United States National Cancer Database Research Articles

390. CONTINUED IMPLICATIONS OF THE COVID-19 PANDEMIC ENVIRONMENT ON ESOPHAGEAL CANCER CHARACTERISTICS AND TREATMENT IN THE UNITED STATES

Abstract Background The COVID-19 pandemic significantly impacted the stage of presentation and subsequent therapies for patients who were diagnosed with esophageal cancer during the first pandemic year. We aimed to assess for continued implications of the altered healthcare landscape on esophageal cancer presentation and treatment in the second year of the pandemic. Methods This was a retrospective review of the United States National Cancer Database (2019-2021). Demographic, cancer-related and treatment variables were compared between patients diagnosed in the pre-pandemic year (2019), pandemic year one (2020) and pandemic year two (2021). Multivariate logistic regression was performed to control for the impact of demographics on oncologic variables, and then for the impact of oncologic variables on treatment modalities and outcomes. Results Of 42,807 esophageal cancer cases, 15,127 (35.3%) were pre-pandemic, 13,975 (32.7%) were pandemic year 1, and 13,705 (32.0%) were pandemic year two. There were significant differences in the distribution of clinical stage at presentation by year (p=0.0001), see figure, suggesting more advanced stage presentation throughout the pandemic. Compared to the pre-pandemic year, patients diagnosed in pandemic year two had risk-adjusted increases in time to first course treatment (incidence rate ratio 1.057 [95% confidence interval [1.036–1.078]), to radiation (1.029 [1.008–1.050]), and to systemic therapy (1.035 [1.018–1.051]). Additionally, when compared to pandemic year one, patients in pandemic year two continued to experience risk-adjusted increases in time to first course therapy (1.084 [1.063–1.106]), to surgery (1.049 [1.000–1.097]), to radiation (1.046 [1.024–1.068]) and to systemic therapy (1.060 [1.043–1.077]). Conclusions Compared to the pre-pandemic year, patients diagnosed with esophageal cancer in in the U.S. during pandemic year two continued to experience delays to treatment including delays to first course therapy, including delays to surgery, radiation and systemic therapy. The treatment characteristics of esophageal cancer have not returned to pre-pandemic baseline in the United States possibly due to compounding delays to diagnosis and treatment and a growing back log of cases.

Cervical cancer disparities in stage at presentation for disaggregated Asian Americans, Native Hawaiians, and Pacific Islanders

Over 20 million people in the United States identified as Asian American, Native Hawaiian, or Pacific Islander (AANHPI) in 2022. Despite the diversity of immigration histories, lived experiences, and health needs within the AANHPI community, prior studies in cervical cancer have considered this group in aggregate. We sought to analyze disparities in cervical cancer stage at presentation in the United States, focusing on disaggregated AANHPI groups. Data from the United States National Cancer Database from 2004 to 2020 of 122,926 patients newly diagnosed with cervical cancer was retrospectively analyzed. AANHPI patients were disaggregated by country of origin. Logistic regression, adjusted for clinical and sociodemographic factors, was used to calculate adjusted odds ratios. Higher adjusted odds ratios indicate an increased likelihood of metastatic versus non-metastatic disease at diagnosis. Out of 122,926 patients with cervical cancer, 5,142 (4.2%) identified as AANHPI. Compared to non-Hispanic White (NHW) patients, pooled AANHPI patients presented at lower stages of cancer (NHW: 58.7% diagnosed local/regional, AANHPI: 85.6% at local/regional, χ2 P<0.001). The largest AANHPI subgroups included Filipino Americans (n=1051, 20.4% of AANHPI), Chinese Americans (n=995, 19.4%), Asian Indian/Pakistani Americans (n=711, 13.8%), Vietnamese Americans (n=627, 12.2%), and Korean Americans (n=550, 10.7%) respectively. AANHPI disaggregation revealed that Pacific Islander American patients had higher odds of presenting with metastatic disease (aOR 1.58, 95% CI 1.21-2.06, p = 0.001) relative to non-Hispanic White patients. Conversely, Chinese American (aOR 0.47, 95% CI 0.37-0.59, p < 0.001), Vietnamese American (aOR 0.54, 95% CI 0.41-0.70, p < 0.001), Hmong American (aOR 0.46, 95% CI 0.22-0.97, p = 0.040), and Indian/Pakistani American (aOR 0.76, 95% CI 0.61-0.94, p = 0.013) patients were less likely to present with metastatic disease. Compared to the largest AANHPI group (Chinese American), nine other subgroups were more likely to present with metastatic disease. The largest differences were observed in Pacific Islander American (aOR 3.44, 95% CI 2.41-4.91, p < 0.001), Thai American (aOR 2.79, 95% CI 1.41-5.53, p = 0.003), Kampuchean American (aOR 2.39, 95% CI 1.29-4.42, p = 0.006), Native Hawaiian American (aOR 2.23, 95% CI 1.37-3.63, p = 0.001), and Laotian American (aOR 2.02, 95% CI 1.13-3.61, p = 0.017). In contrast, Vietnamese American (aOR 1.20, 95% CI 0.85-1.71, p = 0.303) and Hmong American (aOR 1.09, 95% CI 0.50-2.37, p = 0.828) patients did not show a statistically significant difference in presenting with metastatic disease compared to Chinese American patients. Aggregated evaluation of the Asian American, Native Hawaiian, or Pacific Islander monolith masks disparities in outcomes for distinct populations at risk for equity gaps. This disaggregation study shows that marginalized groups within the larger AANHPI population - including Pacific Islander American and Thai American patients - may face different exposures and larger structural barriers to cancer screening and early-stage diagnosis. A future focus on community based disaggregated research and tailored interventions is necessary to close these gaps.

