Liz Allen, a social work manager from south London in her early fifties, was diagnosed with breast cancer in December 2006. Her condition demanded major surgery - bilateral mastectomy and lymph-node removal - followed by intensive chemo- and radiotherapy.

The treatment was a stamina-sapping regime lasting nearly nine months. Today, back at work full-time and restored to complete health - although still on hormone therapy - she admits that as her treatment progressed she feared becoming stuck in what she terms "sick mode".

"I recognised there was a danger of becoming permanently ill'", she says. "I needed something to mark the end of all the treatment, something positive that I could focus on."

That something turned out to be fly fishing. And the catalyst was a just-launched UK charity programme called Casting For Recovery, which provides free weekend angling retreats specifically for breast-cancer victims.

There can be few pastimes that conjure up ideas of pastoral relaxation better than angling. Fly fishing devotees, from Isaac Walton to the late Queen Mother, have counselled on the therapeutic benefits of an hour or two with rod and line beside a tumbling stream or gently lapping lake.

But its role in the after-care of women breast cancer victims is unique and, according to the programme's organisers, is delivering surprising results.

The idea, which a US breast surgeon came up with in 1996, is a simple one according to UK organiser Sue Hunter, herself a former breast-cancer sufferer and now an international gold-medal fly-fisher.

"The casting action provides the gentle exercise recommended by physiotherapists for joint and soft-tissue mobility, while the weekend gives participants a chance to relax, share experiences and make new friends in a tranquil setting supported by professionals.

"A weekend is quite short, but it gives everyone a skill which they can use whenever they need to de-stress from the trauma of illness or life in general."

Richard Collins, a member of the Royal College of Surgeon's council in England and a volunteer advisor to Casting for Recovery, admits the benefits of the programme are essentially diversionary. "This programme is worth supporting because it helps to take patients' minds off the illness," he says. "It provides a measure of group therapy and shared experiences." The effects are more likely to be psychological than physiological, explains Collins, a Kent surgeon and angler. "One of the problems of mastectomy in the past was a residual stiffness in the shoulder and surrounding muscles," he adds. "But radical surgery is no longer applied so that is no longer really a problem."

Allen was a participant at the UK's first weekend retreat in Sussex last September, less than a month after finishing her treatment. She believes the benefits were both physical and mental: "The hotel and location were idyllic. Immediately you felt that you had come somewhere special. I was still quite stiff and sore, but they gave me a lighter rod. The casting really complemented my exercises and helped to give me confidence. I am still fishing."

Four more retreats will take place in England, Wales and Northern Ireland this year. Scotland is set to add its scenery and hospitality to the UK organisation's list of venues next year following an exhaustive survey of locations later this summer. Hunter says: "We are already receiving applications from north of the Border."

Fishing by tranquil Highland lochs and glens may not be practicable, however. Her checklist demands exclusive use of a high-quality small hotel and access to a nearby trout stillwater fishery, all with excellent transport links. A central Scotland location is likely.

Each retreat accommodates 12 women, lasts around 2.5 days and includes talks and counselling on breast cancer as well as the theory and practice of fly-fishing. The support team includes a physician, breast cancer counsellor, male and female fishing guides and administrators.

The Countryside Alliance (CA) has injected £50,000 so far into the programme. Fishing tackle manufacturer Orvis supplies equipment and some hotels have donated entire weekends. With up to five applications arriving every week, demand for the free all-inclusive retreats is already such that places have to be allocated by ballot.

Hunter adds: "Some 40% of our referrals are from within the medical community. We are receiving inquiries from across the UK and would like to help everyone, but we are a charity and depend on volunteers."