California Cancer Registry Research Articles

Disparities in cancer stage shifts associated with the COVID-19 pandemic in California, 2020-2021.

The COVID-19 pandemic and associated shutdowns disrupted healthcare access and resulted in decreased cancer screenings. Cancer diagnosis delays have concerning downstream effects on late-stage cancer, especially for marginalized populations. The study population included 349,458 adults in the California Cancer Registry diagnosed with cancer between January 2019-December 2021, during which California experienced two stay-at-home orders. We examined the percentage of late-stage (III-IV) cancer diagnoses across five periods: Pre-Pandemic (January 2019-February 2020), Shutdown #1 (March-June 2020), Post-Shutdown #1 (July-November 2020), Post-Shutdown #2 (December 2020-March 2021), and Post-Vaccine Rollout (April-December 2021). To examine the association between time-period and late-stage diagnoses, we conducted a multivariable log binomial regression model adjusted for sociodemographic and neighborhood factors. The percentage of late-stage cancer diagnoses increased during Shutdown #1 (+5.2%) and returned to baseline Post-Vaccine Rollout. Groups with notably higher increases in the percentage of late-stage cancer (vs. overall population) during Shutdown #1 include: Pacific Islander (+13.7%), Thai (+11.2%), Chinese (+8.1%), Native Hawaiian (+7.4%), Filipino (+6.6%), and uninsured (+7.4%). Uninsured (vs. private insurance) (PR: 1.41), low neighborhood SES (nSES) (vs. high) (PR: 1.19), and racial and ethnic minoritized groups (vs. NH White) (PR's: 1.04-1.19) had higher likelihood for late-stage cancer diagnosis. The pandemic exacerbated late-stage cancer disparities for racial and ethnic minoritized groups, underinsured, and low nSES communities in California (2020-2021). Interventions to improve cancer screening must be focused on racial and ethnic minoritized, underinsured, and low nSES communities, as they are likely to be more vulnerable to healthcare disruptions like the pandemic.

Liver Resection With Extrahepatic Disease: A Population-Based Analysis of Thoughtful Selection.

The oncologic benefit of liver resection for colorectal liver metastases (CRLM) in the setting of concurrent extrahepatic disease (EHD) is controversial. We performed a population-based, cross-sectional study to determine the practice patterns and overall survival (OS) of patients with CRLM + EHD who underwent liver resection. Patients with CRLM + EHD were identified using the California Cancer Registry from 2000 to 2019. Records were linked to the Office of Statewide Health Planning Inpatient Database. Patient demographics, clinical characteristics, and survival were compared between CRLM + EHD patients with and without liver resection. Of 170 978 patients with CRLM, 62 003 (36%) had concurrent EHD (CRLM + EHD). In all, 3736 (6%) of CRLM + EHD underwent liver resection compared to 22% of patients with liver limited CRLM. Compared to CRLM + EHD without liver resection, CRLM + EHD with resection were younger, had fewer comorbidities, received higher frequencies of perioperative chemotherapy, and were more likely to have only a single site of EHD rather than multiple sites. Median OS was significantly higher for CRLM + EHD with resection compared to without (52 vs. 27 months, HR 0.46 [95% CI 0.44-0.47], p < 0.001). Regarding the location of EHD, this survival benefit was observed with liver resection for lung, peritoneal, intraabdominal lymph nodes, ovarian, and bone metastases. In a large population-based setting, subsets of CRLM + EHD patients that undergo liver resection are associated with prolonged survival. These results support surgery with thoughtful patient selection to optimize survival outcomes in this population.

The role of ethnic enclaves and neighborhood socioeconomic status in invasive breast cancer incidence rates among Asian American, Native Hawaiian, and Pacific Islander females in California.

Few studies have examined whether the incidence rates of invasive breast cancer among Asian American, Native Hawaiian, and Pacific Islander (AANHPI) populations differ by the neighborhood social environment. Thus, we examined associations of ethnic enclave and neighborhood socioeconomic status (nSES) with breast cancer incidence rates among AANHPI females in California. A total of 14,738 AANHPI females diagnosed with invasive breast cancer in 2008-2012 were identified from the California Cancer Registry. AANHPI ethnic enclaves (culturally distinct neighborhoods) and nSES were assessed at the census tract level using 2007-2011 American Community Survey data. Breast cancer age-adjusted incidence rates and incidence rate ratios (IRRs) were estimated for AANHPI ethnic enclave, nSES, and their joint effects. Subgroup analyses were conducted by stage of disease. The incidence rate of breast cancer among AANHPI females living in lowest ethnic enclave neighborhoods (quintile (Q)1) were 1.21 times (95% Confidence Interval (CI) 1.11, 1.32) that of AANHPI females living highest ethnic enclave neighborhoods (Q5). In addition, AANHPI females living in highest vs. lowest SES neighborhoods had higher incidence rates of breast cancer (Q5 vs. Q1 IRR = 1.30, 95% CI 1.22 to 1.40). The incidence rate of breast cancer among AANHPI females living in low ethnic enclave + high SES neighborhoods was 1.32 times (95% CI 1.25, 1.39) that of AANHPI females living in high ethnic enclave + low SES neighborhoods. Similar patterns of associations were observed for localized and advanced stage disease. For AANHPI females in California, incidence rates of breast cancer differed by nSES, ethnic enclave, when considered independently and jointly. Future studies should examine whether the impact of these neighborhood-level factors on breast cancer incidence rates differ across specific AANHPI ethnic groups and investigate the pathways through which they contribute to breast cancer incidence.

