It's more than just cancer biology: Health disparities in patients with pancreatic neuroendocrine tumors.

BACKGROUND AND OBJECTIVES: Pancreatic neuroendocrine tumors (PNETs) represent a rare form of pancreatic cancer. Racial/ethnic disparities have been documented in pancreatic ductal adenocarcinoma, but health disparities have not been well described in patients with PNETs. METHODS: A retrospective review of patients with PNETs in the National Cancer Database was performed for 2004-2014. Approximately 16 605 patients with PNETs and available vital status were identified. Survival was compared by race/ethnicity and socioeconomic status using Kaplan-Meier methods and Cox regression. RESULTS: There were no significant differences in survival between Non-Hispanic, White; Hispanic, White; or Non-Hispanic, Black patients on univariate analysis. Kaplan-Meier analysis showed that patients from communities with lower median household income and education level had worse survival (p < 0.001). Patients age less than 65 without insurance, similarly, had worse survival (p < 0.001). Multivariable modeling found no association between race/ethnicity and risk of mortality (p = 0.37). Lower median household income and lower education level were associated with increased mortality (p < 0.001). CONCLUSIONS: Unlike most other malignancies, race/ethnicity is not associated with survival differences in patients with PNETs. Patients with lower socioeconomic status had worse survival. The presence of identifiable health disparities in patients with PNETs represents a target for intervention and opportunity to improve survival in patients with this malignancy.

Histologic and Racial/Ethnic Patterns of Appendiceal Cancer among Young Patients.

BACKGROUND: Appendiceal cancer incidence among individuals age < 50 years (early-onset appendiceal cancer) is rising with unknown etiologies. Distinct clinicopathologic/demographic features of early-onset appendiceal cancer remain unexplored. We compared patterns of appendiceal cancer among individuals by age of disease-onset. METHODS: Using the NIH/NCI's Surveillance, Epidemiology, and End Results program data, we identified individuals age 20+ years diagnosed with appendiceal cancer from 2007 to 2016. Cochran-Armitage trend tests and multinomial logistic regression models were used to examine age-related differences in clinicopathologic/demographic features of appendiceal cancer. RESULTS: We identified 8,851 patients with appendiceal cancer during the 10-year study period. Histologic subtype, tumor grade, stage, sex and race/ethnicity all significantly differed by age of appendiceal cancer diagnosis. After adjustment for race/ethnicity, sex, stage, insurance status, and tumor grade, young patients were 82% more likely to be Hispanic [OR, 1.82; 95% confidence interval (CI), 1.48-2.25; P < 0.001] and 4-fold more likely to be American Indian or Alaska Native (OR, 4.02; 95% CI, 1.77-9.16; P = 0.0009) compared with late-onset cases. Patients with early-onset appendiceal cancer were also 2- to 3.5-fold more likely to be diagnosed with neuroendocrine tumors of the appendix (goblet cell carcinoid: OR, 1.96; 95% CI, 1.59-2.41; P < 0.0001; carcinoid: OR, 3.52; 95% CI, 2.80-4.42; P < 0.0001) compared with patients with late-onset appendiceal cancer. Among patients with neuroendocrine tumors, early-onset cases were also 45% to 61% less likely to present with high-grade (III-IV) tumors. CONCLUSIONS: Approximately one in every three patients with appendiceal cancer is diagnosed before age 50 years in the United States. Appendiceal cancer in young patients is classified by distinct histologic and demographic features. IMPACT: Early-onset appendiceal cancer determinants can inform discovery of risk factors and molecular biomarkers of appendiceal cancer in young patients, with implications for appendiceal cancer prevention, detection, and treatment.

Prognostic Impact of Tumor Size on Pancreatic Neuroendocrine Tumor Recurrence May Have Racial Variance.

OBJECTIVE: The incidence of pancreatic neuroendocrine tumors (PNETs) has increased over the last decade. Black patients have worse survival outcomes. This study investigates whether oncologic outcomes are racially disparate at a single institution. METHODS: Retrospective analysis was performed on 151 patients with resected PNETs between 2010 and 2019. RESULTS: More White males and Black females presented with PNETs (P = 0.02). White patients were older (65 years vs 60 years; P = 0.03), more likely to be married (P < 0.01), and had higher median estimated yearly incomes ($28,973 vs $17,767; P < 0.01) than Black patients. Overall and disease-free survival were not different. Black patients had larger median tumor sizes (30 mm vs 23 mm; P = 0.02). Tumor size was predictive of recurrence only for White patients (hazard ratio, 1.02; P = 0.01). Collectively, tumors greater than 20 mm in size were more likely to have recurrence (P = 0.048), but this cutoff was not predictive in either racial cohort independently. CONCLUSIONS: Black patients undergoing curative resection of PNETs at our institution presented with larger tumors, but that increased size is not predictive of disease-free survival in this population.

