Increasing colorectal cancer burden among young US Hispanics: is it time to change current screening guidelines?

Orbital Apex Metastases From Primary Colorectal Adenocarcinoma: A Rare Cause for Unilateral Vision Loss

Colorectal cancer is one of the most common causes of cancer-related death in the United States. Although it frequently metastasizes to adjacent structures such as the liver, orbital metastases are exceedingly uncommon. Additionally, the morbidity and mortality associated with colorectal cancer appear to be shifting to a younger population, a phenomenon that is exacerbated in minority populations. We present a case of orbital metastasis from colorectal carcinoma in a young Hispanic male. This uncommon presentation of disease emphasizes the link between healthcare disparity and differential outcomes of colorectal cancer.

Trends and Factors Associated with Fecal Occult Blood Test Utilization among Hispanic Adults in Puerto Rico and the United States: BRFSS 2012-2020

Identifying factors associated with colorectal cancer screening utilization is important to guide colorectal cancer prevention and control programs. We evaluated trends and factors associated with previous-year fecal occult blood test (FOBT) use among Hispanic adults living in Puerto Rico and the U.S. mainland. Using data from the Behavioral Risk Factor Surveillance System (2012-2020), trends in FOBT use were analyzed using joinpoint regression to estimate annual percentage change (APC). Logistic regression stratified by location identified factors associated with FOBT use. FOBT was more common among Hispanic adults ages 50 to 75 years living in Puerto Rico than in the U.S. mainland [Puerto Rico: 20.5%[2012] to 45.6%[2020], APC = 11.4%; U.S. mainland: 9.9%[2012] to 16.7%[2020], APC = 5.9%]. Factors inversely associated with FOBT use were similar in Puerto Rico and the U.S. mainland, including lack of health insurance, not having a personal doctor, having a checkup >12 months ago, and not being able to see a doctor due to cost, as were factors associated with higher FOBT use, including older age, retirement, or having two or more chronic diseases. Among Hispanics living in the U.S. mainland, lack of exercise and less education were inversely associated with FOBT. Factors related to poor access to healthcare were associated with lower use of FOBT among Hispanics. Efforts to improve colorectal cancer screening in Hispanics are necessary to address health disparities across the colorectal cancer care continuum.

PREVENTION RELEVANCE

Colorectal cancer screening reduces cancer incidence and mortality. All screening modalities, including less invasive FOBT tests, are underutilized, especially in non-White and low-income populations. Evaluation of trends and factors associated with the increase in the use of colorectal cancer screening can inform programs to address the lack of screening among racial minorities.

Conundrum of a Large Bowel Neoplasm: Collision Tumor

A 79-year-old Hispanic man was admitted to the intensive care unit with symptomatic iron-deficiency anemia and watery diarrhea. Radiological images revealed diffuse colonic wall thickening, a soft-tissue fullness in the ascending colon, and multiple mesenteric lymphadenopathies. Colonoscopy showed multiple aphthous ulcers throughout the colon and a large deep ulcer with irregular raised borders in the rectosigmoid area. Histological exam of the ulcers showed severe ulcerative colitis, while biopsy of the deep ulcer revealed a well-differentiated adenocarcinoma. Colectomy specimen was consistent with colliding diffuse large B-cell lymphoma and adenocarcinoma.

DNA mismatch repair deficiency and hereditary syndromes in Latino patients with colorectal cancer

BACKGROUND

The landscape of hereditary syndromes and clinicopathologic characteristics among US Latino/Hispanic individuals with colorectal cancer (CRC) remains poorly understood.

METHODS

A total of 265 patients with CRC who were enrolled in the Hispanic Colorectal Cancer Study were included in the current study. Information regarding CRC risk factors was elicited through interviews, and treatment and survival data were abstracted from clinical charts. Tumor studies and germline genetic testing results were collected from medical records or performed using standard molecular methods.

