Assessment of Prognostic Factors of Racial Disparities in Testicular Germ Cell Tumor Survival in the United States (1992-2015)

OBJECTIVE

Testicular germ cell tumors (TGCT) are the most common cancer among men aged 15 to 39 years. Previous studies have considered factors related to TGCT survival rate and race/ethnicity, but histological type of the diagnosed cancer has not yet been thoroughly assessed.

METHODS

The data came from 42,854 eligible patients from 1992 to 2015 in the Surveillance Epidemiology and End Results 18. Frequencies and column percent by seminoma and nonseminoma subtypes were determined for each covariates. We used Cox proportional hazard regression to assess the impact of multiple factors on post-diagnostic mortality of TGCT.

RESULTS

Black males were diagnosed at a later stage, more commonly with local or distant metastases. The incidence of TGCT in black non-seminoma tumors increased most significantly. The difference in survival rates between different ethnic and histological subtypes, overall survival (OS) in patients with non-seminoma was significantly worse than in patients with seminoma. The most important quantitative predictor of death was the stage at the time of diagnosis, and older diagnostic age is also important factor affecting mortality.

CONCLUSION

Histological type of testicular germ cell tumor is an important factor in determining the prognosis of testicular cancer in males of different ethnic groups.

Survival differences by race/ethnicity among children and adolescents diagnosed with germ cell tumors

Survival differences by racial and ethnic group have been reported in children and adolescents with germ cell tumors (GCTs), but whether these differences depend on stage of disease is unclear. Using the SEER 18 registries (2000-2015), we examined GCT survival differences by race/ethnicity (non-Hispanic white [NHW], Black, Asian/Pacific Islander [API], Hispanic) separately for males and females aged 0-19 years at diagnosis. We used Kaplan-Meier survival curves (Log-Rank p values) to characterize survival differences. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for the association between race/ethnicity and death. Using an inverse odds weighting mediation analysis, we estimated the association between race/ethnicity and death treating stage of disease as the mediator. There were no significant racial/ethnic survival differences among females. Male survival differed by race/ethnicity (p < 0.0001) with NHW males having the best survival. Compared to NHW, API and Hispanic males had significantly higher risks of death (API HR: 2.18; 95% CI: 1.32-3.56; Hispanic HR: 1.98; 95% CI: 1.42-2.78) (model adjusted for age and year at diagnosis, tumor histology and location, stage). This association was mediated by stage of disease only among Hispanic males with gonadal tumors (indirect HR: 1.18; 95% CI: 1.03-1.35). The increased risk of death after a testicular GCT diagnosis observed among Hispanic males was mediated by stage of disease. For API males and Hispanic males with extragonadal tumors, other unidentified factors including differences in exposures, tumor biology or treatment received may impact the observed racial/ethnic survival disparities.

International patterns and trends in testicular cancer incidence, overall and by histologic subtype, 1973-2007

Incidence rates of testicular cancer in Northern European and North American countries have been widely reported, whereas rates in other populations, such as Eastern Europe, Central/South America, Asia, and Africa, have been less frequently evaluated. We examined testicular cancer incidence rates overall and by histologic type by calendar time and birth cohort for selected global populations 1973-2007. Age-standardized incidence rates over succeeding 5-year periods were calculated from volumes 4-9 of Cancer Incidence in Five Continents electronic database (CI5plus) and the newly released CI5X (volume 10) database. Annual percent change over the 35-year period was calculated using weighted least squares regression. Age-period-cohort analyses were performed and observed rates and fitted rate ratios presented by birth cohort. Incidence rates of testicular cancer increased between 1973-1977 and 2003-2007 in most populations evaluated worldwide. Of note, incidence rates in Eastern European countries rose rapidly and approached rates in Northern European countries. Rates in Central and South America also increased and are now intermediate to the high rates among men of European ancestry and low rates among men of Asian or African descent. Some heterogeneity in the trends in seminoma and nonseminoma were observed in Denmark, the United Kingdom, and among US whites, particularly in recent generations, with rapid and uniform increases in the incidence of both histologic types in Slovakia. Reasons for the rising incidence rates among European and American populations remain unexplained; however, changing distributions in the prevalence of risk factors for testicular cancer cannot be ruled out.