Risk factors for second primary breast cancer by laterality, age, and race and ethnicity.

Epidemiologic studies of risk factors for second primary breast cancer (SBC) have been conducted primarily in non-Hispanic White (NHW) women. A racially- and ethnically-diverse population-based pooled cohort of 9,639 women with first primary stage I-III invasive breast cancer (FBC) was linked with the California Cancer Registry; 618 contralateral SBC (CSBC) and 278 ipsilateral SBC (ISBC), diagnosed >6 months after FBC, were identified. Using Fine and Gray models accounting for competing risks, we assessed associations of CSBC and ISBC risk with FBC clinical characteristics and epidemiologic factors. In younger women (FBC at age <50 years), higher CSBC risk was associated with ER/PR-negative FBC [hazard ratio (HR)=1.68], breast cancer family history (HR = 2.20), and nulliparity (HR = 1.37). In older women (FBC at age ≥50 years), higher risk was associated with breast cancer family history (HR = 1.32), premenopausal status (HR = 1.49), overweight (HR = 1.39), and higher alcohol consumption (HR = 1.34). For ISBC, higher risk was associated with married status (HR = 1.94) in younger women, and overweight (HR = 1.60) among older women. For CSBC, HR estimates were generally similar across racial and ethnic groups. Even after adjustment for these risk factors, compared with NHW women, risk remained elevated for CSBC in younger African American, Asian American, and Hispanic women, and for ISBC in older African American and Hispanic women with ER/PR-positive FBC. Our findings support genetic risk evaluation, enhanced screening, and lifestyle changes in women at higher risk of SBC. Additional risk factors must contribute to the unequal burden of SBC across racial and ethnic groups.

Cancer diagnosis during pregnancy is associated with severe maternal and neonatal morbidity

BackgroundData on maternal and fetal outcomes in patients diagnosed with cancer during pregnancy are limited. Given expected increase in patients diagnosed with cancer during pregnancy, there is a growing need to evaluate clinical outcomes. ObjectiveTo evaluate obstetric outcomes among women with early-stage gynecologic or breast cancer who were diagnosed during pregnancy compared to women without cancer in a population-based cohort. MethodsWe performed a population-based study of women aged 18-45 years with stage I gynecologic or stage I-III breast cancer reported to the California Cancer Registry for the years 2000-2012. Data were linked to the 2000-2012 California birth data to produce a database with cancer characteristics and obstetric outcomes. We included patients who had a delivery within the 10 months following cancer diagnosis. The primary outcome was severe maternal morbidity (SMM). Secondary outcomes included pre-term birth (PTB) and neonatal morbidity. Propensity scores were used to match similar controls to cases in a 2:1 ratio based on demographic attributes and medical comorbidities included in the Obstetric Comorbidity Index (OB-CMI). Logistic regressions were used to evaluate outcomes. ResultsThe cohort consisted of 503 women with cancer in pregnancy (319 breast, 125 ovarian, 59 cervical), and 1,006 matched controls. Cancer during pregnancy was associated with higher odds of SMM (6.8% vs <1.1%; odds ratio [OR] 8.03, 95% CI 3.82-16.88), PTB between 32-36 weeks (32.6% vs 8.3%, OR 5.38, 95% CI 4.02-7.20), and neonatal morbidity (12.5% vs 6.1%; OR 2.22, 95% CI 1.53-3.21) compared to matched controls. In sub-analysis of SMM indicators, hysterectomy and sepsis were significantly associated with cancer during pregnancy (4.8% vs <1.1%, P<.001; <2.2% vs 0.0%, P=.037, respectively). ConclusionCancer during pregnancy is associated with increased risk of maternal and neonatal morbidity. These findings highlight the need for careful management and consideration of obstetric outcomes in these patients.

Abstract A008: Proof-of-Concept: A machine learning classifier to impute nativity status in Hispanic/Latino/a/x cancer patients in the California Cancer Registry

Abstract Background: Cancer disparities exist within the Hispanic/Latino/a/x (H/L) population by nativity status. Non-US born H/L colorectal cancer (CRC) patients and Prostate Cancer (PCa) patients in California have a statistically significant lower risk of cancer-specific survival when compared to Non-Hispanic White patients after controlling for confounders. However, birthplace information is largely incomplete in population-based cancer registries. For example, more than 40% of H/L patients have missing information on nativity in the California Cancer Registry (CCR) database. With the goal of better imputing missing birthplace, we built a Machine Learning (ML) model to predict nativity among CCR H/L cancer patients. Methods: H/L cases with primary invasive CRC (n = 75,613) and PCa (n = 93,042) at least 18 years old, diagnosed between 1988 and 2021 contained in the CCR research file were analyzed (46.36% had missing birthplace). A binary indicator variable assigning cases with known birthplace to US-born vs. Non-US born was constructed as the target for prediction. A stratified split by levels of the outcome was used to generate training (70%, n = 63,323) and testing (30%, n = 27,139) datasets. We used a pruned classification tree to perform feature selection, with the 10 features with the highest importance (measured by the overall reduction in impurity for any split containing each feature) used to predict nativity. Missing observations of the quantitative and qualitative features were mean, or mode imputed, respectively. The classification methods considered were classification trees, Random Forest (RF), and Boosting. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and the rate of correctly classified observations. Results: The top three features with the highest importance were the NHIA (NAACCR Hispanic/Latino Identification Algorithm) label, the Hispanic/Spanish identity, and the year of social security number issuance (SSN); the latter is part of a current SSN-based algorithm used to impute nativity status in this population. Classification models showed similar prediction performance. The highest AUC was reported by the RF (AUC = 0.9822), followed by Boosting (AUC = 0.9785), and the pruned classification tree (AUC = 0.9647). A similar rate of correctly classified observations was reported for the Boosting and RF models (∼94%). The RF model ranked feature importance in a similar order as the pruned classification tree. Ultimately, the RF model was the best performing classifier with a sensitivity and specificity of 0.61 and 0.90, respectively. This classifier substantially outperforms the SSN-based algorithm, which reported a correct classification rate of 81%, a sensitivity = 0.54, and a specificity = 0.41 in this dataset. Conclusions: This proof-of-concept analysis showcases a potential for developing a ML model to overcome missing nativity status in H/L cancer patients to enable more accurate classification by nativity in future research using CCR data. Citation Format: Proof-of-Concept: A machine learning classifier to impute nativity status in Hispanic/Latino/a/x cancer patients in the California Cancer Registry. Joel Sanchez Mendez, Lihua Liu, Juan P. Lewinger, Laura Fejerman, Mariana C. Stern [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A008.