Clinical Characteristics and Prognostic Factors of Early-Onset Pancreatic Neuroendocrine Tumors.

BACKGROUND: The incidence of pancreatic neuroendocrine tumors (PNETs) has increased significantly. The purpose of this study was to analyze the clinical characteristics and prognosis of patients under 50 years old. METHODS: Patients with PNETs recorded in the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015 were analyzed. The clinical characteristics were analyzed by Chi-square test. The Kaplan-Meier method was used to estimate overall survival (OS). Multivariate Cox proportional risk regression analysis was used to determine independent prognostic factors. RESULTS: 2,303 patients included, of which 547 (23.8%) patients were younger than 50 years old. The number of younger patients has increased steadily, while the proportion in total PNETs decreased recently. Compared with older group, the proportion of the Black, grade I/II, and surgery were higher in early-onset PNETs. Liver was the most frequent metastatic site. There was no significant difference in the incidence of different metastatic sites between younger and older PNETs patients, while younger patients had better OS (P < 0.05). Grade, N stage, M stage, and surgery were independent prognostic factors for OS in early-onset PNETs. CONCLUSIONS: Younger patients have unique clinicopathological characteristics compared with older patients in PNETs. Better OS was observed in younger patients which might due to the higher proportion of well-differentiated tumor and surgery than older patients.

Racial Differences in Gastroenteropancreatic Neuroendocrine Tumor Treatment and Survival in the United States.

OBJECTIVES: The objective of this study was to evaluate racial differences in cancer treatment and survival in gastroenteropancreatic neuroendocrine tumor (GEP-NET) patients. METHODS: Using the Surveillance, Epidemiology, and End Results Registry, we identified patients with GEP-NETs of the stomach, small intestine (SI), colon, rectum, appendix, and pancreas diagnosed between 1973 and 2014. Demographic, cancer, and treatment information were collected and compared using χ2 tests. Multivariable logistic and Cox regression were used to determine disparities in receiving treatment and overall survival. RESULTS: We identified 19,031 GEP-NET patients: 2839 were non-Hispanic Blacks, 12,832 non-Hispanic Whites, 2098 Hispanics, and 1262 Asians. African Americans and Hispanics with SI and pancreatic NETs were less likely to be treated with surgery (odds ratio, 0.6; 95% confidence interval [CI], 0.46-0.69; odds ratio, 0.71; 95% CI, 0.51-0.99, respectively). African American race was not an independent predictor of survival; there was a strong trend in stomach, SI, and pancreas NETs (hazard ratio [HR], 1.31; 95% CI, 1-1.7; HR, 1.2; 95% CI, 0.99-1.45; HR, 1.22; 95% CI, 1-1.48, respectively). CONCLUSIONS: Our study provides evidence of racial disparities in treatment and survival across GEP-NET primary sites and racial groups. Further studies should be performed to improve our understanding of the reason for these disparities.

Pharmacogenetic impact of UGT1A1 polymorphisms on pulmonary neuroendocrine tumours treated with metronomic irinotecan-based chemotherapy in Chinese populations.

OBJECTIVES: To evaluate the effects of UGT1A1*6 and UGT1A1*28 polymorphisms on the safety and efficacy of metronomic irinotecan-based chemotherapy (IBC) in Chinese patients with pulmonary neuroendocrine tumours (PNTs). METHODS: Sixty-eight PNT patients who received metronomic IBC were observed. The quantitative fluorescent polymerase chain reaction was used to detect UGT1A1*6 and UGT1A1*28 polymorphisms. The follow-up data were collected to investigate the relationship between different genotypes and adverse drug reactions. The clinical outcomes of metronomic IBC were also evaluated. KEY FINDINGS: In the genotype-toxicity association analysis, patients with homozygous UGT1A1*6 had the highest incidence of grade 3-4 diarrhoea (P = 0.010). Compared to other groups, patients with the haplotype of UGT1A1*28 showed a trend towards an increased incidence of grade 4 neutropaenia (P = 0.047). A higher incidence of grade 3-4 leucopaenia was found in groups with UGT1A1*1/*28 (P = 0.023) and UGT1A1*28/*28 (P = 0.022). Grade 1 total bilirubin elevation was associated with the homozygous UGT1A1*6 mutation (P = 0.027) or any UGT1A1*6 variants (P = 0.047). However, neither UGTA1A*28 nor UGT1A1*6 showed any significant association with tumour response or clinical outcomes. CONCLUSIONS: The impact of UGT1A1 polymorphisms varies in different irinotecan-based chemotherapies. UGT1A1*6 and UGTA1A*28 were useful for the prediction of irinotecan-related severe toxicity in Chinese PNT patients treated with metronomic IBC.

