The cruel dilemma suddenly facing thousands of women: Those at risk of breast cancer are urged to take a daily pill. But alarming side-effects include early menopause and depression New drugs can protect women from developing deadly disease But side effects include early menopause and depression Carly, 37, wishes she had mastectomy instead By Chloe Lambert You've been offered a drug that protects you from life-threatening disease, but the side-effects are unbearable. This was the dilemma that Carly Gibson faced as she recovered from breast cancer, after a shock diagnosis aged just 29. "I had a lumpectomy and radiotherapy, and then my doctors told me I'd need to take tamoxifen," says Carly, now 37, who lives with her husband Chris and their two children in Wotton-under-Edge, Gloucestershire. Tamoxifen is a drug that blocks the effects of the female sex hormone oestrogen, which is implicated in about 80 per cent of breast cancers. The daily tablet is routinely given to breast cancer patients, usually for five years after treatment, to lower the risk of their cancer recurring. Emotional: Carly Gibson took Tamoxifen after she recovered from cancer treatment and found it altered her personality "I was very young and scared and, of course, I took it, but I didn't find it easy at all," says Carly. Which is a mild way of describing how the drug affected Carly: within days, she started suffering with severe hot flushes, fatigue and extreme mood swings. Last year, 589,277 prescriptions for tamoxifen were written in England alone. But many more thousands of healthy women - those who've never had the disease - could soon be taking it. For this week, the Government's health watchdog the National Institute for Health and Care Excellence (NICE) recommended that tamoxifen - and another anti-oestrogen drug, raloxifene - should be offered to all women with a family history of breast cancer, so that it can be taken as a preventative measure. Happier: The mother, pictured with her husband, Chris, and their two children, feels better now she no longer takes the drug The move has been hailed as a "game changer" that will give women who have inherited a susceptibility to cancer the option to avoid surgery and, instead, pop a daily pill. But there was little mention of the terrible side-effects this drug can wreak on some women who take it. Five-year courses of tamoxifen will be available on the NHS to all women with a family history of breast cancer - meaning those whose mother or sister were affected before the age of 40, or at least two relatives on the same side of the family at any age. This raises their own risk of developing the disease to about 40 per cent. The worst thing was how emotional I felt - I was close to the edge at times There are financial incentives to its wider use, too: treating a woman with tamoxifen for five years would cost the NHS £130, whereas treating a woman with breast cancer can cost £12,000 a year. And so, about half a million women - the number who are thought to now be eligible for preventative tamoxifen - will be offered the drug. Combined with the women who are already prescribed the drug after suffering cancer, more than a million women in the UK could be soon be recommended tamoxifen. But while this is a drug that can no doubt save a woman's life - reducing breast cancer risk by about 40 per cent - it is not without its side-effects. And some experts are questioning whether healthy women should be given such a powerful drug for a disease they may never get. It's a terrible dilemma for those women who are at risk of cancer, as Carly Gibson was to discover. Because tamoxifen acts on oestrogen levels, it brings about menopausal-type symptoms. Shortly after starting on it, Carly felt her body begin to change. At risk: Angelina Jolie, left, and Sharon Osbourne have both had a mastectomy "Within days of starting it, I felt very unwell," she says. I started having hot flushes and night sweats, and a strange feeling of being cold inside. I was also really emotional and would walk around crying. It made me gain weight, too, around my stomach, which I know might not sound like a big thing but when you're a young single woman, it's pretty upsetting. Two years later, Carly had met her husband Chris and they wanted to start a family, so she came off the drug. Tamoxifen should not be taken while pregnant because it can harm a developing baby. She soon became pregnant and gave birth to Lydia, now four. Her doctors were keen for her to go back on to tamoxifen but Carly and Chris wanted another child - so they began trying again and had Rowan, now three. When Carly reluctantly restarted her medication, the side-effects returned with a vengeance. "The worst thing was how emotional I felt - I was close to the edge at times," says Carly. It was probably partly because my hormones had gone from post-baby to menopausal. I just felt terrible. Suppression of oestrogen is linked to low mood because the hormone contributes to the release of serotonin, the "feel good" hormone, yet depression is a fairly uncommon side-effect of tamoxifen. 'Now I wish I'd had a mastectomy because taking the drugs was much worse' "I was tired all the time, but couldn't sleep because of the night sweats, all of which obviously made looking after two young children hard," Carly recalls. I was starting to think about coming off it. My doctors tried me on another brand, but that just made me feel even worse. Carly's doctors urged her to stay on tamoxifen, saying she needed to stay on it for five more years to get the optimum level of protection. But she decided she could stand it no longer and stopped. There are clearly benefits to taking tamoxifen that I considered. But in the end, it was the decision that was right for me. I decided my sanity and my quality of life with Chris, Lydia and Rowan was more important. I felt I'd been given this amazing opportunity to have children, but I wasn't able to enjoy it. As I was so young, the focus was all on preserving my body and breasts, but now I wish I'd had a mastectomy because taking the drugs was much worse. They say tamoxifen stops you from having a mastectomy, but it doesn't stop you worrying. It may sound surprising that anyone who has suffered cancer would give up a protective drug. But tamoxifen is "not the kind of medication the average woman would want to take," says Baroness (Delyth) Morgan, chief executive of Breast Cancer Campaign. For a healthy woman to consider taking an anti-oestrogen