Origin of Subsequent Malignant Neoplasms in Patients with History of Testicular Germ Cell Tumor

Stem Cell Origin of Cancer: Clinical Implications for Cancer Immunity and Immunotherapy

A simple way to understand the immune system is to separate the self from non-self. If it is self, the immune system tolerates and spares. If it is non-self, the immune system attacks and destroys. Consequently, if cancer has a stem cell origin and is a stem cell disease, we have a serious problem and a major dilemma with immunotherapy. Because many refractory cancers are more self than non-self, immunotherapy may become an uphill battle and pyrrhic victory in cancer care. In this article, we elucidate cancer immunity. We demonstrate for whom, with what, as well as when and how to apply immunotherapy in cancer care. We illustrate that a stem cell theory of cancer affects our perspectives and narratives of cancer. Without a pertinent theory about cancer's origin and nature, we may unwittingly perform misdirected cancer research and prescribe misguided cancer treatments. In the ongoing saga of immunotherapy, we are at a critical juncture. Because of the allure and promises of immunotherapy, we will be treating more patients not immediately threatened by their cancer. They may have more to lose than to gain, if we have a misconception and if we are on a wrong mission with immunotherapy. According to the stem cell theory of cancer, we should be careful with immunotherapy. When we do not know or realize that cancer originates from a stem cell and has stem-ness capabilities, we may cause more harm than good in some patients and fail to separate the truth from the myth about immunotherapy in cancer care.

The potential role of miRNAs in the pathogenesis of testicular germ cell tumors - A Focus on signaling pathways interplay

Testicular germ cell tumors (TGCTs) are the most common testicular neoplasms in adolescents and young males. Understanding the genetic basis of TGCTs represents a growing need to cope with the increased incidence of these neoplasms. Although the cure rates have been comparatively increased, investigation of mechanisms underlying the incidence, progression, metastasis, recurrence, and therapy resistance is still necessary. Early diagnosis and non-compulsory clinical therapeutic agents without long-term side effects are now required to reduce the cancer burden, especially in the younger age groups. MicroRNAs (miRNAs) control an extensive range of cellular functions and exhibit a pivotal action in the development and spreading of TGCTs. Because of their dysregulation and disruption in function, miRNAs have been linked to the malignant pathophysiology of TGCTs by influencing many cellular functions involved in the disease. These biological processes include increased invasive and proliferative perspective, cell cycle dysregulation, apoptosis disruption, stimulation of angiogenesis, epithelial-mesenchymal transition (EMT) and metastasis, and resistance to certain treatments. Herein, we present an up-to-date review of the biogenesis of miRNAs, miRNA regulatory mechanisms, clinical challenges, and therapeutic interventions of TGCTs, and role of nanoparticles in the treatment of TGCTs.

Unveiling the genomic landscape of possible metastatic malignant transformation of teratoma secondary to cisplatin-chemotherapy: a Tempus gene analysis-based case report literature review

In this case report, we describe a patient who developed metastatic liver cancer of unknown primary origin one year following the surgical removal of a retroperitoneal adenocarcinoma. The retroperitoneal adenocarcinoma is considered a malignant transformation of teratoma (MTT), given the patient's distant history of testicular tumor excised 25 years prior and treated with chemotherapy. Despite no primary tumor being identified, the leading primary hypothesis is that the liver metastasis stemmed from the resected retroperitoneal adenocarcinoma from one year prior. We theorize that the patient's cisplatin-based chemotherapy 25 years ago may have triggered the MTT, as documented in the existing literature. Using TEMPUS gene testing on both the retroperitoneal adenocarcinoma and the recently discovered liver metastasis, we identified several genes with variants of unknown significance (VUS) that could potentially be linked to cisplatin chemotherapy resistance. While we cannot conclude that this patient definitively underwent MTT, it remains the most plausible explanation. Future research should investigate both the validity of the genes we have uncovered with respect to cisplatin resistance, as well as other genes associated with cisplatin resistance to further understand the pathogenesis of cisplatin resistance for better prediction of treatment response. As the world of medicine shifts towards individualized therapies and precision medicine, reporting and analyzing genetic mutations derived from tumors remains imperative. Our case report aims to contribute to the growing database of defined mutations and underscores the immense potential of genetic analysis in directing personalized treatment options.

