Germline genetic variants with implications for disease risk and therapeutic outcomes

Current Treatment Methods for Charcot-Marie-Tooth Diseases

Charcot-Marie-Tooth (CMT) disease, the most common inherited neuromuscular disorder, exhibits a wide phenotypic range, genetic heterogeneity, and a variable disease course. The diverse molecular genetic mechanisms of CMT were discovered over the past three decades with the development of molecular biology and gene sequencing technologies. These methods have brought new options for CMT reclassification and led to an exciting era of treatment target discovery for this incurable disease. Currently, there are no approved disease management methods that can fully cure patients with CMT, and rehabilitation, orthotics, and surgery are the only available treatments to ameliorate symptoms. Considerable research attention has been given to disease-modifying therapies, including gene silencing, gene addition, and gene editing, but most treatments that reach clinical trials are drug treatments, while currently, only gene therapies for CMT2S have reached the clinical trial stage. In this review, we highlight the pathogenic mechanisms and therapeutic investigations of different subtypes of CMT, and promising therapeutic approaches are also discussed.

Pharmacogenetic Review: Germline Genetic Variants Possessing Increased Cancer Risk With Clinically Actionable Therapeutic Relationships

As our understanding of genomics and genetic testing continues to advance, the personalization of medical decision making is progressing simultaneously. By carefully crafting medical care to fit the specific needs of the individual, patients can experience better long-term outcomes, reduced toxicities, and improved healthcare experiences. Genetic tests are frequently ordered to help diagnose a clinical presentation and even to guide surveillance. Through persistent investigation, studies have begun to delineate further therapeutic implications based upon unique relationships with genetic variants. In this review, a pre-emptive approach is taken to understand the existing evidence of relationships between specific genetic variants and available therapies. The review revealed an array of diverse relationships, ranging from well-documented clinical approaches to investigative findings with potential for future application. Therapeutic agents identified in the study ranged from highly specific targeted therapies to agents possessing similar risk factors as a genetic variant. Working in conjunction with national standardized treatment approaches, it is critical that physicians appropriately consider these relationships when developing personalized treatment plans for their patients.

Unraveling heterogeneity of the clinical pharmacogenomic guidelines in oncology practice among major regulatory bodies

Pharmacogenomics (PGx) implementation in clinical practice is steadily increasing. PGx uses genetic information to personalize medication use, which increases medication efficacy and decreases side effects. The availability of clinical PGx guidelines is essential for its implementation in clinical settings. Currently, there are few organizations/associations responsible for releasing those guidelines, including the Clinical Pharmacogenetics Implementation Consortium, Dutch Pharmacogenetics Working Group, the Canadian Pharmacogenomics Network for Drug Safety and the French National Network of Pharmacogenetics. According to the US FDA, oncology medications are highly correlated to PGx biomarkers. Therefore, summarizing the PGx guidelines for oncology drugs will positively impact the clinical decisions for cancer patients. This review aims to scrutinize side-by-side available clinical PGx guidelines in oncology.

UGT1A1 polymorphism has a prognostic effect in patients with stage IB or II uterine cervical cancer and one or no metastatic pelvic nodes receiving irinotecan chemotherapy: a retrospective study

Background

Uridine diphosphate glucuronosyltransferase 1 family polypeptide A1 (UGT1A1) is a predictive biomarker for the side-effects of irinotecan chemotherapy, which reduces the volume of tumors harboring UGT1A1 polymorphisms. We aimed to determine whether UGT1A1 polymorphisms can predict progression-free survival in patients with local cervical cancer treated with irinotecan chemotherapy.

Methods

We retrospectively analyzed the data of 51 patients with cervical cancer treated at a single institution between 2010 and 2015. All patients were diagnosed with 2009 International Federation of Gynecology and Obstetrics (FIGO) stage IB1, IB2, IIA, or IIB squamous cell carcinoma, underwent radical hysterectomy, and received irinotecan chemotherapy as neoadjuvant and/or adjuvant treatment. All patients were examined for irinotecan side effects using UGT1A1 tests. Conditional inference tree and survival analyses were performed considering the FIGO stage, age, the UGT1A1 status, and the number of metastatic lymph nodes to determine primary factors associated with progression-free survival.