Updates in the management of ovarian germ cell tumors

Ovarian germ cell tumors are rare events at all ages-in pediatrics, adolescence, and during young adulthood. Combining the knowledge and experience of pediatric and gynecologic oncologists can lead to better outcomes for all. In this review, we intend to present the latest consensus on management of women and children with this disease and highlight the opportunities for collaboration and clinical research going forward.

[The distribution of HLA genes in Russian patients with germ cell tumors]

The correlation between DRB1, DQA1, and DQB1 genes of HLA class II, and the development of germ cell tumors (GCTs), as well as serological response to HERV-K proteins were investigated. Genomic DNA prepared from 99 GST patients was subjected to HLA typing by polymerase chain reaction (PCR) using the set of sequence specific primers (PCR-SSP). This set of primers made it possible to detect 14 specificities of DRB 1 locus, 12 alleles and groups of alleles of DQB 1 locus, and 8 alleles of DQA1 locus. Alongside with the definition of the occurrence of HLA markers in the total group of patients, the frequency of the occurrence of HLA-DR-DQ alleles was calculated in: 1) patients with different morphological forms of GSTs (seminomas and non-seminomas); 2) GCT patients producing or non-producing antibodies to Gag and/or Env HERV-K proteins. The comparison group consisted of 300 Moscow blood donors. The study did not reveal statistically significant differences in the frequency of the occurrence of DRB1, DQA1, and DQB1 alleles between the total group of GCT patients, its subgroup, and the control group. Thus, the data obtained demonstrated the absence of a strict correlation between the distribution of HLA class II alleles and GCT occurrence in the Russian population, as well as the ability of GCT patients to develop an antibody to HERV-K proteins, though more numerous observations are required to confirm this conclusion.

Risk factors for cryptorchism among populations at differing risks of testicular cancer

BACKGROUND

Cryptorchism is strongly associated with the development of testicular germ cell tumours (TGCTs), possibly owing to a common aetiology. However, while TGCT incidence varies greatly between white and black men, little variability has been reported between the two groups in cryptorchism prevalence. This may suggest that cryptorchism risk factors differ by ethnicity.

METHODS

To examine this hypothesis, a prospective analysis was conducted among black and white participants in the US Collaborative Perinatal Project. White participants included 238 cryptorchid sons and 12,296 non-cryptorchid sons, while black participants included 188 cryptorchid sons and 11,942 non-cryptorchid sons.

RESULTS

While cryptorchism was significantly more common among white sons (1.90% vs 1.55%; P = 0.04), the difference was incompatible with the 5-fold difference in TGCT rates. The principal maternal risk factors among white sons were age (P = 0.03), hypertension/proteinuria (P = 0.006), and length of time to become pregnant (P = 0.055), while major maternal risk factors among black sons were age (P = 0.06), height (P = 0.007), weight (P = 0.06), and radiation exposure (P = 0.02). Only maternal height, however, had a different relationship with risk among black and white sons. Neonatal associations with risk (shorter gestational age, lower birthweight, shorter length) were similar in the two groups.

CONCLUSIONS

These results do not support the hypothesis that the risk factors for cryptorchism vary dramatically by ethnicity but may suggest that cryptorchism is not as closely linked to TGCT among black men as among white men.

Incidence and survival rates for female malignant germ cell tumors

OBJECTIVE

To evaluate 30-year, population-based trends in incidence and survival rates for malignant germ cell tumors originating within the female genital tract.

METHODS

Surveillance, Epidemiology, and End Results data were used to identify malignant germ cell tumors (1973-2002). Overall and 5-year incidence rates, estimated annual percentage change, and survival rates were calculated and compared by age at diagnosis, race, stage, and histology.

RESULTS

Of 1,262 cases, there were 414 (32.8%) dysgerminomas, 449 (35.6%) immature teratomas, 37 (2.9%) mature teratomas with malignant degeneration, and 362 (28.7%) mixed germ cell tumors. The 30-year, age-adjusted incidence rate per 100,000 women-years was 0.338, decreasing by 29.4% for dysgerminomas (P = .18) and by 31.5% for mixed germ cell tumors (P = .22). Other nonwhites had higher rates than whites and blacks, but dysgerminoma rates were higher in whites and other nonwhites than in blacks. Using the registries for expanded races, rates were higher for Asian/Pacific Islanders (P = .059) and Hispanics (P = .07). By age at diagnosis, 15-19 year olds had the highest rates and the only significant change in rates (37.5% increase, P = .008). The 5-year relative survival was 83.9%. Survival rates improved significantly over calendar time and varied by histologic subtype, race, stage of disease, and age at diagnosis.

