Surveillance, Epidemiology, And End Results Research Articles

Background/Objectives: Metformin is one of the most frequently used concomitant medications among prostate cancer (PCa) patients. However, the effects of metformin on all-cause and PCa-specific mortality among men diagnosed with advanced/metastatic PCa treated with androgen-deprivation therapy (ADT) remain poorly understood, but they may be specifically explained by emulating a target trial. Methods: We emulated a target trial of metformin therapy and survival using observational data on 7361 patients diagnosed with advanced PCa, who were treated with ADT, from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database (2008–2019), with completed follow-up until 2020. We included patients with diabetes, and participants were assigned as either “initiator of metformin within 6 months after advanced PCa diagnosis” or “non-initiator of metformin.” We estimated mortality risks using Cox proportional hazards models with adjustment for risk factors via inverse probability weighting using both intention-to-treat and per-protocol analyses. Results: Over 13 years of follow-up, with a maximum 3 years of follow-up after PCa diagnosis, all-cause mortality occurred in 52 metformin initiators (47.7%) versus 3052 non-initiators (42.1%), while PCa-specific mortality occurred in 36 initiators (33.0%) versus 1919 non-initiators (26.5%). In the intention-to-treat analysis, metformin initiation was not associated with all-cause mortality (Hazard Ratio [HR] = 1.38, 95% CI: 0.98–1.95) or PCa-specific mortality (HR = 0.99, 95% CI: 0.63–1.55). Similarly, in per-protocol analysis, there was no evidence of risk reduction with all-cause (HR = 1.20, 95% CI = 0.80–1.81) or PCa-specific mortality (HR = 1.45, 95% CI = 0.88–2.38) after adjusting for time-varying covariates and allowing a 30-day gap for metformin discontinuation, adjusted for via inverse probability weighting. Conclusions: Our findings align with prior randomized trials showing no survival benefit of metformin in advanced PCa patients receiving ADT. Timing of metformin discontinuation also showed no significant effect. However, the small size of the metformin initiator group precluded subgroup analyses for hormone-sensitive (HSPC) and castrate-resistant prostate cancer (CRPC), limiting our ability to explore potential differential effects.

Background and Objectives: Malignant germ cell tumors (GCTs) are rare but clinically significant neoplasms arising in gonadal and extragonadal sites. Malignant GCTs, divided into seminomatous and non-seminomatous subtypes, show diverse biological behavior. Although molecular studies have advanced understanding of their origins and genetic features, little is known about metastatic patterns due to their rarity and generally favorable outcomes. This study aimed to describe metastatic patterns of malignant GCTs across primary sites and histologic subtypes using population-based database. Materials and Methods: Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) program for patients diagnosed with malignant GCTs between 2010 and 2022. Cases were stratified by primary site (testis, ovary, mediastinum), age group (<8 years vs. ≥8 years), and histologic subtype. Metastatic patterns were assessed using both overall and organotropic metastasis rates, and differences between groups were evaluated descriptively using appropriate statistical tests. Results: A total of 32,015 malignant GCTs were identified, comprising 93.0% testicular, 5.6% ovarian, and 1.4% mediastinal tumors. In patients aged ≥8 years, ovarian tumors tended to show generally lower lymph node and distant metastasis rates. In contrast, mediastinal tumors appeared to have the highest distant metastasis rates. Organotropic analysis suggested distinct subtype- and site-specific differences. For seminoma/dysgerminoma, the organotropic metastasis pattern was generally consistent across different primary sites, whereas the other subtypes showed variable organotropic metastasis rates depending on the primary site. Conclusions: The metastatic patterns of GCTs appear to differ by histologic subtype and primary site. These findings suggest that both subtype and site of origin should be considered when assessing metastatic risk and may provide a framework for improved risk stratification in clinical practice.

