A growing number of cancer patients are becoming victims of their doctors' success, experiencing dangerous side-effects of tough anti-cancer treatments many years after the drugs have cured them of the original illness, scientists said yesterday.
The rising trend of patients surviving cancer long enough to succumb to the side-effects of the cure is, paradoxically, being seen as a sign of the great strides made in treating the disease. But it looks set to mean a radical re-examination of the philosophy that doctors should deploy any means at their disposal to fight cancer.
Research published yesterday in a European cancer journal, Annals of Oncology, suggests that men who were saved from testicular cancer by certain forms of chemotherapy had a heightened risk of heart and kidney problems more than a decade after their treatment had ended. Although many cancers remain resistant to treatment, testicular cancer sufferers now have an excellent chance of being cured if the disease is caught early. Even advanced cases can be successfully treated 50% of the time.
In an editorial commenting on the research, Karim Fizazi, of the Institut Gustave Roussy at Villejuif in France, said: "Long term side effects of treatment need to be considered since patients who reach the stage of complete response are likely to live for decades. In a way, patients have become the victims of the success of treatment."
In one study, scientists in Essen in Germany looked at 32 men aged 30 to 59 who had been given anti-cancer drugs containing two substances, cisplatin and doxorubicin, between 13 and 17 years earlier as treatment for testicular cancer.
All said they felt healthy, but many turned out to have "potentially worrying long term side effects" including abnormal heart function, low testosterone levels, high blood pressure, hearing loss and nerve damage.
Another study in the same journal, by Norwegian researchers, warned of a high level of kidney damage in patients who had been treated for testicular cancer in the mid-1980s, particularly those who had been given high doses of cisplatin or who had received chemo- and radiotherapy.
Richard Sullivan, head of clinical programmes at the charity Cancer Research UK, said the problem had been recognised for some time in children. Many childhood cancers now have very high survival rates and cured children are carefully monitored for the rest of their lives. Treatments have already been changed to reflect heart and nerve problems and even secondary cancers caused by the drugs which cured the original cancer.
"All drugs are poisons, and chemotherapy is a particularly nasty set of poisons," he said. "The pediatric situation has been much more clear-cut. With adults, it's only relatively recently we've realised we've got a problem.