RESULTS

The mean age of the patients at the time of diagnosis was 53.7 years (standard deviation, 10.3 years), and 48.3% were female. Overall, 21.2% of patients reported a first‐degree or second‐degree relative with CRC; 3.4% met Amsterdam I/II criteria. With respect to Bethesda guidelines, 38.5% of patients met at least 1 criterion. Of the 161 individuals who had immunohistochemistry and/or microsatellite instability testing performed, 21 (13.0%) had mismatch repair (MMR)‐deficient (dMMR) tumors. dMMR tumors were associated with female sex (61.9%), earlier age at the time of diagnosis (50.4 ± 12.4 years), proximal location (61.9%), and first‐degree (23.8%) or second‐degree (9.5%) family history of CRC. Among individuals with dMMR tumors, 13 (61.9%) had a germline MMR mutation (MutL homolog 1 [MLH1] in 6 patients; MutS homolog 2 [MSH2] in 4 patients; MutS homolog 6 [MHS6] in 2 patients; and PMS1 homolog 2, mismatch repair system component [PMS2] in 1 patient). The authors identified 2 additional MLH1 mutation carriers by genetic testing who had not received immunohistochemistry/microsatellite instability testing. In total, 5.7% of the entire cohort were confirmed to have Lynch syndrome. In addition, 6 individuals (2.3%) had a polyposis phenotype.

CONCLUSIONS

The percentage of dMMR tumors noted among Latino individuals (13%) is similar to estimates in non‐Hispanic white individuals. In the current study, the majority of individuals with dMMR tumors were confirmed to have Lynch syndrome. Cancer 2017. © 2017 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. Cancer 2017;123:3732–3743. © 2017 American Cancer Society

The landscape of hereditary syndromes and clinicopathologic characteristics among Latino/Hispanic individuals in the United States with colorectal cancer remains poorly understood. Using data from the Hispanic Colorectal Cancer Study, approximately 13% of cases in the current study appear to have mismatch repair‐deficient tumors, 61.9% of which will be confirmed to have Lynch syndrome.

Variability in Cancer Risk and Outcomes Within US Latinos by National Origin and Genetic Ancestry

Latinos have lower rates for most common cancer sites and higher rates of some less common cancers (gallbladder, liver, gastric, and cervical) than other ethnic/racial groups. Latinos are a highly heterogeneous population with diverse national origins, unique genetic admixture patterns, and wide spectrum of socio-demographic characteristics. Across the major cancers (breast, colorectal, prostate, lung, and liver) US-born Latinos have higher incidence and worse survival than foreign-born, and those with low-socioeconomic status have the lowest incidence. Puerto Rican and Cuban Latinos have higher incidence rates than Mexican Latinos. We have identified the following themes as understudied and critical to reduce the cancer burden among US Latinos: (1) etiological studies considering key sources of heterogeneity, (2) culturally sensitive cancer prevention strategies, (3) description of the molecular tumor landscape to guide treatments and improve outcomes, and (4) development of prediction models of disease risk and outcomes accounting for heterogeneity of Latinos.

Genome-wide association study of colorectal cancer in Hispanics

This manuscript describes the first large-scale genome-wide association study of colorectal cancer in Hispanics and Latinos. Our results demonstrate the broad replication of known susceptibility regions and the importance of fine-mapping in ethnic minority populations.

Genome-wide association studies (GWAS) have identified 58 susceptibility alleles across 37 regions associated with the risk of colorectal cancer (CRC) with P < 5×10⁻⁸. Most studies have been conducted in non-Hispanic whites and East Asians; however, the generalizability of these findings and the potential for ethnic-specific risk variation in Hispanic and Latino (HL) individuals have been largely understudied. We describe the first GWAS of common genetic variation contributing to CRC risk in HL (1611 CRC cases and 4330 controls). We also examine known susceptibility alleles and implement imputation-based fine-mapping to identify potential ethnicity-specific association signals in known risk regions. We discovered 17 variants across 4 independent regions that merit further investigation due to suggestive CRC associations (P < 1×10⁻⁶) at 1p34.3 (rs7528276; Odds Ratio (OR) = 1.86 [95% confidence interval (CI): 1.47–2.36); P = 2.5×10⁻⁷], 2q23.3 (rs1367374; OR = 1.37 (95% CI: 1.21–1.55); P = 4.0×10⁻⁷), 14q24.2 (rs143046984; OR = 1.65 (95% CI: 1.36–2.01); P = 4.1×10⁻⁷) and 16q12.2 [rs142319636; OR = 1.69 (95% CI: 1.37–2.08); P=7.8×10⁻⁷]. Among the 57 previously published CRC susceptibility alleles with minor allele frequency ≥1%, 76.5% of SNPs had a consistent direction of effect and 19 (33.3%) were nominally statistically significant (P < 0.05). Further, rs185423955 and rs60892987 were identified as novel secondary susceptibility variants at 3q26.2 (P = 5.3×10^–5) and 11q12.2 (P = 6.8×10⁻⁵), respectively. Our findings demonstrate the importance of fine mapping in HL. These results are informative for variant prioritization in functional studies and future risk prediction modeling in minority populations.