Prof U. Tirelli: The best cure against cancer is a test
Analysis of genetic mutations in cancer cells can be used to identify precisely the correct targeted therapies for patients. This information is therefore of crucial importance in choosing the correct therapeutic approach for each type of cancer.
Oncologists today have limited information with regard to the biological characteristics of a tumour which can be used to identify the right anticancer drugs for their patients. In fact, there are about 500 anti-cancer drugs, but several hundred different cancer types and each of these types of cancer has different genetic mutations that respond differently to therapies. Therefore, even for a good oncologist, the chances of finding the right effective drug combinations are very low and do not exceed 20% of cases.
The promise, therefore, is to use genetic tests to identify precisely the correct cancer treatments that act against these genetic alterations and which therefore have minimal toxicity. Genetic tests are able to help the oncologist make the right choices, increasing the chances of prescribing an effective drug up to 80%. Although the direction is right, the road is still long, but at least there are now two companies, one is the Foundation medicine, a company founded in 2009 in Cambridge, Massachusetts (United States), and other is Oncologica Uk, founded in Cambridge, Great Britain, who have developed tests that detect mutations in several hundred genes in solid cancers. Before targeted therapies there was only chemotherapy, which although killing bad cells, also destroys good cells and therefore their effectiveness is often overwhelmed by the toxic side effects.
However after the mapping of the human genome in 2000, arrived drugs that were able to target the genetic mutations in some tumour types. For example imatinib, with the commercial name Glivec, was a revolution for the treatment of chronic myeloid leukemia linked to the mutation of a single major cancer gene, with the drug acting like a key slipping into a lock blocking the mutated gene. Unfortunately, this happens only in a few tumors and still a lot remains to be done to arrive at a solution, even if the direction seems the right one. For breast cancer, once the mutations of the Her2 gene have been identified, drugs have been developed that act specifically on that mutation with great advantages for patients who have breast cancer with these characteristics, so called Her2-positive tumours.
The areas of application that today can be addressed with these new genetic tests include tumors of unknown origin, rare tumors, difficult to treat and advanced tumors and the ones that do not respond to traditional therapies. In addition to the initial assessment , genetic tests can also be applied several times in the same patient This retesting can be used to assign a new set of anticancer drugs going forward due to the fact that cancer cells can undergo further mutations over time that allows them to become resistant and escape the theraepeutic effects of the initially prescribed drugs. This approach can be compared to the treatment of bacterial diseases with antibiotics which over time can become resistant. The treatment is modified when resistance to the antibiotic develops.
I am director of the cancer center based in the Tirelli Medical Clinic in Pordenone. Here I employ Oncologica UK’s genetic tests, in particular the Oncofocus test, which indicates the correlation between genetic mutations and drugs approved by the major global regulators, for example the American Food and Drug Administration (FDA), the European medicine agency (EMA), and those targeted agents currently undergoing clinical trials. Unlike many other genetic tests that require special processing and shipping conditions, the Oncofocus® test is performed on the routine histology samples stored in the hospital where the patient was diagnosed and the biopsy was taken, and these samples can be sent to the Cambridge laboratories by standard courier service.
After performing DNA and RNA extraction from the routine tumour pathology tissue block, and all tumours can be evaluated in this way, a precise detection of the genetic mutations in the tumor cells is made and these mutations can then be linked to the most effective targeted therapies available. This approach is applicable to all solid tumour types. The Oncofocus test also assesses immunological alterations that identify potential treatment options using immunological drugs such as pembrolizumab or nivolumab which unlock the brake on the immune system allowing it to act against the tumour cells. The reimbursement of the test has not yet been approved by national health system, but the oncologist, and this is what I do in the Tirelli medical clinic in Pordenone, can request the Oncofocus test even though it is not covered by the state. The tissue sample is sent to Cambridge (UK), or if one uses Foundation Medicines to the United States, where they perform the test and give the result. Recently the FDA has approved a therapeutic approach using immunotherapy that goes in this direction, so that patients, regardless of the pathology they have (breast, lung, colon, etc.), undergo DNA profiling enabling mutations detected to be matched to the appropriate therapy.