Stem Cell Theory of Cancer: Implications for Translational Research from Bedside to Bench.

A stem cell theory of cancer considers genetic makeup in the proper cellular context. It is a unified theory of cancer that unites the genome with the epigenome, links the intracellular with the extracellular, and connects the cellular constituents and compartments with the microenvironment. Although it allies with genomic medicine, it is better aligned with integrated medicine. In this perspective, we focus on translational research in cancer care. We expose some intrinsic fallacies in translational research when it relates to the basic principles of the scientific method in the care of patients with genomic medicine versus integrated medicine. We postulate that genomic medicine may be at the root of many failed efforts in drug development and data reproducibility. We propose an alternate heuristic approach that may expedite the development of safe and effective treatments and minimize the generation of unproductive pharmaceutical products and nonreproducible experimental results. Importantly, a heuristic approach emphasizes the role of a pertinent scientific theory and distinguishes therapy development from drug development, such that we discover not only useful drugs but also better ways to use them in order to optimize patient care and maximize clinical outcomes.

Curing Cancer: Lessons from a Prototype.

Germ cell tumor of the testis (TGCT) is a remarkably curable solid tumor even when it is widely metastatic and patently heterogeneous. It provides invaluable clues about the origin and nature of metastasis and heterogeneity, cancer dormancy and late recurrence, drug sensitivity and resistance, tumor immunity, and spontaneous remission that would enable us to enhance the cure and improve the care of patients with other currently intractable solid tumors. After all, germ cells are primeval stem cells and TGCT are a perfect stem cell tumor for us to investigate a stem cell versus genetic origin of cancer. In many respects, TGCT is a prototype stem cell tumor that will enable us to elucidate the role of differentiation versus dedifferentiation in the evolution of a complex mixed tumor. It will help us decipher relevance of the genome versus the epi-genome in a progenitor cancer stem cell versus a progeny differentiated cancer cell. Importantly, clarification of a cellular context versus the genetic makeup in cancer has immense clinical implications. We postulate a unified theory of cancer derived from seminal TGCT research to improve personalized cancer care. Contrary to current norms and conventional wisdom, we propose that when it concerns a complex rather than simple cancer and a mixed rather than pure tumor (which is practically all solid tumors) multimodal therapy trumps targeted therapy and integrated medicine overrides precision medicine.

Intratumoral heterogeneity: Role of differentiation in a potentially lethal phenotype of testicular cancer.

BACKGROUND: Intratumoral heterogeneity presents a major obstacle to the widespread implementation of precision medicine. The authors assessed the origin of intratumoral heterogeneity in nonseminomatous germ cell tumor of the testis (NSGCT) and identified distinct tumor subtypes and a potentially lethal phenotype. METHODS: In this retrospective study, all consecutive patients who had been diagnosed with an NSGCT between January 2000 and December 2010 were evaluated. The histologic makeup of primary tumors and the clinical course of disease were determined for each patient. A Fine and Gray proportional hazards regression analysis was used to determine the prognostic risk factors, and the Gray test was used to detect differences in the cumulative incidence of cancer death. In a separate prospective study, next-generation sequencing was performed on tumor samples from 9 patients to identify any actionable mutations. RESULTS: Six hundred fifteen patients were included in this study. Multivariate analysis revealed that the presence of yolk sac tumor in the primary tumor (P = .0003) was associated with an unfavorable prognosis. NSGCT could be divided into 5 subgroups. Patients in the yolk sac-seminoma subgroup had the poorest clinical outcome (P = .0015). These tumors tended to undergo somatic transformation (P < .0001). Among the 9 NSGCTs that had a yolk sac tumor phenotype, no consistent gene mutation was detected. CONCLUSIONS: The current data suggest that intratumoral heterogeneity is caused in part by differentiation of pluripotent progenitor cells. Integrated or multimodal therapy may be effective at addressing intratumoral heterogeneity and treating distinct subtypes as well as a potentially lethal phenotype of NSGCT. Cancer 2016;122:1836-43. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

An assessment of quality of life following radical prostatectomy, high dose external beam radiation therapy and brachytherapy iodine implantation as monotherapies for localized prostate cancer.

PURPOSE: Monotherapy with radical prostatectomy, high dose external beam radiotherapy or a (125)I implant is reported to produce equivalent outcomes. We assessed the health related quality of life associated with these 3 treatment approaches. MATERIALS AND METHODS: Extended Prostate Index Composite surveys were mailed to all 960 patients treated with a (125)I implant, high dose external beam radiotherapy or radical prostatectomy with or without hormonal therapy at our institution from 1998 to 2000. A total of 625 patients (65%) completed the surveys. Nerve sparing radical prostatectomy was performed when appropriate. The (125)I implant consisted of 145 Gy and high dose external beam radiotherapy consisted of 78 Gy. For urinary, rectal and sexual domains mean scores were calculated, compared by treatment modality and compared to normative values. RESULTS: A total of 234 patients with radical prostatectomy, 135 with external beam radiotherapy and 74 with a (125)I implant were treated with a monotherapy approach. Median age was 61 years in the radical prostatectomy group, 68 years in the high dose external beam radiotherapy group and 64 years in the (125)I implant group (p <0.001). Of the patients 97% [corrected] had cT1-2 disease and Gleason score 7 or less [corrected] Median time from treatment was 4.0 years for radical prostatectomy, 4.7 years for high dose external beam radiotherapy and 3.5 years for (125)I implantation. Radiation caused significantly worse bowel bother and bowel function than radical prostatectomy (p < or =0.018). Patients with high dose external beam radiotherapy had significantly better urinary function than patients with radical prostatectomy (p <0.001). While patients with radical prostatectomy had significantly worse urinary incontinence than those with a (125)I implant or high dose external beam radiotherapy (p <0.0001), patients with a (125)I implant had more urinary irritation than those with high dose external beam radiotherapy and radical prostatectomy (p <0.01 and <0.0001, respectively). Patients with a (125)I implant had significantly better sexual function than those with high dose external beam radiotherapy and radical prostatectomy (p = 0.01 and 0.0003, respectively). CONCLUSIONS: Of patients with prostate cancer treated with a monotherapy approach we noted better urinary continence in those who underwent radiation based therapies, and better bowel function and less urinary irritation in those who underwent surgery. Sexual function was impaired across all monotherapies but higher scores were seen in men who selected brachytherapy.

