WHEN Gillian Quinn felt a dull ache in her knee she thought it was nothing more than a sports injury.

But after several sleepless nights struggling to cope with the pain, the mother-of-three went to her GP for a check-up and was immediately sent for an x-ray.

Six weeks later she was told she had spindle cell osteosarcoma – a type of bone cancer most common in the legs and upper arms.

Almost nine years on, she is still battling the illness, which has left her knee but emerged elsewhere in her body.

To mark National Bone Cancer Awareness Week, she is urging people to be aware of the disease, which does not always show pronounced symptoms until it is well advanced.

Gillian, 43, said: "Being diagnosed with bone cancer came as a huge shock to me because I didn't really feel very ill at the time.

"I had an aching knee, but I thought I'd just hurt it playing hockey.

"Looking back I had classic symptoms of bone cancer, but had no idea at the time.

"I was lucky because my GP immediately sent me for a scan, which was when they discovered the cancer."

Mrs Quinn underwent knee replacement surgery and a course of chemotherapy, which appeared to have got rid of the cancer.

She was told the treatment would make her infertile, but just months after her last round of chemotherapy, she was delighted to find out she was pregnant, giving birth to a baby boy four months later.

But, following eight years in remission, during which time she thought she had seen the last of the illness, she began to feel lethargic.

After going to hospital for a check-up she was devastated to be told secondary tumours had surfaced in her lungs, pelvis and pituitary gland.

Although five months of chemotherapy have halted the growths, she has now been told there is no chance of getting rid of them permanently.

"It was difficult to be told I am now on the list of people classed as terminally ill," she added.

"It sometimes seems when I go in for a check-up, the doctors are assessing how long I have left.

"But I'm still very positive and take the view that you never know what can happen.

"I was told I could not have children, but that proved to be wrong so it just goes to show anything is possible.

"I feel healthy and, when you have three kids to bring up, you can't go around feeling sorry for yourself. I want to let people know about my experience to help raise awareness of bone cancer.

"It's important people take any symptoms seriously, but equally that GPs take decisive action at an early stage, because they are the first line of defence."

Osteosarcoma is the most common type of primary bone cancer, normally occurring in people aged between 10 and 24 years of age.

An estimated 150 patients are diagnosed with it every year, with 80 per cent of tumours occurring in the long bones of the arms and legs.

Professor Tim Eden, an expert on teenage and young adult cancer, said: "The most important thing is that young people are aware painful lumps ought to be investigated.

"We need to empower them to make sure that the doctor takes it seriously and arranges an x-ray to investigate further."