treatment which has side-effects is a very difficult decision (posed by model) She adds: "These new NICE guidelines are a major step forward in the treatment of breast cancer risk, but for a healthy woman to consider taking an anti-oestrogen treatment which has side-effects is a very difficult decision." The new guidelines are not aimed at carriers of the faulty BRCA1 and 2 genes, however. Experts say these women are more likely to choose to have a preventative mastectomy, as did Sharon Osbourne and more recently Angelina Jolie. That's because this group have an 80 per cent risk of cancer, so a drug that reduces risk by 40 per cent just wouldn't be enough to put their minds at rest. Most cancers caused by the BRCA1 gene are also not fuelled by oestrogen, so tamoxifen would not have an effect on these. Tamoxifen's side-effects include hot flushes, sexual dysfunction and musculoskeletal symptoms such as cramping or aches. The drug also slightly raises the risk of blood clots and endometrial cancer. A study published in March by Breast Cancer Campaign involving 3,300 breast cancer patients found that at least half of women prescribed a five-year course of tamoxifen either stopped taking, or took markedly less than their prescribed doses from the third year of treatment onwards. "We know from research that women often don't take tamoxifen as prescribed," says Baroness Morgan. Maybe this is because they've not had the benefits explained to them, or maybe they've forgotten, but there is a real question about whether tamoxifen is easily tolerated. Experts speculate that women who decide to take the drug preventatively will be more likely to complete their course of medication. But despite being anxious about their risk, having watched family members suffer and, in some cases die, studies show many women are still concerned about the side-effects of tamoxifen. In an ongoing trial of 1,700 women in Manchester with a strong family history of breast cancer, only about 12 per cent decided to take tamoxifen when offered it. Professor Tony Howell, scientific director of the charity Genesis Breast Cancer Prevention, who is running the trial, says: "It depends on the individual's experience. Some women said their mother had taken tamoxifen but died of cancer anyway. Some were very worried about the side-effects. But of those who did take the drug, 80 per cent kept going on it. He adds that the factors affecting a woman's decision can vary according to her age. And tamoxifen-induced menopausal symptoms may have much more of an impact on a younger woman than one who is already going through the change. Alison Morton, a mother-of-three who lives in Buxton, Derbyshire, can identify with this. She was given the drug after she developed breast cancer in 2007 at the age of 44. After 50 days, she stopped taking tamoxifen because she found the side-effects unbearable. It was like being thrown into the menopause. I was waking up drenched two or three times a night, and had to change the sheets," says Alison, now 50, who is married to Neil. Bad experience: Alison Morton stopped taking Tamoxifen after it brought on symptoms of the menopause It also gave me bad fatigue and low mood. It felt so unfair - I had already had my breast and lymph nodes removed. Surely, I'd been through enough. Alison was put on to a different type of drug called an aromatase inhibitor. This is also prescribed to protect against breast cancer by blocking oestrogen, but has slightly less evidence for its effectiveness than tamoxifen. She found the drug easier to bear and took it for five years. So how are doctors deciding which women should be given tamoxifen as a preventative? Well, it's a decision that's taken on the basis of an estimate of their risk of cancer, and these estimates are approximate, not exact, says Diana Eccles, professor of cancer genetics at the University of Southampton. We make an estimated risk based on the person's circumstances, but we know there are lots of information gaps, and an individual's risk will be dependent on lots of other things. This might include their lifestyle. These may be very well people. Just because you have a 40 per cent chance of cancer, you still have a 60 per cent chance you won't get it. It's a chance that many have taken - and for some women, tamoxifen can have unexpected side-effects, some of them good. Rising risks One in 20,000 women will develop breast cancer in her 20s. This figure rises to one in 13 in women's 60s Julie Armstrong, 45, took tamoxifen for a year as part of Professor Howell's trial. Her mother was found to have breast cancer at the age of 58 and then three years later her mother's brother was also diagnosed with breast cancer. "I was concerned because I've always had heavy periods and breast pain," says Julie, who lives in Lancashire. My GP referred me to a family history clinic. Thankfully, they found I didn't have the faulty BRCA1 or 2 gene, but they said I probably had another cancer gene that hadn't been identified yet. Julie started having screenings and then, in April last year, she was asked if she wanted to start taking tamoxifen to reduce her risk. It was absolutely life changing for me. I dropped three bra cup sizes within the space of a couple of months, I had much less breast pain and the terrible PMT I used to get went away. I did have hot flushes and a few of them were quite severe. I've always been someone who just gets on with things. I knew the drug was protecting me from cancer. But unfortunately, Julie found that an existing health problem she had, erythema nodosum - which causes painful nodules to form on the legs - started to get worse. Professor Howell said it wouldn't be fair for me to stay on the drug. Instead, she has decided to have her ovaries removed as this will lower her oestrogen levels. These women's different experiences confirms Professor Diana Eccles's conviction that the drug is not for everyone. "It's important people are not railroaded into something, and make an informed choice," says Professor Eccles. Carly Gibson has been off tamoxifen for two years, but she is still suffering some night sweats and irregular bleeding. "Cancer is terrifying and, of course, you want to protect yourself," she says. I stuck with tamoxifen as long as I could, and I know it might well have saved my life. But it makes you feel vile. In the end, I thought it was better to have a life worth living. For more information, visit breastcancercampaign.org and genesisuk.org