Woman, aged 20, dies of rare cancer - which her sister is also battling - 11 years after mum died of breast cancer

Katelyn Harding died earlier this month, her family has announced on Instagram via a page set up to inform people about her health, and also that of her sister Cassandra.

The sisters were both diagnosed with osteosarcoma, a cancer which begins in the bones, within less than a year of each other when they were in their teens.

In July 2022, when she was 19 years old, Cassandra was diagnosed with osteosarcoma in the knee which had progressed to her femur and tibia. Shortly after, June 2023, her sister Katelyn, who was then 18, was also diagnosed with osteosarcoma. In her case, the cancer was located in her pelvis, tailbone and lower spine.

They both received surgical treatmement, along with chemotherapy, to remove the cancer. But, Katelyn, who was known as Katie, lost her battle this month.

Announcing the news on an Instagram page called HardingSisters45, her family wrote: “It is with heavy hearts that we announce the passing of our beloved Katie Bug. . . At the young age of 20 years old Katie touched countless hearts and brought a smile with everyone she met.”

Katie died “peacefully surrounded by her closest family”. It then went on: “She now rests in peace and is not alone as she has joined her mother Devorah Sorger.” The statement ends to thank people who have supported the family over the last few years. The caption of the post reads: “A new bright star will shine above us tonight,” alongside a broken heart emoji.

Devorah died 11 years ago of breast cancer, according to a GoFundMe page which was set up in the wake of the sisters’ cancer diagnosis to help raise funds for the Harding family. Katie and Cassandra, known as Cassie, were raised by their dad Christopher as they lost their mum when they were still young children.

Followers of the page commented with their condolences. “Oh my heart!!!! Truly what a beautiful gem and bright light,” one person said. A second wrote: “Rest in peace angel, im sure you paint the prettiest pictures in the sky for us.”

There has not been an update on Cassie’s health since she finished her latest round of chemotherapy around a year ago.

After they were both diagnosed with cancer, the Harding sisters underwent genetic testing and it was found that they were carriers of a rare gene called TP53. This gene increases the risk of developing other cancers in parts of the body, mainly in the breast, bones and brain.

According to the GoFundMe page, the pair were told by medics that they would eventually require a double mastectomy and would also be tested every three months for their entire lives to spot the cancer before it spreads or has time to develop. They were also told they would not be able to have their own children as this gene is hereditary.

More than $128,000 has been raised on the page, called help the Hardings get through the unthinkable, at the time of writing on Monday July 28.