Pediatric neurosurgical medulloblastoma outcomes in La Paz, Bolivia: How a Lower Middle-Income Country (LMIC) institution in South America compares to the United States.

How pediatric medulloblastoma patients fare in Lower Middle-Income Country (LMICs) in South America is not well understood. Correspondingly, the aim of this study was to summarize the pediatric neurosurgical experience of an institution in La Paz, and compare outcomes to that of a generalized High Income Country (HIC) United States (US) experience. A retrospective review of all pediatric neurosurgical medulloblastoma patients at the Children's Hospital of La Paz, Bolivia (Hospital del Niño "Dr. Ovidio Aliaga Uria") between 2014 and 2023 was conducted and compared to a generalized US experience abstracted from the US National Cancer Database (NCDB) and National Inpatient Sample (NIS) databases. Categorical, continuous and survival data were statistically summarized and compared. A total of 24 pediatric medulloblastoma patients underwent neurosurgical treatment at the Hospital del Niño. In this La Paz cohort, there were 15 (63%) males and 9 (38%) females, with a mean age of 5.6 years old at diagnosis. The majority of patients underwent subtotal resection (STR, 79%), while the remaining patients underwent biopsy only. Ten (42%) patients expired during their hospitalization, and mean length of stay overall was 39 days. Only 8 (33%) patients received adjuvant treatment after surgery. Median overall survival from diagnosis in the La Paz cohort was 1.9 months. Compared to the US databases, the La Paz cohort experienced significantly more emergency room admissions for surgery, less gross total resection, more STR, more return to operating room for ventriculoperitoneal shunting, more bacteremia, more tracheostomy procedures, more percutaneous gastrostomy placements, longer lengths of stay, less adjuvant chemotherapy, less radiation therapy, shorter follow-up, and ultimately, significantly shorter overall survival (all P < 0.050). Pediatric neurosurgical medulloblastoma outcomes at the Children's Hospital of La Paz, Bolivia are significantly inferior to that of a generalized US experience. Future research is required to identify institution- and country-specific initiatives to improve discrepancies between institutions in LMICs in South America compared to HICs.

Site-specific patterns of early-stage cancer diagnosis during the COVID-19 pandemic.

The COVID-19 pandemic caused widespread disruptions in cancer care. We hypothesized that the greatest disruptions in diagnosis occurred in screen-detected cancers. We identified patients (≥18 years of age) with newly diagnosed cancer from 2019 to 2020 in the US National Cancer Database and calculated the change in proportion of early-stage to late-stage cancers using a weighted linear regression. Disruptions in early-stage diagnosis were greater than in late-stage diagnosis (17% vs 12.5%). Melanoma demonstrated the greatest relative decrease in early-stage vs late-stage diagnosis (22.9% vs 9.2%), whereas the decrease was similar for pancreatic cancer. Compared with breast cancer, cervical, melanoma, prostate, colorectal, and lung cancers showed the greatest disruptions in early-stage diagnosis. Uninsured patients experienced greater disruptions than privately insured patients. Disruptions in cancer diagnosis in 2020 had a larger impact on early-stage disease, particularly screen-detected cancers. Our study supports emerging evidence that primary care visits may play a critical role in early melanoma detection.

Factors contributing to time to chemotherapy, immunotherapy and radiation for patients with mycosis fungoides in the United States National Cancer Database.

Factors contributing to time to chemotherapy, immunotherapy and radiation for patients with mycosis fungoides in the United States National Cancer Database.

Racial and Treatment Center Differences on Time to Treatment Initiation for Nonsmall Cell Lung Cancer Patients Receiving Radiation Therapy As an Initial Treatment.

Objective:Because time to treatment has been shown to be associated with increase in the risk of death for Non Small Cell Lung Cancer (NSCLC) patients, we examined the prevalence and magnitude of racial disparities in mean time to radiation therapy (TTRT) for Stage I-III non-small cell lung cancer patients across a variety of treatment facilities.Methods:Utilizing the United States National Cancer Database (NCDB), we determined differences in TTRT between different races and different treatment facilities.Results:Concordant with past research, we found that non-White patients and patients treated at academic facilities, regardless of race, have longer mean TTRT, and that racial disparities in TTRT extend across all treatment facilities (all p<0.05).Conclusions:These findings shed light on the potential presence of and impact of structural racism on patients seeking cancer treatment, and the need for further investigation behind the reasonings behind longer TTI for non-White patients. To elucidate the real-world applicability of these results, further investigation into the societal determinants that perpetuate disparity in time to radiation therapy, and potential interventions in the clinical setting to improve cultural and racial sensitivity among healthcare professionals is recommended.

Racial disparities in treatment delay among younger men with prostate cancer.

