Testicular cancer in blacks. A multicenter experience

CNV Hotspots in Testicular Seminoma Tissue and Seminal Plasma

Seminoma (SE) is the most frequent type of testicular tumour, affecting predominantly young men. Early detection and diagnosis of SE could significantly improve life quality and reproductive health after diagnosis and treatment. Copy number variation (CNV) has already been associated with various cancers as well as SE. In this study, we selected four genes (MAGEC2, NANOG, RASSF1A, and KITLG) for CNV analysis in genomic DNA (gDNA), which are located on chromosomes susceptible to gains, and whose aberrant expression was already detected in SE. Furthermore, CNV was analysed in cell-free DNA (cfDNA) from seminal plasma. Analysis was performed by droplet digital polymerase chain reaction (ddPCR) on gDNA from SE and nonmalignant testicular tissue. Seminal plasma cfDNA from SE patients before and after surgery was analysed, as well as from healthy volunteers. The CNV hotspot in gDNA from SE tissue was detected for the first time in all analysed genes, and for two genes, NANOG and KITLG it was reflected in cfDNA from seminal plasma. Although clinical value is yet to be determined, presented data emphasize a potential use of CNV as a potential SE biomarker from a liquid biopsy.

Racial differences in testicular cancer in the United States: descriptive epidemiology

BACKGROUND

Testicular cancer (TC) is the most common malignancy in young adult men, and in many countries the incidence rates of testicular cancer have been increasing since the middle of the twentieth century. Since disease presentation and tumor progression patterns are often heterogeneous across racial groups, there may be important racial differences in recent TC trends.

METHODS

In this study, Surveillance, Epidemiology, and End Results (SEER) data on TC patients diagnosed between 1973 and 2015 were analyzed, including the following racial/ethnic groups: non-Hispanic whites (NHW), Hispanic whites (HW), blacks, and Asians and Pacific Islanders (API). Patient characteristics, age-adjusted incidence rates, and survival were compared across racial groups. A multivariate Cox model was used to analyze the survival data of TC patients, in order to evaluate racial differences across several relevant factors, including marital status, age group, histologic type, treatment, stage, and tumor location.

RESULTS

NHWs had the highest incidence rates, followed by blacks, HWs, and APIs. There were significant survival differences among the racial groups, with NHWs having the highest survival rates and blacks having the lowest.

CONCLUSION

An analysis of SEER data showed that racial differences existed among TC patients in the United States with respect to patient characteristics, incidence, and survival. The results can be useful to stakeholders interested in reducing the burden of TC morbidity and mortality.

Trends in Testicular Cancer Survival: A Large Population-based Analysis

OBJECTIVE

To determine whether discrepancies in testicular cancer outcomes between Caucasians and non-Caucasians are changing over time. Although testicular cancer is more common in Caucasians, studies have shown that other races have worse outcomes.

MATERIALS AND METHODS

Using the Surveillance, Epidemiology, and End Results registry, we identified 29,803 patients diagnosed with histologically confirmed testicular cancer between 1983 and 2011. Of these, 12,650 patients (42%) had 10-year follow-up data. We stratified the patients by age group, stage, race, and year of diagnosis and assessed 10-year overall and cancer-specific survival in each cohort. Cox proportional hazard models were used to determine the relative contributions of each stratum to cancer-specific survival.

RESULTS

Predicted overall 10-year survival of Caucasian patients with testicular cancer increased slightly from 88% to 89% over the period studied, whereas predicted cancer-specific 10-year survival dropped slightly from 94% to 93%. In contrast, non-Caucasian men demonstrated larger changes in 10-year overall (84%-86%) and cancer-specific (88%-91%) survival. On univariate analysis, race was significantly associated with testicular cancer death, with non-Caucasian men being 1.69 times more likely to die of testicular cancer than Caucasians (hazard ratio, 1.33-2.16; 95% confidence interval, <.001).

CONCLUSION

Historically, non-Caucasian race has been associated with poorer outcomes from testicular cancer. These data show a convergence in cancer-specific survival between racial groups over time, suggesting that diagnostic and treatment discrepancies may be improving for non-Caucasians.

