Questions to Ask About Brain tumors Treatment

There is no TNM stage for a brain tumor. NCI's PDQ summary explains why in three lines. Tumor size matters less than tissue type and location. Node status does not apply, because the brain and spinal cord have no lymphatics. Metastatic spread rarely applies, because most people with CNS tumors do not live long enough to develop it.

So the questions that matter here are about tissue type, molecular markers, how much was removed, and where the tumor sits.

PDQ uses the World Health Organization classification instead. That system pulls together four things: shape under the microscope, chromosome findings, molecular genetics, and immune markers. WHO grade I covers lesions with low growth potential. They are often discrete, and surgery alone may cure them.

PDQ names three genetic changes as powerful prognostic factors in diffuse glioma. That family covers astrocytoma, oligodendroglioma, mixed glioma, and glioblastoma.

• IDH1 or IDH2 variants. Whether the tumor carries a change in one of these genes.
• Codeletion of chromosomes 1p and 19q. Whether both arms are missing.
• MGMT promoter methylation. Whether that gene's switch is chemically silenced.

PDQ says these alterations may guide management, not just predict outcome. It reports an exploratory analysis of 318 patients with low-grade glioma treated with either radiation alone or temozolomide alone.

The result splits by marker. For IDH-mutant tumors without 1p/19q codeletion, radiation delayed growth, with a hazard ratio of 1.86 and a P value of .0043. For IDH-mutant tumors with codeletion, there was no significant difference between the two. The same was true for IDH wild-type tumors. IDH wild-type carried the worst outlook, whatever the treatment. IDH-mutant with codeletion carried the best.

The MGMT numbers in that same low-grade group are worth quoting exactly. All 45 IDH-mutant, 1p/19q codeleted tumors were methylated. So were 86%, or 62 of 72, of IDH-mutant tumors without codeletion. Among IDH wild-type cases, 56%, or 5 of 9, were methylated.

Beyond genetics, PDQ names eight factors that carry a poor prognosis. Age older than 40 years. Progressive disease. Tumor larger than 5 cm. Tumor crossing the midline. Contrast enhancement on MRI. A WHO performance status of 1 or higher. Neurological symptoms. And anything less than a gross total resection.

That last item is why the operative report matters as much as the pathology report.

PDQ states the goal plainly. For most CNS tumors in most locations, complete or near-complete removal is attempted, within the limits of preserving neurological function and overall health.

Then it qualifies its own evidence. The practice rests on observational data. That data shows better survival after removal than after closed biopsy alone. But PDQ says the benefit of removal has not been tested in randomized trials. It adds that selection bias may make the real gap smaller than those studies suggest.

PDQ names two goals of surgery. One is getting a tissue diagnosis. The other is easing pressure inside the skull, by taking out as much tumor as can safely go. It also notes that surgery alone rarely removes a primary malignant tumor inside brain tissue completely.

PDQ describes an operation done while the patient is awake and cooperative. It is a craniotomy with stereotactic removal. Nerve function is checked in real time.

It gives two examples of how that check works. In the first, removal continues until one of two things happens. Either the MRI abnormality being tracked is fully gone. Or subtle trouble appears, such as a slight slowing of rapid alternating movement, or anomia, meaning trouble naming objects. In the second, when the tumor sits in or near language areas, an electrode is used to briefly stop speech while the patient counts or reads.

Some options people are told to ask about are absent from this PDQ summary. Their FDA labels supply the facts instead.

Vorasidenib (Voranigo) is an IDH1 and IDH2 inhibitor. Its label covers adults and children 12 and older. The tumor must be a grade 2 astrocytoma or oligodendroglioma. It must carry a susceptible IDH1 or IDH2 mutation, found by an FDA-approved test. And surgery must have happened first, whether biopsy, sub-total removal, or gross total removal. The adult dose is 40 mg by mouth once daily. The label warns about liver injury. It directs liver tests every 2 weeks for the first 2 months, then monthly for the first 2 years.

Vorasidenib is taken at home, so the prescription your own neuro-oncology team writes is what to go by. The liver blood tests that go with it are not optional.

Aminolevulinic acid (Gleolan), often called 5-ALA, is an imaging agent, not a treatment. Its label covers glioma suspected to be WHO grade III or IV on scans done before surgery. It helps the surgeon see malignant tissue during the operation. The amount is worked out from body weight and given by mouth 3 hours before anesthesia, in a range of 2 to 4 hours. It must not be used in porphyria, and the label warns about phototoxic reactions.

Both facts are checkable. Neither appears in the PDQ summary, which is a reason to ask directly rather than assume availability.

Seizures are the presenting symptom in about 20% of people with supratentorial brain tumors, meaning tumors above the tentorium. PDQ says that in slow-growing tumors, seizures may come months or years before diagnosis.

Over the whole course of illness, 70% of people with primary tumors in brain tissue develop seizures at some point. Among people with brain metastases, that figure is 40%.

PDQ's general symptom list covers more. Headaches. Visual changes. Loss of appetite, with nausea and vomiting. And changes in personality, mood, mental capacity, and concentration.

PDQ describes the two scans as complementary. CT is fast, which matters for an unstable patient. It is better for calcifications, skull lesions, and hyperacute hemorrhage, meaning bleeding less than 24 hours old.

MRI has better soft-tissue resolution. It picks up isodense lesions, contrast enhancement, swelling, and infarctions. It also picks up all phases of bleeding except hyperacute. For spinal cord lesions, PDQ calls high-quality MRI the study of choice.

After treatment, PDQ says SPECT and PET scans may help tell tumor regrowth from radiation necrosis. That is dead tissue caused by the radiation itself. Telling the two apart is a common reason for a confusing scan report.

A brain tumor can cause problems that will not keep until the next clinic visit. Ask your team to write their own instructions down, and use these as the floor.

• Call 911 or go to an emergency department if you have a seizure for the first time, or any seizure lasting longer than five minutes or repeating without you waking up in between. Do the same for a sudden severe headache, repeated vomiting with drowsiness, new confusion, difficulty waking, sudden weakness on one side, or sudden loss of speech or vision. These can mean rising pressure inside the skull or bleeding.
• Call your care team the same day if headaches are clearly worsening or are worst on waking, if you notice new unsteadiness or double vision, or if a known seizure pattern changes. During treatment, a temperature of 100.4 °F (38 °C) or higher needs immediate attention if you are also receiving chemotherapy — the CDC calls fever during chemotherapy a medical emergency, so ring your team's urgent number then and there, night or day, and head to an emergency department only if you cannot get through.
• Call your care team within a day or two if memory, mood, or concentration changes are building, or steroid side effects such as sleeplessness or high blood sugar are hard to live with.

Background on tumor types is in brain tumors. The markers named above are explained in biomarker testing. What a return looks like is covered in brain tumor recurrence.

• NCI PDQ: CNS tumors, HP version
• CDC: Fever during chemotherapy is a medical emergency
• DailyMed: Voranigo label
• DailyMed: Gleolan label