Racial Differences in the Incidence and Survival of Patients With Neuroendocrine Tumors.

OBJECTIVES: The incidence of neuroendocrine tumors (NETs) has been steadily increasing. Racial differences in the incidence and survival are mostly unknown. This study examines the racial differences and the underlying causes. METHODS: We conducted a retrospective, population-based study using datasets from Surveillance, Epidemiology, and End Results (SEER) cancer registry and SEER data linked with Medicare claims (SEER-Medicare). We examined the incidence rates and the effects of patient demographics, clinical characteristics, and socioeconomic factors on survival. RESULTS: Of the 15,786 and 1731 cases from SEER and SEER-Medicare, 1991 and 163 were blacks, respectively. We found that blacks had higher NET incidence for all stages, with the largest difference noted in the local stage (4.3 vs 2.6 per 100,000 in whites). We found worse survival for distant-stage black patients, although they more often had clinical factors typically associated with better prognosis in NETs. However, they were also found to have significant unfavorable differences in socioeconomic and sociodemographic factors. CONCLUSIONS: Blacks have higher incidence of NETs and worse survival compared with other races, especially whites. The influences of neighborhood socioeconomic, sociodemographic, and marital status suggest that social determinants, support mechanisms, and access to health care may be contributing factors.

Prognostic Validity of the American Joint Committee on Cancer Eighth Edition TNM Staging System for Surgically Treated and Well-Differentiated Pancreatic Neuroendocrine Tumors: A Comprehensive Analysis of 254 Consecutive Patients From a Large Chinese Institution.

OBJECTIVES: We aimed to validate the novel American Joint Committee on Cancer (AJCC) eighth edition staging manual for well-differentiated (G1/G2) pancreatic neuroendocrine tumors (pNETs). METHODS: Data of eligible patients were retrospectively collected, grouped, and analyzed by applying the new AJCC system. RESULTS: According to the AJCC eighth staging manual for pNETs, 93, 66, 53, and 42 patients had stage I, II, III, and IV disease, respectively, with estimated 5-year overall survival (OS) rates of 96.9%, 92.8%, 48.4%, and 16.8% (P < 0.005), respectively. A total of 57, 28, 20, and 17 patients with G1 pNETs and 36, 38, 33, and 25 ones with G2 tumors were defined by the new AJCC system as having stage I, II, III, and IV disease, respectively. The estimated 5-year OS for stage I, II, III and IV disease was 100.0%, 97.1%, 52.5%, and 18.2%, respectively, for G1 pNETs (P < 0.005) and 94.2%, 90.3%, 38.7%, and 12.7%, respectively, for G2 tumors (P < 0.005). The novel AJCC classification, tumor grading, and radical resection were all prognostic predictors for OS in patients with pNETs. CONCLUSIONS: The new AJCC eighth staging system for well-differentiated pNETs was prognostic and might be adopted in clinical practice.

Clinicopathological features and prognosis factors for survival in elderly patients with pancreatic neuroendocrine tumor: A STROBE-compliant article.

To investigate the features and prognosis of the elderly patients with pancreatic neuroendocrine tumor (pNET).The patients diagnosed with pNETs between 2004 and 2014 were identified from the Surveillance Epidemiology and End Results database. The ethical approval was waived because the present study was analysis of the data from Surveillance Epidemiology and End Results database.A total of 4608 patients with "one primary only" histologically pNETs were confirmed and 653 were older than 75 years. Cancer-specific survival (CSS) and overall survival (OS) were examined. The elderly patients (≥75 years) have disadvantage in CSS and OS compared with younger cohort. Multivariate logistic regression revealed that the elderly patients have increased poorly differentiated composition, and decreased proportion of Black patients, receipt of surgery, married status, and number of removed lymph node. Multivariate Cox regression analysis demonstrated worse differentiation. Patients of T3-4 and M1 stage were associated with poor CSS, while patients of being female, tumor locating at pancreatic body/tail, receipt of surgery, and being married were associated with better CSS in the elderly patients. Meanwhile, patients with higher histological grade and M1 stage have poor OS, while patients with the characteristics of female, being married, tumor location at pancreatic body/tail and tumor surgery have better OS. Distant metastatic elderly patients underwent primary site surgery had better CSS and OS than the patients without surgery.The elderly patients have increased possibility of poorly differentiated tumor, and decreased proportion of Black patients, surgery of primary site, number of removed lymph node and married status. Worse differentiation and tumor metastasis were independent risk factors for both CSS and OS, while primary tumor located in body/tail of pancreas, female patients, surgery of tumor primary site, and being married were protective factors.