A polymorphic p53 response element in KIT ligand influences cancer risk and has undergone natural selection

The ability of p53 to regulate transcription is crucial for tumor suppression and implies that inherited polymorphisms in functional p53-binding sites could influence cancer. Here, we identify a polymorphic p53 responsive element and demonstrate its influence on cancer risk using genome-wide data sets of cancer susceptibility loci, genetic variation, p53 occupancy, and p53-binding sites. We uncover a single-nucleotide polymorphism (SNP) in a functional p53-binding site and establish its influence on the ability of p53 to bind to and regulate transcription of the KITLG gene. The SNP resides in KITLG and associates with one of the largest risks identified among cancer genome-wide association studies. We establish that the SNP has undergone positive selection throughout evolution, signifying a selective benefit, but go on to show that similar SNPs are rare in the genome due to negative selection, indicating that polymorphisms in p53-binding sites are primarily detrimental to humans.

Testicular germ cell tumours: predisposition genes and the male germ cell niche

Testicular germ cell tumours (TGCTs) of adults and adolescents are putatively derived from primordial germ cells or gonocytes. Recently reported genome-wide association studies implicate six gene loci that predispose to TGCT development. Remarkably, the functions of proteins encoded by genes within these regions bridge our understanding between the pathways involved in primordial germ cell physiology, male germ cell development and the molecular pathology of TGCTs. Furthermore, this improved understanding of the mechanisms underlying TGCT development and dissemination has clinical relevance for the management of patients with these tumours.

Racial disparities and socioeconomic status in men diagnosed with testicular germ cell tumors: a survival analysis

BACKGROUND

Previous reports indicated that African-American men with testicular germ cell tumors (TGCTs) have more aggressive tumor characteristics and less favorable outcomes than other men. The authors of this report evaluated the effects of race and socioeconomic status (SES) on stage distribution, overall mortality (OM), and cancer-specific mortality (CSM) in men with TGCTs.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify 22,553 men who were diagnosed with TGCTs between 1988 and 2006. Kaplan-Meier and Cox regression analyses were generated to predict OM and CSM. Covariates of the analyses included race, SES, age, histologic subtype, disease stage, procedure type, SEER registry, and year of diagnosis. The interaction between race and SES also was examined.

RESULTS

Overall, there were 516 African-American men, 21,090 Caucasian men, and 947 men of other races. African-Americans (14.9%) and individuals with low SES (10.7%) had a higher proportion of distant stage disease. CSM and OM rates were significantly higher for African-American patients and for patients who resided in low SES counties. Multivariate analyses revealed that African-American men and men with low SES were more likely to die of OM and CSM relative to Caucasian men (P < .001) and men with high SES (P < .001), respectively. The interaction between race and SES was not significant.

CONCLUSIONS

African-American race and low SES appeared to predispose men to more advanced disease stages and to higher OM and CSM rates. These observations may warrant race-specific and/or SES-specific adjustments in the treatment of TGCT.

Biology of testicular germ cell tumors

Germ cell tumors are derived from cells of the germ cell lineage and are the most common solid malignancies to affect young Caucasian men between the ages of 15 and 40 years. All testicular germ cell tumors develop from the same precursor lesion, intratubular germ cell neoplasia unclassified, which in turn is thought to arise from malignant transformation of a primordial germ cell or gonocyte. These tumors are characterized by extreme chemosensitivity and are considered a model for curative disease. In spite of this, a small subset of patients with metastatic disease fail to achieve a complete response with cisplatin-based chemotherapy or relapse from complete remission. Understanding the molecular biology may help the design of new therapies for those patients with a poor prognosis and could also improve the treatment of cancer in general. Current understanding of the role of genetic and epigenetic factors in the etiology of germ cell tumors and the biochemical mechanisms underlying chemotherapy sensitivity and resistance is discussed in detail in this review.

