Surgery/Biopsy • Glioma - Center Foundation
Most important at this stage:
01
selecting a method/center which allows for maximal tumor resection
02
securing material for further genetic tests (paraffin block) and immunotherapy (deep-frozen sample)
03
considering participation in a clinical trial, which may require a particular definite procedure at the diagnosis stage (this is particularly relevant in the case of immunotherapy more.
According to standard treatment protocols, in the case of both malignant and benign glioblastoma, surgery is the first intervention following diagnosis. Unfortunately, not all brain tumors are subject to surgery. The decisive factor is the localization of the tumor.
The decision for or against surgery is made by the neurosurgeon. Their opinion is worth consulting, because sometimes estimations by individual doctors may differ. How to proceed? In the section on CONSULTATIONS, we give a step by step account concerning “second opinion”. The proviso is valid not only for neurosurgical problems, but it applies to all consecutive stages of treatment.
Does every surgical operation lead to the same effect?
The glioblastoma tumor is difficult to remove; it invades brain tissue and mingles with healthy tissue; it can be situated adjacent to brain centers critical to the patient’s life. Therefore radical removal of all cancerous cells is extremely difficult. Therefore it is advisable to consider individual methods that help the surgeon to distinguish between ill and healthy cells and to perform radical resection. One of such procedure, still relatively new, is removing the tumor by means of fluorescence. The 5-ALA acid is administered orally, and when exposed to the violet-blue light of a UV lamp, the cancerous lesion emits red light. Observation shows that this method reduces the recurrence risk by half over six months following surgery.
Yet another procedure that can be considered is the so-called Gliadel Wafer System, even though it does not seem to be particularly promising. In the tumor resection bed flake applicators are installed; these are biodegradable polymers with an antineoplastic agent, which becomes gradually released into the surrounding tissue. Depending on the particular case, there can be up to eight such flakes. This method is used both with newly diagnosed patients and with patients after post-recurrence surgery ( the procedure is officially approved in the USA by the FDA). Clinical tests show shows prolonged survival of about two months, but there are relatively numerous side effects, which have to be thoroughly discussed with the doctors in charge.
The so-called NanoTherm therapy seems more promising. It is advisable to investigate it even prior to surgery since the first application of magnetic nanoparticles can be conjugated to surgery.
Biopsy • Glioma – Center Foundation
A biopsy is a specialized diagnostic procedure that involves taking a biological sample which is then subjected to histopathological examination. It is important to know that the material can be also used for other purposes: for genetic tests, viral tests, etc.
How can the biopsy material be used, apart from histopathological assessment?
It is certainly advisable to consider using the material to define genetic mutations. As is well known, medical science has still much to do as far as the treatment of glioblastoma is concerned. Regular clinical trials are conducted, and innovative activities are undertaken. Many researchers agree that it is only by investigating specific properties of the tumor and gathering maximum information can lead to success, that is, they advocate the introduction of personalized procedures. Trials carried out over the past decades have demonstrated that there is no universal method of treatment and that every case of glioblastoma is truly unique. New drugs have been appearing (e.g. ONC-201), which in clinical tests prove effective only in the cases of particular genetic mutations. Theoretically, a hundred of patients could be examined and given the drug x with the following conclusion that it did not prove very effective for the population investigated. It might appear, for instance, that in this particular group there were only two individuals who had the particular mutation for which x does prove effective. For those two patients, x might be invaluable (as for others who did not participate in the trial but have the same mutation). But the trial fails because no coordination of the drug x with the genetic mutation was present, while for the two people who were cured the advantage is almost at the edge of statistical significance.
Historically, a great majority of trials allotted patients to groups solely according to the degree of malignancy of their tumors (and not always even that), and generally, there were no groundbreaking results that would show advantage universal for all subjects. Therefore it can be assumed that further research looking for a universal medicine to treat glioblastoma is bound to end in failure, while advantages can be seen as proportional to the degree of personalization. However, if an individual patient is to profit from this approach, the molecular analysis of material taken during biopsy or surgery is essential.
The situation of the patient is most comfortable if the tumor can be removed and if during surgery (which is part of the treatment) it is possible to take material for genetic tests, Problems appear when the tumor is inoperable: biopsy then turns into additional surgery, which brings no immediate advantage, i.e. tumor reduction, but involves – like any other surgical intervention – the risk of complications. Thus neurosurgeons or oncologists often advise against it.
However, one should discuss all pros and cons with the doctors in charge:
defining mutations means a chance for personalized treatment; for instance, it makes it possible to look for definite inhibitors, even those that are not typically used in glioblastoma treatment
deep-frozen biopsy material can be used for personalized immunotherapy.
Moreover, although stereotactic biopsy, which is usually optimal in cases of inoperable glioblastoma, is believed to only rarely lead to complications (in c. 2 percent of all cases), it still involves risk. Therefore the decision should be taken conscientiously.
Important
If the decision is made to have a biopsy performed, it must be carried out at the very beginning of treatment, even prior to, for instance, radiotherapy, which could influence the results.
Important
In many cases, formalin-fixed samples (paraffin blocks) can be used for molecular diagnostics. However, it can appear that a particular test requires a material that had been recently deep-frozen (immediately after taking). Deep freezing is not a standard procedure, and it should be ensured that arrangements are made with medical staff even prior to surgery or biopsy. Comprehensive information on molecular diagnostics of the tumor sample taken during surgery or biopsy can be found HERE