS (7%), including angina (N=2), angioplasty/stent placement (N=1), myocardial infarction (N=1), transient ischemic attack (N=1), stroke (N=2), peripheral vascular disease (N=12), deep vein thrombosis (N=23), and pulmonary embolism (N=15). Conclusions: A number ofCVD risk factors are present in a contemporary North American cohort of TCS after CHEM. Future analytic studies should focus on mechanistic investigations to facilitate the development of screening and preventive efforts for CVD in high-risk patients.

Impact of bladder cancer on health related quality of life in 1,476 older Americans: a cross-sectional study

PURPOSE

The impact of bladder cancer diagnosis on health related quality of life is poorly understood. We compared health related quality of life measures in patients before and after bladder cancer diagnosis.

MATERIALS AND METHODS

We performed a cross-sectional study in 1,476 patients 65 years old or older with bladder cancer in the SEER-MHOS linkage database between 1998 and 2007 to assess differences in physical and mental component summary scores in 620 and 856 who completed a survey before and after bladder cancer diagnosis, respectively. To determine differences in physical and mental scores in the prediagnosis and post-diagnosis cohorts, we used ANOVA adjusting for baseline covariates.

RESULTS

There were statistically significant differences in physical and mental component summary scores between the prediagnosis and post-diagnosis groups (-2.7, 95% CI -3.8, -1.7 vs -1.4, 95% CI -2.6, -0.3). In patients with nonmuscle invasive bladder cancer the physical and mental score differences were -1.9 (p <0.01) and -1.4 (p = 0.01), respectively. In those with muscle invasive bladder cancer there was a statistically and clinically significant difference in the physical but not the mental score (-5.3, p <0.01 vs -2.7, p = 0.07). This difference in the physical domain persisted up to 10 years after the diagnosis of muscle invasive bladder cancer. Patients with bladder cancer who had 4 or more comorbid medical conditions and 1 or more deficits in daily living activity were most at risk for low physical component summary scores.

CONCLUSIONS

Future research into interventions to improve health related quality of life and methods to incorporate health related quality of life into decision making models are critical to improve outcomes in older patients with bladder cancer.

A case series of transformation of teratoma to primitive neuroectodermal tumor: evolving management of a rare malignancy

Primitive neuroectodermal tumor (PNET) is a pathologic diagnosis that encompasses several different tumor types, including central nervous system tumors and Ewing’s sarcomas. Teratoma, a common element of germ cell tumor (GCT), has the ability to transform to malignant PNET in a small number of patients. Making a definitive diagnosis of PNET is difficult given its deviation from elements of GCT and its non-specific pathologic findings. Establishing the diagnosis is crucial as PNETs respond poorly to standard platinum-based chemotherapy used for treatment of GCT. Primary treatment for PNET is surgical, though this is often not feasible in many patients due to extensive disease at diagnosis. As an alternative, chemotherapy regimens traditionally used for Ewing’s sarcoma, such as vincristine, doxorubicin and cyclophosphamide alternating with ifosfamide and etoposide, have shown limited efficacy in the neoadjuvant, adjuvant, and palliative settings. Future research should delineate the genetic underpinnings of PNET and develop therapeutic options accordingly.

Changes in health-related quality of life (HRQL) after bladder cancer (BC) diagnosis (DX): A longitudinal population-based study

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Background: Few studies have examined longitudinal changes in HRQL among BC patients. To our knowledge, this is the largest prospective population-based study to quantify HRQL changes from before to after BC DX and to compare their HRQL with a non-cancer cohort. Methods: Our sample included 179 BC patients (≥ age 65) and 376,986 non-cancer subjects within the SEER-Medicare Health Outcomes Survey database (1998-2007). We assessed HRQL as measured by physical (PCS) and mental (MCS) component summary scores of the veterans RAND 12-item health survey. An analysis of covariance model was used to estimate changes in HRQL scores for patients after BC DX relative to control subjects with adjustment for baseline HRQL scores and covariates. Results: 84.4% (N=151) of BC patients had non-muscle invasive BC (NMIBC) and 15.6% (N=28) had muscle invasive BC (MIBC). 49.2% and 39.1% of BC patients had ≥2 comorbid conditions and ≥1 activities of daily living (ADL) deficit, respectively. Compared to the control subjects, more BC patients were men (67.0% vs 38.5%; P<0.01), current or former smokers (58.7% vs 37.3%; P<0.01), and had income ≥ $50,000(15.1% vs 8.8%; P=0.02). Other baseline demographic and socioeconomic characteristics were similar (P>0.05). After DX, BC patients reported a significant decline in PCS (1.9; 95% CI 0.1, 3.7) score compared to non-cancer controls whereas the decrease in MCS score (1.4; 95% CI -0.1, 3.0) was not statistically significant. For those with NMIBC, HRQL was not significantly different than that of the non-cancer cohort (P>0.05) after DX. However, the PCS and MCS scores of MIBC patients decreased by 5.3 (95% CI 0.9, 9.8) and 3.8 points (95% CI -0.1, 7.7) after DX, respectively. Older age at BC DX, lower educational and income levels, smoking history, and higher numbers of comorbid conditions and ADL deficits were significantly associated with inferior PCS and MCS scores after BC DX (P<0.01). Conclusions: Treatment-related side effects and/or symptoms due to BC adversely affect HRQL of BC patients, especially in those with MIBC, and should be consistently assessed by health care providers. Future research that examines interventions to improve HRQL is critical to improve BC care.