Background: Cardiovascular disease (CVD) is the leading non-cancer cause of mortality among cancer survivors, with rural populations facing systemic disparities in access to cardio-oncology care. We hypothesized that cardiovascular mortality is disproportionately higher among rural cancer survivors and sought to quantify these disparities using SEER data. Methods: Using Surveillance, Epidemiology, and End Results (SEER) data from 2000 to 2021, we conducted a retrospective cohort study of 1,458,583 deceased cancer patients who had received chemotherapy, as indicated by SEER treatment records coded for “Yes” in the chemotherapy received variable. Rurality was defined using Rural-Urban Continuum Codes (RUCC), distinguishing nonmetropolitan, non-adjacent counties from large metropolitan areas (≥1 million population). Cardiovascular disease mortality, defined as the primary cause of death using SEER cause-of-death codes, was identified in 71,892 patients. Relative risks (RR) were calculated (unadjusted), and rural-urban disparities were assessed using chi-square tests. Results: Patients residing in rural, nonmetropolitan, non-adjacent counties had higher cardiovascular disease mortality (Rural: 5.53%, Urban: 4.81%). This represented a 15% increased proportional risk (RR 1.15, 95% CI 1.12–1.18, p<0.001). Heart diseases accounted for 92% of all cardiovascular deaths, with a slightly higher proportion in rural areas (93.2%) compared to urban areas (91.6%). Hypertension-related deaths were more prevalent in urban patients (Urban: 4.9%, Rural: 3.3%), which may reflect geographic variation in comorbidities or diagnostic coding practices. Conclusion: Rural residence is independently associated with increased cardiovascular disease mortality among chemotherapy-treated cancer survivors. Contributing factors may include limited access to specialty care, higher baseline cardiovascular risk, and fragmented survivorship monitoring in rural settings. These findings highlight the need for targeted interventions, such as expanding telehealth services, developing rural-specific survivorship guidelines, and policy reforms to improve access to cardio-oncology care. Limitations include the lack of detailed treatment data and unmeasured confounders inherent to SEER. Future research should focus on optimizing care delivery models and integrating geographic risk stratification into survivorship care planning.

Introduction: Primary cardiac sarcomas are exceedingly rare and aggressive malignancies, with limited epidemiological data due to their low incidence. This study aims to characterize the incidence trends of cardiac sarcomas over a 21-year period using a population-based cancer registry and to assess differences in incidence by sex. Methods: We conducted a retrospective cohort study using data from the Surveillance, Epidemiology, and End Results (SEER) Program, accessed through SEER*Stat software version 8.4.5. Eligible cases were identified using the International Classification of Diseases for Oncology (ICD-O-3) site code C38.0 (Heart) and histology codes corresponding to soft tissue tumors and sarcomas, including: NOS (8800–8809), fibromatous neoplasms (8810–8839), myxomatous neoplasms (8840–8849), lipomatous neoplasms (8850–8889), myomatous neoplasms (8890–8929), complex mixed and stromal neoplasms (8930–8999), synovial-like neoplasms (9040–9049), and blood vessel tumors (9120–9169). The study period spanned from 2000 to 2021. Only first primary tumors were included, and no duplicate cases were identified. Incidence rates were age-adjusted to the 2000 U.S. standard population and stratified by sex. Temporal trends were evaluated using joinpoint regression. Results: A total of 264 cases of primary cardiac sarcomas were identified between 2000 and 2021. The overall age-adjusted incidence rate remained relatively stable throughout the study period, with no significant annual percent change observed. Males demonstrated a higher incidence rate compared to females (0.0065 vs. 0.0053 per 100,000 person-years, respectively), but this difference did not reach statistical significance (p > 0.05). There were no notable shifts in the incidence of specific sarcoma subtypes over time. Conclusion: This study provides one of the most comprehensive analyses of primary cardiac sarcoma incidence trends in the U.S. to date. Despite the rarity of this malignancy, the incidence has remained stable over the past two decades. While males appear to be more affected than females, the observed sex difference is not statistically significant. Continued surveillance and larger datasets are necessary to better understand risk factors and inform early detection strategies for this rare and often fatal disease.

