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A total of 42,854 patients with TGCTs were identified and included for the final analyses. The median age of the cohort was 33 years (IQR, 27–42 years). Over two-thirds of patients were white (n = 31,280, 73.0%) while 2.6% (n = 1,128) were black, 19.9% (n = 8,509) Hispanic and 4.5% (n = 1,937) other. Over 60% of patients were diagnosed after the year 2004. Considering all subjects, men were almost evenly distributed in three age categories, with a slightly higher proportion diagnosed at ages 15–29 and slightly less at age 40 and up. Almost half were single (never married), and another half were married (including common law). More than two-thirds of male were diagnosed with SEER histological A stage of local, and more than half (58.2%) of the cases were seminoma TGCT. Surgery was performed on 97% patients. More than one-third (41.5%) of patients had a median family income of less than $5,000. 91.8% of the cases were alive during the surveillance period.
The age at diagnosis differed significantly by race (Table 1). Most Hispanic patients (53.9%) were younger than 30 years, but NH-white or black patients were elder than 30 years old or older when they were diagnosed. More than half of Hispanic (55.7%) and black (55.4%) patients were single compare to almost a half (49.0%) of NH-white patients who were married. Black men more likely to be diagnosed at later stages, had higher percentages of regional or distant metastasis, had more seminoma cancers, had fewer nonseminomas, and had less surgeries performed compared to other races. Hispanic men were diagnosed at earlier ages, and lower household incomes compared to other races. Compared to NH-white men and men of other races, Hispanic men had more nonseminoma cancers and fewer seminomas. There was little variation across the different racial groups according to SES. Compared to NH-white men, black and Hispanic men lived in counties with slightly lower median household income.
Variables Whole cohort (%)
(N = 42,854)Race/Ethnicity White (%)
(n = 31,280)Black (%)
(n = 1,128)Hispanic (%)
(n = 8,509)Others (%)
(n = 1,937)SEER histo A stage* Localized 70.0 71.9 61.7 64.3 69.3 Regional 18.5 18.2 22.2 19.4 17.3 Distant spread 11.5 9.9 16.1 16.3 13.4 Age at Diagnosis (year) 15–29 36.0 31.1 29.2 53.9 41.0 30–39 33.7 34.3 37.3 31.1 33.5 > 39 30.2 34.5 33.5 15.0 25.5 Period of Diagnosis 1992–1997 12.9 14.2 10.9 8.6 12.9 1998–2003 23.9 25.4 24.8 19.1 20.2 2004–2009 30.4 30.3 29.2 31.5 27.9 2010–2015 32.8 30.1 35.1 40.8 39.0 Marital status Single 44.5 40.5 55.4 55.7 53.1 Married 45.4 49.0 31.8 35.6 38.8 Other 10.1 10.6 12.8 8.6 8.1 Histologic type Seminoma 58.2 60.2 65.0 49.6 58.9 Nonseminoma 41.8 39.8 35.0 50.4 41.1 Surgery Yes 97.6 98.0 95.1 96.7 97.1 No 2.4 2.0 4.9 3.3 2.9 Income ($) ≤ 5,000 41.5 37.1 53.5 58.1 32.4 5,000–7,500 48.2 51.7 41.5 34.8 55.1 > 7,500 10.2 11.2 5.0 7.1 12.5 Vital status Alive 91.8 92.2 86.3 91.5 91.3 Deceased 8.2 7.8 13.7 8.5 8.7 Note. *SEER histological A stage categories. Some of the results do not add up to 100% due to rounding. Table 1. Characteristics of the SEER study population, overall and separately by race/ethnicity
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Three-year relative survival was calculated for successive intervals for patients with all TGCTs, and calculated for seminoma and nonseminoma subtypes by race (Figure 2). In general, all TGCT and both two subgroups had improved survival rates over the study period.
Figure 2. Relative survival rates by race/ethnicity for TGCT cases in different groups. (A) Relative survival rates of all TGCT cases by race/ethnicity (1992–2015); (B) among nonseminoma TGCT cases by race/ethnicity; (C) among seminoma TGCT cases by race/ethnicity.
Overall (Figure 2A), the 3-year survival rate for patients with TGCT was highest among NH-whites (97.0%, 95% CI: 96.7%–97.2%) and lowest among blacks (91.7%, 95% CI: 89.5%–93.5%). From 1992 to 1997, the 3-year survival rate was 96.6% (95% CI: 95.9%–97.1%) for white patients and 88.4% (95% CI: 80.7%–93.2%) for black patients. Compared with NH-whites, whose 3-year survival rates were consistently on high level, Hispanic, black and other TGCT patients has increased survival rates, especially in blacks.