Racial disparities in pancreatic neuroendocrine tumors survival: a SEER study.

Pancreatic neuroendocrine tumor (pancreatic NETs), is an important cause of cancer-related death worldwide. No study has rigorously explored the impact of ethnicity on pancreatic NETs. We aimed to demonstrate the relationship between ethnicity and the survival of patients with pancreatic NETs. We used the SEER database to identify patients with pancreatic NETs from 2004 to 2013. Kaplan-Meier methods and Cox proportional hazard models were used to evaluate the impact of race on survival in pancreatic NETs patients. A total of 3850 patients were included: 3357 Non-Blacks, 493 Blacks. We stratified races as "Black" and "White/Other." Blacks were more likely to be diagnosed with later stages of tumors (P = 0.021). As for the treatment, the access to surgery seemed to be more limited in Blacks than non-Black patients (P = 0.012). Compared with non-Black patients, Black patients have worse overall survival (OS) (HR = 1.17, 95% CI: 1.00-1.37, P = 0.046) and pancreatic neuroendocrine tumors specific survival (PNSS) (HR = 1.22, 95% CI: 1.01-1.48, P = 0.044). Multivariate Cox analysis identified that disease extension at the time of diagnosis and surgical status contributed to the ethnical survival disparity. Black patients whose stages at diagnosis were localized had significantly worse OS (HR = 2.09, 95% CI: 1.18-3.71, P = 0.011) and PNSS (HR = 3.79, 95% CI: 1.62-8.82, P = 0.002). As for the patients who did not receive surgery, Blacks also have a worse OS (HR = 1.18, 95% CI: 1.00-1.41, P = 0.045). The Black patients had both worse OS and PNSS compared to non-Black patients. The restricted utilization of surgery, and the advanced disease extension at the time of diagnosis are the possible contributors to poorer survival of Blacks with pancreatic NETs.

Rb Loss and KRAS Mutation Are Predictors of the Response to Platinum-Based Chemotherapy in Pancreatic Neuroendocrine Neoplasm with Grade 3: A Japanese Multicenter Pancreatic NEN-G3 Study.

Purpose: Patients with pancreatic neuroendocrine neoplasm grade-3 (PanNEN-G3) show variable responses to platinum-based chemotherapy. Recent studies indicated that PanNEN-G3 includes well-differentiated neuroendocrine tumor with G3 (NET-G3). Here, we examined the clinicopathologic and molecular features of PanNEN-G3 and assessed the responsiveness to chemotherapy and survival.Experimental Design: A total of 100 patients with PanNEN-G3 were collected from 31 institutions, and after central review characteristics of each histologic subtype [NET-G3 vs. pancreatic neuroendocrine carcinoma (NEC-G3)] were analyzed, including clinical, radiological, and molecular features. Factors that correlate with response to chemotherapy and survival were assessed.Results: Seventy patients analyzed included 21 NETs-G3 (30%) and 49 NECs-G3 (70%). NET-G3 showed lower Ki67-labeling index (LI; median 28.5%), no abnormal Rb expression (0%), and no mutated KRAS (0%), whereas NEC-G3 showed higher Ki67-LI (median 80.0%), Rb loss (54.5%), and KRAS mutations (48.7%). Chemotherapy response rate (RR), platinum-based chemotherapy RR, and prognosis differed significantly between NET-G3 and NEC-G3. Chemotherapeutic outcomes were worse in NET-G3 (P < 0.001). When we stratified PanNEN-G3 with Rb and KRAS, PanNENs-G3 with Rb loss and those with mutated KRAS showed significantly higher RRs to platinum-based chemotherapy than those without (Rb loss, 80% vs. normal Rb, 24%, P = 0.006; mutated KRAS, 77% versus wild type, 23%, P = 0.023). Rb was a predictive marker of response to platinum-based chemotherapy even in NEC-G3 (P = 0.035).Conclusions: NET-G3 and NEC-G3 showed distinct clinicopathologic characteristics. Notably, NET-G3 does not respond to platinum-based chemotherapy. Rb and KRAS are promising predictors of response to platinum-based chemotherapy for PanNEN-G3, and Rb for NEC-G3. Clin Cancer Res; 23(16); 4625-32. ©2017 AACR.