Background: Transthoracic echocardiographic (TTE) surveillance for left ventricular dysfunction following cardiotoxic chemotherapy, particularly anthracyclines, is a key component of cardio-oncology care. The 2017 American Society of Clinical Oncology (ASCO) guidelines recommend routine TTE screening in older adults after anthracycline-based chemotherapy, but it remains uncertain if these guidelines had an effect on physician TTE ordering frequency. Methods: The Surveillance, Epidemiology, and End Results (SEER) Medicare dataset was used to identify older adults (>65 years) with HER2-negative breast cancer, lymphoma, or soft tissue sarcoma who received anthracyclines for a first cancer diagnosis from 2010-2020. Monthly TTE surveillance rates (TTEs per eligible patient-month) in the first year following chemotherapy initiation were compared before and after the ASCO guideline release in January 2017 using an interrupted time series approach. Results: Of 15,045 individuals included (mean age 74.1 ± 5.9 years, 64.9% female, 84.9% White), 9,611 (63.9%) had lymphoma, 5,106 (33.9%) breast cancer, and 328 (2.2%) sarcoma. An average of 43.6% ± 1.3% of individuals received a surveillance TTE during the first year after chemotherapy (mean 7.2 ± 0.9% per month). The monthly TTE surveillance frequency remained constant prior to 2017 (-0.003%/month, 95% CI -0.01% to +0.007%, p = 0.58) and after 2017 (+0.18%/month, 95% CI -0.57% to +0.92%, p = 0.65), with no significant change following the ASCO guideline release (+0.03%/month, 95% CI -0.005% to +0.06, p = 0.11) ( Figure ). Conclusion: TTE surveillance rates did not significantly change following the release of the 2017 ASCO guidelines among older Medicare beneficiaries receiving anthracycline chemotherapy for non-HER2+ malignancies. More than half of older anthracycline treated patients did not receive a post-anthracycline TTE in the year after their cancer treatment.

A comprehensive population-based study and predictive survival model for undifferentiated carcinoma of the pancreas.

To establish and validate a nomogram for predicting pathological complete response (pCR) after neoadjuvant therapy (NAT) in breast cancer (BC) patients, aiming to identify subgroups potentially suitable for non-surgical management. Between 2010 and 2015, 4402 BC patients (3037 surgery, 1365 non-surgery) were extracted from the Surveillance, Epidemiology, and End Results (SEER) database, with external validation in 339 BC patients from our hospital. Logistic regression identified pCR predictors and a nomogram model was constructed. Propensity score matching (PSM) was applied to minimize the effect of the imbalance of the prognostic factors between the surgery group and the non-surgery group. Univariable and multivariable analyses revealed that age, marital status, T stage, N stage, differentiation grade, hormone receptor (HR) status, human epidermal growth factor receptor 2 (HER2) status and chemotherapy were significant predictors of pCR in the surgery group (all p < 0.05). The area under the receiver operating characteristic curve (AUC) for predicting pCR was 0.756 (95% CI: 0.736-0.776), 0.717 (95% CI: 0.681-0.754), and 0.744 (95% CI: 0.687-0.800) in the training, internal validation, and external validation sets, respectively. Non-surgery patients were stratified into high (> 375), medium (162.5-375), and low (< 162.5) nomogram score groups, with 5-year OS rates of 70.7%, 49.2%, and 29.2% (p < 0.05). After PSM, 358 pairs of patients were included to compare 5-year OS between the surgery group and the non-surgery group, and the results showed that the 5-year OS of patients stratified by high-score group, medium-score group and low-score group between the surgery group and the non-surgery group were 85.4% vs. 72.8%, 78.3% vs. 59.8% and 79.3% vs. 20.0% (all p < 0.05). We successfully established a nomogram for pCR in BC patients. Based on this predictive model, patients with higher scores may represent potential candidates for non-surgical therapeutic approaches, warranting further investigation in future studies.