H3 histone methylation landscape in male urogenital cancers: from molecular mechanisms to epigenetic biomarkers and therapeutic targets

During the last decades, male urogenital cancers (including prostate, renal, bladder and testicular cancers) have become one of the most frequently encountered malignancies affecting all ages. While their great variety has promoted the development of various diagnosis, treatment and monitoring strategies, some aspects such as the common involvement of epigenetic mechanisms are still not elucidated. Epigenetic processes have come into the spotlight in the past years as important players in the initiation and progression of tumors, leading to a plethora of studies highlighting their potential as biomarkers for diagnosis, staging, prognosis, and even as therapeutic targets. Thus, fostering research on the various epigenetic mechanisms and their roles in cancer remains a priority for the scientific community. This review focuses on one of the main epigenetic mechanisms, namely, the methylation of the histone H3 at various sites and its involvement in male urogenital cancers. This histone modification presents a great interest due to its modulatory effect on gene expression, leading either to activation (e.g., H3K4me3, H3K36me3) or repression (e.g., H3K27me3, H3K9me3). In the last few years, growing evidence has demonstrated the aberrant expression of enzymes that methylate/demethylate histone H3 in cancer and inflammatory diseases, that might contribute to the initiation and progression of such disorders. We highlight how these particular epigenetic modifications are emerging as potential diagnostic and prognostic biomarkers or targets for the treatment of urogenital cancers.

An update on diagnostic tissue-based biomarkers in testicular tumors

Testicular cancer is rare overall but comprises the most common solid malignancy diagnosed in young men aged ∼20-40 years. Most testicular neoplasms generally fall into 2 broad categories: germ cell tumors (GCTs; ∼95%) and sex cord-stromal tumors (SCSTs ∼5%). Given the relative rarity of these tumors, diagnostic biomarkers are highly relevant for their diagnosis. Over the past several decades, diagnostic biomarkers have improved dramatically through targeted immunohistochemical and molecular characterization. Despite these recent advances, most markers are not perfectly sensitive or entirely specific. Therefore, they need to be used in combination and interpreted in context. In this review, we summarize tissue-based biomarkers relevant to the pathologist, with a focus on practical diagnostic issues that relate to testicular GCT and SCST.

Transformed Testicular Teratoma to Embryonic-Type Neuroectodermal Tumor With Metastasis to Mediastinum

Testicular teratomas may present in both prepubertal and adult men; however, the prognosis differs greatly between these 2 populations. In children, teratomas (prepubertal type) most often occur before the age of 4, are generally seen in their pure form, and behave in a benign fashion. In adults (postpubertal type), teratomas are usually part of a mixed germ cell tumor, and they have the potential to be found at metastatic sites, especially following chemotherapy for non-teratomatous germ cell tumor. Analyses of metastases from germ cell tumors and teratomas from the same patient have demonstrated a high degree of concordance in the observed genetic abnormalities. In rare cases, testicular teratoma can transform into a malignant germ cell tumor. One such type of transformation is into a primitive neuroectodermal tumor. These tumors are malignant and often metastasize to the retroperitoneum but may also metastasize to other sites. A multimodal treatment approach is needed, including surgery and adjuvant chemotherapy. We describe a rare case of malignant transformation of a testicular teratoma into a primitive neuroectodermal tumor with metastasis to the mediastinum. The patient was treated with radical orchiectomy, retroperitoneal lymph node dissection, and adjuvant vincristine, adriamycin, and cyclofosfamide alternating with ifosfamide and etoposide (VAC/IE therapy).

Primary mediastinal germ cell tumors

Mediastinal germ cell tumors share similar histopathological, immunohistochemical, and molecular features with their counterparts in the gonads. Therefore, proper clinical and radiological evaluation of patients with an anterior mediastinal mass becomes essential in the final interpretation of these tumors. The gold standard for the diagnosis of these tumors remains histopathological evaluation. However, immunohistochemical stains and molecular studies also provide an aid in cases in which the histology is not typical. It is also important to keep in mind that a small mediastinoscopic biopsy may not be representative of the entire neoplasm. In this review, we will provide our perspective regarding histopathological diagnosis, staging, immunohistochemical and molecular profile, and briefly family of tumors address pertinent epidemiological, clinical and treatment options. However, the main emphasis is to review the process of pathological assessment in pre and post-treated tumors. Knowledge of the different growth patterns and histological associations is important, mainly when confronted with mediastinoscopic biopsies, which ultimately will determine treatment options.