The most significant increase in TGCT survival rate occurred in blacks with nonseminoma TGCT. The 3-year survival rate for this subgroup increased from 80% for patients diagnosed during 1992 through 1997 to 86% for those diagnosed in 2010 through 2015 in the SEER 18 areas (Figure 2B). The survival rate of nonseminoma TGCT patients was high for other races and no significant improvement was observed. A more modest increase in survival was observed for blacks with seminoma TGCT (Figure 2C), which rose from 93% to 96% over the same period. The 3-year survival rate of all TGCTs, especially the nonseminoma subtype was lower in blacks comparing to other races.
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OS among different races and histologic subtypes, OS of TCGTs diagnosis during 2004 to 2015 were used for the current disparities. Racial differences were note in OS. For all TGCTs, Kaplan-Meier survival curve of NH-white patients demonstrated the highest OS compared with Hispanic whites and other races, whereas, blacks demonstrated the lowest survival to compare with other races (Figure 3A). The hazard ratio for death (overall mortality) was 2.00 (P < 0.001) blacks compared to NH whites. The hazard ratio for others for death was 1.23 (P = 0.009) compared to NH whites, a difference which is not statistically significant. It is clear that OS of nonseminoma patients is significantly worse than seminoma patients (Figure 3B) with a hazard ratio at 1.54 (P < 0.001).
Figure 3. OS rate in different guoups. (A) OS rate by race/ethnicity (NH-which, black, Hispanic, and others) among all TCGT cases; (B) OS rates by histological subtype; (C) OS rates by race/ethnicity among cases with seminoma; (D) OS rates by race/ethnicity among cases with non-seminoma; (E) OS rate by age of diagnosis (15–29, 30–39, > 39) among all TCGT cases; (F) OS rate by age of diagnosis among cases with seminoma; (G) OS rate by age of diagnosis among cases with non-seminoma.
For seminoma, there were no racial differences in OS among NH whites, Hispanics or others (Figure 3C). Only blacks had lower OS to compare with NH-whites, with the hazard ratio for death of 1.43 (P < 0.001). For nonseminoma, both Hispanics and others demonstrated lower OS rates to compare to NH-whites (Figure 3D). Lowest survival for blacks compared to NH whites with the hazard ratio of 1.66 (P < 0.001), which was significantly different from Hispanics and other race/ethnic groups.
In addition, we found that the age of diagnosis also has a very important influence on OS both for all TCGTs and for cases with seminoma or nonseminoma. For all TGCTs, Kaplan-Meler survival curve of > 39 patients demonstrated the lowest OS compared with other age group (Figure 3E). The hazard ratio for death was 2.07 (P < 0.001) of > 39 compared to 15–29. For seminoma, > 39 have lower OS rates to compared with 15–29 and 30–39, the risk ratio in the > 39 age group was 2.44 (P < 0.001) (Figure 3F). For nonseminoma, The hazard ratio for death was 3.53 (P < 0.001) of > 39 compared to 15–29 (Figure 3G).
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Black race, older age, single marital status, lower income and later stage at diagnosis were identified to be independent mediators of higher mortality rates by using the Cox proportional hazards model (Table 2). And we considered using SEER histo A stage or AJCC stage alone for cox regression analyses (Table 3). Comparing Tables 2 and 3, it can be seen that the trend is basically the same, but metastasis in the SEER histology A-stage category in Table 3 has a greater risk. The Cox proportional model demonstrated that the most significant quantitative predictor of death was stage at the time of diagnosis, with more advanced stages having higher mortality rates compared to less advanced stages. Age at diagnosis was also significantly associated with mortality in this model. Patients > 39 years age at diagnosis was shown to be worst mortality rates.
