A study of complete responders in cases of metastatic breast cancer treated with combination chemotherapy

Twenty-eight patients with a metastatic breast cancer who have achieved a complete remission from a combination chemotherapy that included doxorubicin have been analyzed to ascertain the factors which affect the duration of the response and the survival time. The median duration of a complete remission was 26 months. Relapses occurred in 17 patients (61%), of which the median duration of the response was 18 months and 71% of the relapses occurred at the sites of the prior dominant disease. Most of the patients suffered a relapse while they were receiving maintenance chemotherapy. The number of metastasized organs were one or two in 89% of the patients. The dominant sites of the disease were mainly the visceral (61%) and soft tissue (29%), and the duration of survival was found to be longer in patients with a visceral metastasis. In the group of patients who experienced a recurrence 2 years or more after their operation showed a statistically longer remission and survival time than those who experienced a recurrence within 2 years. The duration of survival from the start of chemotherapy was 45.5 months for complete responders and 21 months for partial responders. This difference was statistically significant (p less than 0.001), though no difference was found between partial responders and "no-change" patients (18.5 months). The tendency towards a relapse at the site of the initial involvement and while receiving maintenance therapy suggests that the majority of patients with a metastatic breast cancer who achieved a complete remission with this combination chemotherapy still have a substantial subclinical residual tumor. Maintenance treatment should be investigated to ascertain the procedures and duration of therapy. Thus, these results have indicated that it is necessary to achieve a complete remission in order to obtain a long term survival.