Impact of bladder cancer (BC) on health-related quality of life (HRQL) in 1,476 older Americans

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Background: The impact of BC on HRQL is poorly understood. To our knowledge, this is the first and largest cross-sectional study that compares HRQL of patients before and after BC diagnosis (DX). Methods: Our sample included 1,476 BC patients (≥ age 65) within the SEER-Medicare Health Outcomes Survey linkage database (1998-2007). We assessed differences in HRQL as measured by SF-36 physical (PCS) and mental (MCS) summary scores in patients who had a survey >1 yr before BC DX (n=620) and those who had a survey after BC DX (n=856). We compared groups by year from BC DX using regression analyses and results were adjusted for cancer stage, race, gender, age at BC DX, marital status, education, income, smoking status, activity of daily living (ADLs), and non-cancer comorbidities. Results: Patients who had a survey after BC DX were diagnosed with BC at an older age than those with a survey before BC DX (55.9% at age ≥75 yr vs. 36.8%; P<0.01). Other baseline demographic and socioeconomic characteristics were similar. Baseline HRQL were poor in patients before DX (PCS mean=40.1; MCS mean=51.1) with 50.6% and 31.9% of them having comorbidity score ≥2 and impairment of ≥1 ADLs, respectively. After BC DX, significant decreases in PCS (-2.7; 95% CI -3.8,-1.7) and MCS (-1.4; 95% CI -2.6, -0.3) were observed, with HRQL being lowest in those who had BC DX within 1 yr (PCS mean= 36.6; MCS mean=49.7). Declines in PCS during the <1, 1-3, 3-5, 5-10, and 10+ yr periods after BC DX compared to before BC DX were -3.8 (P<0.01), -2.5 (P<0.01), -2.2 (P=0.01), -1.1 (P=0.19) and -0.8 (P=0.57) whereas decreases in MCS were -2.0 (P=0.01), -2.2 (P<0.01), -1.2 (P=0.21), -0.1 (P=0.92), -0.8 (P=0.62) respectively. More advanced BC, lower educational level, higher comorbidity score, and impaired ADLs were significantly associated with both worse PCS and MCS after BC DX (P<0.05). Lower income and older age at BC DX showed significant association with low PCS (P<0.05). Conclusions: Older BC patients are a vulnerable population with poor baseline HRQL. HRQL of patients after BC DX is significantly worse than HRQL of patients before DX, possibly due to therapy and/or disease progression. Future research that evaluates interventions to improve HRQL in older patients with BC is critical.

Abstract 4122: Ras GTPase activating like protein (IQGAP1) in human acute myelogenous leukemia

Background and Significance: Prognosis of acute myelogenous leukemia in patients over the age of 60 is poor. Recent recognition that the process of transformation utilizes a limited number of common pathways as decsribed by Hanahan and Weinberg provided the impetus to validating and extending previously published observation that immunization with normal human white blood cells (WBC) whose surface charge had been modified in vitro elicited an antibody response that cross-reacted against a broad range of leukemias (MB Sahasrabudhe Nature 1971).

Specific Aim: Isolation and molecular characterization of a shared antigenic moiety from human leukemia cells.

Methods: Peripheral blood was collected from healthy volunteers in ACD tubes. Red blood cells were removed by dextran sedimentation and hypotonic shock lysis. The WBCs were incubated with fluorodinitrobenzene (FDNB) at 104 molecules per cell for 12-15 minutes at room temperature. Three rabbits were immunized with FDNB-treated cells. A control rabbit was immunized with sham-treated cells. Immune sera were collected and complement was inactivated. The sera were absorbed against untreated WBCs from normal healthy donors. Absorbed immune sera were tested against leukemia cells lines (agglutination and flowcytometry) and clinical leukemia samples by Western blotting after SDS-PAGE. Antigens from whole cell lysates and membrane prep were immunoprecipitated using IgG adsorbed on protein A/G agarose beads. Liquid chromatography and mass spectrometry (LC-MS) analysis of the immunoprecipitated was performed.