Abstract C019: Peripheral Absolute Lymphocyte Count and Breast Cancer Mortality among Racially Diverse Women

Abstract Background: Among patients with triple-negative breast cancer (TNBC), higher tumor infiltrating lymphocytes (TILs) are associated with increased overall mortality (OM) and breast cancer-specific mortality (BCSM). We previously found that low peripheral absolute lymphocyte count (ALC) is associated with increased OM and BCSM in a sample of mostly non-Hispanic White (NHW) patients with TNBC. Here, we investigated the association between low ALC and mortality (OM and BCSM) across different breast cancer subtypes and whether the association is potentially modified by race and ethnicity. Methods: We used the Oncoshare database, which links electronic medical records (EMRs) data to the California Cancer Registry (CCR), and assessed women diagnosed with stage I-III breast cancer between 2000-2017, who had at least one ALC measurement and treated at two healthcare systems in California. Patient and tumor characteristics were obtained from the CCR and laboratory testing from EMRs. Patients with metastatic disease and chemotherapy receipt after one year of diagnosis were excluded. Multivariable logistic models assessed factors associated with “low ALC” (&amp;lt;1 K/µL, ever vs. never). We applied Cox models to evaluate the association between “min ALC” (lowest ALC value after diagnosis) and OM and BCSM within each breast cancer subtype (Luminal A, HER2-enriched, and TNBC), and further explored the interaction between min ALC and race and ethnicity. All models adjusted for low absolute neutrophil count, demographics, and tumor features. Results: Among 10,750 women analyzed, the risk of “low ALC” was associated with TNBC vs Luminal A (odds ratio (OR) 1.22, p=0.0098), older age (OR 1.01 per year, p&amp;lt;0.001), higher grade (grade 3 vs. 1, OR 1.15, p=0.042), higher stage (stage III vs. I, OR 1.81, p&amp;lt;0.001), and public vs. private health insurance (OR 1.29, p&amp;lt;0.001). Cox models showed that higher min ALC was associated with lower OM across breast cancer subtypes (Luminal A: HR 0.37, HER2-enriched: HR 0.32, TNBC: HR 0.22; all p&amp;lt;0.001) and BCSM (Luminal A: HR 0.29, HER2-enriched: HR 0.23, TNBC: HR 0.19; all p&amp;lt;0.001). Interaction analysis showed that race and ethnicity modified the association between min ALC and OM (interaction-p &amp;lt;0.001) and BCSM (interaction-p &amp;lt; 0.001) in the overall cohort; compared to NHW women (HR 0.38, 95% confidence interval [0.34-0.43]), the association between min ALC and OM was stronger among Hispanic (HR 0.24, [0.18-0.33]), Asian (HR 0.19, [0.14-0.25]), and Black (HR 0.21, [0.13-0.35]) women. Similar results were observed for BCSM. Conclusions: Low peripheral ALC, a routinely measured clinical lab result, strongly predicts higher BCSM and OM across breast cancer subtypes, beyond TNBC. The association between min ALC and BCSM/OM was stronger among Black and Asian women vs. NHW women, suggesting that maintaining normal ALC during breast cancer treatment may reduce BCSM and OM, especially for women from racial and ethnic minoritized groups. Future research should investigate differences in ALC, immune response, and BCSM in diverse populations. Citation Format: Candice N. Thompson, Ingrid Luo, Mina Satoyoshi, Lidia Schapira, Esther M. John, Summer S. Han, Allison W. Kurian. Peripheral Absolute Lymphocyte Count and Breast Cancer Mortality among Racially Diverse Women [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C019.

Abstract A048: Association between ambient particulate matter and colorectal cancer incidence: The Multiethnic Cohort Study

