Formalin-fixed paraffin embedded (FFPE) tissue blocks are a valuable resource for many significant research programs as researchers tend to select this type of biospecimen as frozen or fresh tissue blocks may be harder to acquire. There is also the challenge that the number of fresh frozen tissue samples may not be able to fulfill the requirements of the research protocol. The FFPE preservation technique demands a fast and rapid fixation after the process of resection of the target biospecimen in a neutral buffered formalin. Once fixed, the specimen is then embedded in paraffin wax. FFPE is now the commonest tissue preparation method used to archive research biospecimens. Currently, almost all surgeries in this day generate FFPE tissue samples. FFPE tissue blocks are crucial as they offer the potential for the discovery of significant information especially in biomedical research programs and drug discovery. Other research applications that utilize FFPE biospecimens include:
biomedical identification or authentication
visualization of tissue structure
This, therefore, makes FFPE tissue blocks ideal for:
the study of autoimmune diseases – rheumatoid arthritis, systemic lupus erythematosus
the study of long-term cancers – colon cancer, lung cancer, breast cancer
However, there are several challenges that researchers face when it comes to obtaining FFPE tissue samples. Some of the challenges include:
1) Oversight of the Pathologist
In some cases, the FFPE samples are not obtained or processed appropriately as the certified pathologist is not on site to supervise and ensure that the proper procedures are followed during the procurement of the specimen. Biorepositories should ensure that they hire enough licensed pathologists to ensure that there is no manpower shortage as it could impact the quality of their tissue specimens.
2) Difficulty Acquiring Samples
There are certain situations where a research team or company requires access to FFPE tissue samples that are hard to come by. For example, FFPE samples from patients with metastatic melanoma might present a challenge to biorepositories. Research teams should partner with a biorepository that has a vast network for tissue procurement as it can help tremendously in the collection of special samples needed in specific research protocols.
3) Rapid Turnaround
Studies or research that needs a quick procurement of FFPE tissue blocks may pose a challenge to many biorepositories. These research teams that are looking for a rapid turnaround of samples should ask biorepositories about their accelerated procurement method which may then be able to provide the required biospecimens within the time frame.
Research teams looking to procure tissue samples need to keep in mind about transparency as studies rely on well-annotated tissue blocks that go through the proper fixation and preservation technique. Before obtaining samples from the biorepository, be sure to ask regarding their specifics and standard of procedure for the fixation and quality assurance protocols. This can impact the result and credibility of the entire study.
5) Review of FFPE Biospecimens
Some biorepositories obtain their tissue samples from local sources such as the local hospitals. However, not all providers take the time to ensure that the specimens are of the highest quality. Biorepositories are responsible to ensure that a gross and microscopic examination of the FFPE biospecimens to ensure that the samples obtained are of the highest quality.
With the growing number of organizations and biorepositories, research teams that are looking to source biospecimens should consider companies that follow the best practices and have high standards when it comes to their collection and fixation protocols. Unreliable sources may not be able to provide high-quality FFPE tissue samples. Before procuring the required biospecimens, enquire where the organization obtains their samples and the reliability of it.
7) Patient Information
The patient information from the samples can be valuable and crucial in a research. The more information you can obtain regarding the patient from their data, it can help with some of the results from the research especially in terms of demographics and risk factors of a disease. Patient information also helps you to find the correct patient cohort as some study designs exclude those below or above a certain age. It is therefore important to procure the biospecimens from a biorepository that can provide the necessary data such as the details or a refractory disease, metastatic diseases, or newly diagnosed disease. A new case of cancer or a relapse can also affect the results of a study greatly.
In conclusion, there are many factors to consider when it comes to selecting a new biorepository or organization to partner with to obtain tissue samples. It is important as these specimens ultimately determine the results and credibility of the study. Choosing a credible company that provides the highest quality FFPE tissue samples is one of the most crucial steps in the early stages of a study. Low-quality biospecimens result in wasted hours of study, effort, and decreases the overall morale of the research team.
Doiron L. Typical problems with FFPE tissue samples – and how to solve them. 2014. Folio Conversant. Accessed 7/11/2018.