Breaking Healthcare Barriers for Transgender Individuals With Rare Tumor Presentation

Transgender persons can experience healthcare barriers and potentially suffer from preventable health disparities. Some challenges these individuals may face include the lack of provider education, social stigma, socioeconomic barriers to care, and insurance instability. Combating this problem requires systemic changes. Unfortunately, there are limited data on providers' perspective on taking care of transgender persons, and healthcare delivery systems are often unequipped to adequately manage these patients. This case presentation exemplifies many of these challenges. A 47-year-old transgender female with a history of testicular cancer, presented with bleeding from a lump on her neck. A computed tomography (CT) scan of the neck revealed a large mass suspicious of malignancy. Pathology identified metastatic colorectal adenocarcinoma. Esophagogastroduodenoscopy, colonoscopy, positron emission tomography scan, CT abdomen/pelvis, and serum tumor marker showed no evidence of a primary gastrointestinal malignancy. This presentation likely represents a late relapse of a residual, metastatic germ cell tumor with malignant somatic transformation. This case was greatly impacted by social determinants of health. The patient did not identify with her male anatomy, which delayed the detection of the initial testicular malignancy. In the post-operative period, the patient did not attend follow-up appointments to avoid discussing her male genitalia. When tumor relapse did occur, the patient experienced financial, insurance, and transportation instability; this delayed medical care and allowed the mass to grow to an extraordinary size.

Stem Cell Theory of Cancer: Origin of Metastasis and Sub-clonality

Metastasis may be the secret weapon cancer uses to dominate and subjugate, to persist and prevail. However, it is no longer a secret when we realize that a stem cell has the same ways and means to fulfill its own omnipotence and accomplish its own omnipresence… and when we realize that a cancer cell has its own version of stem-ness origin and stem-like nature. In this perspective, we discuss whether stem-ness enables metastasis or mutations drive metastasis. We ponder about low-grade versus high-grade tumors and about primary versus metastatic tumors. We wonder about stochasticity and hierarchy in the genesis and evolution of cancer and of metastasis. We postulate that metastasis may hold the elusive code that makes or breaks a stem-cell versus a genetic theory of cancer. We speculate that the vaunted model of multistep carcinogenesis may be in error and needs some belated remodeling and a major overhaul. We propose that subsequent malignant neoplasms from germ cell tumors and donor-derived malignancies in organ transplants are quintessential experiments of nature and by man that may eventually empower us to elucidate a stem-cell origin of cancer and metastasis. Unfortunately, even the best experiments of cancer and of metastasis will be left unfinished, overlooked, or forgotten, when we do not formulate a proper cancer theory derived from pertinent and illuminating clinical observations. Ultimately, there should be no consternations when we realize that metastasis has a stem-cell rather than a genetic origin, and no reservations when we recognize that metastasis has been providing us some of the most enduring tests and endearing proofs to demonstrate that cancer is indeed a stem-cell rather than a genetic disease after all.

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.

Morphological spectrum and molecular features of somatic malignant transformation in germ cell tumours

AIMS

Somatic malignant transformation (SMT) arising in germ cell tumours (GCTs) is an infrequent, but clinically relevant event. There is only limited knowledge on the morphological spectrum of SMT, and therapeutic management of these patients is poorly defined. In this work we revisit two consecutive case series (n=756) of GCTs. Clinicopathological data of SMT arising in GCT were determined, with focus on the histopathological spectrum, and molecular aspects were obtained by Fluorescence in situ Hybridization (FISH) and Next Generation Sequencing (NGS).

METHODS AND RESULTS

30 male patients (28 primary testicular, 2 primary extragonadal) were included. These patients represent 4% of GCT patients diagnosed in two institutes (University Hospital Zurich and IPO Porto). The most common SMT were adenocarcinoma (n=8), embryonic-type neuroectodermal tumours (ENETs, n=8) and rhabdomyosarcoma (n=6), but a wide range of challenging morphologies were depicted, including low-grade neuroglial tumour, adenosquamous carcinoma, neuroblastoma and neuroendocrine carcinoma. SMT was found in 15 primary tumour samples and in 27 metastatic samples of these 30 patients, the latter showing poorer overall-survival. Adenocarcinoma occurred only in metastasis post-chemotherapy and in one primary retroperitoneal GCT with SMT, but not in GCT of the testis. 12p gains were identified by FISH in all cases. NGS results were available in 6 patients. Clinical trials and/or targeted treatments based on the molecular profile of SMT were recommended in 4 patients.

CONCLUSIONS

SMT arising in GCTs represents a diagnostic challenge and should be confirmed by a specialized uropathologist. NGS based treatment recommendations may improve outcome of these patients.

