Background: In the Netherlands, 45% of all cancer cases occur in men and women aged 70 years and older. Since the population is ageing and cancer incidence rises with age, the number of new malignancies in the elderly is increasing. It has become apparent that there is a relationship between age at diagnosis and the treatment received. Therefore, age-specific variations in patterns of care for six common forms of cancer in the elderly, are examined. Patients and methods: Patients aged 50 years and older, diagnosed in the period 1988–1992 in Middle and South Limburg with breast, colorectal, lung, ovarian, head and neck cancer and non-Hodgkin lymphoma were included ( n =6911). Data were obtained from the population-based Regional Cancer Registry of the Comprehensive Cancer Centre Limburg. Age-specific differences in diagnostics and treatment were analysed using chi-square analysis (age categories:50–59, 60–69, 70+). Logistic regression analyses were used to examine the extent to which age increased the chance of not being treated or of receiving less intensive treatment, while controlling for the stage of the disease and the sex of the patient. Results: For all malignancies the stage was unknown in a larger proportion of the patients aged 70 years and older than in the younger patient groups. Compared to their younger counterparts, the diagnosis of elderly breast, colorectal and lung cancer patients was more often based solely on clinical grounds. In the total study population, 16% were not treated. Per age category 50–59 years, 60–69 years and 70+ these percentages were 7%, 12% and 22%, respectively, ( P -trend=0.001). For all malignancies the chance of not receiving treatment increased with increasing age. However, the size and nature of the differences varied with the localisation of the tumour. The proportion of untreated patients was par ticularly high in the patients with lung cancer and metastatic colorectal and ovarian cancer, and there was an increase with increasing age ( P -trend=0.001). The vast ...