A Surveillance, Epidemiology and End Results database analysis of the prognostic value of organ‑specific metastases in patients with advanced prostatic adenocarcinoma
- Authors:
- Published online on: June 7, 2019 https://doi.org/10.3892/ol.2019.10461
- Pages: 1057-1070
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Copyright: © Deng et al. This is an open access article distributed under the terms of Creative Commons Attribution License.
Abstract
Introduction
Prostate, lung and colorectal cancer account for ~42% of all cancer types in men, and prostate cancer (PCa) accounts for almost one in five newly diagnosed cancer cases in the United States (1). In the United States, PCa is the most common cancer in men, and PCa-specific mortality ranks second, after that of lung cancer (2). Although four well-established risk factors have been identified, namely increased age, ethnicity, obesity and family history, other potential factors that determine the risk of developing PCa are not well known (3,4). Histologically, most cases of PCa are classified as acinar adenocarcinoma and have a poor prognosis (5).
There is increasing awareness that cancer metastasis plays an important role in the survival of PCa patients. Treatment decisions for PCa patients differ according to both patient- and disease-related factors. Radical prostatectomy (RP) is the standard treatment for clinically localized PCa, and it provides adequate local control in organ-confined disease (6). Traditionally, RP is discouraged in patients with advanced disease, owing to the increased complication rate and treatment-related morbidity (7). In recent years, it has been suggested that prostatectomy may provide a benefit for metastatic PCa patients (8); however, for advanced disease with site-specific metastasis of the bone, brain, liver or lung, there is insufficient evidence to support the efficacy of prostatectomy, particularly RP which includes including total prostatectomy and cystoprostatectomy.
To the best of our knowledge, analyses of the prognostic value of organ-specific metastasis based on large population-based data for PCa are lacking. Thus, in the present study, the data pertaining to metastatic prostate adenocarcinoma patients registered in the Surveillance, Epidemiology and End Results (SEER) database was reviewed, and the prognostic outcomes were analyzed to assess the efficacy of prostatectomy among patients with bone metastasis only.
Materials and methods
Data collection/selection and description of participants
The SEER-18 Regs Research Data released in November 2017 was retrieved using the SEER*Stat software version 8.3.5 (https://seer.cancer.gov/seerstat/software/) (National Cancer Institute; National Institutes of Health, USA). Detailed information about distant metastatic sites was updated to 2013 and was not available before the year 2010. Therefore, the current study was restricted to patients registered between January 2010 and December 2013. The survival data of PCa patients was monitored until December 2017. In order to identify patients with metastatic prostate adenocarcinoma, cases were included with the primary site stated as ‘Prostate’ and the following codes: ICD-O-3 Hist/behave, malignant=‘8140/3: Adenocarcinoma, NOS’. Patients with stage I, II and III PCa according to the 7th AJCC prostate cancer classification criteria were excluded (9). Cases with unknown race data, unknown marital status data, unknown survival data and unknown specific metastatic site data were excluded. Only data from patients with single primary PCa were extracted. Extracted data included the following: Marital status at diagnosis, age at diagnosis, sex, race (white, black or other), grade, TNM stage according to the AJCC (7th edition, 2010), RX Summ-Surg Prim Site (surgical information of primary cancer site), radiation sequence with surgery, CS mets at DX-bone (bone metastases since 2010), CS mets at DX-brain (brain metastases since 2010), CS mets at DX-liver (liver metastases since 2010), CS mets at DX-lung (lung metastases since 2010), cancer-specific factor 1 (serum PSA levels), survival and vital status record (10). At present, systemic therapy data are not available in the SEER database. Exclusion criteria were as follows: i) Patients with unclear derived M stage according to the AJCC (7th edition); ii) patients with unclear RX Summ-Surg Prim Site (1998+); iii) patients classified as clinical stage I/II or III prostate adenocarcinoma according to the AJCC 7th edition.
