Skin cancer is the most common cancer type, affecting more than 2 million people annually in the US alone. Given the rising incidence of skin cancer, mostly attributable to UV exposure, there are a large number of clinical trials in this area designed to test the efficacy of new drugs emerging from pharmaceutical pipelines.
On May 1, Dr. George F. Edeburn will give a webinar focused on the use of the tumor response criteria RECIST 1.1 in clinical trials for tracking and evaluating skin cancer lesions. I sat down with Dr. Edeburn to discuss RECIST 1.1 criteria and some of the challenges sponsors face when integrating RECIST 1.1 for skin cancer trials. Here's what he had to say.
Can you briefly explain what RECIST 1.1 criteria are and why they are important for oncology trials?
Assessment of tumor burden as a surrogate endpoint in oncology clinical trials is important for the evaluation of new therapies. The original 'Response Evaluation Criteria in Solid Tumors' (called RECIST1.0) were published in 2000 and have been adopted by academics, industry, and regulatory authorities for measuring clinical outcomes using a set of standardized 'rules' for physical measurement of target and non-target lesions over time. A number of concerns and issues since then have led to the development of modified criteria called RECIST 1.1, which includes changes in the number of lesions assessed, guidance for measuring lymph nodes, clarification of disease progression, and information for the detection of new lesions including those detected by FDG-PET scans.
RECIST 1.1 criteria are important for oncology trials as they help provide a systematic and widely accepted methodology for the objective evaluation of solid tumors. These criteria help reduce variability associated with tumor measurements, provide clinicians and regulatory authorities with a more accurate and standardized approach for categorizing responses to investigative agents. For skin cancer trials, RECIST1.1 criteria, in addition to establishing guidelines for measuring lesions by conventional imaging, established guidelines for measuring skin lesions by photography. In addition to primary skin cancers, secondary lesions arising from cancers that have metastasized to the skin can also be evaluated using a similar methodology.
What are some of the specific challenges for applying RECIST criteria for skin cancer trials?
For skin cancer trials, skin lesions are often documented, measured and tracked using color photography. This type of assessment presents several challenges for monitoring disease including how to incorporate photography with other imaging modalities to establish overall tumor burden. Additionally, sponsors must select the best modality for following skin lesions and determine the proper classification of lesions as target and non-target disease.
Skin cancer encompasses different cancer types (derived from unique cell types) most commonly melanomas, basal cell carcinomas, squamous cell carcinomas. For certain lesions, imaging modalities like CT or MRI may be superior to medical photography because true tumor extent may be better visualized. In other instances, however, photography may provide more accurate depiction of the skin lesion. Often times, it is beneficial to evaluate the extent of the lesion using both photography and imaging to determine the best modality for a clinical trial. When using photography, there are also guidelines to meet regulatory requirements. BioClinica has taken steps to develop guidelines for this process, helping sponsors effectively utilize medical photography for their trials. I will be reviewing some of these guidelines in my upcoming webinar.
If a clinical trial sponsor is considering using an imaging core lab for their next skin cancer trial, what are some of the benefits?
There are many key benefits for engaging an imaging core lab for skin cancer trials (or other oncology studies), including protocol and imaging charter development, training and education of clinical sites, and expert independent review of images. Imaging core labs have extensive experience in implementing RECIST criteria for clinical trials with regulatory submission in mind and can help tailor the trial protocol to include medical photography and other relevant imaging modalities to fit the needs of your study. Once a protocol and imaging charter are established, core labs typically offer site training and educational resources to get all sites involved in a study up to speed with the proper use of medical photography (e.g. photo requirements, ruler placements, etc.) along with other imaging modalities. This becomes especially important for large trials involving multiple sites. Finally, core labs provide independent review of medical images photographs and clinical data by board certified radiologists, oncologists and other specialists, providing a means for unbiased data analysis in support of regulatory approval.