Dr. Tejinder Kataria, Chairperson, Radiation Oncology, Medanta – The Medicity, Gurgaon
In 2022, India saw an estimated 1.46 million new cancer cases, which translates to an incidence rate of slightly more than 100 per 100,000 people. Recent projections indicate that the number of cases will exponentially rise to 1.57 million by 2025, with incidence rates among the highest in the North Eastern states.
Within this larger dataset, brain tumors are growing at a rapid pace in the country, with the incidence of central nervous system (CNS) tumors estimated at 5 to 10 cases per 100,000 population in the country, accounting for about 2% of all malignancies.
Each year, India reports 30,000 to 50,000 new incidences of brain tumors, with around 20% of cases occurring in children. Many experts are of the view that that the true number may be even higher due to underreporting in rural areas.
A substantial number of brain tumors are deemed inoperable at diagnosis, as growths in deep-seated or eloquent regions of the brain, such as those controlling speech or movement, often pose excessive surgical risks. Additionally, late diagnosis and limited access to specialized neurosurgical care can further increase the complexity of the surgery, leaving many patients with limited treatment options and poor prognoses.
However, the advent of targeted therapy has brought new hope for patients previously considered untreatable.
Changing landscape through targeted therapy
Targeted therapy refers to a class of drugs that attack specific genes or proteins involved in the growth of cancer cells. Unlike conventional chemotherapy, which affects both healthy and cancerous cells, targeted therapies zero in on molecular abnormalities that are unique to the tumor.
With the rise of targeted therapy, oncologists now have tools to intervene even in the most complex brain tumors, and while surgery still remains a central tool in many cases, molecularly guided treatment strategies are opening new doors for those previously left with few options.
Researchers have identified several actionable mutations in brain tumors — especially gliomas and glioblastomas — allowing oncologists to select drugs that specifically inhibit these mutations, and slowing or halting the growth of the tumor while sparing the healthy brain tissue.
Patients with low-grade gliomas that test positive for IDH1/IDH2 mutations can benefit from IDH inhibitors, which help control the disease and improve progression-free survival. Similarly, certain pediatric brain tumors with BRAF V600E mutations can respond to therapies that target that particular mutation, resulting in a significant shrinkage of the tumor and symptomatic relief.
Molecular diagnostics, next-generation sequencing, and non-invasive tools like liquid biopsies are being used to map out the tumor’s genetic landscape, allowing the management of brain tumors to shift from a one-size-fits-all approach to healthcare that is personalized.
This precision approach not only guides the patient’s treatment but also enables better monitoring of the progression of the disease as well as the response to treatment. New remedies, such as DNA repair inhibitors, immune checkpoint inhibitors, and small-molecule drugs, are entering clinical practice, offering patients with limited surgical prospects even more options.
Role of radiation therapy
Another treatment used to treat certain types of cancer is radiation therapy or radiotherapy, which is often used along with surgery or chemotherapy to treat brain tumors. In this method, strong beams of energy are used to kill cancer cells.
There are basically two types of radiation therapy — external beam radiation therapy (EBRT), in which a machine sends the radiation beams to the tumor over multiple sittings; and internal radiation or brachytherapy, in which a radiation source is placed directly inside the body — next to or inside the tumor — during surgery, thus limiting the effect on nearby healthy tissue.
Some inoperable brain gliomas or tumors may be benefited by stereotactic biopsy, followed by radiation therapy or in conjunction with chemotherapy/anti-angiogenic agents. Brain stem gliomas in children typically cannot be operated or biopsied, and are treated by conformal radiation.
As we move forward, continued investment in research, diagnostics, and access to advanced therapies will be key to ensuring that every brain tumor patient, regardless of the location of the growth, has a fighting chance.