Study variables
Patient characteristics were extracted from the SEER database, including marital status, race, age at diagnosis, TNM stage at diagnosis, primary tumor site, grade, surgery condition, radiotherapy condition, bone metastasis, brain metastasis, liver metastasis and lung metastasis. According to the AJCC 7th edition criteria of TNM stage and clinical stage of prostate cancer, PCa patients with T4, N0, M0 any T stage, N1, M0, and any T stage, any N stage, M1 were classified as stage IV patients.
Statistical analysis
In the present study, the χ2 test was used to compare the clinicopathological characteristics among cases with and without bone metastasis. Kaplan-Meier analysis was used to build survival curves and log-rank testing was employed for the comparison of long-term survival outcomes. The Cox proportional hazards regression model was employed to perform univariate and multivariate analyses of the hazard ratios with corresponding 95% confidence intervals (CIs) of the study variates. Associations between marital status, age at diagnosis, race, histological grade and TNM stage at diagnosis were examined by binary logistic regression. A two-tailed P-value of <0.05 was considered to indicate a statistically significant difference. All statistical analyses were performed using SPSS software 20.0 (IBM Corporation).
Results
Incidence of different metastatic sites among stage IV PCa patients
The selection criteria are shown in Fig. 1. Among 210,730 cases identified in the SEER database, a total of 10,777 patients with stage IV prostatic adenocarcinoma between January 2010 and December 2013 were included in the present study.
Table I summarizes the distribution of different clinical characteristics of PCa patients. The majority of patients (n=5,963, 55.33%) presented with bone metastasis, followed by lung (n=512, 4.75%), liver (n=280, 2.60%) and brain (n=83, 0.77%) metastasis. Prostatectomy (RP, including total prostatectomy and cystoprostatectomy) was performed in 2,981 (27.66%) patients, and 1,085 (10.07%) patients received radiation therapy. There were 4,258 (39.51%) patients with lymph node metastasis.
 | Table I.Baseline characteristics of patients with stage IV prostate adenocarcinoma (n=10,777) in the present study. |
Identification of statistically significant variates with regard to survival outcomes in patients with stage IV PCa
Several variates were identified by univariate and multivariate analysis of cancer specific-survival (CSS) and overall survival (OS) in PCa patients using Cox hazards regression models. Single/unmarried status, age ≥50 years, black race, M1 stage, bone metastasis, liver metastasis and lung metastasis were associated with worse CSS and OS. Races classified as ‘other’ (American Indian/Alaska native and Asian/Pacific Islander), radiation therapy and prostatectomy were associated with better CSS and OS (Tables II and III). Based on multivariate Cox regression analysis, the following factors were significantly associated with poor OS and/or CSS: Single/unmarried status [hazard ratios (HRs), 1.164 (CSS) and 1.211 (OS), P<0.001], age ≥50 years [HRs, 1.309 (CSS), P=0.034 and 1.421 (OS), P=0.003], black race vs. white race; [HR, 1.151 (CSS), P=0.009], M1 stage [HRs, 3.096 (CSS) and 2.419 (OS), P<0.001] and PSA level >20 ng/ml [HR, 1.27 (OS), P=0.035]. On the other hand, ‘other’ race (American Indian/Alaska native and Asian/Pacific Islander) was a significant predictor of better CSS and OS (vs. white race; HRs, 0.750, P=0.005 and 0.774, P=0.004, respectively), as was prostatectomy (HR, 0.147 and 0.143, respectively, P<0.001). Radiation therapy was a significant predictor of better OS only (HR, 0.756, P=0.003) (Table III). Next, Kaplan-Meier survival analysis was performed to calculate the differences in OS and CSS by the variates identified through multivariate Cox hazards regression analysis (Fig. 2). The 3-year CSS rate of patients who received prostatectomy was 97.3%, compared with 54.3% in patients who did not undergo prostatectomy (P<0.0001). The 3-year OS rate of patients who received prostatectomy was 96.0%, whereas that of patients who did not was only 47.4% (P<0.001) (Fig. 2E). Married status, age <50 years and radiation therapy also led to higher 3-year CSS and OS rates (Fig. 2A, B and D). By contrast, M1 stage, bone metastasis, liver metastasis, lung metastasis and black race were associated with reduced survival in stage IV PCa patients (Fig. 2C and F-I).