Results: Sera from experimental rabbits immunized with modified WBCs agglutinated leukemia cell lines (titers 1:256 to 512) whereas serum from the rabbit immunized with untreated WBCs did not. Sera from experimental rabbits also showed greater intensity of staining of leukemia cell lines by flowcytometry. Western blots of whole cell lysates and membrane preps from clinical acute myelogenous leukemia samples and normal bone marrow were probed with pre-immune serum and immune sera from the control rabbit as well as one of the experimental rabbits. Several bands recognized by the serum from experimental rabbits, immunized with FDNB-treated WBCs, but not by serum from control rabbit, immunized with sham-treated WBCs. LC-MS of the immunoprecipitated material revealed IQGAP1 and major vault transporter proteins as being differentially recognized.

Conclusion and Future Directions: Immunization of rabbits with normal peripheral blood WBCs that had been incubated with nanogram quantities of FDNB elicited an antibody response that identified IQGAP1 and major vault transporter proteins as shared feature in human acute myelogenous leukemias. Investigation of the role of IQGAP1, a critical regulator of multiple cellular functions, in human acute myelogenous leukemia will be undertaken.

Citation Format: Deepak M. Sahasrabudhe, Jeremy Bechelli. Ras GTPase activating like protein (IQGAP1) in human acute myelogenous leukemia. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4122. doi:10.1158/1538-7445.AM2013-4122

Characteristics and outcomes of elderly patients with systemic prostate cancer (PCa) treated with peripheral androgen blockade (PAB)

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Background: The side effect profile of androgen deprivation (ADT) warrants exploration of alternative options for elderly patients with systemic PCa. In phase 2 trials, the combination of anti-androgen and 5 alpha reductase inhibitor (PAB) demonstrated efficacy with low morbidity in the fit population. The objective of this retrospective study was to evaluate the characteristics and outcomes of elderly patients treated with PAB in lieu of ADT. Methods: We reviewed records of patients ≥65 yrs who received PAB in the geriatric oncology program from 2007-2012. Patients were evaluated with a validated comprehensive geriatric assessment (CGA) prior to PAB. Descriptive statistics were used to evaluate PAB type, characteristics of patients and their cancers, as well as PCa –specific and overall outcomes Results: Twenty-one asymptomatic PCa patients received PAB (bicalutamide alone-57%, or bicalutamide and finasteride-43%) in lieu of ADT. Indications for treatment were metastatic disease (53%) or biochemical relapse with PSA doubling time≤ 6 months (47%). Median age at the initiation of PAB was 86 years (range 65-94) and 76 % had ECOG PS≥ 2. By CGA, 57 % were vulnerable, 33% frail and 10% fit. 76% had contraindications for standard ADT (e.g., dementia, falls, etc.); the rest declined ADT due to concern about adverse effects (AE). The median PSA at PAB initiation was 14.78 (range 0.9-165.8). PSA nadir (i.e. 1st of 3 consecutive PSA levels where values were within 90%) was reached in 57% of patients at the time of analysis with the remainder demonstrating a continuing decline. Median PSA at nadir was 0.86(range 0.02-11.24). The median follow up time was 11 months (range 1-30). The median time to PSA nadir was 5 months; (range 1-19). PSA nadir was maintained for median of 10.5 months (range 3-24).The median % decline in PSA was 92 % (range 13-99%).No patients reported AE or required treatment interruption. Two fit patients of the 4 who progressed on PAB responded to subsequent ADT. Conclusions: These results provide evidence that PAB is feasible, active and well tolerated in patients for whom ADT may be contraindicated. A prospective phase II study for an older vulnerable patient population is planned.