BackgroundSurgical delay is often unavoidable in the management of localized renal cell carcinoma (RCC), but the safe duration for postponing surgery remains unclear, particularly for RCC of varying sizes.MethodsPatients diagnosed with T1a-T2bN0N0 RCC between 2000 and 2022 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Multivariable Cox proportional hazards models were used to assess the impact of surgical delays of more than 1, more than 2, and more than 3 months on cancer-specific survival (CSS). Subgroup analyses were performed according to tumor size categories (4.0–5.9 cm, 6.0–7.9 cm, and 8.0–10.0 cm) at each surgical delay interval.ResultsA total of 39,242 patients were included, with a median follow-up time of 80 months (Interquartile range [IQR], 37–138 months). Surgical delays of more than 1 month did not worsen CSS in patients with tumors 4.0–5.9 cm (adjusted HR = 1.05, 95% CI, 0.93–1.18, p = 0.412), 6.0–7.9 cm (adjusted HR = 1.04, 95% CI, 0.92–1.17, p = 0.512), or 8.0–10.0 cm (adjusted HR = 1.07, 95% CI 0.93–1.23, p = 0.376). Delays of more than 2 months showed no significant CSS difference in tumors 4.0–5.9 cm (adjusted HR = 1.06, 95% CI 0.91–1.21, p = 0.496) or 6.0–7.9 cm (adjusted HR = 1.06, 95% CI 0.90–1.25, p = 0.463), but CSS worsened in tumors sized 8.0–10.0 cm (adjusted HR = 1.29, 95% CI 1.06–1.57, p = 0.012). For delays of more than 3 months, CSS was unaffected in tumors 4.0–5.9 cm (adjusted HR = 1.11, 95% CI 0.92–1.31, p = 0.508), but was worse in tumors 6.0–7.9 cm (adjusted HR = 1.28, 95% CI 1.03–1.66, p = 0.021) and 8.0–10.0 cm (adjusted HR = 1.29, 95% CI 1.09–1.52, p = 0.003).ConclusionSurgical delay was not associated with worse CSS for RCC measuring 4.0–5.9 cm within 3 months. For tumors measuring 6.0–7.9 cm and 8.0–10.0 cm, delays of more than 3 months and more than 2 months, respectively, appeared to be linked with worse CSS. However, due to the retrospective nature and potential residual confounding of this study, these findings should be interpreted with caution. Prospective studies are needed to confirm these findings.

ObjectivesMalignant pleural mesothelioma is a rare and aggressive thoracic tumor with a poor prognosis, wherein distant metastasis is associated with the lowest survival rates. It is imperative and emergent to construct nomograms based on risk factors and prognostic factors for distant metastasis in patients with malignant pleural mesothelioma.MethodsWe extracted data for the duration between 2010 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database and randomly categorized the patients into the training (70%) and validation (30%) cohorts. Risk factors for distant metastasis in patients with malignant pleural mesothelioma were identified using univariate and multivariate logistic regression analyses, and prognostic factors for patients with distant metastasis were determined using univariate and multivariate Cox regression analyses. Two nomograms were established based on the training cohort and evaluated using the validation cohort. The C-index, receiver operating characteristic curve, calibration curve, and decision curve analysis were used to assess the performance of the two nomograms.ResultsIn total, 2056 primary malignant pleural mesothelioma patients were included, and 341 patients were initially diagnosed with metastatic malignant pleural mesothelioma. Histology, laterality, grade, tumor stage, and node stage were independent risk factors for distant metastasis in patients with malignant pleural mesothelioma. Chemotherapy and metastasis to the lung, bone, and brain were independent prognostic factors for patients with malignant pleural mesothelioma and distant metastasis. The C-index values of the risk nomogram in the training and validation cohorts were 0.723 and 0.782, respectively. The C-index values of the prognostic nomogram in the training and validation cohorts were 0.678 and 0.712, respectively. The receiver operating characteristic curves, calibration curves, and decision curve analysis also demonstrated good predictive performance for the two nomograms in the training and validation cohorts.ConclusionsNomograms are useful and reliable tools for predicting distant metastatic risk in patients with malignant pleural mesothelioma and overall survival in patients with malignant pleural mesothelioma who had distant metastasis. These nomograms can provide strong references to clinicians to facilitate clinical decisions.

Cardiovascular and cancer-specific mortality in older patients with advanced non-small cell lung cancer following the introduction of immuno-oncology therapies.

Neighborhood socioeconomic status and endometrial cancer mortality: Racial disparities persist across the spectrum.