Impact of site-specific metastasis on survival outcomes
As it was found that metastasis to different organs may induce different survival outcomes in stage IV PCa patients, Kaplan-Meier survival analysis was performed to compare OS in advanced PCa patients with metastasis to the bone, brain, liver and lung. A total of 608 patients with metastatic lesions in multiple organs were excluded, and 10,169 patients were included in the analysis. Of these patients, 52.74% had bone metastasis, 0.22% had brain metastasis, 0.42% had liver metastasis, and 0.78% had lung metastasis (Fig. 3A). It was demonstrated that PCa patients with only liver metastasis had the worst 3-year CSS and OS rates (31.9 and 22.8%, respectively). The 3-year CSS and OS rates of patients with only bone metastasis were 49.6 and 41.6%, respectively. Patients with only lung metastasis (3-year CSS and OS, 79.9 and 63.7%) had improved OS compared with those with only bone or liver metastasis (Fig. 3B and C).
Identification of risk factors for bone metastasis in patients with stage IV PCa
As the present results indicated that stage IV PCa was most prone to distant metastasis to the bone, multivariate binary logistic regression analysis was performed to identify risk factors of bone metastasis in 10,777 patients with advanced PCa. The results suggested that single/unmarried status, black race, NX stage and grade IV (undifferentiated adenocarcinoma) were risk factors for bone metastasis. T3 and T4 stage patients, as well as N1 stage patients, were less likely to have bone metastasis (Table IV).
| Table IV.Multivariate binary logistic regression analysis of patient characteristics classified by bone metastasis at diagnosis (n=10,777). |
Identification of ‘risk’ factors and ‘protective’ factors for CSS and OS in patients with advanced PCa with only bone metastasis
Univariate and multivariate COX hazards regression analyses were conducted in 5,363 patients with stage IV PCa with only bone metastasis to identify the contribution of different variates to CSS and OS. According to the results, single/unmarried status was deemed as risk factor for CSS and OS; age ≥50 years was deemed as risk factor for OS (Tables V and VI). On the other hand, ‘other’ race (American Indian/Alaska native and Asian/Pacific Islander), T1 stage, T3 stage and prostatectomy were regarded as ‘protective’ factors in stage IV patients with only bone metastasis, moreover, T2 stage was additionally regarded as a ‘protective’ factor for CSS in stage IV PCa patients but not OS (Tables V and VI).
| Table V.Univariate COX analysis of CSS and OS in patients with advanced prostate cancer and only bone metastasis. |
| Table VI.Multivariate COX analysis of CSS and OS in patients with stage IV prostate cancer with only bone metastasis. |
Prostatectomy is effective in improving survival outcomes in patients with advanced PCa with only bone metastasis
Kaplan-Meier analysis was conducted using significant factors from Cox regression analysis to determine their impact on survival in patients with stage IV PCa with only bone metastasis. According to the results, married patients had better 3-year survival rates than single/unmarried patients (CSS, 51.9 vs. 46.2%; OS, 45.6 vs. 38.5%; Fig. 4A). ‘Other’ race patients (American Indian/Alaska native and Asian/Pacific Islander) also had better CSS and OS than white patients (Fig. 4B). T1 and T3 stage patients had better CSS and OS than T0 stage patients, although this difference was not statistically significant (Fig. 4C). Radiation therapy did not significantly improve patient's survival (Fig. 4D). Moreover, it was found that prostatectomy could potently improve the 3-year CSS and OS rates (vs. no prostatectomy; CSS, 85.1 vs. 49.0%; OS, 81.5 vs. 42.1%; Fig. 4E). The HR of CSS in patients with T2 stage bone metastases was 0.523; suggesting that patients with stage T2 cancer had improved specific survival outcomes compared with T0 patients (Table VI). However, as the effect of T2 stage did not significantly affect OS, it is possible that T2 stage would be a protective factor for survival outcomes in single bone metastasis PCa patients.