C35: A new prognostic tool and potential target in prostate cancer

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Background: Identification and validation of biomarkers can help prognosticate patients and potentially serve as therapeutic targets. C35, a protein encoded by novel gene C17orf37 is located on 17q12 “the hotspot of cancer”. Dasgupta et al. (Oncogene 2009) noted higher expression of C35 in prostate cancer cell lines as compared to minimal expression in normal prostate cells. Furthermore, over expression of C35 enhanced motility and invasion. We hypothesized that C35 expression would correlate with other markers of aggressive clinical behavior and tested this by studying C35 expression in tissue microarrays (TMAs). Methods: TMAs were constructed using tissue samples obtained from normal organs including prostate, primary prostate cancers and prostate cancer from various metastatic sites. The TMAs had triplicates of each specimen which was then stained with rabbit polyclonal anti -C35 antibody. Each sample was scored based on the product of intensity (0-3) and distribution (0-4) of staining, with the maximum score being 12. A blinded review of the final scores and Gleason’s sum were independently conducted by a pathologist. Results: The C35 expression scores were higher in primary prostate cancer compared to benign prostate tissue. The average expression scores increased with increasing Gleason sum. Prostate cancer specimens from the metastatic sites had significantly lower expression scores when compared with the primary prostate cancer specimens. There was minimal to no expression in other normal organs. All these differences were statistically significant (p<0.001). The protein was predominantly cytosolic with membrane localization. Distributions of expression scores according to specimen type are summarized below. Conclusions: C35 expression directly correlates with Gleason sum, a validated prognostic marker. C35 may be a potential target for therapeutic agents. Further studies are needed to determine if increased expression of C35 in normal prostate can predict future development of prostate cancer. [Table: see text]

Serum proteomics and ingenuity pathway analysis (IPA)-guided discovery of response markers to androgen ablation (AA) in prostate cancer

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Background: Currently there are no serum markers of response to AA. We performed a proteome based analysis of serum from prostate cancer patients, followed by mapping of candidate markers to networks based on known molecular interactions in Ingenuity Knowledge Base (IKB). Methods: Isobaric mass tags for relative and absolute quanititation (iTRAQ) analyzed by reverse-phase liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) was performed in serum of 3 non-localized prostate cancer cohorts. The first cohort included 15 paired untreated hormone-sensitive “pre AA” and 3-month “post AA” specimens; the second included 10 “early AA failure” (median failure time: 11 months) and the third included 10 “late AA failure” specimens (median failure time: 95 months). Differentially expressed candidate proteins were identified by comparisons of (i) paired pre/post AA proteomes and (ii) post AA proteome with the combined AA failure cohorts at a False Discovery Rate of 0.2. To facilitate biological interpretation of multiple candidates identified in the comparisons, IPA was used. Candidate markers implicated in IPA networks with statistical significance were pursued in a second, independent patient cohort for association with time to AA failure using univariate Cox regression analysis. Results: Median PSA for pre/post AA first cohort were 3.15 and 0.29 ng/ml. Median PSA for the second and third cohorts were 27.3 and 4.3 ng/ml. Between post AA and AA failure cohorts, 149 proteins were differentially expressed. Between early and late AA failure 98 proteins were differentially expressed; 47 proteins were common in both comparisons. Network enrichment analysis of the 47 proteins by IPA identified four interaction networks (p<0.01), one of which highlighted a role for 17-β-estradiol (E1). Gas chromatography used for measuring 3-month post AA initiation serum E1, estrone (E2) and testosterone levels (N=38) detected high E1, E2 levels associated with longer time to AA failure (P=0.07 for E1; P=0.08 for E2) in the independent cohort. Conclusions: A global proteomic analysis identified post AA initiation serum E1, E2 levels as potential response markers, which needs validation.

An observational study of plasma vascular endothelial growth factors (VEGF) A and D expression in non-localized prostate cancer

BACKGROUND

The aim of the study was to measure plasma levels of the vascular endothelial growth factors (VEGF) A and D in serially collected blood specimens from non-localized prostate cancer (PCa) subjects.

METHODS

Plasma VEGF A and D levels were measured in two serial specimens 3-6 months apart in two groups of non-localized stage PCa patients. Group 1 was comprised of patients with biochemical relapse after localized PCa treatments and/or patients with clinically metastatic hormone-sensitive stage PCa prior to receiving hormonal therapy. Group 2 included patients failing hormonal therapy for non-localized hormone-sensitive stage PCa. VEGF A and D levels were compared within each cancer group between the two time-points using the Wilcoxon Rank Sum test.

RESULTS

At the first time-point in Group 1 (n = 46), median VEGF-A and D levels were measured at 5.2 (pg/ml) (range = 0-97) and 319 (range = 172-780) (pg/ml). For Group 2 (n = 34) VEGF-A level was 9.6 pg/ml (range = 0-78) and VEGF-D level was 377 pg/ml (range = 243-989) for the first measurement. Median time-period for the serial second specimen was 189 days in Group 1 and 84 days in Group 2. At the second time-point, in Group 1, VEGF-A levels were 0.0 pg/ml (P = 0.0002) while VEGF-D increased to 349 pg/ml (P = 0.002). For Group 2 patients at the second time-point, median VEGF-A was 0.0 pg/ml (P = 1.0) and VEGF-D was measured at 442 pg/ml (P = 0.008).

