Cancer Screening in Older Adults

Aberrant HMGA2 Expression Sustains Genome Instability That Promotes Metastasis and Therapeutic Resistance in Colorectal Cancer

Colorectal cancer (CRC) is one of the most lethal cancers worldwide, accounting for nearly ~10% of all cancer diagnoses and deaths. Current therapeutic approaches have considerably increased survival for patients diagnosed at early stages; however, ~20% of CRC patients are diagnosed with late-stage, metastatic CRC, where 5-year survival rates drop to 6–13% and treatment options are limited. Genome instability is an enabling hallmark of cancer that confers increased acquisition of genetic alterations, mutations, copy number variations and chromosomal rearrangements. In that regard, research has shown a clear association between genome instability and CRC, as the accumulation of aberrations in cancer-related genes provides subpopulations of cells with several advantages, such as increased proliferation rates, metastatic potential and therapeutic resistance. Although numerous genes have been associated with CRC, few have been validated as predictive biomarkers of metastasis or therapeutic resistance. A growing body of evidence suggests a member of the High-Mobility Group A (HMGA) gene family, HMGA2, is a potential biomarker of metastatic spread and therapeutic resistance. HMGA2 is expressed in embryonic tissues and is frequently upregulated in aggressively growing cancers, including CRC. As an architectural, non-histone chromatin binding factor, it initiates chromatin decompaction to facilitate transcriptional regulation. HMGA2 maintains the capacity for stem cell renewal in embryonic and cancer tissues and is a known promoter of epithelial-to-mesenchymal transition in tumor cells. This review will focus on the known molecular mechanisms by which HMGA2 exerts genome protective functions that contribute to cancer cell survival and chemoresistance in CRC.

Ethnic disparities in cancer incidence and survival among the oldest old in the United States

Objective: To examine potential ethnic disparities in cancer incidence and survival rates among the oldest old using data from the SEER Program.Design: Cases diagnosed with one of the leading four cancer sites (lung and bronchus, colon and rectum, female breast, prostate) and four cancer sites (stomach, liver and intrahepatic bile duct, gallbladder, and cervical) that disproportionally affect Hispanics were reported to one of 18 SEER registries. Differences in cancer incidence were examined for cases aged ≥85 years diagnosed during the most recent 5-year time period (2009-2013) and, to examine changes over time, from 1992 to 2013. Five-year relative cancer survival probability was examined for Hispanics and non-Hispanics aged ≥85 years diagnosed 2006-2012.Results: From 2009 to 2013, non-Hispanics aged ≥85 years had higher incidence rates compared to Hispanics for colon and rectum, lung and bronchus, female breast, and prostate cancers. Five-year survival probability for cancers of all stages combined was higher for non-Hispanics than Hispanics in this age group. However, Hispanics had higher survival probability of colon and rectum and lung and bronchus cancers diagnosed at regional (colon and rectum: 67.2% vs. 60.5%; lung and bronchus: 15.9% vs. 12.7%) and distant (colon and rectum: 5.4% vs. 3.8%; lung and bronchus: 2.8% vs. 2.2%) stages than non-Hispanics, respectively.Conclusion: Ethnic differences in cancer incidence and survival probability exist for the ≥85 population. Continued efforts are needed to understand and reduce ethnic disparities in cancer prevention and treatment for this population.

Evolving Therapeutic Strategies to Exploit Chromosome Instability in Cancer

Cancer is a devastating disease that claims over 8 million lives each year. Understanding the molecular etiology of the disease is critical to identify and develop new therapeutic strategies and targets. Chromosome instability (CIN) is an abnormal phenotype, characterized by progressive numerical and/or structural chromosomal changes, which is observed in virtually all cancer types. CIN generates intratumoral heterogeneity, drives cancer development, and promotes metastatic progression, and thus, it is associated with highly aggressive, drug-resistant tumors and poor patient prognosis. As CIN is observed in both primary and metastatic lesions, innovative strategies that exploit CIN may offer therapeutic benefits and better outcomes for cancer patients. Unfortunately, exploiting CIN remains a significant challenge, as the aberrant mechanisms driving CIN and their causative roles in cancer have yet to be fully elucidated. The development and utilization of CIN-exploiting therapies is further complicated by the associated risks for off-target effects and secondary cancers. Accordingly, this review will assess the strengths and limitations of current CIN-exploiting therapies, and discuss emerging strategies designed to overcome these challenges to improve outcomes and survival for patients diagnosed with cancer.

White-Black Differences in Cancer Incidence, Stage at Diagnosis, and Survival among Adults Aged 85 Years and Older in the United States

BACKGROUND

Increased life expectancy, growth of minority populations, and advances in cancer screening and treatment have resulted in an increasing number of older, racially diverse cancer survivors. Potential black/white disparities in cancer incidence, stage, and survival among the oldest old (≥85 years) were examined using data from the SEER Program of the National Cancer Institute.

METHODS

Differences in cancer incidence and stage at diagnosis were examined for cases diagnosed within the most recent 5-year period, and changes in these differences over time were examined for white and black cases aged ≥85 years. Five-year relative cancer survival rate was also examined by race.

RESULTS

Among those aged ≥85 years, black men had higher colorectal, lung and bronchus, and prostate cancer incidence rates than white men, respectively. From 1973 to 2012, lung and bronchus and female breast cancer incidence increased, while colorectal and prostate cancer incidence decreased among this population. Blacks had higher rates of unstaged cancer compared with whites. The 5-year relative survival rate for all invasive cancers combined was higher for whites than blacks. Notably, whites had more than three times the relative survival rate of lung and bronchus cancer when diagnosed at localized (35.1% vs. 11.6%) and regional (12.2% vs. 3.2%) stages than blacks, respectively.

CONCLUSIONS

White and black differences in cancer incidence, stage, and survival exist in the ≥85 population.

IMPACT

Continued efforts are needed to reduce white and black differences in cancer prevention and treatment among the ≥85 population. Cancer Epidemiol Biomarkers Prev; 25(11); 1517-23. ©2016 AACR.