Kelley Mack, best known for portraying Addy in AMC’s The Walking Dead, has tragically passed away at just 33 years old following a battle with a rare brain cancer. Born Kelley Klebenow in Cincinnati, she gained recognition for her vibrant on-screen presence and creative spirit. Her family revealed she succumbed to a rare and aggressive brain cancer called central nervous system glioma on August 2 in Cincinnati.In September 2024, Kelley publicly shared her diagnosis of central nervous system glioma, a rare and aggressive brain cancer. This cancer arises in the brain or spinal cord and is known for rapid progression and difficult treatment. She underwent aggressive treatment in hopes of beating the disease. Despite her fight, she passed away peacefully on August 2, surrounded by family, her mother Kristen and aunt Karen by her side during her final moments in Cincinnati.Her family’s statement described her as “a bright, fervent light” and a soul who continues to visit loved ones, “in the form of various butterflies.”
What is a central nervous system glioma?
A central nervous system (CNS) glioma is a type of tumor that originates in the glial cells of the brain and spinal cord. These tumors are the most common type of primary brain tumor and can vary significantly in their aggressiveness and prognosis.What are glial cells?Glial cells are a type of cell in the brain and spinal cord that support and protect nerve cells (neurons). There are several types of glial cells, including astrocytes, oligodendrocytes, and ependymal cells. Gliomas are named after the type of glial cell they originate from (e.g., astrocytomas, oligodendrogliomas, ependymomas).What makes a glioma cancerous?Gliomas are generally considered cancerous, meaning they can grow and potentially spread to other parts of the brain. However, some gliomas can be slow-growing and less aggressive, while others are highly malignant and fast-growing, according to cancer research centers. The aggressiveness of a glioma is often categorized into low-grade or high-grade, with high-grade gliomas being more likely to spread and cause damage.What causes gliomas?Central nervous system (CNS) gliomas, while not all rare, are considered uncommon compared to other cancers. The rarity stems from a combination of factors, including the specific type of cells involved, the location within the CNS, and the challenges in studying these tumors due to their low incidence. Additionally, certain subtypes of gliomas are more frequent than others, contributing to the overall perception of rarity for specific types.The exact cause of gliomas is not fully understood, but it’s thought to be related to changes in the DNA of glial cells. These DNA changes can lead to uncontrolled cell growth and the formation of a tumor. Risk factors for gliomas include older age, exposure to ionizing radiation, and certain genetic predispositions.What are the symptoms?Symptoms can vary depending on the size and location of the tumor, but common ones include headaches, seizures, cognitive changes, and neurological deficits (e.g., weakness, numbness).How are gliomas treated?Central nervous system (CNS) glioma treatment can be rare due to several factors, including the tumor’s location and biology, the difficulty of delivering drugs to the brain, and the limited capacity of the brain to repair itself. Furthermore, the rarity of specific glioma subtypes and the challenges in conducting clinical trials for these rare tumors also contribute to the difficulty in developing and implementing effective treatments.Treatment options depend on the type and grade of the glioma, but often include surgery, radiation therapy, and chemotherapy.
Who was Kelley Mack?
Born Kelley Klebenow on July 10, 1992, she grew up in Cincinnati with a deep love for filmmaking fueled by a childhood video camera. After graduating from Hinsdale Central High School in 2010, she earned a cinematography degree from Chapman University in 2014. Over her career, she accumulated 35 acting roles and five producer credits, proving her creative versatility.
Her breakthrough role came in Season 9 of The Walking Dead (2018–2019) as Addy, a resident of the Hilltop Colony. Though her time on the show was brief, her performance was memorable and showed her ability to bring depth to ensemble casts.Kelley’s talents extended beyond the zombie world. She portrayed Penelope Jacobs in Season 8 of Chicago Med and appeared in 9‑1‑1. Her film roles include Alice in the psychological thriller Broadcast Signal Intrusion (2021) and Wilda in Delicate Arch (2024).Her final on-screen project was the comedy-drama Universal, released just weeks before her passing, where she was both in a starring role and as an executive producer alongside Joe Thomas.
