IMPROVEMENT IN THE PROGNOSIS OF BREAST-CANCER FROM 1965 TO 1984

Purpose: The prognosis of breast cancer has improved over the past thr ee decades. It is uncertain, however, whether this improvement results from an increase in the cure rate, extension of the life span of uncu red patients, or some combination. Methods: From the Connecticut Tumor Registry, we obtained data on 25,091 patients with localized (node-ne gative) and regionally metastatic (node-positive) breast cancer who we re diagnosed over the two decades between 1965 and 1984, with follow-u p through 1993. The data for these patients were analyzed using a vari ety of parametric models to quantitate likelihood of cure and median s urvival time among uncured patients. These models incorporate the assu mption that time to death from breast cancer follows a specific distri bution. Results: For patients with node-negative disease, parametric a nalysis revealed no significant difference in cured-fraction or median survival time over the two decades studied. For patients with node-po sitive disease, however, a significant increase in median survival tim e (P < .001) was found during the second decade (1970 to 1979). There was also a trend toward a higher cured-fraction over time, but this wa s not statistically significant. Conclusion: This study confirms that patients with node-positive disease had an improved prognosis over the two decades studied. Parametric analysis suggests that this improveme nt reflects primarily an increase in the median survival time for uncu red patients, although there is a trend toward an increase in the like lihood of cure. (C) 1998 by American Society of Clinical Oncology.