Young men (≤55 years) with prostate cancer (PC) may experience treatment delays despite clinical consequences of delays beyond six months. Using the United States National Cancer Database (2004-2017), we employed multivariable logistic regression analysis to retrospectively examine racial disparities in localized PC treatment delays >6 months since diagnosis. Of the 89,196 men ≤55 years included, young Black men experienced treatment delays beyond six monthsmore frequently than young White men (7.39% vs. 3.96%; AOR 1.95, 95% CI 1.81-2.09, p < 0.001), a disparity that was greater than that among men ages 56-64 (pinteraction < 0.001). This result persisted upon restricting the sample to men with private insurance/managed care. The finding that Black men with localized PC experienced treatment delays almost twice as frequently as White men underscores access barriers that may go beyond the direct costs of care.

P-OGC87 Robotic Techniques in Esophagogastric Cancer Surgery: An Assessment of Short- and Long-term Clinical Outcomes

Abstract Background Robotic esophagogastric cancer surgery is gaining widespread adoption. This population-based cohort study aimed to compare rates of textbook outcomes (TO) and survival from robotic minimally invasive techniques for esophagogastric cancers. Methods Data from the United States National Cancer Database (NCDB) (2010-2017), was used to identify patients with non-metastatic esophageal and gastric cancers receiving open (esophagus, n = 11,442; stomach, n = 22,183), laparoscopic (esophagus (LAMIE), n = 4,827; stomach (LAMIG), n = 6,359) or robotic (esophagus (RAMIE), n = 1,657; stomach (RAMIG), n = 1,718) surgery. TO were defined as lymph nodes examined &amp;gt;15, margin-negative resections, length of stay &amp;lt;21 days, no 30-day readmission, and no 90-day mortality. Multivariable logistic regression and Cox analyses were used to account for treatment selection bias. Results Patients receiving robotic surgery were more commonly treated within high volume, academic centers and with advanced clinical T and N stage disease. From 2010 to 2017, TO rates increased for esophageal and gastric cancer treated by all surgical techniques. RAMIE (odds ratio (OR):1.41, (CI 95% : 1.27-1.58) and RAMIG (OR:1.30, CI 95% : 1.17-1.45) had significantly higher TO rates compared to open surgery. For esophagectomy, TO (hazard ratio (HR):0.64, CI 95% : 0.60-0.67) and RAMIE (HR:0.92, CI 95% : 0.84-1.00) were both associated with long-term survival. For gastrectomy, TO (HR:0.58, CI 95% : 0.56-0.60) and both LAMIG (HR:0.89, CI 95% : 0.85-0.94) and RAMIG (HR:0.88, CI 95% : 0.81-0.96) were all associated with long-term survival. Subset analysis in high volume centers confirmed similar findings. Conclusions Despite potentially adverse learning curve effects and more advanced tumor stages captured within the study period, both RAMIE and RAMIG, as performed in mostly high-volume centers, were associated with improved TO and long-term survival. Therefore, consideration for wider adoption but a well-designed phase III RCT is required to fully evaluate the benefits of robotic techniques in esophageal and gastric cancers.

Robotic Techniques in Esophagogastric Cancer Surgery: An Assessment of Short- and Long-Term Clinical Outcomes

BackgroundRobotic esophagogastric cancer surgery is gaining widespread adoption. This population-based cohort study aimed to compare rates of textbook outcomes (TOs) and survival from robotic minimally invasive techniques for esophagogastric cancer.MethodsData from the United States National Cancer Database (NCDB) (2010–2017) were used to identify patients with non-metastatic esophageal or gastric cancer receiving open surgery (to the esophagus, n = 11,442; stomach, n = 22,183), laparoscopic surgery (to the esophagus [LAMIE], n = 4827; stomach [LAMIG], n = 6359), or robotic surgery (to the esophagus [RAMIE], n = 1657; stomach [RAMIG], n = 1718). The study defined TOs as 15 or more lymph nodes examined, margin-negative resections, hospital stay less than 21 days, no 30-day readmissions, and no 90-day mortalities. Multivariable logistic regression and Cox analyses were used to account for treatment selection bias.ResultsPatients receiving robotic surgery were more commonly treated in high-volume academic centers with advanced clinical T and N stage disease. From 2010 to 2017, TO rates increased for esophageal and gastric cancer treated via all surgical techniques. Compared with open surgery, significantly higher TO rates were associated with RAMIE (odds ratio [OR], 1.41; 95% confidence interval [CI], 1.27–1.58) and RAMIG (OR 1.30; 95% CI 1.17–1.45). For esophagectomy, long-term survival was associated with both TO (hazard ratio [HR 0.64, 95% CI 0.60–0.67) and RAMIE (HR 0.92; 95% CI 0.84–1.00). For gastrectomy, long-term survival was associated with TO (HR 0.58; 95% CI 0.56–0.60) and both LAMIG (HR 0.89; 95% CI 0.85–0.94) and RAMIG (HR 0.88; 95% CI 0.81–0.96). Subset analysis in high-volume centers confirmed similar findings.ConclusionDespite potentially adverse learning curve effects and more advanced tumor stages captured during the study period, both RAMIE and RAMIG performed in mostly high-volume centers were associated with improved TO and long-term survival. Therefore, consideration for wider adoption but a well-designed phase 3 randomized controlled trial (RCT) is required for a full evaluation of the benefits conferred by robotic techniques for esophageal and gastric cancers.

