Dietary Factors Differ Between Young-Onset and Older-Onset Colorectal Cancer Patients.

We aimed to evaluate differences in dietary factors between young-onset (diagnosed at ages <50) and older-onset colorectal cancer (CRC). CRC patients diagnosed from 1998 to 2018 reported to the Puget Sound Surveillance, Epidemiology, and End Results registry were recruited using mail and telephone. Consented patients completed questionnaires assessing demographics, medical history, and CRC risk factors, including dietary factors. We used multi-variable logistic regression to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) comparing dietary intake in young-onset vs. older-onset CRC. Analyses included 1,087 young- and 2,554 older-onset CRC patients. Compared to older-onset CRC, young-onset CRC patients had lower intake of vegetables (OR for highest intake vs. lowest = 0.59 CI: 0.55, 0.64) and fruit (OR for highest intake vs. lowest = 0.94 CI: 0.88, 0.99) and higher intake of processed meat (OR for highest intake vs. lowest = 1.82 CI: 1.11, 2.99) and spicy food (OR for highest intake vs. lowest = 1.69 CI: 1.09, 2.61). There was no statistically significant difference between young- and older-onset CRC patients for red meat consumption. Dietary patterns differed between young- and older-onset CRC; young-onset CRC patients had lower intake of vegetables and fruit and higher intakes of processed meat and spicy food.

Frameshift mutations in peripheral blood as a biomarker for surveillance of Lynch syndrome.

BACKGROUND: Lynch syndrome is a hereditary cancer predisposition syndrome caused by germline mutations in DNA mismatch repair genes, which lead to high microsatellite instability and frameshift mutations at coding mononucleotide repeats in the genome. Recurrent frameshift mutations in these regions are thought to play a central role in the increased risk of various cancers, but no biomarkers are currently available for the surveillance of high microsatellite instability-associated cancers. METHODS: A frameshift mutation-based biomarker panel was developed and validated by targeted next-generation sequencing of supernatant DNA from cultured high microsatellite instability colorectal cancer cells. This panel supported selection of 122 frameshift mutation targets as potential biomarkers. This biomarker panel was then tested using matched tumor, adjacent normal tissue, and buffy coat samples (53 samples) and blood-derived cell-free DNA (cfDNA) (38 samples) obtained from 45 high microsatellite instability and mismatch repair-deficient patients. We also sequenced cfDNA from 84 healthy participants to assess background noise. RESULTS: Recurrent frameshift mutations at coding mononucleotide repeats were detectable not only in tumors but also in cfDNA from high microsatellite instability and mismatch repair-deficient patients, including a Lynch syndrome carrier, with a varying range of target detection (up to 85.2%), whereas they were virtually undetectable in healthy participants. Receiver operating characteristic curve analysis showed high sensitivity and specificity (area under the curve = 0.94) of the investigated panel. CONCLUSIONS: We demonstrated that frameshift mutations can be detected in cfDNA from high microsatellite instability and mismatch repair-deficient patients and asymptomatic carriers. The 122-target frameshift mutation panel described here has promise as a tool for improved surveillance of high microsatellite instability and mismatch repair-deficient patients, with the potential to reduce the frequency of invasive screening methods for this high-cancer-risk cohort.

Two genome-wide interaction loci modify the association of nonsteroidal anti-inflammatory drugs with colorectal cancer.

Regular, long-term aspirin use may act synergistically with genetic variants, particularly those in mechanistically relevant pathways, to confer a protective effect on colorectal cancer (CRC) risk. We leveraged pooled data from 52 clinical trial, cohort, and case-control studies that included 30,806 CRC cases and 41,861 controls of European ancestry to conduct a genome-wide interaction scan between regular aspirin/nonsteroidal anti-inflammatory drug (NSAID) use and imputed genetic variants. After adjusting for multiple comparisons, we identified statistically significant interactions between regular aspirin/NSAID use and variants in 6q24.1 (top hit rs72833769), which has evidence of influencing expression of TBC1D7 (a subunit of the TSC1-TSC2 complex, a key regulator of MTOR activity), and variants in 5p13.1 (top hit rs350047), which is associated with expression of PTGER4 (codes a cell surface receptor directly involved in the mode of action of aspirin). Genetic variants with functional impact may modulate the chemopreventive effect of regular aspirin use, and our study identifies putative previously unidentified targets for additional mechanistic interrogation.