Epigenetics and Testicular Cancer: Bridging the Gap Between Fundamental Biology and Patient Care

Testicular cancer is the most common solid tumor affecting young males. Most testicular cancers are testicular germ cell tumors (TGCTs), which are divided into seminomas (SGCTs) and non-seminomatous testicular germ cell tumors (NSGCTs). During their development, primordial germ cells (PGCs) undergo epigenetic modifications and any disturbances in their pattern might lead to cancer development. The present study provides a comprehensive review of the epigenetic mechanisms–DNA methylation, histone post-translational modifications, bivalent marks, non-coding RNA–associated with TGCT susceptibility, initiation, progression and response to chemotherapy. Another important purpose of this review is to highlight the recent investigations regarding the identification and development of epigenetic biomarkers as powerful tools for the diagnostic, prognostic and especially for epigenetic-based therapy.

Stem Cell Theory of Cancer: Implications for Drug Resistance and Chemosensitivity in Cancer Care

Simple Summary

Science and history teach us that stemness properties pave all drug resistance pathways. Evidence and experience inform us that stemness origin and nature etch all cancer hallmarks. A stem cell origin of drug resistance encompasses heterogeneity and dormancy, embraces ABC transporters and DNA repairs, and explicates chemotherapy and chronotherapy. It alludes to a unified theory of cancer and suggests that cancer is a stem cell disease—uniting chemoresistance with chemosensitivity, connecting progenitor cells with progeny cells, and linking multicellularity with the microenvironment. Importantly, it clarifies genetic content vs. cellular context, delineates drug vs. therapy development, and enlightens precision medicine vs. integrated medicine and targeted therapy vs. multimodal therapy in cancer care.

Abstract

When it concerns cancer care and cancer therapy, drug resistance is more than an obstacle to successful treatment; it is a major cause of frustration in our attempts to optimize drug development versus therapy development. Importantly, overcoming the challenges of drug resistance may provide invaluable clues about the origin and nature of cancer. From this perspective, we discuss how chemoresistance and chemosensitivity in cancer therapy could be directly linked to the stem cell origin of cancer. A stem cell theory of cancer stipulates that both normal stem cells and cancer stem cells are similarly endowed with robust efflux pumps, potent antiapoptotic mechanisms, redundant DNA repair systems, and abundant antioxidation reserves. Cancer stem cells, like their normal stem cell counterparts, are equipped with the same drug resistance phenotypes (e.g., ABC transporters, anti-apoptotic pathways, and DNA repair mechanisms). Drug resistance, like other cancer hallmarks (e.g., tumor heterogeneity and cancer dormancy), could be intrinsically ingrained and innately embedded within malignancy. We elaborate that cellular context and the microenvironment may attenuate the effects of cancer treatments. We examine the role of circadian rhythms and the value of chronotherapy to maximize efficacy and minimize toxicity. We propose that a stem cell theory of drug resistance and drug sensitivity will ultimately empower us to enhance drug development and enable us to improve therapy development in patient care.

MicroRNAs in Differentiation of Embryoid Bodies and the Teratoma Subtype of Testicular Cancer

BACKGROUND

Testicular germ cell tumours (TGCTs) are the most frequent tumour type among young, adult men. TGCTs can be efficiently treated, but metastases of the teratoma subtype, for which there are no circulating biomarkers, represent a challenge.

MATERIALS AND METHODS

Global microRNA expression in teratoma tissue and embryoid bodies was assessed using next-generation sequencing. Levels of microRNAs identified as potential biomarkers were obtained from serum of patients with teratoma and matched healthy men.

RESULTS

We identified miR-222-5p, miR-200a-5p, miR-196b-3p and miR-454-5p as biomarker candidates from the tumour tissue and embryoid body screening but the expression of these microRNAs was very low in serum and not statistically different between patients and controls. miR-375-3p was highly expressed, being highest in patients with teratoma (p=0.012) but the levels of expression in serum from these patients and healthy controls overlapped. miR-371a-3p was not expressed in serum from patients with pure teratoma, only in patients with mixed tumours.

CONCLUSION

The microRNA profiles of the teratoma subtype of TGCT and embryoid bodies were obtained and assessed for candidate circulating biomarkers, but none with high sensitivity and specificity for teratoma were identified in our study. We conclude that neither the proposed teratoma marker miR-375-3p nor miR-371a-3p are suitable as circulating teratoma markers.

Stem Cell Theory of Cancer: Rude Awakening or Bad Dream from Cancer Dormancy?