Discussion
The main findings of the present study were: i) Prostate adenocarcinoma patients with only liver metastasis had worse prognostic outcomes than those with only bone or only lung metastasis; ii) prostatectomy potently improved the CSS and OS of stage IV PCa patients with only bone metastasis; and iii) unmarried status, age ≥50 years, M1 stage, bone metastasis, liver metastasis and lung metastasis were risk factors for survival in patients with stage IV PCa.
The Cox regression model is widely used in survival analysis with censoring data and different covariates (11). When analyzing survival data of the patients, the HR generated by Cox regression model represents the probability of death at a particular time. The Kaplan-Meier curve can efficiently use all data, including the censored data, to estimate the time-to-event curve. Comparisons of different groups is assessed by log-rank test, which is able to estimate the long-term prognosis of patients (11). Therefore, survival analysis of stage IV PCa patients and single bone metastasis advanced PCa patients was performed using the Cox regression model and Kaplan-Meier analysis methods.
Using COX regression models, M1 stage, bone metastasis, liver metastasis and lung metastasis were first identified to be significantly associated with impaired CSS and OS (Tables II and III) among stage IV PCa patients. Radiation therapy and prostatectomy were also identified to be effective therapeutic methods to improve patient CSS and OS in advanced PCa.
The bone was revealed to be the most common metastatic site for stage IV PCa, and patients with bone metastases had significantly impaired CSS and OS rates. Therefore, it was necessary to find risk factors that were associated with bone metastasis in stage IV PCa. Multivariate binary logistic regression analysis suggested that single/unmarried patients, black patients and patients with grade IV (undifferentiated adenocarcinoma) were more likely to have bone metastasis (Table VI). However, T3 stage, T4 stage and N1 stage were ‘protective’ factors. One possible explanation for this result is that certain groups of patients were included that were diagnosed as having stage IV PCa according to the AJCC 7th edition, but did not have metastatic disease: Patients with i) any T stage, N1, M0; ii) T4,any N stage, M0; and iii) T3, N1, M0.
As bone metastasis may potently impair survival outcomes for patients with stage IV PCa, finding effective treatment methods to improve the CSS and OS of patients with bone metastasis is necessary. Historically, RP has not been recommended for patients with advanced PCa presumed to have extra-prostatic disease; instead, patients with advanced PCa were counseled to undergo radiation therapy or hormonal therapy (12). However, local resection of the primary site for metastatic solid tumors has been demonstrated to be helpful in various cancer types, including metastatic renal cell carcinoma, hepatocellular carcinoma, pancreatic cancer and metastatic breast cancer (13–21). Culp et al (8) demonstrated that metastatic PCa patients undergoing definitive local treatment had higher 5-year OS and CSS rates than those not undergoing local therapy. For patients with PCa, there is still no consensus about the benefit of primary site surgery in the presence of metastatic disease. The current findings demonstrate that, for patients with bone metastasis, prostatectomy may significantly improve both CSS and OS (Fig. 4). Although radiation therapy provided obvious improvements in both CSS and OS in stage IV PCa patients (Fig. 2), the present results indicated that there was no significant improvement in CSS and OS with the administration of radiation therapy to patients with only bone metastasis (Fig. 4).
Mechanisms underlying the survival benefit of primary tumor resection remain unknown. According to the ‘self-seeding’ hypothesis, cancer cells may seed distant sites, as well as the primary tumor site (22,23). Eliminating the primary source of the metastatic tumor cells by removing the prostate may reduce the number of circulating tumor cells (24). Therefore, it is reasonable to believe that prostatectomy may be beneficial for patients with metastatic PCa.
