CCCU biobank: indispensable for cancer researchers
If everything goes according to plan, it takes no more than six minutes to prepare and place a tissue sample into the cryotank. Stored in liquid nitrogen at a temperature of minus 196°C, the biomaterial is ready to be used by the researchers from the Comprehensive Cancer Center at the Ulm University Hospital (CCCU). The biobank, which is currently being established at the CCCU, is funded by German Cancer Aid.
According to Hartmut Döhner, CCCU spokesperson and medical director of the Department of Internal Medicine III at Ulm University Hospital, biobanks have become an “indispensable part of basic and clinical research” in the field of oncology. Döhner, who is an internationally renowned haematologist, knows from his own experience that this change in opinion has only happened over the last few years. “Around 10 to 15 years ago, the prevailing opinion was that it was perfectly sufficient to use animal models or cell lines for research into cancer and other areas and transfer the results to the human situation. However, this is not 100% possible; the treatment and diagnosis of diseases in hospitals is based on research into human samples such as tumour biopsies, blood and bone marrow, to name just a few.”
Tissue for biological and genetic analyses
Three years ago, the CCCU in Ulm, which is one of eleven oncology centres of excellence in Germany, decided to establish a biobank. The centre’s concept foresees that informed consent will be obtained from all cancer patients who undergo surgery at one of the university’s clinical departments and that some of the biopsied tissue not required for diagnostic assessment will be frozen. It further anticipates that the biological samples will be stored for an unlimited period of time and will be used for general research purposes rather than being earmarked for specific purposes. According to Döhner, the informed consent of patients “allows us to use the donated tissue for all biological and genetic analyses.” This also includes the possibility of working alongside the biopharmaceutical industry and using the donated tissue for experiments.
The biobank concept is currently being implemented step by step in all hospitals that are part of the Ulm-based CCCU (“a complex and time-consuming process,” said Döhner). The concept was established in the hospital’s internal medicine and urology departments and is also due to be implemented in the gynaecological and surgical departments. However, no information is yet available on the number of patients who have given their informed consent for use of the tissue they have donated. However, Döhner knows from experience that a relatively large number of patients usually give their approval, both for clinical studies as well as biobanking. “If patients are given clear information about how their samples will be used, only a handful of patients generally refuse to give their consent,” said Döhner.
The biobank in Ulm is maintained by the Institute of Pathology, which also carries out standardized quality assurance measures. Four people are currently tasked with the biobank project, including the director of the Institute of Pathology and the biobank, Peter Möller, the project leader and medical information scientist Gabriela Rheinfelder, biologist Ulrike Kostezka and the medical doctor Robert Rottscholl.
A tank for 25,000 samples
What does the establishment of a biobank involve? “A software package for data administration, patients who are willing to donate tissue, a clinical process chain that is able to process fresh tissue and a cryoroom equipped with a liquid nitrogen tank. The samples are stored in cold nitrogen vapour at a temperature of –196 °C,” said Ulrike Kostezka. The nitrogen tank is big enough to store 25,000 samples and will suffice to store all samples that will accumulate within the next three years or so.
The CCCU biobank uses commercial software specifically adapted to the requirements of the Ulm researchers. The software takes into account personal data protection and only acquires certain key data, including date of birth, gender and an anonymized patient ID. “We do not include the donors’ names,” Gabriela Rheinfelder explained.
Biobanks collect all types of human bodily material, urine, saliva, blood and tissue; the CCCU biobank specializes in tumour tissue. In addition to malignant, i.e. tumour tissue, the biobank also stores healthy samples of the same organ if available. The biobank is still quite new, which is why there are no samples originating from follow-up surgical interventions (i.e. surgeries that become necessary as tumours recur, become resistant to treatment or develop metastases) which can provide the researchers with valuable information about the medical progression of a certain disease.