CONCLUSION

Over the past 30 years, germ cell tumor incidence rates have declined in women and differ from rising trends reported for testicular tumors. Survival rates have improved but were lower for older women and for nondysgerminoma subtypes.

Germ-cell testicular cancer in offspring of Finnish immigrants to Sweden

Variation in testicular cancer incidence can be used to assist in identification of risks. Finland has a significantly lower germ-cell testicular cancer risk than Sweden. Finns who immigrate to Sweden maintain their lower risk irrespective of age at immigration. We investigated difference in risk between Finland and Sweden by examining germ-cell testicular cancer incidence in males born in Sweden to Finnish immigrant parents. Swedish general population registers were used to identify 11,662 males born in Sweden where both Finnish parents immigrated to Sweden from Finland from 1969 or afterward. All of these offspring were at least 15 years old by final follow-up in 2001. Some six offspring (all diagnosed between ages 20 and 24 years) had a diagnosis of germ-cell testicular cancer. Comparison with the Swedish population rate produced standardized incidence ratios [SIR (95% confidence interval)] of 0.85 (0.31-1.84) for all the men and 1.75 (0.64-3.81) for the 20- to 24-year age group. SIRs calculated using the Finnish population rates produced an overall SIR (95% confidence interval) of 1.11 (0.41-2.41) and 2.95 (1.08-6.42) for the 20- to 24-year age group. Although the substantially reduced risk of testicular cancer previously observed in Finnish immigrant to Sweden was not found, this study had insufficient statistical power to conclude that environmental exposures explain the difference in germ-cell testicular cancer risk between Finland and Sweden.

Factors associated with non-epithelial ovarian cancer among Mexican women: A matched case-control study

The purpose of this study was to identify risk factors associated with the development of non-epithelial ovarian cancer in Mexican women. A case-control study was carried out on women registered with the Mexican Institute of Social Security in Mexico City over a period of two years (1995-97). Twenty-eight new cases were recruited from the Gynecology and Obstetrics Hospital no. 4, "Luis Castelazo Ayala", and were matched by age with 84 controls selected randomly. Eighteen (64.3%) cases of germ cell tumors and 10 (35.7%) stromal sex cord tumors were found. The number of full term pregnancies was associated inversely to development of stromal sex cord tumors with lower risk in women with more than three full term pregnancies (odds ratio, 0.02: 95% confidence interval, 0.001-0.56) compared to nulliparous women. No associations were found respecting to germ cell tumors. Parity was inversely associated to development of stromal sex cord tumors, probably as a result of the endocrine system's influence on the ovaries. The development of germ cell tumors could be associated to factors not evaluated in this study.

Identical characteristics of the patient populations with pineal region tumors in Japan and in Korea and therapeutic modalities

The therapeutic modalities used for tumors of the pineal region in Western countries differ from those in Japan, mainly because of the different patient populations. An extensive survey was conducted to delineate the racial differences in Japan and in Korea in the epidemiology and recent therapeutic modalities for this tumor group. Among the members of International Society for Pediatric Neurosurgery (ISPN), 15 from Japan and 5 from Korea reported their recent findings in 118 (1-25 years of age, mean 7.38-year period) and 125 (1-12 years of age, mean 6.69-year period) histologically verified cases, respectively. The patient populations in the two countries were found to be almost identical, with an extremely high incidence of germ cell tumors representing 71.2% (in Japan) and 80.0% (in Korea) of all pineal region tumors and neuroectodermal tumors representing only 15.2% and 16.8%, respectively. The most common type of pineal region tumor was germinoma (46.6% in Japan and 47.2% in Korea). The majority of tumors were radio- and/or chemosensitive, and adjuvant therapy rather than extensive surgery played the major role in the treatment in both countries. Radical resection of the tumor was recommended as the initial procedure by only 22.2% of neurosurgeons in Japan and 16.6% in Korea. Biopsy was recommended by 38.9% and 50.0%, and radiation therapy by 38.9% and 37.5%, respectively. A minimally invasive procedure, by either a neuroendoscopic (33.3% of biopsies in Japan) or a stereotactic approach (33.3% of biopsies in Korea), was considered to be appropriate as the initial procedure. The study disclosed the almost identical epidemiology of this brain tumor in Japan and in Korea and clarified the consequent therapeutic modalities. The authors emphasize that minimally invasive tissue diagnosis with or without tumor debulking should be considered as the initial step for the treatment planning of the pineal region tumor, followed by the most commonly indicated major procedures, including radiation therapy, chemotherapy and/or radical resection with various methodologies.