Results

The tree-structured survival model determined high recurrence-risk factors related to progression-free survival. The most relevant factor was ≥2 metastatic lymph nodes (p = 0.004). The second most relevant factor was UGT1A1 genotype (p = 0.024). Among patients with ≤1 metastatic lymph node, those with UGT1A1 polymorphisms benefited from irinotecan chemotherapy and demonstrated significantly longer progression-free survival (p = 0.020) than those with wild-type UGT1A1.

Conclusions

Irinotecan chemotherapy might be beneficial in patients with cervical cancer, UGT1A1 polymorphisms, and ≤ 1 metastatic lymph nodes.

Does cardiology hold pharmacogenetics to an inconsistent standard? A comparison of evidence among recommendations

Current guideline recommendations for pharmacogenetic testing for clopidogrel by the American Heart Association/American College of Cardiology (AHA/ACC) contradict the Clinical Pharmacogenetics Implementation Consortium and the US FDA. The AHA/ACC recommends against routine pharmacogenetic testing for clopidogrel because no randomized controlled trials have demonstrated that testing improves patients' outcomes. However the AHA/ACC and the National Comprehensive Cancer Network (NCCN) recommend other pharmacogenetic tests in the absence of randomized controlled trials evidence. Using clopidogrel as a case example, we compared the evidence for other pharmacogenetic tests recommended by the AHA/ACC and NCCN. In patients that received percutaneous coronary intervention, the evidence supporting pharmacogenetic testing for clopidogrel is stronger than other pharmacogenetic tests recommended by the AHA/ACC and NCCN.

Integration of Germline Pharmacogenetics Into a Tumor Sequencing Program

PURPOSE

Evidence-based guidelines inform treatment decisions for patients for whom germline genetic information is available. Our real-time tumor sequencing program, which makes precision treatment decisions for patients with cancer, produces matched germline information, providing a unique opportunity to efficiently implement pharmacogenetics and benefit patients.

METHODS

The germline genetic database from the Michigan Oncology Sequencing (MI-Oncoseq) program was searched for 21 clinically actionable polymorphisms in five cancer-relevant genes: TPMT, DPYD, CYP2C19, CYP3A5, and UGT1A1. Residual germ line DNA was sent to an external Clinical Laboratory Improvement Amendments-approved laboratory for confirmatory genotyping. The medical records of MI-Oncoseq patients with actionable phenotypes were searched for receipt of relevant drugs and to determine whether having genetic information at the time of treatment would have led to a treatment recommendation.

RESULTS

All nine variants in TPMT, DPYD, and CYP2C19 that were detected in MI-Oncoseq were confirmed by external genotyping. Genotype determinations could not be made for CYP3A5*3, UGT1A1*28, or UGT1A1*80. On the basis of retrospective assessment of 115 adult and pediatric patient records, 4.3% (n = 5) had a potentially clinically actionable phenotype for TPMT, DPYD, or CYP2C19 and received a relevant medication. After accounting for differences in adult and pediatric recommendations, three of these patients could have received a treatment recommendation at the time of prescribing.

CONCLUSION

Germline genotype determinations for TPMT, DPYD, and CYP2C19 can be used to make evidence-based treatment recommendations in MI-Oncoseq patients. Although the proportion of patients for whom recommendations can be made is small, this added value to MI-Oncoseq and patient care comes at no additional genotyping cost. Pharmacogenetic assessment should be integrated into tumor sequencing programs that genotype matched germline DNA; however, the complexity and additional cost of implementing pharmacogenetics remain challenging.

The Future Medical Science and Colorectal Surgeons

Future medical technology breakthroughs will build from the incredible progress made in computers, biotechnology, and nanotechnology and from the information learned from the human genome. With such technology and information, computer-aided diagnoses, organ replacement, gene therapy, personalized drugs, and even age reversal will become possible. True 3-dimensional system technology will enable surgeons to envision key clinical features and will help them in planning complex surgery. Surgeons will enter surgical instructions in a virtual space from a remote medical center, order a medical robot to perform the operation, and review the operation in real time on a monitor. Surgeons will be better than artificial intelligence or automated robots when surgeons (or we) love patients and ask questions for a better future. The purpose of this paper is looking at the future medical science and the changes of colorectal surgeons.