Throughout her life my mother, Rose, prayed for good health. My father left when I was 12 and money was tight, so she couldn't afford to take time off work. I have a younger sister and three older brothers, and she used to panic that we'd be taken into care if she wasn't able to look after us.

Mum was born in 1938 in Guyana and came to Britain at the end of the 60s. She settled in Tottenham, north London, and worked for London Transport and then as a home help, a care assistant and finally a local authority officer. Bringing up five children singlehandedly with little money can't have been easy, but she did it with tremendous style. She was always beautifully turned out and she had a wicked sense of humour.

She was also very ambitious for her children. Parents' evenings were a big event in our social calendar and school reports were taken very seriously; "C" was not a grade my mother recognised. Her favourite shop was WH Smith, where every week there would be a new book or pen or calculator to buy. But most importantly, she was my best friend. We would talk late into the night on anything from idle gossip to current affairs and politics.

She had been enjoying her retirement for only about a year or so when my wife, Nicola, asked me if I thought that Mum had lost some weight. I had to admit I hadn't noticed, but Nicola was slightly concerned. Mum said she hadn't been on a diet, and mentioned that she'd had back pain for a while and was bloated and constipated. We were all sympathetic and did our best to help. My brother bought her some herbal teas and I took her out to buy a beautiful new bed, which I hoped would take care of her bad back; I don't think any of us thought for one minute it could be cancer.

Then Mum began to get what she described as twinges, which eventually turned into stabbing pains, and she went to see her GP. In fact she went to see her GP three times, only to be told she was badly constipated and given laxatives. Then, in May 2006, she felt a lump in her stomach and went back for the fourth time to find a different, younger doctor on duty. He examined her and immediately sent her to hospital for a series of scans.

We had to wait about a week for the results, and even then we weren't unduly worried. I thought it was probably only a cyst. I had come out of the House of Commons and was in my car, about to go off and make a speech, when my sister rang. The lump was a tumour the size of a grapefruit. It was advanced ovarian cancer.

It seems amazing that it had gone undetected for so long, but that seems to be a pattern with this disease - which is terrible, because if it is caught early enough, 90% of patients will survive for more than five years. Obviously if I had been aware that my mother had all the potential signs of cancer, I would have made sure that she got the right treatment immediately.

That autumn, Mum had one bout of chemotherapy and then an operation to remove the tumour, followed by another three lots of chemotherapy before she decided not to continue with the treatment. People could not believe the way she handled it. She insisted on having my two-year-old son to stay overnight so that my wife and I could go out to the cinema, and she refused to give up her car until about four months before she died. Right up until the end, she was determined to walk by herself, dress herself and cook for herself. She even managed to cook an enormous roast dinner for the family about 10 days before she died, though she could hardly walk.

My experience of cancer is that it is horribly debilitating for the person who has it, and onerous in terms of chemotherapy and treatment, but you do have the chance to say goodbye properly and there is something quite special about that. All of her children took the opportunity to spend as much time as they could with her. During her illness, Nicola became pregnant, which is why Mum decided to have her fourth round of chemotherapy - in the hope that she would see her new grandchild, which she did. She was very grateful to the NHS for managing to keep her alive a little longer.

Mum had a very strong faith, and she didn't want to waste the time she had left wallowing in self-pity, so although there was sadness, there wasn't gloom. One thing she did find difficult, however, was meeting so many younger women with the disease who would not live to see their children grow up. She also realised that the cancer her own mother had died of at the age of 41 was probably ovarian, too, because the symptoms had been the same. My mother hadn't been told, because people didn't talk about "women's problems" in those days.

When you're with someone every day, their physical deterioration is not quite so marked, and I'm shocked now when I look at photographs and see how skeletal Mum became. I think she must have found that hard, because she was always so proud of her appearance, although when her hair grew back white and wiry after chemotherapy, she claimed she'd always wanted hair like that and thought she looked quite cool.

For many years, I'd wanted to tape my mum talking about her experiences as a young woman in Guyana. One evening, as I was leaving home to visit her, I saw my dictaphone and decided to take it with me. By this time, Mum was in a hospice, and I don't think she was that keen at first, but once she started talking it all came out and she became quite emotional. I'm so glad I managed to do that, because when I got home later that night the hospice rang to say that Mum had taken a sudden turn and all the family should be there. She never spoke again and died two days later, on 15 March last year.

I miss her terribly but - and this is very hard to explain - it is as if she instilled a strength in me that makes it easier. And she would be very moved if she knew that by talking about her, I can raise awareness of ovarian cancer and the need for the type of research undertaken at Ovarian Cancer Action Research at Imperial College, and help other women.

• David Lammy was talking to Hilary Whitney.

Ovarian cancer facts

• It is the biggest gynaecological killer of women in the UK, and the fourth most common cause of death from cancer in women. The disease affects about 6,800 women a year.

• About 70% of women diagnosed with the disease will die within five years, a statistic that has not significantly improved in the UK for 20 years.

• Most women cannot name a single symptom of ovarian cancer. Research conducted by Ovarian Cancer Action shows that women are more likely to know about male cancers than ovarian cancer.

• The three most common symptoms are: pelvic and abdominal pain; increased abdominal size/bloating; difficulty eating and feeling full quickly. (Other possible symptoms include frequent urination, changes in bowel habits, extreme fatigue or back pain.)

• There is no proven screening method for ovarian cancer (although a study is being undertaken to remedy this: ukctocs.org.uk), so awareness of the symptoms gives the greatest chance of early detection.

• Two out of three cases aren't diagnosed until the disease has spread, and treatment options are limited. If detected in its early stages, the survival rate is 90%.

• The average GP will only see one case of ovarian cancer every five years.

• Little is known about what causes it, although age and a family history of ovarian and breast cancer are significant.

• Call 020-8238 7605 or visit ovarian.org.uk for more information.