Momcology is a US-based patient advocacy organization that provides support for families of children with cancer. This study describes Momcology for researchers by detailing the demographic, clinical, and socioeconomic (socioeconomic status [SES]) data within its registry and comparing it to the National Surveillance, Epidemiology, and End Results (SEER) dataset. This study contextualizes differences within the cohort and highlights opportunities for similar organizations to improve research partnerships. In 2020, Momcology transitioned its membership registry to Research Electronic Data Capture (REDCap), a secure, web-based platform designed for standardized data collection and research collaboration. Caregivers of children with cancer completed surveys capturing diagnosis, demographics, and socioeconomic information. We compared children aged 0-19 years diagnosed between 2000 and 2020 in the Momcology registry with cases from SEER-22 for demographic and clinical variables and SEER-18 (2006-2018) for SES. Multivariable logistic regression was used to examine associations between registry membership and age, sex, race/ethnicity, cancer subtype, and SES. Among 4,305 Momcology patients and 156,407 SEER cases, Momcology children were younger at diagnosis, more likely to be non-Hispanic White, and from higher SES backgrounds. Momcology showed a substantially greater proportion of leukemias compared to SEER. Additionally, the REDCap database enables efficient data queries and targeted family outreach based on specific circumstances. Momcology's membership is large and includes all pediatric cancer types and demographic backgrounds. Despite representation gaps in certain populations, Momcology maintains a presently characterized and active cohort that facilitates connections between families and researchers for community-based participatory research and caregiver support initiatives within pediatric oncology.

To examine the prognostic differences between metachronous and synchronous sporadic bilateral renal cell carcinoma (BRCC). This cohort study was conducted in the Surveillance, Epidemiology, and End Results (SEER) database among patients diagnosed with BRCC between 2004 and 2021. Patients were categorized into synchronous and metachronous groups (synchronous tumors occurred within six months of the first RCC diagnosis, while metachronous tumors occurred more than six months after the first RCC diagnosis). The propensity score matching (PSM) approach was employed to compare these two groups. Cox's regression analysis evaluated cancer-specific survival (CSS) and overall survival (OS). Interaction, sensitivity, and subgroup analyses were also performed to test the results' robustness. 4,694 patients with BRCC were included, with 2,710 (57.7%) in the synchronous group and 1,984 (42.3%) in the metachronous group. After applying PSM, patient characteristics between the two groups were well-balanced. Over a median follow-up of 85months (interquartile range [IQR]: 43-132months), significant differences were noted between the synchronous and metachronous groups in both CSS (hazard ratio [HR]=2.661, 95% confidence interval [CI]: 1.987-3.564, P < 0.001) and OS (HR=2,481, 95% CI: 2.060-2.988, P < 0.001). Stratified Cox regression accounting for matched pairs indicated poorer CSS (HR=3.170, 95% CI: 2.081-4.828, p < 0.001) and OS (HR=2.631, 95% CI: 2.116-3.270, p < 0.001) in the synchronous group. The robustness of these results was supported by multivariate competing risk regression, as well as interaction, sensitivity and subgroup analyses. Synchronous BRCC was associated with poorer survival than the metachronous group. These findings may offer important insights for managing patients with BRCC.

The role of axillary lymph node dissection (ALND) in breast cancer patients with sentinel lymph node (SLN) micrometastases, particularly after neoadjuvant therapy, remains debated. The present study aimed to assess whether adding ALND provides a survival benefit in this population. Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) database (2010-2021) and a validation cohort from the First Affiliated Hospital of Xi'an Jiaotong University (2018-2024) for female breast cancer patients with SLN micrometastases (pTxN1miM0) after neoadjuvant therapy. Machine learning techniques (LASSO, random forest, and SVM-RFE) were used to identify key prognostic factors. Survival analyses were conducted using Kaplan‒Meier, Cox regression, and competing risk models to evaluate the impact of ALND on overall survival (OS), disease-free survival (DFS), breast cancer-specific survival (BCSS), and death from other causes (OCSD). After propensity-score matching, 2166 patients from the SEER cohort and 116 from the hospital cohort were included. Survival analysis revealed no significant differences in OS (HR 1.26, P = 0.118), BCSS (HR 1.16, P = 0.378), or DFS (HR 1.88, P = 0.239) between the sentinel lymph node biopsy (SLNB) only group and the SLNB with complete ALND group. No significant differences in the BCSD (P = 0.378) or OCSD (P = 0.121) were found. Machine learning identified 10 prognostic factors, and higher tumor grade, T stages 3-4, PR-negative status, and HER2-negative status were identified as independent unfavorable factors. ALND does not improve survival in breast cancer patients with SLN micrometastases after neoadjuvant therapy. These findings support a more conservative approach to axillary management.