Variables All TGCTs Seminoma Nonseminoma HR 95% CI HR 95% CI HR 95% CI SEER histo A stage* Localized Ref − Ref − Ref − Regional 1.74 1.59–1.91 1.78 1.57–2.01 1.66 1.43–1.92 Metastasis 7.47 6.93–8.05 5.40 4.78–6.08 8.09 7.24–9.05 Race/Ethnicity NH-white Ref − Ref − Ref − Black 1.56 1.33–1.84 1.36 1.08–1.71 1.90 1.51–2.39 Hispanic 1.35 1.24–1.48 1.20 1.05–1.38 1.45 1.29–1.63 Others 1.23 1.05–1.44 1.13 0.90–1.42 1.38 1.11–1.72 Age at Diagnosis (year) 15–29 Ref − Ref − Ref − 30–39 1.49 1.36–1.64 1.68 1.41–2.01 1.63 1.45–1.83 > 39 3.33 3.04–3.64 4.48 3.78–5.30 3.27 2.88–3.72 Period of Diagnosis 1992–1997 Ref − Ref − Ref − 1998–2003 0.96 0.87–1.06 0.93 0.81–1.06 0.98 0.85–1.14 2004–2009 0.91 0.82–1.02 0.83 0.72–0.97 0.97 0.83–1.12 2010–2015 0.91 0.81–1.03 0.90 0.75–1.08 0.90 0.77–1.06 Marital status Single Ref − Ref − Ref − Married 0.56 0.51-0.60 0.51 0.46-0.57 0.63 0.56-0.71 Other 0.96 0.86-1.06 1.00 0.86-1.15 0.91 0.85-1.07 Income ($) ≤ 5,000 Ref − Ref − Ref − 5,000–7,500 0.80 0.75–0.86 0.77 0.70–0.86 0.83 0.76–0.92 > 7,500 0.69 0.61–0.78 0.61 0.51–0.73 0.80 0.68–0.96 Note. *SEER histological A stage categories. Table 2. Cox regression analyses of 5-year seminoma TGCT mortality in 25,000 US patients according to histology and clinical characteristics
Variables Only SEER histo A stage* Only AJCC stage All TGCT Seminoma Nonseminoma All TGCT Seminoma Nonseminoma HR 95% CI HR 95% CI HR 95% CI HR 95% CI HR 95% CI HR 95% CI Derived AJCC Stage Group, 6th ed TNM I − − − − − − Ref − Ref − Ref − TNM II − − − − − − 1.57 1.29–1.91 1.91 1.48–2.49 1.21 0.89–1.64 TNM III − − − − − − 9.10 8.15–10.15 5.84 4.90–6.96 10.14 8.60–11.95 SEER histo A stage Localized Ref − Ref − Ref − − − − − − − Regional 1.84 1.58–2.15 2.09 1.71–2.55 1.49 1.17–1.91 − − − − − − Metastasis 10.91 9.72–12.24 7.19 5.96–8.67 11.39 9.61–13.51 − − − − − − Race/Ethnicity NH-white Ref − Ref − Ref − Ref − Ref − Ref − Black 1.54 1.21–1.96 0.95 0.95–1.95 1.79 1.30–2.48 1.49 1.17–1.90 1.32 0.92–1.89 1.80 1.30–2.49 Hispanic 1.32 1.17–1.50 0.85 0.85–1.31 1.47 1.26–1.71 1.32 1.17–1.50 1.05 0.84–1.31 1.47 1.27–1.71 Others 1.32 1.05–1.66 0.73 0.73–1.60 1.51 1.14–2.02 1.34 1.07–1.69 1.10 0.74–1.63 1.56 1.17–2.07 Age at Diagnosis (year) 15–29 Ref − Ref − Ref − Ref − Ref − Ref − 30–39 1.42 1.23–1.64 1.01 1.01–1.80 1.69 1.43–2.00 1.38 1.20–1.59 1.32 0.98–1.76 1.68 1.42–1.99 > 39 2.95 2.59–3.37 2.75 2.75–4.64 3.31 2.78–3.95 2.95 2.59–3.37 3.61 2.78–4.68 3.40 2.86–4.06 Period of Diagnosis 2004–2009 Ref − Ref − Ref − Ref − Ref − Ref − 2010–2015 1.04 0.93–1.16 0.95 0.95–1.37 0.98 0.85–1.12 1.12 1.00–1.25 1.19 0.99–1.43 1.04 0.91–1.20 Marital status Single Ref − Ref − Ref − Ref − Ref − Ref − Married 0.56 0.50–0.64 0.43 0.43–0.62 0.64 0.54–0.75 0.58 0.51–0.65 0.52 0.43–0.63 0.65 0.55–0.77 Other 0.91 0.77–1.07 0.79 0.79–1.24 0.83 0.66–1.04 0.90 0.77–1.06 1.01 0.80–1.26 0.79 0.63–0.99 Income ($) ≤ 5,000 Ref − Ref − Ref − Ref − Ref − Ref − 5,000–7,500 0.73 0.65–0.81 0.62 0.62–0.86 0.74 0.64–0.85 0.73 0.65–0.81 0.73 0.62–0.86 0.74 0.64–0.85 > 7,500 0.64 0.52–0.79 0.42 0.42–0.80 0.70 0.53–0.92 0.64 0.52–0.79 0.58 0.42–0.80 0.68 0.52–0.89 Note. *SEER histological A stage categories Table 3. Comparison of only SEER histo A stage and only AJCC stage in patients after 2004 using cox regression analyses
In addition, lower income is also a very important factor. Black low income has worsened in recent years (2010–2015) (Figure 4A). The three-year survival rate of the middle- and high-income situation is stable over 90%, but there is still a gap with white (Figure 4B). Above we all use multivariate analysis.