Cooperberg et al (25) showed that PCa patients aged ≥50 years may show higher CAPRA scores (the CAPRA score was developed using the Cancer of the Prostate Strategic Urologic Research Endeavor registry data) (26), implying that older age increases the risk of metastasis in PCa patients. Similarly, in the present study, it was demonstrated that age ≥50 years was a risk factor for both CSS and OS in patients with only bone metastasis (Tables V and VI). The current study also revealed that patients with grade IV PCa (undifferentiated) had a higher risk of bone metastases than grade I patients (Table IV). Moreover, Brawley et al (27) suggested that mortality rates for patients with PCa are higher for black Americans than for white Americans. The findings of the current study also suggested that black patients with stage IV PCa had worse CSS and OS compared with white patients (Fig. 2). A recent study by Guo et al (28) suggested that liver, lung or brain metastasis resulted in a poorer prognosis in prostate cancer patients diagnosed with bone metastasis (28). By contrast, the present study assessed the effects of four specific single metastasis sites on the survival of patients with advanced PCa. Moreover, prostatectomy was identified as an effective treatment for PCa patients with single bone metastases instead of radiation therapy.
Analysis of the association between disease prognosis and metastatic site may help in optimizing disease management and devising systemic therapy strategies for PCa. The current findings suggested that patients with only liver metastasis had worse CSS and OS rates compared with those with only bone or liver metastasis (Fig. 3).
The following limitations of the present study should be considered. First, information about smoking, obesity, Gleason scores and other risk factors for PCa were not registered in the SEER database. The current analysis only evaluated prostatectomy (RP; total prostatectomy and cystoprostatectomy were included) for metastatic PCa patients, but specific surgical information was not included (e.g., the use of laparoscopic or robotic-assisted surgeries). Resection of metastatic lesions can also affect the survival outcomes of patients with metastatic PCa, but such information cannot be retrieved from the SEER database. In addition, information on androgen deprivation therapy and neoadjuvant chemotherapy, are not included. The dataset used was representative only of the United States, so the applicability of the results to a wider population is uncertain. As the current study was based on patient data from 2010-2013, 5-year survival rate, which is deemed as an effective indicator for predicting the long-term prognosis of patients, was not available. Instead, 3-year survival rate was used as an indicator to estimate the prognosis of patients with advanced PCa. Studies based on updated SEER PCa data that include >5 years of records of ‘specific site metastases’ can provide 5 year-survival rate, as a long-term prognosis indicator, to further validate the current results. Although the prognosis of PCa patients can be changed with improvements of treatment, we still hypothesize that prostatectomy is beneficial for prognosis outcomes of patients with stage IV PCa.
In conclusion, based on the results of SEER analysis, patients with advanced prostatic adenocarcinoma with only liver metastasis have worse outcomes than those with only bone or lung metastasis. Despite the limitations of the SEER database, the current results suggest that prostatectomy confers a survival advantage in PCa patients with only bone metastasis.
Acknowledgements
Not applicable.
Funding
This study was supported in part by funding from the National Natural Science Foundation of China (grant nos. 81772183 and 5177030177).
Availability of data and materials
The datasets generated and/or analyzed during the current study are available in the SEER repository (https://seer.cancer.gov/).
Authors' contributions
YD, RB and CW designed the study. YD and ZZ extracted the data. ZZ, BX, SL and WAR assisted with the data processing and statistical analysis. YD and WAR wrote the article. CW funded the study. All authors read and approved the final manuscript.
Ethics approval and consent to participate
Not applicable.
Patient consent for publication
Not applicable.
Competing interests
The authors declare that they have no competing interests.