BackgroundThis study aims to evaluate the impact of adjuvant chemotherapy on cancer-specific survival (CSS) and overall survival (OS) in patients with Stage IA ovarian clear cell carcinoma (OCCC) using data from the Surveillance, Epidemiology, and End Results (SEER) database.MethodsWe conducted a retrospective cohort study utilizing SEER data (2000–2021) to compare the prognosis of Stage IA OCCC patients who received adjuvant chemotherapy versus those who did not. Propensity score matching (PSM) was used to balance baseline characteristics between the groups. Competing risks regression and multivariate Cox regression analyses identified prognostic factors for CSS and OS.ResultsA total of 1422 Stage IA OCCC patients were identified. After PSM, 776 patients (388 in each group) were included. For patients aged ≤ 50 years, chemotherapy was linked to worse CSS (89.5% vs. 96.2%, p=0.007) and OS (89.3% vs. 95.9%, p=0.008). Conversely, in patients aged > 70 years, chemotherapy was associated with improved CSS (93.0% vs. 81.9%, p=0.038) and OS (86.0% vs. 72.4%, p=0.006). These trends remained after PSM. Multivariate analysis showed that chemotherapy had little impact on OS and CSS. Subgroup analysis further indicated that chemotherapy negatively affected CSS and OS in patients aged ≤ 50 years.ConclusionsAdjuvant chemotherapy did not significantly improve survival outcomes in patients with Stage IA OCCC. However, its effects were age-dependent, with older patients (> 70 years) experiencing improved survival, while younger patients (≤ 50 years) exhibited worse outcomes. These findings underscore the importance of individualized treatment strategies for Stage IA OCCC.

To explore whether the Human Papillomavirus (HPV) status plays a role in the selection of treatments for hypopharyngeal squamous cell carcinoma (HSCC), we compared the survival outcomes of patients with different HPV statuses who underwent surgery combined with chemoradiotherapy and chemoradiotherapy alone. Patient's data were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM), multivariate Cox regression analysis, and Kaplan‒Meier analysis were conducted. 591 patients were obtained from the SEER database. The study revealed that HPV-positive HSCC patients had better cancer specific survival (CSS) (P = 0.009) and overall survival (OS) (P < 0.001). These findings were also supported by Multivariate Cox regression analysis. Kaplan‒Meier analysis revealed that surgery significantly improved CSS (P = 0.023) and OS (P = 0.004) in HPV-negative HSCC patients. However, for HPV-positive patients, there was no significant improvement in CSS (P = 0.565) or OS (P = 0.863). Similar results were obtained after PSM. We further analyzed that among HPV-negative patients with stage T3 disease, surgery significantly improved the 5-year OS rate (12.17% vs. 62.06%; P = 0.002) and CSS rate (25.90% vs. 68.15%; P = 0.019). For stage N2-3 HPV-negative HSCC patients, the 5-year OS and CSS of the surgery group and no surgery group were 62.31% vs. 29.76% (P = 0.011) and 65.59% vs. 44.39% (P = 0.104), respectively. However, for HPV-positive patients with different T stages and N stages, there was no significant survival difference. Surgery combined with chemoradiotherapy is more suitable for HPV-negative patients with stage T3 and stage N2-3 disease.