Abstract Background: Growing evidence suggests that air pollution may be a risk factor for colorectal cancer (CRC). We examined the association between ambient particulate matter (PM) exposure and CRC risk within the Multiethnic Cohort Study (MEC), representing the first study to include a large sample of racial and ethnic minoritized populations. Methods: The MEC is a prospective study that recruited, from 1993 through 1996, men and women ages 45-75 years largely from five racial and ethnic groups (African American, Japanese American, Latino, Native Hawaiian, and Non-Hispanic White) living in Hawai‘i and California. This study included 98,675 California MEC participants, residing predominately in Los Angeles County. Satellite-based PM2.5 (PM with an aerodynamic diameter &amp;lt;2.5μm) exposures were estimated from a published spatiotemporal model. Kriging interpolation was used to estimate PM10 (PM &amp;lt;10μm) exposures using routine air monitoring data from the US Environmental Protection Agency. Time-varying PM exposures were assessed from time of recruitment through 12/31/2018. Incident invasive CRC cases were identified via linkage with the California Cancer Registry (n=3,217). Cox proportional hazards models were used to examine the association between PM and CRC risk using age as the time metric, with strata defined by age at cohort entry and race and ethnicity, and adjusting for demographic and lifestyle factors. Heterogeneity of the PM-CRC association was assessed by sex, race and ethnicity, and CRC subsite (right colon, left colon, rectum). Results: Risk of CRC increased with PM2.5 (per 10μg/m3 hazard ratio [HR] 1.13, 95% confidence interval [CI] 0.96-1.33) with a larger HR observed among females (HR 1.29, 95% CI 1.03-1.62) than males (HR 0.96, 95% CI 0.76-1.22) (Pheterogeneity=0.24). CRC risk was positively associated with PM2.5 across race and ethnicity (except for African American participants) with the largest HR observed among Latino participants (HR 1.47, 95% CI 1.03-2.08) (Pheterogeneity=0.20). There was no statistically significant heterogeneity of PM2.5 effect by tumor subsite (Pheterogeneity=0.07); although larger HRs were seen for left colon (HR 1.52, 95% CI 1.08- 2.14) and rectal cancers (HR 1.54, 95% CI 1.05-2.25) than right colon cancers (HR 1.09, 95% CI 0.88-1.35). PM10 was not associated with CRC risk (per 10 μg/m3; HR 1.02, 95% CI 0.93-1.22) with no evidence of heterogeneity in associations by sex or race and ethnicity (respective Pheterogeneity 0.75, 0.44). Although HRs for PM10 appeared to differ by CRC subsite (Pheterogeneity=0.03), the 95% CI of these HRs included the null (right HR 0.95, 95% CI 0.84-1.06; left HR 1.13, 95% CI 0.95-1.35; rectal HR 1.18, 95% CI 0.97-1.43). Conclusions: Preliminary findings suggest that PM2.5 exposure is associated with CRC risk with larger associations in females and, possibly, for left colon and rectal cancer. Additional studies are needed to confirm these findings and evaluate the potential biological pathways underlying these associations. Citation Format: Ugonna Ihenacho, Chiuchen Tseng, Jun Wu, Scott Fruin, Timothy V. Larson, Salma Shariff-Marco, Loïc Le Marchand, Daniel O. Stram, Lynne R. Wilkens, Christopher A. Haiman, Beate Ritz, Iona Cheng, Anna H. Wu. Association between ambient particulate matter and colorectal cancer incidence: The Multiethnic Cohort Study [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A048.

Abstract A025: Trends in liver cancer mortality by sex, race, and ethnicity in California from 2000-2019

Abstract Background: Liver cancer disproportionately affects foreign-born individuals and racial and ethnic minoritized groups, with higher incidence among Asian American/Pacific Islander (AAPI) and Hispanic populations than non-Hispanic (NH) White populations. California has one of the highest overall mortality rates from liver cancer and a large proportion of AAPI and Hispanic residents compared to other U.S states. While prior studies have examined racial and ethnic disparities in liver cancer incidence and treatment, few studies have examined trends in liver cancer mortality in California by sex, race, and ethnicity. Methods: Adults aged 20+ years diagnosed with first primary malignant liver and intrahepatic bile duct cancer from January 2000 through December 2019 were identified through the California Cancer Registry, a statewide population-based cancer registry. We used SEER*Stat software to compute age-adjusted mortality rates (per 100,000 population; standardized to the 2000 U.S. standard million population) by sex, race, and ethnicity. To analyze temporal trends of mortality rates, we calculated annual percent change (APC) using Joinpoint regression. Results: Overall, the mortality rate of liver cancer increased from 8.05 to 10.75 per 100,000 (average APC=1.53, 95% CI 1.23, 1.82) from 2000-2019. For males, rates increased from 11.39 in 2000 to 15.77 until 2013 (APC=2.53, 95% CI 2.07, 3.21), and stabilizing thereafter (APC=-0.74, 95% CI -2.37, 0.30). In contrast, for females, mortality rates increased continuously from 2000-2019 from 5.27 to 7.17 (APC=1.63, 95% CI 1.27, 2.04). Across racial and ethnic groups, the mortality rate for liver cancer was highest for the AAPI adults at 16.77 in 2000, and this decreased over time to 12.29 in 2019 (APC=-3.17, 95% CI -5.36, -2.24). Similarly, the liver cancer mortality rate among Hispanic adults increased initially and then decreased. Mortality among non-Hispanic Black adults increased from 10.98 in 2000 to 12.99 in 2019 (APC=0.89, 95% CI -0.07, 2.02), though this did not reach statistical significance. The liver cancer mortality rate was lowest among non-Hispanic White adults from 5.65 in 2000 but increased over time to 7.87 in 2019 (APC=1.76, 95% CI 1.39, 2.08), which is still the lowest compared to other racial and ethnic groups. Discussion: In contrast to studies that show a decline in liver cancer mortality in recent years, liver cancer mortality rates have continued to increase in California, particularly for females. Liver cancer mortality rates initially increased for AAPI and Hispanic populations but have started to stabilize. Next steps are to understand multilevel drivers contributing to these trends in liver cancer mortality in California, including individual sociodemographic and clinical factors, healthcare system factors, and neighborhood factors, including neighborhood socioeconomic status and ethnic enclaves. Citation Format: Janet N. Chu, Meera Sangaramoorthy, Meg Mckinley, Stephen Li, Mindy C. DeRouen, Alice Guan, Michele M. Tana, Ma Somsouk, Caroline A. Thompson, Chanda Ho, Hashem B. El-Serag, Iona Cheng, Scarlett L. Gomez, Salma Shariff-Marco. Trends in liver cancer mortality by sex, race, and ethnicity in California from 2000-2019 [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A025.