To be dormant or not depends on the origin and nature of both the cell and its niche. Similar to other cancer hallmarks, dormancy is ingrained with stemness, and stemness is embedded within dormancy. After all, cancer dormancy is dependent on multiple factors such as cell cycle arrest, metabolic inactivity, and the microenvironment. It is the net results and sum effects of a myriad of cellular interactions, interconnections, and interplays. When we unite all cancer networks and integrate all cancer hallmarks, we practice and preach a unified theory of cancer. From this perspective, we review cancer dormancy in the context of a stem cell theory of cancer. We revisit the seed and soil hypothesis of cancer. We reexamine its implications in both primary tumors and metastatic lesions. We reassess its roles in cell cycle arrest, metabolic inactivity, and stemness property. Cancer dormancy is particularly revealing when it informs us about the mysteries of late relapse, prolonged remission, and second malignancy. It is paradoxically rewarding when it delivers us the promises and power of cancer prevention and maintenance therapy in patient care.

Somatic-type Malignancies in Testicular Germ Cell Tumors: A Clinicopathologic Study of 63 Cases

The development of somatic-type malignancies (SMs) in testicular germ cell tumors (GCTs) is a rare but well-recognized phenomenon. We studied the pathologic features of 63 GCTs with SMs in the testis (n=22) or metastases (n=41) and correlated these features with clinical outcomes. The patients with SMs in the testis (median age, 26 y) were younger than those with metastatic SMs (median age, 38.5 y). The SMs consisted of carcinomas (n=21), sarcomas (n=21), primitive neuroectodermal tumors (n=15), nephroblastomas (n=3), and mixed tumors (n=3). Sarcoma was the most common SM in the testis (n=11), and most sarcomas were rhabdomyosarcomas (n=9). Carcinoma was the most common SM in metastases (n=20), and most carcinomas were adenocarcinomas (n=12). In metastases, carcinomatous SMs developed after a longer interval from the initial orchiectomy (median times, 213 mo) than sarcomatous SMs (median times, 68 mo). Patients with metastatic SMs had significantly poorer overall survival than those with SMs in the testis (5-y survival rate, 35% vs. 87%; P=0.011). Furthermore, patients with carcinomatous SMs had a significantly worse prognosis than those with sarcomatous or primitive neuroectodermal tumor SMs (5-y survival rates, 17%, 77%, and 73%, respectively; P=0.002), when the whole cohort, including testicular and metastatic SMs, were analyzed. Our results demonstrate that SMs in metastatic GCTs are associated with a significantly worse prognosis than those in the testis. Furthermore, the histologic subtype of SM has a significant effect on the clinical outcome, with the carcinomatous SM carrying the highest risk for mortality.

Stem Cell Theory of Cancer: Origin of Tumor Heterogeneity and Plasticity

In many respects, heterogeneity is one of the most striking revelations and common manifestations of a stem cell origin of cancer. We observe heterogeneity in myriad mixed tumors including testicular, lung, and breast cancers. We recognize heterogeneity in diverse tumor subtypes in prostate and kidney cancers. From this perspective, we illustrate that one of the main stem-ness characteristics, i.e., the ability to differentiate into diverse and multiple lineages, is central to tumor heterogeneity. We postulate that cancer subtypes can be meaningless and useless without a proper theory about cancer's stem cell versus genetic origin and nature. We propose a unified theory of cancer in which the same genetic abnormalities, epigenetic defects, and microenvironmental aberrations cause different effects and lead to different outcomes in a progenitor stem cell versus a mature progeny cell. We need to recognize that an all-encompassing genetic theory of cancer may be incomplete and obsolete. A stem cell theory of cancer provides greater universality, interconnectivity, and utility. Although genetic defects are pivotal, cellular context is paramount. When it concerns tumor heterogeneity, perhaps we need to revisit the conventional wisdom of precision medicine and revise our current practice of targeted therapy in cancer care.

Late adverse effects and quality of life in survivors of testicular germ cell tumour

Currently, ~95% of patients with testicular germ cell tumour (TGCT) are cured, resulting in an increasing number of TGCT survivors. Although cured, these men face potential late adverse effects and reduced quality of life. Survivors face a twofold increased risk of second malignant neoplasms after chemotherapy and radiotherapy, with evidence of dose-dependent associations. For survivors managed with surveillance or treated with radiotherapy, the risk of cardiovascular disease (CVD) is comparable to the risk in the general population, whereas treatment with chemotherapy increases the risk of life-threatening CVD, especially during treatment and after 10 years of follow-up. Other adverse effects are organ-related toxicities such as neuropathy and ototoxicity. Pulmonary and renal impairment in patients with TGCT treated with chemotherapy is limited. Survivors of TGCT might experience psychosocial distress including anxiety disorders, fear of cancer recurrence and TGCT-specific issues, such as sexual dysfunction. Late adverse effects can be avoided in most patients with stage I disease if followed on a surveillance programme. However, patients with disseminated disease can experience toxicities associated with radiotherapy and chemotherapy, and/or adverse effects related to surgery for residual disease. The severity of adverse effects increases with dose of both chemotherapy and radiotherapy. This Review discusses the most recent data concerning the late adverse effects of today's standard treatments for TGCT.