FIGO staging for carcinoma of the vulva: 2021 revision.

To revise the FIGO staging for carcinoma of the vulva using a new approach that involves analyses of prospectively collected data. The FIGO Committee for Gynecologic Oncology reviewed the recent literature to gain an insight into the impact of the 2009 vulvar cancer staging revision. The Committee resolved to revise the staging with a goal of simplification and actively collaborated with the United States National Cancer Database to analyze prospectively collected data on carcinoma of the vulva. Many tumor characteristics were collected for all stages of vulvar cancer treated between 2010 and 2017. Statistical analysis was performed with SAS software. Overall survival was estimated based on tumor characteristics. Log‐rank and Wilcoxon tests were used to analyze overall survival similarities between and within groups of tumor characteristics. Characteristics with similar survivals were then grouped into the same stages and substages. Kaplan–Meier overall survival curves were generated for the resulting stages and substages. There were 12 063 cases with available data. The resulting new staging for carcinoma of the vulva has two substages in Stage I, no substage in Stage II, three substages in Stage III, and two substages in Stage IV. The Kaplan–Meier overall survival curves showed clear separation between stages and substages. The 2021 vulvar cancer staging is the first from the FIGO Committee for Gynecologic Oncology to be derived from data analyses. This revision has a new definition for depth of invasion, uses the same definition for lymph node metastases utilized in cervical cancer, and allows findings from cross‐sectional imaging to be incorporated into vulvar cancer staging. The 2021 FIGO staging for carcinoma of the vulva is data‐derived, validated, and much simpler than earlier revisions.

Therapeutic Underuse and Delay in Hepatocellular Carcinoma: Prevalence, Associated Factors, and Clinical Impact.

Prognosis of hepatocellular carcinoma (HCC) could be affected by lack of or delayed therapy. We aimed to characterize the prevalence, correlates, and clinical impact of therapeutic underuse and delay in patients with HCC. Patients with HCC diagnosed between 2010 and 2017 were analyzed from the United States National Cancer Database. Logistic regression analysis identified factors associated with no and delayed (>90 days after diagnosis) HCC treatment. Cox proportional hazards regression with landmark analysis assessed the association between therapeutic delay and overall survival (OS), accounting for immortal time bias. Of 116,299 patients with HCC, 24.2% received no treatment and 18.4% of treated patients had delayed treatment. Older age, Black, Hispanic, lower socioeconomic status, earlier year of diagnosis, treatment at nonacademic centers, Northeast region, increased medical comorbidity, worse liver dysfunction, and higher tumor burden were associated with no treatment. Among treated patients, younger age, Hispanic, Black, treatment at academic centers, West region, earlier tumor stage, and receipt of noncurative treatment were associated with treatment delays. In multivariable Cox regression with a landmark of 150 days, patients with and without treatment delays had similar OS (adjusted hazard ratio [aHR], 1.01; 95% confidence interval [CI], 0.98‐1.04) with a median survival of 33.7 vs. 32.1 months, respectively. However, therapeutic delay was associated with worse OS in patients who had tumor, nodes, and metastases (TNM) stage 1 (aHR, 1.06; 95% CI, 1.01‐1.11) or received curative treatment (aHR, 1.12; 95% CI, 1.05‐1.18). Conclusion: One‐fourth of patients with HCC receive no therapy and one‐fifth of treated patients experience treatment delays. Both were associated with demographic, socioeconomic, and clinical characteristics of patients as well as facility type and region. The association between therapeutic delay and survival was stage and treatment dependent.

Factors associated with utilization of neoadjuvant chemotherapy in charlson comorbidity zero non-metastatic muscle-invasive bladder cancer patients.

ABSTRACTBackground:Guideline-based best practice treatment for muscle invasive bladder cancer (MIBC) involves neoadjuvant chemotherapy followed by radical cystectomy (NACRC). Prior studies have shown that a minority of patients receive NACRC and older age and renal function are drivers of non-receipt of NACRC. This study investigates treatment rates and factors associated with not receiving NACRC in MIBC patients with lower comorbidity status most likely to be candidates for NACRC.Materials and Methods:Retrospective United States National Cancer Database analysis from 2006 to 2015 of MIBC patients with Charlson comorbidity index (CCI) of zero. Analysis of NACRC treatment trends in higher CCI patients was also performed.Results:15.561 MIBC patients met inclusion criteria. 1.507 (9.7%) received NACRC within 9 months of diagnosis. NACRC increased over time (15.0% in 2015 compared to 3.6% in 2006). Higher NACRC was noted in females, cT3 or cT4 cancer, later year of diagnosis, and academic facility treatment. Lower utilization was noted for blacks and NACRC decreased with increasing age and CCI. Only 16.9% of patients aged 23-62 in the lowest age quartile with muscle invasive bladder cancer and CCI of 0 received NACRC.Conclusions:Although utilization is increasing, receipt of NACRC remains low even in populations most likely to be candidates. Further study should continue to elucidate barriers to utilization of NACRC.