Abstract B178: Examining ovarian cancer survival by Asian American ethnic subgroup: An analysis of California Cancer Registry data

Abstract Background: Ovarian cancer is the leading cause of death among gynecologic malignancies. However, outcomes are not the same for all women with studies showing Asian Americans having the highest survival across all major racial groups. Since the Asian American population is heterogeneous, we examined ovarian cancer survival by Asian ethnic subgroup using data from the California Cancer Registry. Most ovarian cancer survival studies evaluate Asian Americans as a single aggregated group, which may mask important ethnic-specific disparities. Methods: A total of 31,230 ovarian cancers diagnosed among non-Hispanic Whites and Asian/Pacific Islanders between 1996 and 2020 were included in the analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to evaluate the risk of dying from ovarian cancer comparing the Asian ethnic subgroups to non-Hispanic Whites using Cox proportional hazards models. The survival analyses also considered demographic, tumor, socioeconomic, and treatment characteristics. Results: For most Asian ethnic subgroups, risk of dying from ovarian cancer was comparable to non-Hispanic Whites with the only exception being Other Asians who showed a statistically significant 15% decreased risk of ovarian cancer death (HR=0.85, 95% CI 0.73-0.97, p-value=0.02). Another notable finding was the increased risk of death observed among Pacific Islander ovarian cancer patients when compared to non-Hispanic White patients (HR=1.27, 95% CI 0.99-1.62, p-value=0.06). Conclusion: Although most studies show Asian Americans having the highest ovarian cancer survival, our analyses indicate that only Other Asians have better survival and Pacific Islanders may have poorer survival relative to non-Hispanic Whites, highlighting the importance of disaggregation in future studies. These ethnic-specific disparities that were observed even after accounting for relevant survival-related characteristics should be further explored as it may inform important biological and behavioral factors associated with survival, which are not captured in cancer registry data. Citation Format: Alice W. Lee, Jenny Chang, Sannia Siddiqui, Argyrios Ziogas, Robert E. Bristow. Examining ovarian cancer survival by Asian American ethnic subgroup: An analysis of California Cancer Registry data [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr B178.

Abstract B177: Association between ethnicity and ovarian cancer tumor characteristics in Asian Americans in California

Abstract Background: Ovarian cancer is often associated with poor survival given that most patients are diagnosed at advanced stages when treatment is less effective. The disease is also very heterogeneous, consisting of various histologic subtypes that each have distinct epidemiologic and pathologic profiles. Given that some studies have noted ethnic-specific disparities in ovarian cancer survival when the Asian American population is disaggregated and certain tumor characteristics are associated with more favorable outcomes, we examined the relationship between Asian ethnic subgroup and ovarian cancer disease presentation. Methods: We included a total of 31,230 non-Hispanic White and Asian/Pacific Islander ovarian cancer cases diagnosed between 1996 and 2020 from the California Cancer Registry. Multivariable logistic regression with odds ratios (ORs) and 95% confidence intervals (CIs) was used to examine the likelihood of being diagnosed with tumors of a certain stage, grade, and histologic subtype, for each Asian ethnic subgroup compared to non-Hispanic Whites. Demographic and socioeconomic factors were considered in the analyses. Results: Most, but not all, Asian ethnic subgroups were less likely to be diagnosed with advanced stage ovarian cancer and more likely to be diagnosed with clear cell ovarian cancer compared to non-Hispanic Whites. For South East Asians, the odds of having advanced stage tumors were 43% lower than non-Hispanic Whites (OR=0.57, 95% CI 0.41-0.79) and the odds of having clear cell tumors were almost 200% higher than non-Hispanic Whites (OR=2.97, 95% CI 1.92-4.61); only South Asians did not show lower odds of an advanced stage tumor diagnosis (OR=1.06, 95% CI 0.86-1.29) and higher odds of a clear cell tumor diagnosis (OR=0.93, 95% CI 0.63-1.37). Conclusion: There are clear differences in ovarian cancer disease presentation when each Asian ethnic subgroup is examined separately with South Asians constituting the only subgroup who did not show a lower likelihood of an advanced stage diagnosis and a higher likelihood of a clear cell diagnosis when compared to non-Hispanic Whites. Given that tumor stage and histologic subtype are considered important prognostic factors for ovarian cancer, identifying the underlying factors that may contribute to being diagnosed with certain tumor characteristics could provide clues to help us improve the survival of this highly fatal malignancy. Citation Format: Alice W. Lee, Jenny Chang, Sannia Siddiqui, Argyrios Ziogas, Robert E. Bristow. Association between ethnicity and ovarian cancer tumor characteristics in Asian Americans in California [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr B177.