Assessment of isochromosome 12p and 12p abnormalities in germ cell tumors using fluorescence in situ hybridization, single-nucleotide polymorphism arrays, and next-generation sequencing/mate-pair sequencing

The identification of isochromosome 12p [i(12p)] and 12p gains have significant clinical utility in the diagnosis of germ cell tumors (GCTs). We have summarized the results of fluorescence in situ hybridization (FISH) assays to identify i(12p), performed in a Clinical Laboratory Improvement Amendments (CLIA)-validated setting for 536 specimens. In addition, the American Association for Cancer Research (AACR) Project GENIE registry and The Cancer Genome Atlas (TCGA) data sets were evaluated for chromosome 12p gains, and a limited number of cases were concurrently evaluated using FISH, single-nucleotide polymorphism (SNP) arrays and next-generation sequencing (NGS; including mate-pair sequencing). Specimens submitted for FISH testing were frequently from potential sites of metastases (male: 70.9% and female: 69.3%), and polysomy of chromosome 12 with or without concurrent i(12p) was a frequent finding, seen in 3% (16/536) and 35% (186/536) of cases, respectively. Our analysis suggests that 12p gains are likely to be present in approximately 73% of male GCT and in 32% of female GCT (AACR GENIE, n = 555). When comparing TCGA cases of testicular GCT (n = 149) to combined cases of sarcoma, colorectal, prostate, and urothelial carcinoma (n = 1754), 12p gains had a sensitivity of 77.2% and specificity of 97.3% for GCT. Some advantages of FISH over SNP arrays/NGS include relatively lower cost, rapid turnaround time, the ability to analyze biopsy material with a limited number of tumor cells (50 cells), and the ability to distinguish i(12p) from polysomy. The ability to spatially restrict the analysis to cells of interest is critical, as specimens submitted for testing often have low tumor purity. Disadvantages include false negative results due to an inability to detect segmental gains due to FISH probe design. With the availability of numerous testing modalities, including FISH, SNP arrays, and NGS-based assays, a nuanced understanding of the advantages and disadvantages of each methodology, as has been presented in this study, may inform appropriate testing strategies.

Curing Cancer: Lessons from a Prototype

Simple Summary

Germ cell tumor of the testis (TGCT) teaches us that to cure cancer, we need to acquire and apply proper biological insight and clinical acumen. In 1946, about 90% of patients with metastatic TGCT died within the first year of diagnosis. Today, over 90% of the same patients are curable. This complete reversal in the cure rate of TGCT is not because we have designed better drugs (we have not), but because we have learned how to use the same drugs in the right patients under the right settings. Importantly, TGCT is a prototype stem cell tumor that may hold the key to unlocking the origin of cancers, thereby enhancing our understanding of cancer and improving the cure and care of patients with cancer.

Abstract

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.

Application of a Successful Germ Cell Tumor Paradigm to the Challenges of Common Adult Solid Cancers

When we aspire to cure cancer, we may need to search no further than a curable cancer, such as Germ Cell Tumor of the Testis (TGCT). After all, a germ cell is a primordial stem cell. Importantly, TGCT provides a classic stem cell model of cancer that teaches us some invaluable lessons about curing other intractable solid tumors. The intrinsic intratumoral heterogeneity of TGCT alludes to its stem-ness origin and nature. Which implicates the existence of putative lethal TGCT subtypes-the identification and detection of which may further enhance the cure rate and improve the therapeutic ratio of TGCT. In this Mini review, we discuss about the role of biologic insights, clinical lessons, and therapeutic strategies in drug and therapy development. We illustrate some clinical pearls and perils when it concerns drug versus therapy development in the cure and care of patients with TGCT. In many respects, we have cured more TGCT patients when we apply multimodal therapy rather than targeted therapy and integrated medicine rather than precision medicine. In principle and in practice, this is the implication of therapy versus drug development in improving the overall outcome and cure rate of patients with cancer.