Hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome, is a common autosomal dominant syndrome characterized by early age at onset, neoplastic lesions, and microsatellite instability (MSI). Because cancers with MSI account for approximately 15% of all colorectal cancers and because of the need for a better understanding of the clinical and histologic manifestations of HNPCC, the National Cancer Institute hosted an international workshop on HNPCC in 1996, which led to the development of the Bethesda Guidelines for the identification of individuals with HNPCC who should be tested for MSI. To consider revision and improvement of the Bethesda Guidelines, another HNPCC workshop was held at the National Cancer Institute in Bethesda, MD, in 2002. In this commentary, we summarize the Workshop presentations on HNPCC and MSI testing; present the issues relating to the performance, sensitivity, and specificity of the Bethesda Guidelines; outline the revised Bethesda Guidelines for identifying individuals at risk for HNPCC; and recommend criteria for MSI testing.

In the past three decades, the approach to cancer prevention has moved from population and epidemiological studies to molecular targeting and immunological approaches and to identifying high-risk pre-cancerous lesions in individuals using emerging early detection technologies. Global implementation of these scientifically-sound lifestyle- and medical-based cancer prevention strategies has the potential to reduce worldwide cancer incidence, prevalence and mortality rates in the decades ahead. As more is learned about the mechanisms and pathways that are influenced by genetic and molecular changes that initiate cancer or encourage its progression, targeted therapies are being developed to interrupt these processes. Additional strategies are specifically focused on interrupting the late-stage, but still pre-malignant, processes that lead to in situ cancers, with the goal of averting progression to actual invasive cancer. The success of vaccines for human papilloma virus (HPV)- and hepatitis B virus (HBV)-related cancers has led to an increased focus on immunologically based research for many other cancers. Efforts are ongoing to develop immune response modulation strategies to augment the innate immunity and to develop vaccines against oncogenic infectious agents, as well as tumour-associated and tumour-specific antigens. The groundwork for the future of cancer prevention is currently being developed through multidisciplinary initiatives that involve researchers from tradition biology-based laboratories, as well as collaborators from the fields of information technology, imaging technologies, '-omics' (such as genomics, proteomics and metabolomics) and communication. Expertise in communication is essential to disseminate research findings to the communities that are likely to benefit from these findings. Inherent to this future progress is a focus on precision (individualized) medicine that will include identifying those who are at a high risk of developing cancer.

Purpose: To assess whether MUC1 peptide vaccine produces an immune response and prevents subsequent colon adenoma formation. Patients and Methods: Multicenter, double-blind, placebo-controlled randomized trial in individuals age 40 to 70 with diagnosis of an advanced adenoma ≤1 year from randomization. Vaccine was administered at 0, 2, and 10 weeks with a booster injection at week 53. Adenoma recurrence was assessed ≥1 year from randomization. The primary endpoint was vaccine immunogenicity at 12 weeks defined by anti-MUC1 ratio ≥2.0. Results: Fifty-three participants received the MUC1 vaccine and 50 placebo. Thirteen of 52 (25%) MUC1 vaccine recipients had a ≥2-fold increase in MUC1 IgG (range, 2.9–17.3) at week 12 versus 0/50 placebo recipients (one-sided Fisher exact P < 0.0001). Of 13 responders at week 12, 11 (84.6%) responded to a booster injection at week 52 with a ≥2-fold increase in MUC1 IgG measured at week 55. Recurrent adenoma was observed in 31 of 47 (66.0%) in the placebo group versus 27 of 48 (56.3%) in the MUC1 group [adjusted relative risk (aRR), 0.83; 95% confidence interval (CI), 0.60–1.14; P = 0.25]. Adenoma recurrence occurred in 3/11 (27.3%) immune responders at week 12 and week 55 (aRR, 0.41; 95% CI, 0.15–1.11; P = 0.08 compared with placebo). There was no difference in serious adverse events. Conclusions: An immune response was observed only in vaccine recipients. Adenoma recurrence was not different than placebo, but a 38% absolute reduction in adenoma recurrence compared with placebo was observed in participants who had an immune response at week 12 and with the booster injection.