Abstract C127: Patterns of mortality risk in insured patients with cancer by race/ethnicity and socioeconomic status in Southern California

Abstract Purpose. Several factors including, socioeconomic status (SES), access to screening and healthcare coverage, tumor biology, differences in disease management and care delivery in various healthcare settings, and implicit bias among healthcare providers contribute to mortality disparities in individuals with cancer. Further, health insurance is strongly associated with better survival. Previous studies that examined disparities in cancer mortality included patients with and without healthcare coverage, making it difficult to disentangle the effects of health insurance coverage from other SES factors. Thus, we evaluated the influence of race/ethnicity and geocoded SES on all-cause mortality in cancer patients with health insurance. Methods. We identified adults with health insurance coverage diagnosed with eight common cancers from 2009 to 2014 from the California Cancer Registry (stages I-IV) and followed them through 2017 (8 years maximum). Specifically, we identified those who lived in southern California counties. Patients had managed care, preferred provider organization, Medicare, Medicaid, dual Medicare and Medicaid, and other private insurance. We calculated person-year mortality rates by race/ethnicity and geocoded SES quintiles. Adjusted hazard ratios for the association between overall mortality and race/ethnicity and SES were estimated using Cox proportional hazards models accounting for other demographics, stage at diagnosis, and cancer treatments. Results. 164,197 adults were diagnosed with cancer originating from breast, prostate, lung, colon, skin melanoma, uterus, kidney, and bladder. For all racial/ethnic groups combined, the mortality rates from lowest to highest SES groups were 112.1/1000 PY (lowest); 100.2/1000 PY (lower-middle); 91.2/1000 PY (middle); 79.1/1000 PY (upper-middle); and 63.5/1000 PY (upper). These rates suggest that people with the lowest SES have a markedly increased mortality risk after cancer diagnosis even if they have health insurance. In multivariable analyses, those in the lowest SES group had a 40–78% increased risk of all-cause mortality compared to those in the upper SES group across all races/ethnicities. For example, within African Americans, the adjusted mortality risk was up to 61% higher (HR 1.61, 95% CI 1.41–1.83) in the lowest SES group compared to the highest SES group. Conclusion. This study suggests disparities in overall mortality risk after cancer diagnoses persist even in a cohort with health insurance, and that SES is an important driver of this disparity. Issues related to travel distance, access to transportation to cancer care facilities, and access to telemedicine may be magnified among those with lower SES during cancer care where optimal management becomes more complex. To potentially mitigate the effects of these social determinants, healthcare systems must either implement programs to support patients, or have partnerships with local community organizations to do so. All of this requires systems level support through social work, patient navigation, and cancer case management. Citation Format: Reina Haque, Amrita Mukherjee, Robert M. Cooper. Patterns of mortality risk in insured patients with cancer by race/ethnicity and socioeconomic status in Southern California [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C127.

Maternal Exposure to Heavy Metals From Industrial Sources During Pregnancy and Childhood Cancer Risk in California.

The study investigated maternal exposure to heavy metals from industrial sources during pregnancy as potential risk factors for childhood cancer. Cases ages 0-19 were identified from California Cancer Registry. Controls (20:1 ratio) were randomly selected from California Birth Registry, frequency-matched by birth year (1998-2016). We estimated maternal exposure to lead, nickel, and cobalt in ambient air from the Toxics Release Inventory. We examined "ever/never" and "high/low" exposures categorized by median exposure. Models were adjusted for maternal age, race/ethnicity, method of payment for prenatal care, neighborhood socioeconomic status, and urban/rural residence. Among highly exposed persons, lead was associated with an increased teratoma risk (adjusted odds ratio [aOR]: 1.52; 95% confidence interval [CI]: 0.97, 2.37), whereas nickel was associated with an increased rhabdomyosarcoma risk (aOR: 1.45; 95% CI: 1.03, 2.04). Cobalt was associated with an increased glioma risk (aOR: 2.25; 95% CI: 1.39, 3.65) among ever-exposed persons. Inverse associations were found between Wilms tumor and nickel among the ever exposed and highly exposed (ever: aOR: 0.75; 95% CI: 0.59, 0.96; high: aOR: 0.64; 95% CI: 0.45, 0.93). Findings suggest that air pollution from heavy metals released by industrial sources may elevate childhood cancer risk.

Prostate Cancer Disparities in Clinical Characteristics and Survival among Black and Latino Patients Considering Nativity: Findings from the California Cancer Registry.

We investigated clinical characteristics and prostate cancer survival patterns among Latino patients considering nativity compared with non-Latino Black (NLB) and non-Latino White (NLW) patients. We used data from the California Cancer Registry (1995-2021), which included 347,540 NLW, 50,032 NLB, and 75,238 Latino patients with prostate cancer. Frequencies of sociodemographic and clinical variables were assessed using χ2 tests. Multivariable regression models were fitted to evaluate determinants of treatment reception, Gleason upgrade, and survival differences. Exploratory analyses were conducted grouping Latino cases into US born and non-US born by country of origin. Compared with NLW, NLB cases had the greatest proportion of younger patients, whereas non-US-born Latino patients had the greatest proportion of low socioeconomic status and uninsured patients. Non-US-born Latinos showed a greater proportion of diagnoses completed with <6 core biopsies, Gleason >8, stage IV tumors, and metastasis. Multivariable analyses showed that compared with NLW, Latino patients were as likely to receive treatment, whereas NLB cases were less likely (OR = 0.81; 95% confidence interval, 0.67-0.98; P = 0.029). Compared with NLW, non-US-born Latino cases were less likely to die of prostate cancer (HR = 0.78; 95% confidence interval, 0.64-0.94; P = 0.011), with no difference reported for NLB cases. Considering sociodemographic and clinical characteristics, non-US-born Latino patients with prostate cancer had better survival than NLW. This highlights the need to identify key determinants of these survival differences and the importance of sociodemographic and clinical determinants in survival disparities. Our study emphasizes the importance of considering nativity among Latino patients to understand prostate cancer disparities and outcomes in this population.

Utilization of allogeneic hematopoietic stem cell transplantation among patients with newly diagnosed acute myeloid leukemia in California: a population-based linked dataset study.