Pediatric Pleomorphic Xanthoastrocytoma: A National Database Inquiry on Current Treatment Approaches in the United States.

BackgroundPleomorphic xanthoastrocytomas (PXAs) account for <1% of primary brain tumors, occurring predominantly in children and young adults. Surgical resection serves as the primary treatment for PXAs, while radiotherapy (RT) and chemotherapy protocols remain poorly defined.AimThis study aims to determine current care patterns utilized for pediatric patients (≤ 18 years) diagnosed with PXAs and their effect on overall survival.MethodsThe United States National Cancer Database (NCDB) was queried between 2004 and 2015 for pediatric patients (≤18 years) diagnosed with PXAs.ResultsFrom the 224 qualifying patients, most patients proceeded with surgery only (78.1%), while 11.6% of patients received both adjuvant RT and chemotherapy. In the 2010‐2015 cohort, patients with subtotal resection were associated with poorer prognosis than those with gross‐total resection (hazard ratio = 17.44, 95% confidence interval = 2.10‐144.90, p < .001). RT and chemotherapy recipients were similarly associated with poorer survival than those treated with surgery only, with p‐values of <.001 and respective hazard ratios of 3.82 (95% confidence interval = 1.85‐7.90) and 6.68 (95% confidence interval = 3.21‐13.89). The key factors impacting the probability of RT delivery involved WHO grade (p < .001) and chemotherapy administration (p < .001). However, WHO grade alone did not significantly impact survival (p‐value = .088).ConclusionMaximally safe resection is the current treatment goal for patients with PXAs. RT and chemotherapy are poorly utilized but had a greater role in managing more aggressive cases of PXAs. Additional research focusing on the impact of adjuvant therapies on tumor progression is needed to better guide treatment decisions.

Patterns of care and treatment outcomes in locoregional squamous cell carcinoma of the prostate.

260 Background: Primary pure prostate squamous cell carcinoma (PSCC) is a rare, aggressive disease accounting for less than 0.5-1% of prostate cancer diagnoses. PSCC is a distinct entity from adenocarcinoma with historically poor outcomes, often presenting in younger patients with lower urinary tract symptoms and normal PSA. There are currently no established treatment guidelines. Case reports are limited but describe multiple treatment approaches including various combinations of surgery, platinum and non-platinum-based chemotherapy, radiotherapy and androgen deprivation therapy, with selected reports showing longer survival times with a combined modality approach. Methods: Seeking to identify practice patterns and treatment outcomes, we performed a retrospective analysis of the United States National Cancer Database to identify 66 males with locoregional, nonmetastatic primary pure squamous cell carcinoma of the prostate and treated with surgery, chemotherapy, and/or radiotherapy between 2004 and 2015. Clinical factors in analysis included pretreatment PSA, clinical T-stage, histology, treatment modality and demographic factors including age, comorbidity index, race, insurance status and treatment facility type. Patients were stratified into treatment groups consisting of local therapy alone (n = 40, 60%), local therapy and chemotherapy (n = 13, 20%), chemotherapy alone (n = 7, 11%), and observation (n = 6, 9%). Survival analysis was estimated using the Kaplan-Meier method and analyzed with log-rank testing. A Cox proportional hazards model was used to evaluate the association between patient characteristics and survival. Univariable and multivariable logistic regression was performed to identify covariates associated with receipt of each treatment modality. Results: With an overall median follow-up of 21.9 months, median survival was 19.7 months for patients treated with local therapy alone, 10.9 months with chemotherapy alone, and 36.5 months with combined local therapy and chemotherapy. Overall survival was not statistically significant between treatment groups. Statistically significant predictors of death included age (HR 1.1, 95% CI [1.03-1.17]) and clinical stage ≥T3a (HR 4.05, 95% CI [1.35-12.2]). Statistically significant predictors of receipt of chemotherapy were clinical stage T3a or greater (OR 34.6, 95% CI [2.65-364]) and age (OR 0.91, 95% CI [0.82-99]). Conclusions: This analysis represents the largest reported cohort analysis of locoregional pure PSCC. Unfortunately, due to the rarity of this disease, prospective or randomized trials to determine the optimal treatment strategy are not feasible. Despite limitations in sample size, and in the absence of prospective data, this analysis suggests the addition of chemotherapy to local therapy is a reasonable treatment approach in appropriately selected patients and may result in improved survival.

Abstract PS1-05: Trends in breast-conserving surgery in Mexico after the implementation of a public health insurance system

