Cancer news usually involves unremittingly grim stories about carcinogens or rising cancer rates. But recently there was something more positive. A Cancer Research UK report shows that deaths are "set to fall dramatically" by 2030. The 17% drop will be the result of major improvements in diagnosis, treatment and fewer people smoking. Many more of us can expect to survive cancer.

This is marvellous news but unfortunately it's not the full story. "It is not that a magic wand has been waved and they are all cured," says Ciarán Devane, chief executive of Macmillan Cancer Support. "It actually means many people will be living longer with the disease. The impact of cancer does not suddenly stop when treatment is over. Many cancer patients have to deal with the physical and emotional effects of their cancer for years afterwards."

Christina Buffham, 32, from Staines, was diagnosed with breast cancer when her son, Jack, was only four months old. During her maternity leave from British Airways she had a mastectomy followed by gruelling chemotherapy. "I got the all-clear on Jack's first birthday," she says, "and I thought, 'Life's going to be brilliant now.' I was euphoric. But when all that dies down, it hits you: your body still isn't right and you are terrified that the cancer will come back."

This is a common reaction. "Rates of depression and anxiety are very high when treatment ends," says Dr Michelle Kohn, director of Living Well, a programme that offers emotional and practical support to cancer patients at Leaders in Oncology Care, a private London-based clinic. "Other emotional issues, such as low self-esteem, anger, stress or sleep problems are also widespread."

On top of this, cancer survivors are often battling with physical and practical challenges, anything from huge financial losses, to the side effects of medication, profound fatigue, a confused-feeling known as "chemo brain", or lymphoedima (swelling). Their loved ones, meanwhile, might be increasingly baffled as to why they can't bounce back and make the most of life. "People suffer for years, often in silence, without any real support," says Kohn. "Life after cancer can actually be very difficult and lonely."

It does not help, says Devane, that, "the current system is woefully inadequate at supporting the changing nature of cancer survivors". In the United States, most major cancer units have survivorship programmes where teams of psychologists, nurses, and other specialists offer ongoing information, advice and emotional support to patients when treatment ends. This, of course, is funded by health insurance. In contrast, NHS post-treatment psychological or practical services are limited, to say the least.

The National Cancer Survivorship Initiative (NCSI), a partnership between the Department of Health and Macmillan, was launched in 2008 to help improve the situation but it has a massive job on its hands. According to NCSI research, 60% of cancer survivors have unmet physical or psychological needs; over 33% have problems with close relationships, careers, or have difficulty performing household duties; over 90% have suffered financial losses. Waving these people off with a six-month followup appointment, is simply not working.

The NCSI is launching a range of programmes that take a more holistic approach to the needs of cancer survivors, for example encouraging physical activity, or helping with issues including work and finance. "It is essential the NHS now implements these solutions," says Devane. But there is a very long way to go.

Other cancer charities, in smaller ways, are also trying to plug the gaping hole in post-cancer care. The charity Maggie's runs a free six-week programme called "Where Now?" that aims to help people adjust to life after treatment ends.

There are, in fact, many highly effective ways to cope with tricky post-treatment issues. But without expert guidance, few people know where to begin. "The fear that cancer will come back again is huge for me," says Christina. "It's impossible to ignore. There are reminders everywhere, on TV, the newspaper, the internet. Other people also say things without realising the impact they're having – more than once I've had people tell me about someone they know whose cancer came back, spread and killed them."

In fact, Christina's cancer has already returned, twice. And she has also had to contend with complications from breast reconstructions (so far she has had four reconstructive surgeries). She is now cancer-free and "determined to enjoy life to the full". But still, whenever she feels unwell the fear sets in and – despite a supportive family – she says that she can feel very alone.

"My GP is brilliant," she explains, "But there's only so much she can do. The consultants are absolutely inundated, and understandably, since I don't have cancer, I can't be their top priority. But I also know that all three times my cancer was dismissed at first by doctors, so it can be terrifying, if I feel an unusual symptom, to be told to wait and see."

None of this must dampen the brilliant news about falling death rates. But there is a clear message behind the headlines, and one that must not be ignored: NHS post-cancer treatment services need to change dramatically.

• Frances Goodhart, of The Cancer Survivor's Companion: Practical ways to cope with your feelings after cancer (Piatkus).