Acute myeloid leukemia (AML) often requires allogeneic hematopoietic cell transplantation (alloHCT) for cure, but historically alloHCT has been strikingly underutilized. Reasons for this remain uncertain at the population level. We examined alloHCT utilization over time and explored associations between demographic/healthcare factors and use of alloHCT by age group (AYA 15-39y, adult 40-64y, older adult 65-79y) using a linked dataset merging the Center for International Blood and Marrow Transplant Research, California Cancer Registry, and California Patient Discharge Database. Eligibility included patients newly diagnosed with AML in California between 2001-2016 who received induction therapy and had no prior HCT. Multivariable Fine-Gray regression analyses were fitted separately across age groups. Among 7,925 patients with AML, alloHCT utilization increased over time across all age groups; however, in the most recent time period studied (2011-2016), utilization within 2 years of diagnosis remained lowest in older adults (13%) relative to adults (41%) and AYAs (49%). Factors statistically significantly associated with lower alloHCT utilization: (1) AYAs: female sex, lower neighborhood socioeconomic status (nSES), uninsured or Indian Health Services (IHS) coverage; (2) adults: older age, male sex, non-Hispanic Black or Asian race and ethnicity, unmarried, lower nSES, uninsured or covered by Medicaid, Medicare, or IHS, higher comorbidity, and living 100+ miles from a transplant center; and (3) older adults: older age, Asian race, and unmarried. In conclusion, using a population-based linked dataset, we demonstrate that utilization of alloHCT among older patients newly diagnosed with AML remains low in California, and factors associated with utilization vary by age group.

Liver Resection for Gastroenteropancreatic Neuroendocrine Tumors with Extrahepatic Disease.

Background: Although survival outcomes for neuroendocrine liver metastases (NETLM) are improved with liver-direct therapies (LDT), including hepatic debulking and nonsurgical trans-arterial embolization, the benefit is less established in the setting of concurrent extrahepatic disease (EHD). We performed a population-based study to characterize the rates of LDT being performed for NETLM with EHD patients and whether LDT is associated with survival outcomes. Methods: Patients with NETLM and EHD were identified using the California Cancer Registry database merged with data from the California Office of Statewide Health Planning and Development between 2000 and 2012. Demographics, clinical characteristics, and survival outcomes were analyzed for these patients with and without LDT. Results: 327 NETLM patients with EHD were identified. EHD sites included lung, peritoneum, bone, and brain. A total of 71 (22%) of these patients underwent LDT. Compared to NETLM with EHD patients who did not undergo LDT, patients who received LDT had longer median overall survival (27 vs. 16 months, p = 0.006). Within the LDT group, 23 patients underwent liver resection. Liver resection was associated with longer median overall survival compared to nonsurgical LDT (138 vs. 13 months, p < 0.001). Conclusions: LDT candidacy should be determined for patients on a case-by-case basis, but the presence of EHD should not preclude LDT with appropriate patient selection.

Disparities in Cancer Stage of Diagnosis by Rurality in California, 2015 to 2019.

Cancer rates in rural areas vary by insurance status, socioeconomic status, region, race, and ethnicity. California Cancer Registry data (2015-2019) were used to investigate the stage of diagnosis by levels of rurality for the five most common cancers. The percentage of residents in rural blocks within census tract aggregation zones was categorized into deciles up to 50%. Multivariable logistic regression was used to estimate associations with rurality, with separate models by cancer site, sex, race, and ethnicity (non-Hispanic White and Hispanic). Covariates included individual-level and zone-level factors. The percentage of late-stage cancer diagnosis was 28% for female breast, 27% for male prostate, 77% for male lung, 71% for female lung, 60% for male colorectal, 59% for female colorectal, 7.8% for male melanoma, and 5.9% for female melanoma. Increasing rurality was significantly associated with increased odds of late-stage cancer diagnosis for female breast cancer (Ptrend < 0.001), male lung cancer (Ptrend < 0.001), female lung cancer (Ptrend < 0.001), and male melanoma (Ptrend = 0.01), after adjusting for individual-level and zone-level factors. The strength of associations varied by sex and ethnicity. For males with lung cancer, odds of late-stage diagnosis in areas with >50% rural population was 1.24 (95% confidence interval, 1.06-1.45) for non-Hispanic White patients and 2.14 (95% confidence interval, 0.86-5.31) for Hispanic patients, compared with areas with 0% rural residents. Increasing rurality was associated with increased odds for late-stage diagnosis for breast cancer, lung cancer, and melanoma, with the strength of associations varying across sex and ethnicity. Our findings will inform cancer outreach to these rural subpopulations.

Disparities in the Occurrence of Long-Term Effects of Bone Marrow Suppression after Treatment in Adolescent Young Adult Breast Cancer Survivors.

