Survival rates from the Vaud Cancer Registry were compared for incident cases registered in 1974-1978 and 1979-1983. No appreciable difference was evident for most major cancer sites: 5-year relative survival rates were 0.21 in 1974-1978 and 0.23 in 1979-1983 for stomach, 0.49 and 0.46 for colon, 0.45 and 0.47 for rectum, 0.04 and 0.03 for pancreas, 0.08 and 0.10 for lung, 0.41 and 0.42 for kidney, 0.21 and 0.13 for brain, and 0.32 and 0.30 for multiple myeloma, respectively. A modest advancement in 5-year relative survival rates was, however, registered for total cancer mortality (non-melanomatous tumours excluded, from 0.41 to 0.43) while, with regard to specific sites, a significant improvement was seen only for cancer of the testis (from 0.73 to 0.88). More than 10% non-significant improvements in survival were recorded for melanomatous skin cancer (from 0.67 to 0.78), thyroid cancer (from 0.73 to 0.85), particularly in females, non-Hodgkin lymphomas (from 0.37 to 0.45), Hodgkin's disease (from 0.61 to 0.78), cancer of the ovary (from 0.28 to 0.32) and the prostate (from 0.44 to 0.52). However, significant declines in survival rates were seen for cancer of the larynx, gallbladder and biliary tract, and for connective tissue neoplasms. A few differences in the modification of relative survival rates according to age (less than 60 versus greater than or equal to 60 years) were noted for a few cancer sites. Changes were larger in older patients with respect to cancer of the prostate and thyroid and non-Hodgkin lymphomas (increases) and connective neoplasms (decreases). Conversely, changes in survival were greater or restricted to younger individuals for testis, bladder and leukaemias (improvements) and cancer of the mouth or pharynx (decline), thus suggesting the different play of age-specific biological characteristics of some tumours, in addition to diagnostic improvements and gradual spread of effective cancer treatments to more advanced age groups.