Jemima was 5 when she started having tummy pains. No one expected the diagnosis that followed.

The symptoms of ovarian cancer are frighteningly vague. Abdominal pain. Backache. Bloating. Fatigue. Indigestion. Fullness. All signs that can easily be dismissed or misdiagnosed.

Especially when the person experiencing them is five years old.

South Australian teenager Jemima Leydon was in her first year of primary school when she received her diagnosis: a malignant germ cell tumour on her right ovary. The only, potentially life-saving clue had been pain in her abdomen.

“My parents kind of pushed [the pains] aside, thinking there was just a stomach bug going around in our year level,” the now 17-year-old told Mamamia. “Then Mum leant over at dinner one night and happened to feel my stomach, and she noticed a weird little bump there.”

Fortunately, the family’s neighbour at the time was a GP.

“She came over and examined me and told us that it wasn’t normal, that we should have it checked out,” Jemima said.

A paediatric appointment followed, then scans, and within two days the reception student was under the knife at Women’s and Children’s Hospital, Adelaide, where surgeons removed her ovary. After that, there was four rounds of chemotherapy, and months in and out of hospital.

Jemima only remembers snatches of it all. Being wheeled into the operating theatre. Receiving chemo. Being isolated from friends to protect her fragile immune system. At the time, her parents, Megan and Gavin, did what they could to protect her from the gravity of the situation. The passage of time has swallowed much of the rest.

"I never felt that I was worried for my life or anything like that," she said. "I feel really fortunate about that, but it meant the stress was a lot more on my parents."

The family hadn't had any previous exposure to cancer and the rigours of treatment. Now she's older Jemima can appreciate the toll it took.

"It just sounded like it was a really traumatic time. You don't expect a child having a stomach ache to go on to have cancer," she said.

"And because the diagnosis and treatment happened so quickly, it would have been quite a whirlwind... But I'm really grateful to them, because they handled that really well and never let on to me that they were struggling."

Ovarian cancer: the silent killer.

Ovarian cancer is the most lethal of the gynaecological cancers, claiming one life every eight hours. Roughly 1600 women are diagnosed in Australia every year, most commonly around the age of 50.

The majority of ovarian cancers are either ovarian epithelial carcinomas, in which the cancer begins in the cells on the surface of the ovary, or malignant germ cell tumours, in which the cancer begins in egg cells.

The latter accounts for about five per cent of ovarian cancers and typically affects women under 30 years old.

In children and adolescents, symptoms can include painful menstrual periods, a lump in the abdomen, pain or swelling in the abdomen, having male sex traits such as body hair or a deep voice, and early signs of puberty.

Twelve years on from her diagnosis, Jemima is now healthy, and only has to undergo annual blood tests and ultrasounds. Beyond that there are few ongoing concerns.

Questions around her fertility had to be raised far more prematurely than for most. But, she said, "at the moment, we're thinking that should be completely fine, which is exciting."

For now though, the teenager is dedicating herself to her school work and her advocacy work. She's an ambassador for the Ovarian Cancer Research Foundation (OCRF), and is hoping her story raises awareness of this potentially deadly disease.

"When I was younger I couldn't really use my voice as well as I'd like to. Now I've been fortunate to be able to do it for others," she said.

She's one of many who will this month take part in Frocktober, the OCRF's annual fundraising campaign, which encourages women to get together throughout the month of October, slip on a fancy frock and raise funds to help "frock cancer".

"We don't have an early detection test at the moment and that's what OCRF are striving for," Jemima said.

"With my story, the crucial part was that I was lucky to have it detected early. Early detection really is the key to surviving, and I know there are a lot of women that aren't as fortunate as I was."

For more information about ovarian cancer or to donate, visit the Ovarian Cancer Research Foundation website.
To register for Australia's most fashionable fundraiser, head to the Frocktober website.