Abstract Introduction Although temporal trends in breast conserving surgery (BCS) have been described for developed countries like the United States (US), there is a lack of information regarding the uptake of breast conservation in developing regions of the world. In developing countries, the implementation of breast conservation might be hindered by the availability of radiation therapy, lack of training among surgeons, or concerns regarding compliance with follow-up care and surveillance. In 2006, the Mexican government created Seguro Popular, which provided coverage for breast cancer care for all Mexican women, thus potentially mitigating the difficulties with obtaining care after BCS and improving access to multidisciplinary care. We undertook an overview of ten years of breast cancer surgery at our Mexican cancer center following the implementation of Seguro Popular, and explored changes in surgical technique over time. Methods A retrospective cohort analysis was conducted using the National Cancer Institute of Mexico (INCAN) database from 2006 to 2016. All patients with a diagnosis of breast cancer seen during that period were included. Patients who received surgery for breast cancer where then grouped together based on the type of surgery (mastectomy versus BCS). The effect of the year of diagnosis and of clinical stage at the time of presentation was evaluated. Logistic regression was used to model temporal trends in use of BCS over mastectomy for three 3-year periods (2006-2009, 2010-2012, and 2013-2016). Results The patient cohort consisted of 5289 women from the INCAN database, of which 4519 received some form of local surgical treatment. Sixty-one percent (n = 2764) had locally advanced disease (stages IIB-IIIC) at the time of presentation, and a quarter (n = 1156) had ≥60 days between diagnosis and receipt of surgical treatment. Eighty percent of the patients in the entire cohort (n = 3611) were treated with mastectomy, while 20% (n = 908) received BCS. For the 2006-2009 period, out of 1596 total surgeries, 9.9% were BCS (n = 158). The proportion of BCS increased for each of the other two studied periods, being 18.5% for the 2010-2012 period (n = 276/1490), and 33.1% for the 2013-2016 period (n = 474/1433) (p&amp;lt;0.01 for trend). While the increase in BCS was significant for all stages, it was most pronounced for women with early-stage disease (Stages I-IIA), going from 17% in 2006-2009 to 52% in 2013-2016 (p&amp;lt;0.01), than in those with locally-advanced disease (6.5 to 18%, p&amp;lt;0.01). Conclusions In the ten years after the start of the Seguro Popular public insurance program, the proportion of BCS at a Mexican cancer center increased significantly, particularly for women with early-stage disease. The rates seen at INCAN for the period between 2013-2106 resemble those reported by the US National Cancer Database, in which approximately 61% of women with stage I-II breast cancer and 20% of women with stage III disease receive BCS. Potential reasons for the increase in the uptake of BCS include improved access to adjuvant radiation therapy, improved access to systemic treatment, and higher adherence to follow-up care after the start of Seguro Popular, as well as improvements in surgical training. In addition, changes in BCS may also be related to improvements in the implementation of multidisciplinary teams over time, which may lead to a more homogeneous and comprehensive care. Our results show that improving access to care for patients living in developing countries positively impacts the uptake of BCS for women with breast cancer. Citation Format: Enrique Bargalló-Rocha, Nancy Reynoso-Noveron, Jaime Corona, Nereida Esparza-Arias, María Teresa Ramírez-Ugalde, Caros Daniel Robles-Vidal, Robin Shaw-Dulin, Armen Stankov, Rafael Vazquez-Romo, Patricia Villarreal-Colin, Sergio Aguilar-Villanueva, Jaime Hidalgo-Bahena, Milagros Perez-Quintanilla, Fernando U Lara-Medina, Juan Alejandro Torres, Enrique Soto-Perez-de-Celis, Paula Cabrera-Galeana, Alejandro Mohar, Abelardo Meneses-García. Trends in breast-conserving surgery in Mexico after the implementation of a public health insurance system [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-05.

Stage IV gastrointestinal stromal tumors: Epidemiology, treatment and outcomes in adult US patients.

462 Background: To evaluate epidemiology, treatment and outcomes of stage 4 gastrointestinal stromal tumors (GIST). Methods: The 2010-2016 United States National Cancer Database was queried for adult patients diagnosed with invasive GIST (ICD code 8936) at AJCC stage 4, without prior malignant disease. Overall survival (OS) was evaluated using Cox proportional hazards regression, accounting for potential confounders in multivariable models. Results: A total of 1,578 stage 4 GIST were included (13.3% of all GIST) with a male:female ratio of 1.38:1. The most common cancer site was the stomach (55.4%) and small intestine (40% of stage 4 GIST). At diagnosis, median age was 62 years and median tumor diameter 10 cm. Distant organ metastases were reported in 58.7%, the most frequent being hepatic (n = 801, 50.8% of stage 4 GIST). The majority of stage 4 GIST patients received systemic therapy (78.6%), either alone (35.4%) or combined surgery+systemic therapy (43.3%). Systemic therapy was administered neoadjuvant in 6.9%, adjuvant in 32%, and neoadjuvant+adjuvant in 5.1% of surgically resected patients. Another n = 204 patients (12.9% of all stage 4 GIST) were treated with surgical resection alone. GIST overall survival rates were 88%, 77%, 67% and 51% at 1, 2, 3, and 5 years, respectively. On multivariable Cox proportional hazard models, primary GIST treatment independently affected OS: compared to combined surgery+systemic therapy, OS was shorter for patients receiving systemic therapy alone (HR = 2.77 (95% CI: 2.12-3.61, p &lt; 0.001)) and no treatment (HR = 4.2 (95% CI: 2.75-6.43, p &lt; 0.001)). No significant OS difference was evident comparing surgery+systemic therapy and surgery alone (HR = 1.23 (95% CI: 0.88-1.72, p = 0.227)). In subgroup analyses of patients undergoing surgical resection, no statistically significant OS difference was evident comparing neoadjuvant, adjuvant and combined neoadjuvant+adjuvant systemic therapy on multivariable analyses. Treatment at non-academic vs. academic centers was associated with shorter OS (multivariable HR = 1.36 (95% CI: 1.1-1.69, p = 0.005)). Further independent OS predictors were male sex (vs. female HR = 1.28 (95% CI: 1.03-1.59, p = 0.023)), older age, higher comorbidities, higher cancer grade, and larger cancer diameter. Conclusions: Stage 4 GIST is a rare gastrointestinal malignancy that most commonly manifests in the stomach and small intestine in male patients, with frequent hepatic metastases and excellent 5-year OS rates of up to 51%. Combined surgery+systemic therapy demonstrates best outcomes, although surgical resection alone might yield comparable results in selected patients.