CONCLUSIONS

Higher plasma VEGF-D than VEGF-A expression in advanced PCa stages suggests a greater role for VEGF-D dependent lymph angiogenesis in advanced stage PCa, which needs further evaluation.

Germline predictors of androgen deprivation therapy response in advanced prostate cancer

OBJECTIVE

To evaluate whether germline variations in genes involved in sex steroid biosynthesis and metabolic pathways predict time to treatment failure for patients with advanced prostate cancer undergoing androgen deprivation therapy (ADT), because there are few known clinical predictors of response.

PATIENTS AND METHODS

In a cohort of 304 patients with advanced prostate cancer undergoing ADT, we genotyped 746 single-nucleotide polymorphisms (SNPs) from 72 genes from germline DNA (680 tagSNPs from 58 genes and 66 candidate SNPs from 20 genes [6 genes common in both]). Association with the primary end point of time to ADT failure was assessed using proportional hazards regression models at the gene level (for genes with tagging SNPs) and at the SNP level. False discovery rates (FDRs) of 0.10 or less were considered noteworthy to account for multiple testing.

RESULTS

At the gene level, TRMT11 showed the strongest association with time to ADT failure (P<.001; FDR=0.008). Two of 4 TRMT11 tagSNPs were associated with time to ADT failure. Median time to ADT failure for rs1268121 (A>G) was 3.05 years for the AA, 4.27 years for the AG, and 6.22 years for the GG genotypes (P=.002), and for rs6900796 (G>A), it was 2.42 years for the GG, 3.52 years for the AG, and 4.18 years for the AA genotypes (P<.001). No other gene level or SNP level tests had an FDR of 0.10 or less.

CONCLUSION

Genetic variation in TRMT11 was associated with time to ADT failure. Confirmation of these preliminary findings in an independent cohort is needed.

Serum proteomics guided discovery of predictive biomarkers of response to androgen ablation (AA) in prostate cancer

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Background: Currently there are no serum predictive markers of response to AA. We used a proteomic based analytic approach to identify candidates.

Methods: Serum from three non-localized prostate cancer cohorts was analyzed. The first included15 paired untreated hormone-sensitive “pre-AA” and 3-month “post-AA” specimens; the second included 10 “early AA failure” (median time to AA failure:11 months) and the third included 10 “late AA failure” specimens (median time to AA failure: 95 months). Proteomic analysis was performed with isobaric mass tags for relative and absolute quanititation (iTRAQ) analyzed by reverse-phase liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS). Differentially expressed candidate proteins were identified by comparisons of (i) paired pre/post-AA proteomes and (ii) post-AA proteome with the combined AA failure cohorts at a False Discovery Rate of 0.2. ELISA assays were used to verify candidate markers in a second stored aliquot of first cohort specimens. This cohort was followed for AA failure. Association of post-AA ELISA levels of candidate markers with time to AA failure was performed using Cox proportional hazards regression, summarized as relative risk (RR) for AA failure.

Results: Median PSA in pre/post-AA first cohort were 3.15 ng/ml and 0.29 ng/ml. Median PSA in the second and third cohorts were 27.3 and 4.3 ng/ml. Between post-AA and AA failure cohorts, 149 proteins were differentially expressed. Between early and late AA failure 98 proteins were differentially expressed; 47 proteins were common in both comparisons. ELISA assays verified expression levels of 2/47 proteins in the first cohort; zinc alpha-2 macroglobulin (ZAG), and Neuropilin-2 (NPL2). Median change in ZAG decreased by 2073.5 ng/ml (post versus pre-AA) while median change in NPL2 levels increased by 2.9 ng/ml. After a median follow-up of 43 months from the post-AA time-point, 4/15 first cohort subjects had failed AA. The RR of AA failure for ZAG levels below the median change was 3.8 (95% CI: 0.4-37) and 3.0 (95% CI: 0.3-29) for NPL2.

Conclusions: A global proteomic analysis identified ZAG and NPL2 as candidate serum predictive markers of AA response which needs further validation.

Individualized strategy for dosing luteinizing hormone-releasing hormone agonists for androgen-independent prostate cancer: identification of outcomes and costs

PURPOSE

Continuing androgen suppression is the current standard in men with androgen-independent prostate cancer (AIPC). An individualized strategy, wherein luteinizing hormone-releasing hormone agonists (LH-RHas) are redosed when serum testosterone approaches a non-castrate level, may decrease costs without worsening outcomes. To understand possible outcomes, we performed a cost-utility analysis comparing individualized and fixed LH-RHa dosing strategies in men with AIPC.