Residence may influence cancer management. However, the role of residence in primary bone cancer is not well explored. In this study, patients diagnosed with primary bone cancer were identified from the surveillance, epidemiology, and end results (SEER) database and divided into urban and rural groups based on residence. Multivariable ordinal logistic regression was used to determine the relationship between residence and stage at diagnosis. Multivariable logistic regression was used to explore the association between residence and receipt of local surgery, radiotherapy, and chemotherapy. Propensity score matching (PSM) was used to balance the baseline between the 2 groups, and Kaplan–Meier curves were used to estimate the overall survival (OS) and cancer-specific survival (CSS) of the 2 groups. A total of 13,876 patients with primary bone cancer were included. Compared with urban patients, rural patients were less likely to receive local surgery (OR = 0.78, 95% CI: 0.70–0.89, P < .001), radiotherapy (OR = 0.69, 95% CI: 0.60–0.88, P < .001), and chemotherapy (OR = 0.85, 95% CI: 0.77–0.94, P < .001). After PSM, rural patients had significantly worse OS (HR = 1.10, 95% CI: 1.03–1.19, P = .029) and CSS (HR = 1.08, 95% CI: 1.02–1.18, P = .036) than urban patients. However, residence was not associated with the stage at diagnosis (Rural vs Urban, OR = 1.00, 95% CI: 0.88–1.14, P = .989). In conclusion, rural residence is associated with lower likelihood of receiving definitive treatments (local surgery, radiotherapy, and chemotherapy) and worse survival for primary bone cancer. However, residence is not associated with stage at diagnosis.

Updated estimates of oropharyngeal cancer (OPC) in the US are needed. To calculate the most recent epidemiologic estimates of OPC in the US and provide projections for future trends up to 2040. This cross-sectional epidemiological analysis used data from the recent National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. The SEER-22 (excluding Illinois and Massachusetts) database provided data for incidence, prevalence, survival, and initial treatment by OPC stage. Patients with OPC diagnosed according to International Classification of Diseases for Oncology, Third Edition morphology codes were included. The analysis was conducted from September to October 2024. A diagnosis of OPC. The primary outcomes were annual age-adjusted OPC incidence per 100 000 persons, limited-duration prevalence, survival rate, and initial treatment. The incidence rate and the estimated annual percentage change for the most recent period were determined according to trend analysis from 2006 to 2021 and were used to estimate the incidence rate up to 2040. There were 103 107 new OPC cases (40 051 patients [38.8%] aged ≥65 years; 82 820 male patients [80.3%]) recorded during 2006 to 2021. From 2006 to 2021, the incidence of OPC increased from 3.8 to 4.4 cases per 100 000 person-years. The projected incidence rates indicated a significant decrease for both female (1.1 cases per 100 000 person-years) and younger (aged <65 years, 2.0 cases per 100 000 person-years) patients in 2040. The 10-year limited-duration prevalence increased from 0.024% in 2012 to 0.033% in 2021. The 1-year period survival rate of OPC was 88.2% (95% CI, 87.7%-88.7%), the 3-year period survival rate was 76.5% (95% CI, 75.9%-77.1%), and the 5-year period survival rate was 69.2% (95% CI, 68.5%-69.9%). Of 7495 patients with OPC in 2021, 1621 (21.6%) were classified as receiving no treatment, 1647 (22.0%) received single treatment, and 4227 (56.4%) received multiple treatments initially. The distribution of treatments was similar from 2006 to 2021. Of 15 648 patients with localized stage disease, 7171 (45.8%) received no treatment. In 2021, more patients aged 65 years and older received no treatment compared with patients younger than 65 years (865 of 3525 patients [24.5%] vs 756 of 3970 patients [19.0%]). In this cross-sectional study of OPC, the incidence of OPC in the US increased rapidly from 2006 to 2021 among male individuals, particularly among those aged 65 years and older. Although the distribution of treatment was similar through the assessed years, increased limited-duration prevalence and higher than previously reported survival were observed. A smaller proportion of patients with localized stage OPC were treated, especially among those aged 65 years and older, suggesting that further research is needed for optimal patient outcomes.