Figure 4. Relative survival rates by race/ethnicity for different income groups cases. (A) Relative survival rates of low income cases by race/ethnicity; (B) among middle & high income cases by race/ethnicity.
After assessment of the mortality in TGCTs with different histology types, we identified that black patients had a statistically significantly higher hazard ratio compared to white patients (HR = 1.56; 95% CI: 1.59–1.91) among overall TGCT cases. However, black patients with the seminoma subtype were not did not have a significantly higher mortality rate comparable with NH-white patients (HR = 1.36; 95% CI: 1.08–1.71). Contrary, black patient with the nonseminoma subtype had a significantly higher mortality rate when compared with NH-white patients (HR = 1.90; 95% CI: 1.51–2.39). In the cohort we can see the obvious difference in the number of people of different races, with the largest number of whites and three times the sum of the other three races. The most localized in whites, the highest proportion of blacks with a diagnosis age of > 39 (Supplementary Table S1, available in www.besjournal.com).
Variables Whole cohort (%)
N = 17,928Race/Ethnicity White (%)
n = 12,444Black (%)
n = 395Hispanic (%)
n = 4,292Others (%)
n = 797SEER histo A stage* Localized 58.4 60.1 51.4 54.2 57.1 Regional 22.3 23.0 19.7 21.1 20.8 Distant spread 19.3 17.0 28.9 24.7 22.1 Age at Diagnosis (year) 15–29 55.8 50.1 48.4 71.9 60.9 30–39 28.0 30.2 30.9 21.9 26.2 > 39 16.2 19.7 20.8 6.2 12.9 Period of Diagnosis 1992–1997 12.3 14.0 11.1 7.9 10.5 1998–2003 22.3 24.0 25.6 17.9 18.4 2004–2009 30.9 30.6 27.8 32.4 28.7 2010–2015 34.5 31.4 35.4 41.8 42.3 Marital status Single 57.0 53.0 62.3 66.3 66.4 Married 34.2 37.6 27.1 26.3 27.2 Other 8.8 9.4 10.6 7.4 6.4 Surgery Yes 97.3 97.7 94.2 96.8 96.1 No 2.7 2.3 5.8 3.2 3.9 Income ($) ≤ 5,000 43.3 38.1 58.2 59.0 33.4 5,000–7,500 47.4 51.6 37.5 34.7 54.0 > 7,500 9.3 10.3 4.3 6.3 12.7 Vital status Alive 90.1 90.8 80.0 89.0 89.1 Deceased 9.9 9.2 20.0 11.0 10.9 Note. *SEER histological A stage categories. Some of the results do not add up to 100% due to rounding. Table S1. Characteristics of the nonseminoma, overall and separately by race/ethnicity
Assessment of Prognostic Factors of Racial Disparities in Testicular Germ Cell Tumor Survival in the United States (1992–2015)
doi: 10.3967/bes2021.021
- Received Date: 2019-12-09
- Accepted Date: 2020-11-04
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Key words:
- Testicular cancer /
- Germ cell tumor /
- Race /
- Survival rate /
- Survival analysis
Abstract:
Citation: | WU Jing, JI Yi Bing, TANG Bi Wei, BROWN Matthew, WANG Bao Hua, DU Chen Lei, DU Jian Shu, WANG Xue Mei, CAI Li Jun, WU Guo Yi, ZHOU Yan. Assessment of Prognostic Factors of Racial Disparities in Testicular Germ Cell Tumor Survival in the United States (1992–2015)[J]. Biomedical and Environmental Sciences, 2021, 34(2): 152-162. doi: 10.3967/bes2021.021 |