Survival rates for patients with cancer continued to improve substantially throughout the 1990s despite expectations that they would level off, according to a Dutch study analysing cancer registration data since the 1950s.
The Comprehensive Cancer Centre South, in Eindhoven, has data on 200000 patients with cancer dating back 45 years covering the south east of the Netherlands. The data show a strong trend of increasing survival rates at five years compared with both the 1960s and the 1980s.
Patients aged 15-44 years had a 73% chance of surviving five years in the 1990s, compared with 55% in the 1970s. Patients aged 45-69 and 70-89 also showed a trend towards better five year survival, with their chances improving from 40% to 55% and from 34% to 49% respectively.
The researchers argue that the data provide hard proof of a continuing trend for patients with cancer to live longer despite scepticism that there were few further improvements to be made.
Dr Jan-Willem Coebergh, associate professor in cancer epidemiology at Rotterdam's Erasmus University, who led the research, said that the trends were even stronger than he had expected. Earlier detection and better treatment since the 1980s were important factors.
He said: “We have detailed analysis of how patients have benefited from major improvements in surgery for treating cancer of the bowel and rectum together with improved preoperative radiotherapy.”
The trend was also influenced by earlier detection, especially of prostate cancer by general practitioners and urologists. Patients with breast cancer have benefited from better screening and treatment.
Survival rates at five years for breast and prostate cancer have risen steadily in the past 25 years, from about 60% to about 80%; survival for cancer of the colon and rectum have also improved, from about 40% to 60% Survival rates among patients with Hodgkin's disease and cancer of the testis have also improved markedly.
The only exception is skin cancer among men older than 60, in whom survival rates at five years have fallen slightly from more than 60% in the late 1980s. Researchers believe this could be due to older men not coming forward for diagnosis early enough.
But Professor Coebergh warned that the research also had a downside. There are now 375000 Dutch patients who have or have had cancer, and the figure is increasing at 5% a year. This will place heavy demands on services, especially complex, rehabilitation services for elderly patients. Meanwhile longer waiting lists could result in a slowing down of the trend towards earlier diagnosis.
Cancer Incidence and Survival in the Southeast of the Netherlands 1955-1999 is available from Integraal Kankercentrum Zuid (IKZ), Comprehensive Cancer Centre South, PO Box 231, 5600 TE Eindhoven, Netherlands (ikz@ikz.nl). 