Many adolescent and young adult (AYA) patients with breast cancer (BC) receive adjuvant therapy as initial treatment, with long-term bone marrow suppression as a potential complication, but no studies have evaluated the impact of race/ethnicity on the development of bone marrow suppression in AYA BC survivors. Female patients ages 15-39 years diagnosed with BC (2006-2018) and surviving ≥ 2 years were identified from the California Cancer Registry and linked to statewide hospitalization data. We estimated the cumulative incidence of developing late effects of bone marrow suppression, such as leukopenia, anemia, thrombocytopenia, bleeding, and infection/sepsis, during hospital discharge diagnoses present ≥ 2 years after diagnosis. We examined the impact of sociodemographic and clinical factors on late effects using multivariate Cox proportional hazards regression. Of 11,293 patients, 42.8% were non-Hispanic (nH) White, 28.8% Hispanic, 19.5% nHAsian/Pacific Islander, and 7.5% nH Black. In multivariable analyses, nH Blacks had the highest risk (versus nH Whites) of anemia [hazard ratio (HR) 1.72, 95% confidence interval (CI) 1.47-2.02], leukopenia (HR 1.56, CI 1.14-2.13), thrombocytopenia (HR 1.46, CI 1.08-1.99), major infection/sepsis (HR 1.64, CI 1.4-1.92), and bleeding (HR 1.89, CI 1.39-2.58). Hispanics had a higher risk of developing anemia (HR 1.17, CI 1.04-1.32), bleeding (HR 1.4, CI 1.12-1.76), and major infections/sepsis (HR 1.36, CI 1.21-1.52). Asian/Pacific Islanders had only a higher risk of developing bleeding (HR 1.33, CI 1.03-1.72). Patients from a low neighborhood socioeconomic status had a 20% higher risk of infection/sepsis (HR 1.21, CI 1.1-1.34), but there were no associations for the other late effects. We identified that AYAs of nH Black, Hispanic, and Asian/Pacific Islander race/ethnicity are at an increased risk of several late effects after adjuvant therapy compared with nH White patients. From these data, providers can implement early/frequent screening of hematologic late effects in these high-risk survivors.

Racial and ethnic disparities in access to total neoadjuvant therapy for rectal cancer

BackgroundTotal neoadjuvant therapy has revolutionized the treatment of locally advanced rectal cancer and quickly become the new standard of care. Whether patients from all racial and ethnic groups have had equal access to these potential benefits, however, remains unknown. MethodsWe identified all adults diagnosed with locally advanced rectal cancer in California who underwent neoadjuvant chemotherapy and radiation from 2010 to 2020 using the California Cancer Registry. We used logistic regression to estimate the predicted probability of receiving total neoadjuvant therapy as opposed to traditional chemoradiotherapy for each racial and ethnic group and used a time–race interaction to evaluate trends in access to total neoadjuvant therapy over time. We also compared survival by racial and ethnic group and total neoadjuvant therapy status using Kaplan-Meier plots and Cox proportional hazards models. ResultsIn total, 6,856 patients met inclusion criteria. Overall, 36.6% of patients received total neoadjuvant therapy in 2010 compared with 66.3% in 2020. Latino patients were significantly less likely than non-Latino White patients to undergo total neoadjuvant therapy ; however, there was no difference in the rate of growth in total neoadjuvant therapy over time between racial and ethnic groups. Non-Latino Black patients appeared to have lower risk-adjusted survival compared with non-Latino White patients, although not among patients who underwent total neoadjuvant therapy . ConclusionAccess to total neoadjuvant therapy has increased significantly over time in California with no apparent difference in the rate of growth between racial and ethnic groups. We found no evidence of racial or ethnic disparities in survival among patients treated with total neoadjuvant therapy, suggesting that increasing access to high-quality cancer care may also improve health equity.

The Multi-Institutional Medullary Thyroid Cancer Collaborative Registry: Can a Rare Tumor Registry Accurately Represent the Real-World Patient Population?

Background: Large population-based registries, such as the Surveillance, Epidemiology and End Results (SEER) Registry, help in the study of rare tumors, including medullary thyroid cancer (MTC), but lack data to understand the natural history of the disease. The Medullary Thyroid Cancer Collaborative Registry (MTCCoRe) is an exhaustive multi-institutional collection of demographic, clinical, and pathological data. To determine the extent to which MTCCoRe represents the real-world MTC population, we compared the characteristics of patients enrolled in MTCCoRe with patients enrolled in population-based cancer registries. Methods: Comparison of demographic and clinical characteristics of MTC patients who were enrolled in MTCCoRe, Texas Cancer Registry (TCR), California Cancer Registry (CCR), and SEER between 1995 and 2018. Results: A total of 1416 patients were identified in MTCCoRe, 329 in TCR, 2105 in CCR, and 3820 in SEER. Percentages of patients 20-54 years in MTCCoRe were 58.0%, 50.2% in TCR, 47.2% in CCR, and 44.8% in SEER (p < 0.0001). About half of the patients were female (55.9% in MTCCoRe, 61.4% in TCR, 59% in CCR, and 57.5% in SEER (p = 0.3). Percentages of Hispanic and Black patients differed among cohorts (10.1% and 3.8% for MTCCoRe, 23.7% and 8.2% for TCR, 24.8% and 4.9% in CCR, and 15.9% and 8.2% for SEER, respectively; p < 0.001). MTCCoRe patients presented with more advanced T and N classifications than patients in the other registries (MTCCoRe, 28.6% T3-4 and 49.4% N1; TCR, 12.7% and 32.2%; CCR, 18.6% and 32.4%; and SEER, 24% and 37.8%; p < 0.0001). Prevalence of M1 disease was 10% in MTCCoRe, 11.9% in TCR, 14.1% in CCR, and 9.5% in SEER (p < 0.0001). In the MTCCoRe, 11.4% underwent systemic therapy (compared with 0.3% in TCR and 5.6% in CCR). Conclusions: The clinicodemographic profile of patients with MTC enrolled in a multi-institutional registry differs from those enrolled in population-based databases, with lower proportions of Hispanic and Black patients but additive data on treatment modalities. Moving forward, MTCCoRe and other registry and clinical trial enrollment efforts should intentionally include underrepresented groups via community engagement techniques, patient stakeholder involvement, and inclusion of languages other than English in study materials to yield more generalizable results and conclusions.