Early-onset colorectal cancer (EOCRC), defined as a diagnosis under age 50, is an emerging public health burden. As many of these individuals fall outside of screening guidelines, the development of a minimally invasive, accurate screening modality for this population is warranted. We evaluated the FDA-approved blood-based biomarker methylated Septin9 (mSEPT9) test as screening tool for EOCRC. EOCRC plasma, healthy plasma, and serum-free conditioned media from cancer cell lines were collected. Cell-free DNA (cfDNA) was isolated and bisulfite converted for use in the assay. mSEPT9 and ACTB measured using Epi proColon V2.0. EOCRC plasma was collected at Massachusetts General Hospital (2005–2019) and controls were collected at the NIH and by ZenBio Inc. (prior to 2019). Twenty-seven EOCRC cases, 48 healthy controls <50 years old, and 39 healthy controls ≥50 years old were included in this study. mSEPT9 was detected more frequently in EOCRC cases (88.9%) compared with healthy controls age <50 (4.2%) and ≥50 (15.4%), respectively (P < 0.001). The sensitivity, specificity, positive predictive value, and negative predictive values of the mSEPT9 assay to detect EOCRC was 90.8% (95% CI, 84.7%–96.9%), 88.9% (95% CI, 77.0%–100.0%), 96.3% (95% CI, 92.3%–100.0%), and 75.0% (95% CI, 60.0%–90.0%), respectively, compared with all healthy controls. mSEPT9 cfDNA level was an independent predictor of survival (P = 0.02). mSEPT9 is a sensitive and specific biomarker for EOCRC detection. These results suggest that mSEPT9 may be useful in the detection of EOCRC, providing a minimally invasive method for screening in this growing population of patients with colorectal cancer.Significance: mSEPT9 may be a novel biomarker for the detection of early-onset colorectal cancer, as it demonstrated high sensitivity and specificity in our study.

Polyphenon E (Poly E) is a green tea polyphenol preparation whose most active component is epigallocatechin gallate (EGCG). We studied the cancer preventive efficacy and safety of Poly E in subjects with rectal aberrant crypt foci (ACF), which represent putative precursors of colorectal cancers. Eligible subjects had prior colorectal advanced adenomas or cancers, and had ≥5 rectal ACF at a preregistration chromoendoscopy. Subjects (N = 39) were randomized to 6 months of oral Poly E (780 mg EGCG) daily or placebo. Baseline characteristics were similar by treatment arm (all P >0.41); 32 of 39 (82%) subjects completed 6 months of treatment. The primary endpoint was percent reduction in rectal ACF at chromoendoscopy comparing before and after treatment. Among 32 subjects (15 Poly E, 17 placebo), percent change in rectal ACF number (baseline vs. 6 months) did not differ significantly between study arms (3.7% difference of means; P = 0.28); total ACF burden was also similar (−2.3% difference of means; P = 0.83). Adenoma recurrence rates at 6 months were similar by arm (P > 0.35). Total drug received did not differ significantly by study arm; 31 (79%) subjects received ≥70% of prescribed Poly E. Poly E was well tolerated and adverse events (AE) did not differ significantly by arm. One subject on placebo had two grade 3 AEs; one subject had grade 2 hepatic transaminase elevations attributed to treatment. In conclusion, Poly E for 6 months did not significantly reduce rectal ACF number relative to placebo. Poly E was well tolerated and without significant toxicity at the dose studied. Prevention Relevance: We report a chemoprevention trial of polyphenon E in subjects at high risk of colorectal cancer. The results show that polyphenon E was well tolerated, but did not significantly reduce the number of rectal aberrant crypt foci, a surrogate endpoint biomarker of colorectal cancer.