Is the risk of cancer increased in Asians living in the UK?

The pattern of cancer in white and Asian (Indian, Pakistani, and Bangladeshi) children living in the West Midlands Health Authority Region was investigated using age standardised incidence rates. Two sets of rates were calculated, a 10 year rate (1982-91) using survey based estimates of the ethnic population and a four year rate (1989-92) using the ethnic population counts from the 1991 census. The 10 year rates showed a significantly higher annual incidence of cancer in Asian (159.1/million/year) than in white (130.8) children. The pattern of cancers in Asian children was different, with an excess of lymphomas and germ cell tumours, and a deficit of rhabdomyosarcomas. These findings were confirmed by the four year rates. Although underestimation of the Asian population probably contributes to the apparent excess, there remains cause for concern that UK Asian children may be at higher risk of cancer. Accurate ethnic population figures and confirmatory studies are urgently required.

Incidence of childhood cancer in Osaka, Japan, 1971-1988: reclassification of registered cases by Birch's scheme using information on clinical diagnosis, histology and primary site

In 1971-1988, 4,021 malignant tumors occurring among children under 15 years of age were registered in the Osaka Cancer Registry, a population-based registry which covers Osaka Prefecture, Japan. These patients were reclassified into 12 diagnostic groups by Birch's scheme using information on clinical diagnosis, histology and primary site. The annual age-standardized incidence rate for childhood cancer per million children was 130.3 for males and 104.9 for females in 1971-88. Comparing the incidence rates for both sexes in 1981-88 with those in 1971-80 in Osaka, we observed a significant decrease of acute non-lymphocytic leukemia (ANLL) and a significant increase of all cancers, acute lymphocytic leukemia, non-Hodgkin lymphoma, sympathetic nervous system tumors, soft-tissue sarcomas, and gonadal and germ-cell tumors. Age-standardized incidence rates in around 1971-80 of the above-mentioned diagnostic groups were compared among 4 population-based registries; Osaka, Miyagi (Japan), SEER (U.S.), and the National Registry of Childhood Tumors (England and Wales). Rates for ANLL and gonadal and germ-cell tumors were higher and those for other diagnostic groups were lower in Osaka, especially for Hodgkin's disease. Thus, in 1980-88 in Osaka, rates for Hodgkin's disease remained low and rates for gonadal and germ-cell tumors increased, though rates for other cancers appeared to resemble the levels in caucasian populations. The incidence of childhood cancer in Japan was estimated according to the diagnostic groups in Birch's scheme.

Testicular cancer and cryptorchidism

The records of 273 patients with germ cell tumours of the testis referred between 1970 and July 1991 were reviewed. There were 25 (9%) black, 40 (14%) mixed race and 214 (77%) white patients. Histology showed seminoma in 53% and non-seminomatous and germ cell tumours in 47% of patients. Maldescent of the testis (MDT) was found in 30 patients--an incidence of 11% overall. MDT was present in 8 of 25 (32%) black, 7 of 40 (18%) mixed race and 15 of 214 (7%) white patients with testicular cancer. The incidence of MDT was statistically significantly higher in both black and mixed race patients compared with white patients. None of the black patients had undergone orchiopexy but 71% of mixed race and 87% of white patients had done so. This resulted in a different pattern of presentation in black compared with mixed race and white patients with MDT and testicular cancer. The mean age was 40 years for black, 32 years for mixed race and 33 years for white patients. Black patients presented with abdominal or inguinal tumours rather than scrotal tumours and they had an increased tendency to present with seminomas.

Increased incidence of germ cell testicular cancer in New Zealand Maoris

A higher incidence of germ cell testicular cancer was found in Maoris (6.84/100,000) compared with non-Maoris (5.26/100,000) in New Zealand from 1975 to 1986, especially in the 15-49 year age group (Maoris 12.30/100,000, non-Maoris 9.47/100,000; P = 0.04). Previous studies have shown Whites to have the highest incidence of this malignancy. Possible reasons for this and some other epidemiological features are discussed.