Disclosure: S. Keritum: None. J. kenmoe: None. A. Shrestha: None. H. Ghumman: None.Background: Paragangliomas are rare neuroendocrine tumors arising from the autonomic nervous system.Despite their low incidence, understanding their trends and potential disparities by sex is criticalfor clinical and public health strategies. This study investigates the incidence of paragangliomasin the United States, with a focus on sex-based disparities, using data from the Surveillance,Epidemiology, and End Results (SEER) database from 2000 to 2021. Methods: A retrospective analysis of paraganglioma incidence data was performed using SEER*Statsoftware. Cases diagnosed between 2000 and 2021 were included. Incidence rates werecalculated per 100,000 person-years and stratified by sex (male vs. female). Temporal trendswere analyzed using Joinpoint regression models to identify significant changes in incidenceover time. Results: The overall incidence of paragangliomas from 2000 to 2021 was stable at 0.05 per 100,000person-years for both males and females. From 2000 to 2019, no significant change in incidencewas observed. However, a sharp and statistically significant increase in incidence was notedfrom 2019 to 2021. This rise was consistent across both sexes, with no significant sex-baseddisparities identified over the study period. Conclusions: The incidence of paragangliomas remained stable from 2000 to 2019 but exhibited a markedincrease from 2019 to 2021. This trend underscores the need for further investigation intopotential factors driving this rise, including advances in diagnostic techniques and changes indisease awareness. Understanding these trends is crucial for guiding early detection andmanagement strategies. Figure 1: Incidence of Paragangliomas by Sex 2000-2021Presentation: Saturday, July 12, 2025

Abstract Disclosure: L.N. Diamantopoulos: None. M. Tsikala-Vafea: None. D. Makrakis: None. E. Fisher: None. N. Profaizer: None. D. Korentzelos: None. M. Alevizakos: None. V. Bountziouka: None. K. Vadikolias: None. M. Lambropoulou: None. D. Matthaios: None. G. Tripsianis: None. Introduction: Adrenocortical carcinoma (ACC) is a rare entity with limited prognostic data in the literature. We hereby present a novel prognostic model for overall survival (OS), for patients with ACC, derived from the Surveillance, Epidemiology and End Results (SEER) database. Materials and Methods: The SEER database (18 registries/November 2020) was queried with the case listing method by using the ICD-10 topography codes C74.0-9 (adrenal gland), and the morphologic code 8370 (ACC). Patients were randomly divided into a training (TC) and a validation cohort (VC) (7:3 ratio). Variables significantly associated with OS were identified with multivariate Cox regression and backwards stepwise conditional approach; Each variable received “points” according to its beta coefficient, based on the formula: Probability of an event at time t=S0(t)exp(β1x1, β2x2⋯), (β = regression coefficients, x = observed covariate values, S0(t) = survival function). Cumulative risk points were assigned to each patient to calculate a risk score and four distinct risk categories for OS were constructed. Harrel’s optimism-corrected C-statistic with bootstrap resampling was used for internal (TC) and external (VC) validation. Discriminatory performance of the model was compared to the AJCC staging system with the likelihood ratio test (LRT). Results: 1388 patients were included in the study (992 TC, 396 VC). No statistically significant differences in baseline characteristics and survival outcomes were identified between TC and VC. Age, race, AJCC stage, adrenalectomy, radiation and chemotherapy were significant variables inserted in the multivariate model. Based on their risk score patients were stratified to four risk groups (low; score 0-49, intermediate; score 50-99, high; score 100-149, very high; score 150+). Median OS was 106 (95%CI; 59-153), 33 (95% CI; 25-41), 16 (95% CI; 12-20) and 4 months (95% CI; 3-5) for the low, intermediate, high and very high-risk categories respectively (log-rank p&amp;lt;.001). Optimism-corrected C-statistic for the prognostic score was 0.75 (95%CI;0.73-0.77) in the TC and 0.74 (95%CI; 0.72-0.76) in the VC. In comparison C-statistic for AJCC was 0.70 (95% CI; 0.68-0.72) and 0.69 (95% CI; 0.66 to 0.72) in the TC and VC respectively. The LRT demonstrated superior discriminatory performance of our prognostic model compared to AJCC (p&amp;lt;.001). Conclusion: We present a novel prognostic model for OS of patients with ACC composed of clinicopathologic and treatment variables. Our model had superior performance to the AJCC system and may serve as a useful tool for individualized risk assessment in patients with ACC. Presentation: Monday, July 14, 2025