Kelley Mack, who starred in 'The Walking Dead' and '9-1-1,' dies at 33. What is a glioma and who is at risk of the rare cancer?

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a day ago

Co-stars, directors and other people in the entertainment world offered their condolences to the late actress.
Kelley Mack, an actress known for her work on popular TV shows like The Walking Dead, 9-1-1 and Chicago Med, has died at 33. The American-born star died in her hometown of Cincinnati over the weekend, according to her family, on Saturday, Aug. 2.
"It is with indelible sadness that we are announcing the passing of our dear Kelley," reads a statement from her sister, Kathryn Klebenow, posted on Tuesday, Aug 5. "Such a bright, fervent light has transitioned to the beyond, where we all eventually must go.
"Kelley passed peacefully on Saturday evening with her loving mother Kristen and steadfast aunt Karen present. Kelley has already come to many of her loved ones in the form of various butterflies. She will be missed by so many to depths that words cannot express."
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Contact a qualified medical professional before engaging in any physical activity, or making any changes to your diet, medication or lifestyle.
Kathryn shared a longer obituary online, noting her sister — whose real name is Kelley Lynne Klebenow — grew up in various states in addition to Ohio, including Missouri, Connecticut, North Carolina and Illinois. However, she lived and worked in the Los Angeles area for the past 11 years, and earned 35 actress and five producer credits within her career.
"She is survived by her mother and father, Kristen and Lindsay Klebenow, sister Kathryn, brother Parker, grandmother and grandfather Lois and Larry Klebenow and her dearest boyfriend, Logan Lanier," the statement added.
On Instagram, people she worked with on various sets chimed in to share their condolences. Kathryn added in the post's caption that Kelley "would want you all to know how much she loves you."
"What an incredible human. So proud to have fought alongside her in our final episode together," wrote The Walking Dead actress Alanna Masterson, who plays Tara Chambler in the series.
"I was lucky enough to create with Kelley on TWD. A bright light on every level. All my love to those who love her," added director Michael Satrazemis.
"A true talent and lovely, lovely soul. May you rest in peace and keep shining through all the hearts you touched," penned Jessy Schram, who plays Dr. Hannah Asher in Chicago Med.
Mack died after battling a glioma of the central nervous system, according to the statement from her sister. But what exactly does that mean and is it a common health condition? Read on to learn more.
What is a glioma?
According to the Cleveland Clinic, a glioma is a tumour that often forms in the brain but can sometimes begin in the spinal cord. They're formed when glial cells — non-neuronal cells in the nervous system that provide support and protection for neurons — grow out of control.
These tumours are malignant, but can sometimes be very slow growing. However, they typically don't spread outside of the brain or spine, but can become life-threatening when they're hard to reach or treat with surgery, or if they grow into other parts of the brain.
What are the different types of gliomas?
There are three main types of glioma, which are grouped by the type of glial cell they grow in. Sometimes, they can contain multiple cells, in which cased they're called mixed gliomas. The types include:
Astrocytomas: These start in star-shaped glial cells called astrocytes and are the most common malignant brain tumour in adults. This category includes glioblastomas, which account for 24 per cent of brain tumours
Ependymomas: These start in ependymocytes, which are cells of the ependyma. This type of glioma accounts for two per cent of all brain tumours, and are more common in kids than adults.
Oligodendrogliomas: This rare tumour starts in oligodendrocytes, and tend to grow slowly but become more aggressive over time. They account for one to two per cent of all brain tumours, and are more common in adults than children.
Mack announced earlier in January that she was diagnosed with a diffuse midline glioma, which is an extremely rare type of an astrocytoma. "Due to the biopsy surgery on my spinal cord, I have lost the use of my right leg and most of my left leg, so I now get around with a walker and a wheelchair," she wrote in an Instagram post at the time.
In the health update, she noted that she had experienced persistent lower back pain for about a month after moving into a new apartment with her boyfriend last September. She thought she "slipped a disc" or had a herniated disc in her back, until she had neuropathic itching in her right quad.
"Then, the shooting pains in my legs and back began, which resulted in me having to sleep in a recliner for a month because laying down was too painful," she continued, explaining later had emergency MRIs completed, which showed an abnormal mass in her spinal cord.
According to the Brain Tumour Foundation of Canada, diffuse midline gliomas are "generally high-grade tumours that infiltrate through the entire substance of the brain stem." They most often occur in children, but can appear in adults as well.
What are the symptoms of a glioma?
The Cleveland Clinic notes the symptoms of a glioma may include:
Problems speaking and communicating, or aphasia
Vision changes or loss
Cognitive problems, like trouble thinking or memory issues
Walking or balance problems
Dizziness
Headaches
Weakness or numbness on one side of the body
Nausea and vomiting
Personality or behavioural changes
Seizures
For diffuse midline gliomas, the Brain Tumour Foundation of Canada adds that difficulty swallowing, double vision and facial weakness are some common symptoms on top of those mentioned above.
What causes a glioma?
Health-care providers aren't exactly sure what causes a glioma, according to Mayo Clinic. But research suggests changes, or mutations, in DNA can lead to the development of brain and spinal cord tumours, including gliomas.
The Cleveland Clinic notes it's possible to inherit mutations from your parents, but they can also occur randomly in one's lifetime. When it comes to astrocytomas like the one Mack had, the majority develop randomly, with radiation exposure and genetics being the only known risk factors.
What are the risk factors for a glioma?
While it remains uncertain what causes a glioma, some of the following can increase your risk factor:
Aging: Getting older can increase your risk of a glioma, with most occurring in adults between ages 45 and 65.
Radiation exposure: People who have been exposed to ionizing radiation, including radiation therapy, have an increased risk of gliomas.
Genetics: While rare, having a family history of gliomas can increase your risk.
How is a glioma treated?
Gliomas are often initially treated with surgery. But if the glioma grows into an important part of the brain or if it can't be reached, surgery might not be an option. In that case, other treatments like radiation therapy and chemotherapy may be offered.
To control symptoms, you may also be offered various medicines. These may include medications to control seizures, reduce swelling, help with memory issues and improve alertness if you're fatigued.
The Cleveland Clinic notes there are four grades of astrocytomas, with grade one being curable using surgery and grade two being rarely curable. For grade three and grade four (glioblastomas), there is no cure.
Is a glioma deadly?
The Canadian Cancer Society notes that survival statistics for brain and spinal cord tumours cannot be used to predict a person's survival chances, since these are very general estimates. Survival rates for brain tumours will vary widely, depending on the tumour type, grade and location in the brain. But in general:
Low-grade tumours have a better prognosis that high-grade tumours
People under age 65 have a better prognosis
Tumours that can be surgically removed have a better prognosis
Tumours that grow into parts of the brain where it can't be removed by surgery come with lower survival rates
For astrocytomas, the Canadian Cancer Society's most recent data includes patients diagnosed and treated between 1973 and 2004, meaning survival rates may have risen since then. But out of that data, the median survival rates for each grade of astrocytoma include:
Grade 1: A greater than 90 per cent five-year survival rate
Grade 2: Five to seven years
Grade 3: Two to three years
Grade 4 (glioblastoma): 12 to 14 months