Genes, chromosomes and the development of testicular germ cell tumors of adolescents and adults

Testicular germ cell tumors (TGCTs) of adults and adolescents are thought to be derived from primordial germ cells or gonocytes. TGCTs develop postpuberty from precursor lesions known as intratubular germ cell neoplasia undifferentiated. The tumors can be divided into two groups based on their histology and clinical behavior; seminomas resemble primordial germ cells or gonocytes and nonseminomas resemble embryonic or extraembryonic tissues at various stages of differentiation. The most undifferentiated form of nonseminoma, embryonal carcinoma, resembles embryonic stem cells in terms of morphology and expression profiling, both mRNAs and microRNAs. Evidence supports both environmental factors and genetic predisposition underlying the development of TGCTs. Various models of development have been proposed and are discussed. In TGCTs, gain of material from the short arm of chromosome 12 is invariable: genes from this region include the proto-oncogene KRAS, which has activating mutations in approximately 10% of tumors or is frequently overexpressed. A number of different approaches to increase the understanding of the development and progression of TGCTs have highlighted the involvement of KIT, RAS/RAF/MAPK, STAT, and PI3K/AKT signaling. We review the role of these signaling pathways in this process and the potential influence of environmental factors in the development of TGCTs.

Testicular cancer patterns in African-American men

OBJECTIVES

To compare the testicular cancer incidence, pathologic grade, stage, and survival between African Americans and whites. African Americans had a worse outcome relative to whites with regard to a number of different malignancies.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) database, we extracted all testicular cancer cases among white and African-American males for 1985 to 2000. Baseline demographic data included age at diagnosis, year of diagnosis, stage at diagnosis, and histologic type. Survival was examined using the Kaplan-Meier method and Cox proportional hazards modeling.

RESULTS

The incidence of testicular cancer among African Americans was one fourth that observed among whites. However, African-Americans presented with a higher disease stage at diagnosis. African Americans also presented with significantly lower proportions of embryonal cell carcinoma. Overall survival among African-Americans was significantly worse at both 5 and 10 years. When overall survival was adjusted for stage at presentation and histologic type, the observed survival differences disappeared.

CONCLUSIONS

African Americans appear to present with a higher disease stage than do whites. Observed differences in survival for the African-American group relative to whites appear to be primarily due to delayed presentation. Cultural perceptions of malignancy and understanding of cancer screening may be an important determinant of later presentation. Healthcare access and education issues, rather than inherent biologic differences, appear to be the primary underlying factor for the observed survival differences in African-American males.

Cancer incidence patterns among adolescents and young adults in the United States

OBJECTIVE

The purpose of this study was to examine age-specific cancer incidence patterns among adolescents and young adults (ages 15--49).

METHOD

Cancer incidence data for 1995--1999 from 22 population-based central cancer registries, covering about 47% of the US population, were used. Relative frequencies and average annual age-specific incidence rates per 100,000 person-year were computed for the five-year age groups from age 15--19 years through 45--49 years. Tests of significance for comparison were at a level of p<0.05.

RESULTS

The age at crossover from a predominance of non-epithelial cancers to a predominance of epithelial cancers during adolescence and young adulthood varied by gender and race. Epithelial cancer became the predominant type of tumor after age 40 years among males while it was the predominant type after age 25 years among females. There was also a shift in the top five cancer types with increasing age, which varied by race and gender. Epithelial cancers of the thyroid, breast, ovary, and cervix uteri started to increase sharply among young women in their 20s while among males epithelial cancers rarely occurred until the early 30s (ages 30--34). Cancers of the female breast, colon and rectum, and lung began to occur at an earlier age and increased more sharply among blacks than among whites. However, the incidence rates of epithelial thyroid and ovarian cancers rose more quickly among whites than blacks. Non-Hodgkin lymphoma and soft tissue sarcoma (excluded Kaposi's sarcoma) increased with age among both whites and blacks but the rates were significantly higher among blacks than among whites. Both Kaposi's sarcoma and testicular cancer incidence increased with age and peaked in the early 30s (ages 30--34). The former was significantly higher among blacks than whites while the latter was significantly higher among whites than blacks. Cervical cancer incidence leveled off when white women reached their 30s, but for black women the rate continued to rise with advancing age. Cutaneous melanoma rates were significantly higher among females than among males between the ages of 15 and 39. Conclusion Cancer incidence patterns among adolescents and young adults are distinctive. Specific cancer prevention and control strategies should be targeted accordingly and tailored to their specific needs.