Selenium accumulation in prostate tissue during a randomized, controlled short-term trial of l-selenomethionine: a Southwest Oncology Group Study.

PURPOSE: Epidemiologic and clinical data suggest that selenium could prevent prostate cancer, but it has not been shown that supplemental selenium leads to an increased concentration of selenium in prostate tissue compared with adjacent tissue. EXPERIMENTAL DESIGN: We conducted a randomized, controlled, short-term trial of l-selenomethionine (SeMet) versus observation in men with organ-confined prostate cancer. The primary endpoint was the measurement of selenium concentration in prostate tissue and seminal vesicle (SV). We assessed baseline selenium levels in serum and in toenail specimens (reflecting long-term intake) and post-intervention selenium levels in serum, and in prostate and SV tissues using hydride generation atomic fluorescence spectroscopy. RESULTS: Sixty-six eligible patients were randomly assigned to the SeMet (n = 34) or observation (n = 32) arm; both arms had similar baseline patient characteristics. Baseline serum selenium was similar in the two groups (P = 0.64). Baseline toenail selenium levels were slightly higher in the SeMet group than in the control group (P = 0.07). After the intervention, the mean serum selenium level increased 15% in the SeMet arm and was higher than in the observation arm (P = 0.001). The selenium concentration in prostate tissue was 22% higher in the SeMet arm (n = 26) than in the observation arm (n = 25; 1.80 versus 1.47 ppm; P = 0.003, Wilcoxon rank sum test) and remained significantly higher after adjusting for chronic selenium intake (P = 0.021, ANCOVA). SV selenium concentration was similar in both groups (P = 0.384) and was lower than in prostate tissue. CONCLUSIONS: The present study is the first to show that selenium taken as oral supplementation accumulates preferentially in the human prostate gland as opposed to the SV. These findings support the hypothesis that oral selenium supplementation may contribute to the cancer preventive effects of selenium.

Changes in serum proteomic patterns by presurgical alpha-tocopherol and L-selenomethionine supplementation in prostate cancer.

BACKGROUND: Evidence of the chemopreventive effects of the dietary antioxidants alpha-tocopherol (vitamin E) and l-selenomethionine (selenium) comes from secondary analysis of two phase III clinical trials that found treatment with these antioxidants reduced the incidence of prostate cancer. To determine the effects of selenium and vitamin E in blood and prostate tissue, we undertook a preoperative feasibility study complementary to the currently ongoing Selenium and Vitamin E Cancer Prevention Trial. METHODS: Forty-eight patients with clinically localized prostate cancer enrolled on this 2 x 2 factorial design study were randomized to take selenium, vitamin E, both, or placebo for 3 to 6 weeks before prostatectomy. Sera were collected from patients before and after dietary supplementation. Thirty-nine patients were evaluable, and 29 age-matched disease-free men served as controls. Mass profiling of lipophilic serum proteins of lower molecular weight (2-13.5 kDa) was conducted, and mass spectra data were analyzed using custom-designed software. RESULTS: Weighted voting analyses showed a change in sera classification from cancerous to healthy for some patients with prostate cancer after dietary intervention. ANOVA analysis showed significantly different treatment effects on prediction strength changes among the four groups at a 95% confidence level. Eliminating an outlying value and performing post hoc analysis using Fisher's least significant difference method showed that effects in the group treated with the combination were significantly different from those of the other groups. CONCLUSION: In sera from patients with prostate cancer, selenium and vitamin E combined induced statistically significant proteomic pattern changes associated with prostate cancer-free status.

Multimodality management of urachal carcinoma: the M. D. Anderson Cancer Center experience.

PURPOSE: Enteric type adenocarcinomas arising in the dome of the bladder or along the urachal ligament are uncommon. To improve our understanding of urachal carcinoma and define outcome with current management, we performed a retrospective review of cases seen at the M. D. Anderson Cancer Center. MATERIALS AND METHODS: We reviewed the records of 42 patients with urachal carcinoma evaluated at our institution from 1985 to 2001. Specifically, we sought to evaluate the importance of extent of disease, surgical characteristics and systemic therapy on clinical outcome. RESULTS: Of the 42 patients 7 had clinically evident metastases at diagnosis and 35 had resectable disease that was managed initially with surgery. Overall survival from diagnosis for all 42 patients was 46 months with 40% surviving at 5 years. Of the resected cases 16 (46%) remain disease-free (median followup 31 months). Covariates associated with long-term survival were negative surgical margins (p = 0.004) and absence of nodal involvement (p = 0.01). Median survival from recognition of metastatic disease was 24 months in 26 patients in whom metastases ultimately developed. Chemotherapy for metastatic disease produced only 4 significant responses, including 3 of 9 patients treated with 5-fluorouracil and cisplatin containing regimens. CONCLUSIONS: Urachal carcinomas are usually locally advanced at presentation with a high risk of distant metastases. However, long-term survival following radical resection occurs in a significant fraction of patients (16 of 35 in our series), supporting an attempt at margin-negative, en bloc resection if at all possible. Chemotherapy appropriate for enteric type adenocarcinoma can induce objective responses but meaningful improvement in survival is not yet demonstrated.