Clinical characteristics and prognostic factors of gastroenteropancreatic neuroendocrine tumors: a single center experience in China.

BACKGROUND/AIMS: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a unique subgroup of tumors in the digestive system but with great clinical heterogeneity. The information on clinical characteristics and prognostic factors of Chinese patients is rather limited. METHODOLOGY: We retrospectively analyzed the clinical features, prognostic factors of this disease in a consecutive cohort (N=294) between January 2007 and December 2012. RESULTS: Functioning tumors accounted for 9.2%. Rectum was the most predominant GEP-NETs locations. Abdominal pain occurred in 46.5% patients which was the most common initial symptom. G1, G2 and G3 tumors accounted for 41.5%, 34.7% and 23.8%, respectively. Endoscopy provided the highest detection rate of 95.7%. Consistence between endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNAB) and surgically obtained histological Ki-67 index was 36.4%. Serum CgA test showed a 80.0% consistence with the tissue biopsy. The median follow up duration was 2.8 years (0.02-5.90 years), the median survival was 4.8 years, overall 5-year survival rate was 69.6%. We found colonic localization, tumor size larger than 20 mm, G3 tumor and metastasis were associated with worse outcome (p<0.05). CONCLUSION: We found both consistence and differences in GEP-NETs characteristics between our study and previous reports.

Characteristics of young colorectal cancer in Brunei Darussalam: an epidemiologic study of 29 years (1986-2014).

BACKGROUND: Colorectal cancer (CRC) is the most common gastrointestinal cancer and the incidence is increasing. CRC is more common with increasing age, but a proportion occurs in young adults, termed young CRC. This study assessed the incidence and the demographic of young CRC in Brunei Darussalam. MATERIALS AND METHODS: All histologically proven CRC between 1986 and 2014 registered with the Department of Pathology cancer registry were reviewed and data extracted for analyses. Young CRC was defined as cancer in patients aged less than 45 years. The various population groups were categorized into locals (Malays, Chinese and Indigenous) and expatriates. RESULTS: Over the study period, there were 1,126 histologically proven CRC (mean age 59.1 ± 14.7 years, Male 58.0%, Locals 91.8% and 8.2% expatriates). Young CRC accounted for 15.1% with the proportion declining over the years, from 29% (1986-1990) to 13.2% (2011-2014). The proportion of young CRC was highest among the indigenous (30.8%), followed by the expatriates (29.3%), Malays (14.3%) and lowest among the Chinese (10.8%). The mean age of young CRC was 35.9 ± 6.2; lowest among the indigenous (33.5 ± 6.7), expatriate (34.9 ± 6.0) groupd and the Malays (35.6 ± 6.5) compared to the Chinese (38.6 ± 4.6), a similar trend being observed in the non-young CRC groups. There were no difference between the genders and tumor locations (rectum or colon) between the young and the non-young CRC cases. Female young CRC was significantly younger than male (p<0.05) without any significant variation between the various population groups (p>0.05). CONCLUSIONS: Our study showed that the young CRC accounted for 15.1% of all CRC with declining trend observed over recent years. Young CRC was more common among indigenous, expatriates and Malays and least common among the Chinese. There were no differences in the gender and tumor locations.

Gut neuroendocrine tumor blood qPCR fingerprint assay: characteristics and reproducibility.

