Remembering Dikembe Mutombo and Understanding Brain Tumors

Two years between the announcement and the loss

BBC Sport reported in October 2022 that Dikembe Mutombo, the eight-time NBA All-Star, was undergoing treatment for a brain tumor. NBA.com reported that his family had said the treatment was in Atlanta.

He died on Monday, September 30, 2024, at 58. The NBA announced that the cause was brain cancer and that he was surrounded by his family. Commissioner Adam Silver said: "Dikembe Mutombo was simply larger than life."

Mutombo was a four-time Defensive Player of the Year. He was also the league's first global ambassador, and a philanthropist who funded a hospital in Kinshasa. His family did not publicly name the specific type of tumor, and this page will not guess at it.

That gap is a good place to start, because "brain cancer" is a category rather than a diagnosis.

The two questions that define a brain tumor

The first question is where it started. The National Cancer Institute separates primary CNS tumors from metastatic brain tumors. Primary tumors begin in the brain or spinal cord. Metastatic ones started elsewhere and travelled there. A lung cancer that reaches the brain is still lung cancer, and it is treated with lung cancer drugs.

The second question is grade. Unlike most cancers, brain tumors are not staged with the usual TNM system. NCI explains why. Metastatic spread "rarely applies because most patients with CNS neoplasms do not live long enough to develop metastatic disease." Instead the World Health Organization assigns a grade from I to IV. The grade reflects how the cells look and behave.

NCI describes each level. Grade I covers lesions with low growth potential that are often discrete. NCI notes "the possibility of cure following surgical resection alone." Grade II lesions spread into nearby tissue and divide slowly. They still recur more often than grade I after local therapy. Grade III lesions show clear signs of malignancy under the microscope, with odd nuclei and faster division. They are usually treated with aggressive added therapy. Grade IV lesions are "mitotically active, necrosis prone, and generally associated with a rapid preoperative and postoperative progression and fatal outcomes."

Grade, not the word tumor, carries the meaning. Meningiomas and other tumors of the supporting tissues make up 27 percent of primary brain tumors. Many of them are low grade.

How brain tumors announce themselves

Symptoms depend on which part of the brain is affected, not on size alone. NCI's patient guidance lists the common signs. The wording of the first is worth noting: "morning headache or headache that goes away after vomiting."

The rest of the list runs long. It includes seizures, problems with vision, hearing, or speech, loss of appetite, and frequent nausea and vomiting. It also includes changes in personality, mood, focus, or behavior, loss of balance, trouble walking, weakness, and unusual sleepiness.

Seizures are common enough to deserve their own statistic. NCI reports that they are the presenting symptom in about 20 percent of patients with tumors in the upper brain. It adds that "70% with primary parenchymal tumors and 40% with metastatic brain tumors develop seizures at some time."

When to get checked

Most of these turn out to be something else. All of them still deserve prompt attention, and the first two are emergencies.

• A first-ever seizure at any age, including staring spells
• Sudden one-sided weakness, numbness, or speech trouble
• A headache worst on waking, or one that eases after vomiting
• A headache pattern that is new for you and worsening weekly
• Double vision, a narrowing field of vision, or one-sided hearing loss
• New clumsiness, veering when walking, or repeated falls
• Personality or concentration changes that others notice first

Why imaging alone is not enough

NCI is emphatic on this point. "Biopsy confirmation to corroborate the suspected diagnosis of a primary brain tumor is critical," whether by needle before surgery or during the operation itself.

The reason is that scans can mislead. NCI notes that all brain tumors "must be differentiated from other space-occupying lesions that can have similar clinical presentations." It names abscesses, tangles of abnormal blood vessels, and strokes. A definitive biopsy also rules out metastatic cancer or infection.

There is one exception NCI allows. When clinical and radiological evidence clearly points to a benign tumor, active surveillance without biopsy or treatment can be reasonable.

MRI is the imaging workhorse, because NCI notes it "has superior soft-tissue resolution." Biopsies can be placed precisely using CT-guided or MRI-guided stereotactic technique. That means the target is located by coordinates mapped from the scan.

How the WHO classification changed

NCI describes the modern approach as one that "incorporates and interrelates morphology, cytogenetics, molecular genetics, and immunological markers." In practice that means the pathology report is no longer just a description of what cells look like. It includes genetic findings that alter both the name and the expected course.

For high-grade glioma, two markers matter most. IDH1 and IDH2 variants are present in only 5 to 10 percent of glioblastomas, so most are IDH wildtype. MGMT is a gene whose activity can be silenced by a chemical tag. NCI reports median overall survival of 18.2 months when MGMT was methylated, against 12.2 months when it was not.

What treatment involves, and what the numbers say

For glioblastoma, NCI describes the standard as "surgery followed by concurrent radiation therapy and daily temozolomide, and then followed by six cycles of temozolomide." Radiation is given as 60 Gy in 2 Gy fractions over six weeks. NCI reports overall survival at three years of 16.0 percent with that combination. Radiation alone gave 4.4 percent.

The American Cancer Society projects 24,740 new cases of brain and other nervous system cancer and 18,350 deaths in the United States for 2026, and SEER, the federal cancer surveillance program, publishes that pair. SEER's own measurements give a rate of 6.1 per 100,000 people per year, five-year relative survival across all these cancers of about 33 percent, and a most common age at diagnosis of 65 to 74.

That combined figure covers every malignant CNS tumor, including slow-growing types with much better outcomes. It should not be read as a figure for high-grade disease, and no group statistic describes an individual.

Sources

• https://www.nba.com/news/dikembe-mutombo-passes-away
• https://www.bbc.co.uk/sport/africa/63284976
• https://www.cancer.gov/types/brain/hp/adult-brain-treatment-pdq
• https://www.cancer.gov/types/brain/patient/adult-brain-treatment-pdq
• https://seer.cancer.gov/statfacts/html/brain.html