Testicular germ-cell tumours in a broader perspective

The germ-cell tumours are a fascinating group of neoplasms because of their unusual biology and the spectacular therapeutic results that have been obtained in these tumours. Traditionally, this group of neoplasms is presented in an organ-oriented approach. However, recent clinical and experimental data convincingly demonstrate that these neoplasms are one disease with separate entities that can manifest themselves in different anatomical sites. We propose five entities, in which the developmental potential is determined by the maturation stage and imprinting status of the originating germ cell. Recent progress begins to explain the apparent unpredictable development of germ-cell tumours and offers a basis for understanding their exquisite sensitivity to therapy.

Sonography of the scrotum

Ultrasonography (US) with a high-frequency (7.5-10-MHz) transducer has become the imaging modality of choice for examination of the scrotum. US examination can provide information valuable for the differential diagnosis of a variety of disease processes involving the scrotum that have similar clinical manifestations (eg, pain, swelling, or presence of mass). The pathologic condition that may be at the origin of such symptoms can vary from testicular torsion to infection to malignancy. The ability of color and power Doppler US to demonstrate testicular perfusion aids in reaching a specific diagnosis in patients with acute scrotal pain. This review covers the anatomy of the scrotum and the scanning protocol for scrotal US, as well as detailed descriptions of disease processes and their US appearances. Newly described conditions such as intratesticular varicoceles and other benign intratesticular cystic lesions are also discussed.

Testicular self-examination in young adult men

PURPOSE

To describe patterns of testicular self-examination (TSE) in a sample of young adult men and to identify factors distinguishing between men who do and do not practice TSE.

DESIGN

A comparative descriptive design with a convenience sample of 191 adult men aged 18-35 years, recruited from a large industrial complex in the U.S. Midwest. Data were collected during several occupational health fairs held from 1999-2001.

METHODS

A self-report, 75-item health risk appraisal (HRA) was administered to identify health-related lifestyle habits. Men who did and did not perform TSE regularly were compared using Mann-Whitney U statistics for discrete variables and t tests for continuous data. Discriminant function analysis was used to identify factors allowing prediction of frequent or infrequent TSE performance.

FINDINGS

Sixty-four percent of 191 participants reported rarely or never performing TSE, and 36% practiced TSE monthly or every few months. Men who infrequently performed TSE were more often African American or Hispanic and had less than a college education. Other significant factors associated with infrequent TSE practice included less satisfaction with current job assignment; less satisfaction with life in general; greater worries interfering with daily life; more serious family problems in dealing with spouse, children, or parents; and reduced availability of people to turn to for support.

CONCLUSIONS

Demographic and socioeconomic variables were related to TSE knowledge and performance. Further investigation is required to determine why men, especially ethnic minority men, are not performing this important cancer-screening activity.

Factors involved in diagnostic delay of testicular cancer

In testicular cancer, which is one of the highly curable cancers, the beneficial effect of early diagnosis on survival has been well accepted for years. This study was planned to determine the probable factors involved in diagnostic delay of testicular cancer. A total of 140 patients with testicular cancer were included in this study. We attempted to find a relationship between the mode of presentation, stage of the tumour, patients' socioeconomic status and the delay in diagnosis. Majority of patients presented with scrotal pain (49.3%). No significant correlation was found between the mode of presentation and stage of the disease (p>0.05). The median time of delay in diagnosis was 5.4 months. The stage at presentation was not influenced by the delay in diagnosis. Similarly the annual income and the educational level of the patients had no significant impact on the delay in diagnosis. No effect of delay in diagnosis on the stage at presentation could be demonstrated in our study. Our results indicate that in this country people are not thoroughly educated about the importance of routine self-examination of the testes. It must also be emphasized that painful testicular masses need to be evaluated carefully to rule out malignancy.

Germ cell testis cancer: 15-year review

Testis cancer affects 2-3 men per every 100,000 in the United States, making it the most common solid tumor of men in the 20-35-year-old age range. Since the average age of active duty military personnel is included in the age range of those at greatest risk for germ cell testis cancer, it is of pertinent clinical importance to physicians who treat these young patients. The National Naval Medical Center has been using cisplatin-based protocols since the time of their introduction. This study reviews the success of treating these patients and examines the treatment failures.