METHODS

The model used a societal perspective, a 5-year time horizon, and 3% annual cost discounting. The model accounted for direct costs of androgen suppression. Utilities were varied in accordance with published preference data.

RESULTS

Under base-case assumptions, individualized LH-RHa dosing yielded 1.089 expected quality-adjusted life years (QALYs), compared with 1.094 expected QALYs for fixed LH-RHa dosing. In cost analysis, lifetime per-patient costs for androgen suppression were estimated to be $5,694 for individualized LH-RHa dosing and $9,157 for fixed LH-RHa dosing. Applied to the total population, a strategy of individualized LH-RHa dosing would cost $170 million for androgen suppression, compared with $274 million for fixed LH-RHa dosing. Under these assumptions, adopting the individualized strategy resulted in $692,600 gained from a societal perspective for each QALY lost (the decremental cost utility).

CONCLUSION

The results suggest that an individualized LH-RHa dosing strategy would be associated with moderate savings on an individual basis but substantial savings on a population basis, and would not adversely affect quality of life or life expectancy. Further research is needed to establish the effects of this strategy on symptoms and survival, as well as patient satisfaction and true costs.

C35 (C17orf37) is a novel tumor biomarker abundantly expressed in breast cancer

Identification of shared tumor-specific targets is useful in developing broadly applicable therapies. In a study designed to identify genes up-regulated in breast cancer, a cDNA clone corresponding to a novel gene C35 (C17orf37) was selected by representational difference analysis of tumor and normal human mammary cell lines. Abundant expression of C35 transcript in tumors was confirmed by Northern blot and real-time PCR. The C35 gene is located on chromosome 17q12, 505 nucleotides from the 3' end of the ERBB2 oncogene, the antigenic target for trastuzumab (Herceptin) therapy. The chromosomal arrangement of the genes encoding C35 and ERBB2 is tail to tail. An open reading frame encodes a 12-kDa protein of unknown function. Immunohistochemical analysis detected robust and frequent expression of C35 protein, including 32% of grade 1 and 66% of grades 2 and 3 infiltrating ductal carcinomas of the breast (in contrast to 20% overexpressing HER-2/neu), 38% of infiltrating lobular carcinoma (typically HER-2/neu negative), as well as tumors arising in other tissues. C35 was not detected in 38 different normal human tissues, except Leydig cells in the testes and trace levels in a small percentage of normal breast tissue samples. The distinct and favorable expression profile of C35 spanning early through late stages of disease, including high frequency of overexpression in various breast carcinoma, abundant expression in distant metastases, and either absence or low level expression in normal human tissues, warrants further investigation of the relevance of C35 as a biomarker and/or a target for development of broadly applicable cancer-specific therapies.

The influence of host response on colorectal cancer prognosis

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide. Several tumor characteristics have been shown to be of prognostic significance, although stage at diagnosis continues to be the most important predictor of survival. Emerging new data suggest that the presence of a host response to CRC may also influence survival and other outcomes in CRC. This review summarizes recent evidence regarding the prognostic significance of the host response to CRC. In retrospective analyses, tumor-associated macrophages and tumor-infiltrating lymphocytes appear to be the elements most significantly associated with improved outcomes in CRC. The presence of other cells, including dendritic cells, natural killer cells, eosinophils, and mast cells, also appears to be associated with increased survival. The influence of the host response to CRC needs confirmation in prospective studies, but in the meantime should be part of risk stratification. Novel approaches to further augmenting this response merit study.

Pilot study using gabapentin for tamoxifen-induced hot flashes in women with breast cancer

In this pilot study, 22 women with breast cancer on tamoxifen therapy with at least two hot flashes a day took oral gabapentin at 300 mg three times a day for 4 weeks. The 16 women who completed the study had a mean decrease in hot flash duration of 73.6% (P = 0.027), frequency of 44.2% (P < 0.001), and severity of 52.6% (P < 0.001), with a complete response in 8/16 women. Side effects reported by four women who did not complete 4 weeks of the study were nausea (1/4), rash (1/4) and excessive sleepiness (3/4). Two additional patients did not provide complete data. Gabapentin is a promising new agent in the treatment of tamoxifen induced hot flashes, and should be studied further.

A phase I trial of immunotherapy with intratumoral adenovirus-interferon-gamma (TG1041) in patients with malignant melanoma

AIMS

Interferon-gamma (IFN-gamma) has been shown to upregulate MHC class I and II expression, and to promote generation of specific antitumor immune responses. We hypothesized that intratumoral administration of an IFN-gamma gene transfer vector facilitates its enhanced local production and may activate effector cells locally. We conducted a phase I dose-escalation study of a replication-deficient adenovirus-interferon-gamma construct (TG1041) to determine safety and tolerability of intratumoral administration, in advanced or locally recurrent melanoma.

