Geraldine Lowe, 64, lost twin Vicky to breast cancer several years ago and will march around Reading's Green Park on Saturday, September 29, as part of Sue Ryder's Starlight Hike.
She said: "I was also diagnosed with breast cancer after my sister died, but a couple of weeks ago I was given the five year all clear.
"My sister was in the Nettlebed Hospice for respite many times during the last few months of her life and I will be eternally grateful to them.
"It gave me the respite I needed from caring for her but also she never minded having to go there and, in a way, it became her second home.
"Our lives, hers and her family's, were made so much easier because of Sue Ryder."
Event fundraiser Emma Harpaul added: "We're really pleased this year to have developed a special area along the route which is designed for reflection, to think about the work that Sue Ryder does, or to remember loved ones.
"Starlight Hike is going to be a great event and we're hoping that the whole of the local community will get behind us and support the event to raise much needed funds that we need to keep our services going."
The 10K walk starts at midnight and entry is £18. Visit: http://www.starlighthike.org/SiteReading