References
|
Siegel RL, Miller KD and Jemal A: Cancer statistics, 2017. CA Cancer J Clin. 67:7–30. 2017. View Article : Google Scholar : PubMed/NCBI | |
|
Yamada Y, Naruse K, Nakamura K, Taki T, Tobiume M, Zennami K, Nishikawa G, Itoh Y, Muramatsu Y, Nanaura H, et al: Investigation of risk factors for prostate cancer patients with bone metastasis based on clinical data. Exp Ther Med. 1:635–639. 2010. View Article : Google Scholar : PubMed/NCBI | |
|
Heidenreich A, Bellmunt J, Bolla M, Joniau S, Mason M, Matveev V, Mottet N, Schmid HP, van der Kwast T, Wiegel T, et al: EAU guidelines on prostate cancer. Part 1: Screening, diagnosis, and treatment of clinically localised disease. Eur Urol. 59:61–71. 2011. View Article : Google Scholar : PubMed/NCBI | |
|
Yang L, Drake BF and Colditz GA: Obesity and other cancers. J Clin Oncol. 34:4231–4237. 2016. View Article : Google Scholar : PubMed/NCBI | |
|
Humphrey PA: Histopathology of prostate cancer. Cold Spring Harb Perspect Med. 7:a0304112017. View Article : Google Scholar : PubMed/NCBI | |
|
Bill-Axelson A, Holmberg L, Filén F, Ruutu M, Garmo H, Busch C, Nordling S, Häggman M, Andersson SO, Bratell S, et al: Radical prostatectomy versus watchful waiting in localized prostate cancer: The Scandinavian prostate cancer group-4 randomized trial. J Natl Cancer Inst. 100:1144–1154. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
Veeratterapillay R, Goonewardene SS, Barclay J, Persad R and Bach C: Radical prostatectomy for locally advanced and metastatic prostate cancer. Ann R Coll Surg Engl. 99:259–264. 2017. View Article : Google Scholar : PubMed/NCBI | |
|
Culp SH, Schellhammer PF and Williams MB: Might men diagnosed with metastatic prostate cancer benefit from definitive treatment of the primary tumor? A SEER-based study. Eur Urol. 65:1058–1066. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Stephen B, David R, Carolyn C and April G: AJCC cancer staging manual seventh edition. Am Joint Committee Cancer. 2010, https://cancerstaging.org/references-tools/deskreferences/Pages/default.aspxAugust 29–2017 | |
|
Adamo M, Dickie L and Ruhl J: SEER program coding and staging manual 2016. National Cancer Institute; Bethesda, MD 20850-9765, U.S.: Department of Health and Human Services National Institutes of Health National Cancer Institute, . 2016, https://seer.cancer.gov/tools/codingmanuals/historical.htmlAugust 29–2017 | |
|
Fisher LD and Lin DY: Time-dependent covariates in the Cox proportional-hazards regression model. Annu Rev Public Health. 20:145–157. 1999. View Article : Google Scholar : PubMed/NCBI | |
|
Freedland SJ, Partin AW, Humphreys EB, Mangold LA and Walsh PC: Radical prostatectomy for clinical stage T3a disease. Cancer. 109:1273–1278. 2007. View Article : Google Scholar : PubMed/NCBI | |
|
Heng DY, Wells JC, Rini BI, Beuselinck B, Lee JL, Knox JJ, Bjarnason GA, Pal SK, Kollmannsberger CK, Yuasa T, et al: Cytoreductive nephrectomy in patients with synchronous metastases from renal cell carcinoma: Results from the international metastatic renal cell carcinoma database consortium. Eur Urol. 66:704–710. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Keutgen XM, Nilubol N, Glanville J, Sadowski SM, Liewehr DJ, Venzon DJ, Steinberg SM and Kebebew E: Resection of primary tumor site is associated with prolonged survival in metastatic nonfunctioning pancreatic neuroendocrine tumors. Surgery. 159:311–318. 2016. View Article : Google Scholar : PubMed/NCBI | |
|
Hüttner FJ, Schneider L, Tarantino I, Warschkow R, Schmied BM, Hackert T, Diener MK, Büchler MW and Ulrich A: Palliative resection of the primary tumor in 442 metastasized neuroendocrine tumors of the pancreas: A population-based, propensity score-matched survival analysis. Langenbecks Arch Surg. 400:715–723. 2015. View Article : Google Scholar : PubMed/NCBI | |