METHODS

Patients were enrolled at four successive dose levels: 10(7) infectious units (iu) (n=3), 10(8) iu (n=3), 10(9) iu (n=3), and 10(10) iu (n=2) per injection per week for 3 weeks. TG1041 was injected in the same tumor nodule weekly in each patient. Safety, toxicity, local and distant tumor responses and biologic correlates were evaluated.

RESULTS

A total of 11 patients were enrolled and received the planned three injections per cycle. One patient with stable disease received a second cycle of treatment. A maximum tolerated dose was not reached in this study. No grade 4 toxicities were observed. Two grade 3 toxicities, fever and deep venous thrombosis were observed in one patient. The most frequently reported toxicities were grade 1 pain and redness at the injected site (n=8), and grade 1 fatigue (n=5) patients. Clinical changes observed at the local injected tumor site included erythema (n=5), a minor decrease in size of the injected lesion (n=5) and significant central necrosis by histopathology (n=1). Systemic effects included stable disease in one patient. Correlative studies did not reveal evidence of immunologic activity.

CONCLUSION

Weekly intratumoral administration of TG1041 appears to be safe and well tolerated in patients with advanced melanoma.

Vascular endothelial growth factor, CD68, and epidermal growth factor receptor expression and survival in patients with Stage II and Stage III colon carcinoma: a role for the host response in prognosis

BACKGROUND

The elucidation of new therapeutic targets of prognostic significance in colon carcinoma is necessary to improve outcomes. In the current study, the authors examined the expression of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) in primary colon carcinoma cases and VEGF in tumor-associated macrophages (TAM)/stroma, and their correlation with survival.

METHODS

The authors identified 131 consecutive American Joint Committee on Cancer Stage II and Stage III colon carcinoma patients seen at the University of Rochester between 1990-1995. Expression of VEGF, EGFR, and CD68 were examined by immunohistochemistry in paraffin-embedded primary colon tumors and graded as the percentage of cells stained. Data were analyzed using a multivariate Cox proportional hazards model.

RESULTS

VEGF expression in tumor was not found to be significantly associated with survival. However, 42% of the patients expressed VEGF in TAM/stroma. The median survival in this group was 9.7 years versus 4.3 years in the VEGF-negative (TAM/stroma) group (hazards ratio of 0.57, 95% confidence interval [95% CI], 0.34-0.95; P = 0.03). Although TAM infiltration alone was not found to be significant in multivariate analysis, the presence of both CD68 and VEGF (TAM/stroma) was predictive of improved survival (hazards ratio of 0.48, 95% CI, 0.28-0.83; P = 0.006). High grades of EGFR expression (> or = Grade 2) were found to be associated with a trend toward worsened survival.

CONCLUSIONS

The greater than twofold increase in median survival associated with VEGF-expressing TAM suggests a hitherto unknown role for this subset of cells in the host response to colon carcinoma and requires further investigation. Overexpression of EGFR may be associated with worsened survival, providing a rationale for trials of anti-EGFR agents as adjuvant therapy.

Lethality-based selection of recombinant genes in mammalian cells: application to identifying tumor antigens

Many biological processes result in either cell death or cessation of cell growth. However, plasmid- and retrovirus-based mammalian expression vectors in which it has been possible to construct representative cDNA libraries cannot be readily recovered from cells that are not actively dividing. This has limited the efficiency of selection of recombinant genes that mediate either lytic events or growth arrest. Examples include genes that encode the target antigens of cytotoxic T cells, genes that promote stem-cell differentiation and pro-apoptotic genes. We have successfully constructed representative cDNA libraries in a poxvirus-based vector that can be recovered from cells that have undergone lethality-based selection. This strategy has been applied to selection of a gene that encodes a cytotoxic T-cell target antigen common to several independently derived tumors.

CD-20 expression in post-transplant lymphoproliferative disorders: treatment with rituximab

B-cell lymphoproliferative disorders are rare but serious complications of solid organ and bone marrow transplantation. We report that these tumors frequently express the CD-20 antigen, and immunotherapy directed at this antigen may be a well-tolerated and effective treatment.