Abstract 2350: Transarterial radioembolization versus systemic treatment for the management of hepatocellular carcinoma with vascular invasion: Analysis of the US National Cancer Database

Abstract Background and Aims: For hepatocellular carcinoma (HCC) with vascular invasion, systemic treatment is recommended but transarterial radioembolization (TARE) is often used in clinical practice. The aim of this study was to investigate the current usage of TARE vs. systemic therapy as a first-line treatment for HCC with vascular invasion in the United States (US). Method: We performed a retrospective cohort study using the National Cancer Database (NCDB), which represents more than 70 percent of newly diagnosed cancer cases nationwide. All HCC patients diagnosed between 2010 and 2015 with the tumor stage of T3BN0M0 according to the 7th edition of the American Joint Committee on Cancer TNM staging system (tumor involving a major branch of a large vein of the liver without lymph nodes or extrahepatic metastasis) and received TARE or systemic treatment as a first-line treatment were included. Multivariable logistic regression was used to estimate factors associated with the utilization of TARE vs. systemic therapy. Results: A total of 1979 patients who received systemic treatment and 524 patients who received TARE were included. The proportion of patients receiving TARE increased from 15.7% in 2010 to 31.4% in 2015 (P&amp;lt;0.01). The median tumor size of the largest lesion was comparable (7.0cm for TARE vs. 7.1 cm for systemic treatment, P=0.43). Factors independently associated with increased likelihood of receiving TARE over systemic treatment were: advanced age (Odds Ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01 - 1.03, p=0.005), insurance status: private (OR: 3.06, 95% CI: 1.61 - 5.65, p&amp;lt;0.001), Medicaid/Medicare (OR: 2.91, 95% CI: 1.52 - 5.31, p&amp;lt;0.001), others (OR: 4.85, 95% CI: 1.90 - 11.62, p&amp;lt;0.001) vs. no insurance, and receiving care in the Midwest vs. Northeast region of the US (OR: 1.89, 95% CI: 1.38 - 2.53, p&amp;lt;0.001). Patients were significantly less likely to receive TARE if receiving treatment at community cancer program (OR: 0.24, 95% CI: 0.098 - 0.49, p&amp;lt;0.001) or comprehensive community cancer program (OR: 0.62, 95% CI: 0.48 - 0.82, p&amp;lt;0.001) vs. academic cancer program. Larger tumor size (OR per 1cm: 0.97, 95% CI: 0.95 - 1.00, p=0.03) and higher Charlson comorbidity index of ≥3 vs. 0 (OR: 0.53, 95% CI: 0.38 - 0.73, p&amp;lt;0.001) were inversely associated with receiving TARE. Recent HCC diagnosis year was associated with an increased likelihood of receiving TARE (OR: 1.23, 95% CI:1.16 - 1.32, p&amp;lt;0.001). Conclusion: The proportion of patients receiving TARE as a first-line treatment for HCC with macrovascular invasion has been increasing in the US. Age, comorbidities, insurance status, tumor size, and the type and location of cancer centers are associated with the usage of TARE vs. systemic treatment in HCC patients with vascular invasion. Citation Format: Joseph C. Ahn, Michael Luu, Walid Ayoub, Alexander Kuo, Andrew Hendifar, Jun Gong, Kambiz Kosari, Shelly Lu, Nicholas Nissen, Ju Dong Yang. Transarterial radioembolization versus systemic treatment for the management of hepatocellular carcinoma with vascular invasion: Analysis of the US National Cancer Database [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2350.

Immunotherapy in sinonasal melanoma: treatment patterns and outcomes compared to cutaneous melanoma.

Although treatment with checkpoint blockade is now accepted as standard of care for cutaneous melanoma, few studies have investigated its role in sinonasal melanoma (SNM). We aimed to evaluate whether immunotherapy was associated with improved survival in SNM and to compare the effect of immunotherapy in metastatic sinonasal and cutaneous melanoma. This was a cohort study of patients included in the United States National Cancer Database who had been diagnosed with sinonasal or cutaneous melanoma between 2012 and 2015 and had complete information regarding immunotherapy status. The primary outcome was overall survival. The influence of immunotherapy on overall survival was compared by Kaplan-Meier and Cox proportional hazards models. Propensity score matched analyses between SNM patients who received immunotherapy and those who did not were based on clinicopathological covariates associated with survival in univariate Cox models. The analytic cohort consisted of 704 patients with SNM, 94 of whom were treated with immunotherapy and 152,896 patients with cutaneous melanoma, 8055 of whom were treated with immunotherapy. Immunotherapy was not associated with survival in the propensity-score matched cohort (n = 195; hazard ratio [HR] = 1.0; 95% confidence interval [CI], 0.7 to 1.5; p = 0.88) or in adjusted Cox proportional hazards model (n = 549; HR = 1.0; 95% CI, 0.74 to 1.4; p = 0.88). Regimens including immunotherapy were associated with improved overall survival in metastatic cutaneous melanoma (HR = 0.57; 95% CI, 0.49 to 0.66; p < 0.0001), but not metastatic SNM (HR = 1.1; 95% CI, 0.67 to 1.7; p = 0.75). Compared to current standard of care therapy, inclusion of immunotherapy as first-line therapy was not associated with improved survival in SNM.