BACKGROUND: We have developed a PCR-based tool that measures a 51-gene panel for identification of gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs) in peripheral blood. This manuscript assesses the robustness (performance metrics) of this tool with a specific focus on the effects of individual parameters including collection, storage, acid suppressive medication [proton pump inhibitor (PPI)], age, sex, race and food on accuracy. METHODS: Performance metrics were evaluated using a gold standard (mRNA derived from three individual human neuroendocrine tumor cell lines) and clinical samples using qPCR. RESULTS: One hundred percent of the 51 transcripts were amplified in the gold standard (NEN cell line-derived mRNA) (CQ<35, average efficiency 1.94). The inter- and intra-assay variations were 1%-2%. In clinical samples, 50 of 51 targets (98%) were amplified. The inter- and intra-assay reproducibility ranged between 0.4% and 1.2%. The coefficient of variation (CV) was 5.3%. Expression of the reference gene, ALG9, was robust [low variation, low M-value, high (99.5%) PCR efficiency] and unaffected by sample processing. Test meals, long-term PPI use (>1 year), age, sex and ethnicity had no effect on the signature. Expression of two genes, ALP2 and CD59 correlated strongly with RNA integrity (R=0.72, p<0.001) and could be used to assess storage and processing. CONCLUSIONS: The 51 marker gene signature was robust and reproducible, exhibiting acceptable inter- and intra-assay metrics (<5%). Feeding, PPI intake, age, sex and ethnicity do not affect the signature. Expression levels of APLP2 and CD59 are effective surrogate markers of proper sample collection and processing.

Chromogranin A is a reliable biomarker for gastroenteropancreatic neuroendocrine tumors in an Asian population of patients.

PURPOSE: To evaluate the significance of plasma chromogranin A (CgA) levels in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NET) in terms of disease status and treatment responses. MATERIALS AND METHODS: Forty-four GEP-NET patients comprising 15 disease-free patients and 29 patients with active disease, as well as 26 healthy participants were enrolled in this study between April 2010 and April 2011. Clinicopathological factors were collected and serial plasma CgA levels were measured. RESULTS: Plasma CgA levels were significantly higher in GEP-NET patients with active disease than in disease-free patients (p = 0.011) or healthy participants (p = 0.001). No difference in CgA levels was observed in terms of primary tumor location, tumor grade, and functional status in patients with active disease. CgA values at 94 U/l distinguished healthy individuals or disease-free patients from patients with active disease. Sensitivity and specificity rates were 86 and 88%, respectively. CgA levels at 110 U/l differentiated patients without recurrence from those with recurrence, with a sensitivity rate of 100% and a specificity rate of 80%. Patients (5/5, 100%) with stable disease and who showed partial response after treatment had a more than 20% decrease in CgA levels compared with the baseline values. Patients (6/6, 100%) with progressive disease showed a less than 20% decrease or increase in CgA levels. CONCLUSION: The plasma CgA level is a reliable biomarker for GEP-NET. We conclude that changes in CgA levels are associated with disease status and treatment responses.

Small intestinal cancer: a population-based study of incidence and survival patterns in the United States, 1992 to 2006.

BACKGROUND: The etiology of cancers of the small intestine is largely unknown. To gain insight into these rare malignancies, we evaluated contemporaneous incidence and survival patterns. METHODS: Using small intestine cancer data from 12 population-based registries of the Surveillance, Epidemiology and End Results Program, we calculated age-adjusted and age-specific incidence rates (IRs), IR ratios, and relative survival (RS) rates. RESULTS: In total, 10,945 small intestine cancers (IR = 2.10/100,000 person-years) were diagnosed during 1992 to 2006, including carcinomas (n = 3,412; IR = 0.66), neuroendocrine cancers (n = 4,315; IR = 0.83), sarcomas (n = 1,084; IR = 0.20), and lymphomas (n = 2,023, IR = 0.38). For all histologic groups, males had significantly higher IRs than females, and distinct age-specific gender patterns were limited to intermediate-/high-grade lymphomas. Neuroendocrine cancer rates varied significantly by race, with rates highest among blacks and lowest among Asians/Pacific Islanders. Carcinoma IRs were highest among blacks; sarcoma IRs were highest among Asians/Pacific Islanders; and lymphoma IRs were highest among whites. Age-specific IR patterns were similar across racial/ethnic groups. During 1992 to 2006, duodenal cancer IRs increased more markedly than those for other subsites. RS varied little by gender or race. Neuroendocrine cancers had the most favorable RS, and carcinomas had the least favorable. The greatest improvement in 5-year RS from 1992 to 1998 to 1999 to 2005 was observed for sarcomas and lymphomas. CONCLUSIONS: Distinct small intestine cancer IR patterns according to histologic subtype suggest different underlying etiologies and/or disease biology, with susceptibility varying by gender, racial/ethnic groups, and subsite. Temporal patterns support a possible role for diagnostic bias of duodenal cancers. IMPACT: Future epidemiologic studies of small intestine cancer should consider histologic subtype by gender, race/ethnicity, and subsite.