Humans have tens of thousands of genes. When one is exposed to carcinogens, radiation, viruses, or infection for an extended period of time, genetic mutations can be the result, leading to an abnormal growth in cells and cancer. To treat cancer, it is necessary to identify how cancer cells grow and divide so that the patients can be treated with more personalised medicine to improve clinical outcome. Currently, genetic testing has been used to help patients with lung cancer, breast cancer, or ovarian cancer to develop a cancer treatment plan that meets their needs.
Personalised cancer therapy has been gaining traction as a new medical development in cancer treatment. Instead of relying on the stages and types of cancer, doctors can target cancer cells with the new generation of precision medicines, including targeted therapy and immunotherapy drugs, after identifying the nature and genetic sequences of cancer cells through advanced genetic tests. Regardless of the type of cancer, genetic tests can identify the mutated genes, allowing precision medicines to effectively target and attack cancer cells without being restrained to the location of the cancer tumor.
Personalised cancer therapy and genetic tests allow a more precise targeting of cancer cells, not only improving the effectiveness of treatment and chances of complete recovery, but also reducing the side effects on patients. From screening and diagnosis to treatment, personalised cancer therapy is carried out by a multidisciplinary team (MDT) that consists of specialist medical professionals across disciplines working together to develop the most suitable treatment plan that meets patients’ needs. HKIOC has always been on the forefront in introducing new medicines registered in the USA and Europe, allowing for a wide range of treatment combinations.
An Australian medical study found that the survival rate of patients who received MDT cancer treatment was higher than that of those receiving general cancer treatment. In 2015, a local medical institute conducted an observational study with 586 early-stage cancer patients to investigate the effectiveness of MDT in cancer treatment. The results demonstrated that the five-year survival rate of patients receiving MDT cancer treatment was 63.1% with a median of 16 months, while that of patients who received general cancer treatment was only 48.2%.
Genetic testing is mainly used for two purposes: cancer prevention and treatment. It is performed on a sample of blood, hair, skin, or other tissue. The results usually take weeks or even longer to return. In recent years, liquid biopsy has been increasingly applied to diagnostic tests. This method is able to identify genetic mutations through the sampling and analysis of non-solid biological tissue such as blood, pulmonary edema, pericardial fluid, and cerebrospinal fluid. Because this method is a non-invasive alternative to surgical biopsies, liquid biopsy has been named by MIT as one of “10 Breakthrough Technologies”. It is particularly suitable for patients with advanced cancer or for those who are old and weak to undergo surgery for tissue biopsy, as the test can be done with a sample of blood.
There have been major advances in molecular biology in the past years, one of them being Next Generation Sequencing technology (NGS). This cutting-edge technology has been applied clinically, enabling researchers to conduct DNA sequencing much more quickly with high levels of accuracy. This provides a wealth of disease information for medical teams to analyse patients’ cancer and conditions more precisely at different stages.
Cancer patients can undergo a genetic test to look for specific genes, opening up possibilities for new combinations of therapy.
Conventionally, molecular genetic tests are performed on cancer patients. Each tissue sample taken can only be used for three different genetic tests. With the new genetic sequencing technology, biopsy is needed only once to identify all the biomarkers and 300 different types of genetic mutations in cancer cells.
Take lung cancer as an example. If there is a mutation in the epidermal growth factor receptor (EGFR), patients could opt for precision medicines to identify the growth of cancer cells and attack it with accuracy. Unlike traditional chemotherapy, this method minimizes the damage on normal cells and thus significantly reduces the side effects on the patients. It is also more effective at treating cancer.
Patients who have a family history of cancer can assess their risk of cancer and develop plans to monitor and prevent cancer through genetic tests. About 50 hereditary cancer syndromes have been identified so far.
Take ovarian cancer as an example. Patients with BRCA mutations have 10 and 50 times higher risk of developing breast cancer and ovarian cancer, respectively, compared to those who don’t have these mutated genes. 1% of females experience BRCA1 or BRCA2 genetic mutations. Among those who are diagnosed with breast cancer, about 10-15% of them are found to have one of these two genetic mutations.
This therapy option uses drugs or other substances to block the growth and spread of cancer by interfering with the cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth. For example, Crizotinib, a tyrosine kinase inhibitor, is used to treat ROS1 positive lung cancer. Studies have demonstrated that over 70% of lung cancer patients who took Crizotinib found their tumors reduced and experienced no disease progression for 16 months after taking it.
Immunotherapy helps improve or restore immune system function to identify and attack cancer cells by blocking the signals transmitted by cancer cells. In other words, T-cells are a type of immune system cells that can attack cancer cells. However, when cancer cells are bound to immune checkpoint inhibitors such as PD-1, T-cells are kept from killing cancer cells. Anti-PD-1 immunotherapy drugs restore the function of T-cells and help destroy cancer cells.
At the moment, 7 types of immunotherapy drugs have been approved by the FDA (USA) to be used in the treatment of dozens of cancers including lung cancer and liver cancer. At the same time, over 2,500 clinical trials have been carried out across countries to investigate the applications of immunotherapy in cancer treatment.
Apart from the use of new-generation precision medicines, personalised cancer therapy also includes combined therapy that is specially designed according to the patients’ conditions and needs. Patients who are not eligible for surgery can receive chemotherapy before the surgery to shrink the tumor, enabling the possibility for the patient to undergo surgery afterwards. Also, some patients might receive radiotherapy after chemotherapy to eliminate the remaining cancer cells. The doctors can develop a treatment plan based on the patients’ conditions and needs, for example, allowing them to receive infusion chemotherapy treatment at home or outpatient cancer treatment in HKIOC Daycare Medical Centre.
Chimeric antigen receptor (CAR) T-cell therapy is a form of cancer immunotherapy that uses specially altered T cells from the patients’ own immune system to destroy cancer cells. A sample of their T-cells are collected to be modified to produce special structures called CARs on their surface. Currently, it has been approved for use in lymphoma treatment.