|
Abdel-Rahman O: Role of liver-directed local tumor therapy in the management of hepatocellular carcinoma with extrahepatic metastases: A SEER database analysis. Expert Rev Gastroenterol Hepatol. 11:183–189. 2017. View Article : Google Scholar : PubMed/NCBI | |
|
Abou-Alfa GK and Venook AP: The impact of new data in the treatment of advanced hepatocellular carcinoma. Curr Oncol Rep. 10:199–205. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
Oweira H, Petrausch U, Helbling D, Schmidt J, Mannhart M, Mehrabi A, Schöb O, Giryes A, Decker M and Abdel-Rahman O: Prognostic value of site-specific metastases in pancreatic adenocarcinoma: A surveillance epidemiology and end results database analysis. World J Gastroenterol. 23:1872–1880. 2017. View Article : Google Scholar : PubMed/NCBI | |
|
Shien T, Nakamura K, Shibata T, Kinoshita T, Aogi K, Fujisawa T, Masuda N, Inoue K, Fukuda H and Iwata H: A randomized controlled trial comparing primary tumour resection plus systemic therapy with systemic therapy alone in metastatic breast cancer (PRIM-BC): Japan Clinical Oncology Group Study JCOG1017. Jpn J Clin Oncol. 42:970–973. 2012. View Article : Google Scholar : PubMed/NCBI | |
|
Ruiterkamp J, Voogd AC, Tjan-Heijnen VC, Bosscha K, van der Linden YM, Rutgers EJ, Boven E, van der Sangen MJ and Ernst MF; Dutch Breast Cancer Trialists' Group (BOOG), : SUBMIT: Systemic therapy with or without up front surgery of the primary tumor in breast cancer patients with distant metastases at initial presentation. BMC Surg. 12:52012. View Article : Google Scholar : PubMed/NCBI | |
|
Fields RC, Jeffe DB, Trinkaus K, Zhang Q, Arthur C, Aft R, Dietz JR, Eberlein TJ, Gillanders WE and Margenthaler JA: Surgical resection of the primary tumor is associated with increased long-term survival in patients with stage IV breast cancer after controlling for site of metastasis. Ann Surg Oncol. 14:3345–3351. 2007. View Article : Google Scholar : PubMed/NCBI | |
|
Comen E, Norton L and Massagué J: Clinical implications of cancer self-seeding. Nat Rev Clin Oncol. 8:369–377. 2011. View Article : Google Scholar : PubMed/NCBI | |
|
Norton L: Cancer stem cells, self-seeding, and decremented exponential growth: Theoretical and clinical implications. Breast Dis. 29:27–36. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
Resel Folkersma L, San José Manso L, Galante Romo I, Moreno Sierra J and Olivier Gómez C: Prognostic significance of circulating tumor cell count in patients with metastatic hormone-sensitive prostate cancer. Urology. 80:1328–1332. 2012. View Article : Google Scholar : PubMed/NCBI | |
|
Cooperberg MR, Broering JM and Carroll PR: Risk assessment for prostate cancer metastasis and mortality at the time of diagnosis. J Natl Cancer Inst. 101:878–887. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Cook MM, Rosenberg PS, McCarty FA, Wu M, King J, Eheman C and Anderson WF: Racial disparities in prostate cancer incidence rates by census division in the United States, 1999–2008. Prostate. 75:758–763. 2015. View Article : Google Scholar : PubMed/NCBI | |
|
Brawley OW, Jani AB and Master V: Prostate cancer and race. Curr Probl Cancer. 31:211–225. 2007. View Article : Google Scholar : PubMed/NCBI | |
|
Guo X, Zhang C, Guo Q, Xu Y, Feng G, Li L, Han X, Lu F, Ma Y, Wang X and Wang G: The homogeneous and heterogeneous risk factors for the morbidity and prognosis of bone metastasis in patients with prostate cancer. Cancer Manag Res. 10:1639–1646. 2018. View Article : Google Scholar : PubMed/NCBI |