Active specific immunotherapy for metastatic colorectal carcinoma: phase I study of an allogeneic cell vaccine plus low-dose interleukin-1 alpha

A vaccine consisting of four allogeneic colon carcinoma cell lines (DLD-1, HCT116, WiDr, and T84) mixed with the adjuvant DETOX (Mycobacterium phlei cell wall and Salmonella minnesota lipid A) was administered to 25 patients with low-volume metastatic colorectal carcinoma. The first eight patients received vaccine only, given intradermally on three occasions at 3-week intervals. Subsequent patients also received subcutaneous interleukin-1 alpha (IL-1 alpha), 0.3-0.5 microgram/m2 per day for 8 days after each vaccination in an outpatient setting. Vaccine alone caused local erythema, induration, and pruritus. IL-1 caused fevers, chills, and rigors that started in 4 h and lasted 1-2 h. One patient developed a brief loss of consciousness with a rigor that resolved without sequelae. One episode of mild hypotension occurred. Fatigue occurred by day 8 of IL-1. A substantial increase in the number of patients with positive skin tests to DLD-1 and HCT116 occurred after vaccine treatment both without and with IL-1 alpha. An allogeneic cell vaccine plus subcutaneous IL-1 was administered safely to outpatients with some evidence of in vivo effect observed.

Medical oncology and geriatric medicine: is it time for fellowship integration?

Although training programs exist in both medical oncology and geriatrics (approved by the American Board of Internal Medicine), neither is adequate to ensure an appropriate supply of physicians to assume a leadership role in the treatment of the increasing number of geriatric patients who have or will develop a malignancy. A proposal for offering a 3-4 year program leading to dual certification is under consideration. A careful review of both the medical oncology training program and added qualifications in geriatrics has identified key components of each that can serve as a basis for a combined program. Such a program can encourage research into behavior modification of existing biases in referring geriatric oncology patients for treatment as well as a better understanding of the biology of aging, addressing in particular the pharmacology of anticancer agents in this unique population. It is anticipated that pilot projects will be undertaken to develop common pathways for developing combined programs in medical oncology and geriatrics. The second phase will include recruitment of selected candidates who are interested in an academic career in geriatric oncology. A need for additional academic-based geriatric oncologists has been identified that can address the anticipated increase in the incidence and presence of cancer in an aging population. Such a cadre of specialists will be in an excellent position to recommend changes in the current (mostly negative) approach to the management of cancer in patients age > 65 years.

Effect of murine interferon alpha/beta on tumour-induced suppressor function

T-lymphocyte-mediated immunosuppression has been described in several animal models and in man. In animal models. T-cell-mediated immunosuppression can hasten the development of cancers, permit the growth of tumors in immunocompetent hosts, and inhibit otherwise effective antitumor immunotherapy. Cyclophosphamide can abrogate the T-cell-mediated immunosuppression. However, inappropriately administered cyclophosphamide can adversely affect antitumor immunity. On the basis of data showing that interferon alpha/beta (IFN alpha/beta) and IFN beta selectively abrogate the T-cell-mediated dinitrofluorobenzene-specific suppressor function, we investigated the efficacy of purified murine IFN alpha/beta in manipulating tumor-induced T-cell-mediated immunosuppression in the well-characterized P815 mastocytoma model. In this model, generation of cytotoxicity in vitro and its inhibition by T cells correlates with antitumor immunity in vivo. We report that IFN alpha/beta selectively diminishes the generation of tumor-induced suppressor activity.

Shared T cell-defined antigens on independently derived tumors

We report that a subset of tumors independently derived from a cloned line of contact-inhibited, non-tumorigenic murine fetal fibroblasts confer cross-protective immunity against each other in vivo. Concordant with the in vivo cross-protection, cytolytic T cell clones from mice immunized with one of these tumor lines specifically lyse the three other lines in the same set but do not cross-react with either the nontumorigenic parental line or another similarly derived tumor line representing a different antigenic profile. This and other recent evidence for shared expression of tumor rejection Ag contrasts with the antigenic diversity previously described for chemical- and radiation-induced tumors. In the interpretation of such data it is essential to distinguish between Ag expressed in association with the transformation process and Ag induced by random mutation of already transformed cells.

Shared T cell-defined antigens on independently derived tumors

We report that a subset of tumors independently derived from a cloned line of contact-inhibited, non-tumorigenic murine fetal fibroblasts confer cross-protective immunity against each other in vivo. Concordant with the in vivo cross-protection, cytolytic T cell clones from mice immunized with one of these tumor lines specifically lyse the three other lines in the same set but do not cross-react with either the nontumorigenic parental line or another similarly derived tumor line representing a different antigenic profile. This and other recent evidence for shared expression of tumor rejection Ag contrasts with the antigenic diversity previously described for chemical- and radiation-induced tumors. In the interpretation of such data it is essential to distinguish between Ag expressed in association with the transformation process and Ag induced by random mutation of already transformed cells.