Have you ever wondered why physicians recommend annual screening mammograms for women with an average risk of breast cancer at the age of 40? Or why new guidelines suggest annual screening colonoscopies for men and women should start at age 45 instead of 50?

Cancer care and screening, like many other diseases, are standardized based on data demonstrating the effectiveness—or ineffectiveness—of various treatment options. By standardizing care, patients can be confident that they are receiving the best possible treatment for their condition based on how well a particular therapy works, regardless of their healthcare provider.

Establishing guidelines.

One organization responsible for establishing cancer treatment guidelines is the National Comprehensive Cancer Network (NCCN). The NCCN is a non-profit group of 33-member cancer centers in the US that develops recommendations for the treatment of various cancers based on clinicians' experience and the evidence-based effectiveness of specific treatments and interventions.

The NCCN sets clinical and screening guidelines with over 1,700 cancer care clinicians, patient advocates, and primary care physicians divided between 61 panels specific to each guideline. The guidelines set the standard of care for more than 97% of all cancers affecting patients in the US, including guidelines for young and elderly patient populations.

All current NCCN guidelines are reviewed and updated at least once yearly during the organization’s annual institutional review. Depending on new treatment evidence, guidelines can also be reviewed and updated through interim panel meetings.

During the review process, clinical questions and issues are raised by panel members or outside submissions and discussed by members of the panel based on:

• Clinical evidence
• Third-party data  
• FDA approvals
• Scientific meetings
• Review of medical and scientific literature
• Cost of therapy or intervention

When panel debates result in significant changes to current guidelines, including changes in therapy, follow-up treatment or the timing of various therapies, a vote is taken from panel members. The exact process is followed for any interim meetings to address new treatments between annual meetings (see Figure).

Figure. Flowchart illustrating the NCCN guideline development process for annual and interim panel meetings.

Overall, NCCN develops guidelines based on thoroughly evaluating all the evidence provided at panel meetings. Clinicians participating in these meetings reach a consensus on the benefits of a particular therapy or intervention, the usefulness and affordability of tests or screenings, and the potential toxicity or side effects of a particular treatment.

Integrating new therapies and interventions.

Today, however, new cancer therapies and tests are being developed at a breakneck pace, leading many patients to wonder whether the latest cancer treatment options have even been considered in the most current NCCN treatment guidelines. Third parties can send submissions to NCCN to consider specific treatments or interventions for consideration during annual panel meetings. Interim panel meetings are also held when new data is available from studies using existing drugs or treatments or following FDA approval of new therapies that may improve the current standard of care. Despite this, it takes an estimated 17 years for new treatment breakthroughs to integrate into standard patient care practices.

Notably, specific treatments or tests not included in standard treatment guidelines can benefit some patients, depending on their disease and genetics. Screening guidelines are developed for individuals with an average risk of developing disease or possessing specific gene variants, with additional testing suggestions for people or populations with a greater-than-average risk.

While beneficial, some disease therapies or tests may not be included in standard care guidelines simply due to the high cost. For example, specific variants in the DPYD gene can reduce or even eliminate affected patients’ ability to metabolize the common chemotherapy 5-fluorouracil (5-FU) properly. The FDA recently added new safety labeling changes to the chemotherapy, suggesting that clinicians consider pharmacogenomic (PGx) testing of the DYPD gene to avoid adverse side effects. Currently, PGx testing of the DPYD gene is not included in current NCCN cancer treatment guidelines.

Benefits of pharmacogenomic testing.

While genetic screenings won’t necessarily reveal changes in how a person metabolizes every drug, these screenings will identify at least one gene variant that changes how a person metabolizes or transports at least one drug in 99% of the population. Clinicians can use this knowledge to develop personalized treatment regimens for patients that factor in their unique clearance or sensitivity to specific medications, improving disease prognosis and protecting future quality of life.

Biomedical research is uncovering the genetic underpinnings of disease more and more each day. State-of-the-art, personalized medicine options allow patients to proactively manage disease risk and leverage the latest treatments even before they are included in standard treatment guidelines. Biomedical testing and treatment are getting personal, and the future has never looked more hopeful.

The Kadance Precision Health Management program is designed to help you understand how your genetics influence medication interactions. This article is the second of a three-part series outlining how PGx currently optimizes medication therapy for patients. You can access part one of this series here and part three here.