Tissue is temporarily stored for pathology departments
When a patient (currently in the internal medicine and urology departments only) undergoes surgery, malignant tissue is removed, which is then prepared by a surgical assistant and taken to the Institute of Pathology, which is located in close vicinity to the hospital. The tissue can be stored in the research biobank if the patient has given his or her informed consent for this to be done. Before the biomaterial is stored in cryotanks it is temporarily stored on ice or other media in order to prevent it being destroyed. Different tissues require different treatments; they are either stored in a sodium chloride solution, on dry ice, in a nutrient medium at a temperature of 4°C, on normal ice or in liquid nitrogen. The tissue is then further processed, i.e. cut to size, histologically analyzed, diagnosed and classified in a special room at the Institute of Pathology. These steps are necessary in order to obtain and archive high-quality tissue and are carried out by different pathologists.
The tissue comes with an accompanying letter citing a case number that assigns the tissue to the patient from whom it was removed and also provides information on the organ from which the tissue was taken. Information about the sample is acquired at the bench where it is prepared and fed into the pathology information system: year and six-digit number and letter codes. The code is provided by the system and enables the unambiguous identification of the sample to be stored in the biobank. The code is also associated with diagnostic information as soon as it becomes available, something that might take longer in certain cases, especially when prostate tissue is used.
Software determines site where tissue is to be stored
The CCCU tissue biobank uses special 1.8-ml tubes with a label indicating a two-dimensional barcode (QR code) and a number. The pathologists transfer the punched-out samples into small tubes in which up to four tissue slices can be placed. The software also suggests a storage location for the sample. Ulrike Kostezka then stores the sample, which was previously immersed in liquid nitrogen by a pathologist. The biobank software is also able to find samples in the nitrogen tank, for example when researchers need an overview of samples related to a specific tumour.
The CCCU biobank assigns different roles to its staff, beginning with the doctor who cuts the tissue section to size and ending with the technicians who store the samples. Other people such as researchers are only given limited, i.e. “read-only” access. Gabriela Rheinfelder has the administrative rights of the CCCU biobank: she can define work processes or create a login for new users, doctors for example. She is the only person who has access to tissue samples and associated patient data; she can also re-identify the samples and data if necessary and only when the biobank council authorizes her to do so.
The fresher the better
In principle, it is best to process and store tissue samples as soon as possible after they have been removed from the patient. Sweden has published exact guidelines for such procedures; Germany does not have such guidelines, but this does not reflect upon the quality of the samples. The upcoming relocation of Ulm University Hospital’s surgery department to the “Oberer Eselsberg” campus and hence nearer to the biobank will reduce the time it presently takes to transport samples from the hospital to the biobank.
The CCCU biobank is currently being established and several details and processes still need to be improved. One such improvement involves letting pathologists know in advance when a surgical intervention is to be carried out. Rheinfelder also has plans to provide better and more comprehensive information to patients. The CCCU website expressly and comprehensively informs patients on how they can withdraw their consent at any time. Patients can download a form from the website which they can fill out should they wish to withdraw their consent; Rheinfelder believes that this is useful, for psychological reasons if nothing else. She believes that it is important that patients are aware that they can leave the scheme whenever they want.
A crucial aspect: well maintained and described data
Ulm University Hospital’s initial goal is to use the biobank to channel research and gather experience about the collection and use of the tissue samples stored. As a biobank, it is only as good as its archived information, and biobank staff depend on the good working relationship with their colleagues who are responsible for archiving, typing and classifying the diagnostic data according to OECD or WHO coding – at least this is how Rheinfelder wants it to be done.
The biobank team will now develop a concrete business model. The operation of the biobank requires money and the funds provided by German Cancer Aid are limited. In the meantime, many more samples continue to be stored in the CCCU biobank, and boards such as the tissue biobank working group of German Cancer Aid will hopefully agree on standardized procedures that will facilitate the integration of biobanks into hospital procedures for the best possible benefit of researchers and patients.