Use of combined androgen deprivation therapy with postoperative radiation treatment for prostate cancer: Impact of randomized trials on clinical practice

PurposeTo assess the impact of RTOG-9601 and GETUG-AFU-16 on the routine use of combination androgen deprivation therapy (ADT) with postoperative radiotherapy (PORT) for prostate cancer (CaP). Material and methodsPatients with localized CaP treated with radical prostatectomy (RP) and PORT with or without ADT at a comprehensive cancer center from January 2006 to June 2007 (Period 1 = P1), July 2011 to December 2012 (Period 2 = P2), and January 2017 to June 2018 (Period 3 = P3) were included. Clinicopathologic features and treatment characteristics were analyzed and compared. Multivariable logistic regression was used to assess prognostic factors and association with ADT use. Statistical tests were two-sided and a P value <0.05 was considered significant. To validate the findings, United States National Cancer Database (NCDB) and Surveillance, Epidemiology, and End Results (SEER) data were collected to assess rates of combined ADT and PORT from 2004 to 2015. ResultsFive hundred and two patients were included: 152 (P1), 185 (P2), and 165 (P3). PORT was most commonly delivered as early SRT (delivered >1 year post-RP with undetectable PSA or PSA >0.05 and ≤0.5 ng/ml) in all periods. The use of combination PORT and ADT increased over time: 14.5% (P1), 32% (P2), and 41% (P3) (P < 0.001). The proportion of patients that met eligibility criteria for either GETUG-AFU-16 or RTOG-9601 decreased from 47% (P1) to 35% (P3) (P = 0.04). International Society of Urological Pathology grade ≥4 (P < 0.002) and pre-PORT PSA >0.5 ng/ml (P < 0.001) were associated with use of ADT. Positive surgical margin status had a negative association (RR 0.5, P < 0.002). The NCDB demonstrated similar trends for use of combined ADT with PORT, increasing from 37% to 49% from 2004 to 2015. ConclusionThe use of combined ADT with PORT increased over time. However, only a third of contemporary patients undergoing PORT are represented in the major trials supporting the evidence for combination treatment, highlighting the need to characterize the modern impact of this intensification strategy.

Microsatellite instability and KRAS mutation in stage 4 CRC: Prevalence, geographic discrepancies and outcomes from the National Cancer Database.

e16052 Background: To assess microsatellite instability (MSI) and KRAS mutation prevalence, discrepancies and their impact on outcome in AJCC stage IV colorectal adenocarcinoma (colorectal cancer; CRC). Methods: The 2010-2016 United States National Cancer Database was queried for stage IV CRC patients &gt; 18yo and information on MSI and KRAS mutation. Microsatellite status was stratified as stable microsatellites (MSS, including low instability) and microsatellite instability high (MSI-H). KRAS status was stratified as mutation and wildtype. Prevalence and discrepancies were evaluated according to patient demographics, US geography and CRC factors. Overall survival (OS) was assessed using Cox proportional hazards models adjusting for age, gender, race, comorbidities, metastatic burden, CRC treatment, treatment center type, and year of CRC diagnosis. A priori, a statistical interaction test between microsatellite status, KRAS status and primary CRC site was planned. Results: Microsatellite/KRAS status was available for n = 10,844/n = 25,712 patients, respectively. OS was assessed in n = 5,904 patients with data on both microsatellite and KRAS status, and follow-up. Overall prevalence of MSI-H was 3.1% and KRAS mutation 42.4%. Microsatellite and KRAS status varied according to primary CR site, as presented in Table. Further variation was evident according to US-geography, with MSI-H rates ranging from 1.6% to 4.1%, and KRAS mutation rates ranging from 41.1% to 44%. On multivariable analyses, longer OS was observed in patients with KRAS wildtype versus mutation (HR = 0.91, 95% CI: 0.85-0.97 p = 0.004), MSS versus MSI-H (HR = 0.75, 95% CI: 0.62-0.9, p = 0.003), and left-sided versus right-sided CRC (HR = 0.65, 95% CI: 0.6-0.7, p &lt; 0.001). The effect of KRAS mutation further varied with CRC site and microsatellite status (interaction p = 0.002). Conclusions: Depending on its primary site and US geography, stage IV CRC shows distinct mutational behavior. KRAS mutation, MSI-H, MSI-H and primary CRC sidedness independently affect overall survival and interact with distinct prognostic profiles. Generically classifying adenocarcinomas of different site as “CRC” might deprecate this diversity. [Table: see text]