Campaigners are calling for menopause support to be included into cancer treatment care plans.
The majority (90%) of the 1,200 people surveyed by Menopause and Cancer said they were not provided plans to help manage menopause-related health changes brought on by cancer treatment.
Its founder Dani Billington said the results were "not a surprise".
NHS England has been approached for comment.
Ms Billington said there was currently no direct pathway for menopause treatment support included in cancer care plans.
"We call for improved training for healthcare professionals, better access to therapies and specialist care so people can manage menopause safely and effectively," she said.
Ms Billington, who lives in Thames Ditton, Surrey, was diagnosed with breast cancer at 33, and she said that her treatment caused her to experience early menopause aged 39.
She subsequently set up the charity to support patients and run workshops to equip healthcare professionals with better knowledge.
Rachel Bowman, from Brighton, East Sussex, was first diagnosed with breast cancer at 46 and was on hormone treatment therapy (HRT) to help relieve perimenopause symptoms.
The now 49-year-old, who is the director of Menopause and Cancer, said she was only given a menopause management plan after she was diagnosed with cancer again in 2023.
"Support teams who have this specific experience is very patchy," she added.
Kent resident Penny Giles-McLoughlin, 54, was diagnosed with breast cancer aged 50, but said she too was not provided guidance on how to manage menopause caused by cancer treatment.
Dr Carys Sonnenberg, a GP and menopause specialist, from Surrey, said historically the focus in oncology was treating and surviving the cancer and "less attention to long-term quality of life issues including menopause".
"Oncology, gynaecology, and primary care may not always coordinate well, so patients can fall between the cracks," she added.
Dr Sonnenberg said menopause care should be built into cancer care plans from the start.