[Prognosis after surgical treatment of breast cancer. 3. The low-risk group of the DBCG (Danish Breast Cancer Cooperative Group)].

The two therapeutic protocols of The Danish Breast Cancer Cooperative Group (DBCG) DBCG 77a (1977-1982) and 82a (1982-1990) comprise patients who were classified as low risk patients after operation for cancer of the breast, a total of 7,315 women. Treatment consisted of mastectomy and dissection of the lower and middle axillary levels. The median period of observation for DBCG 77a was 9 1/2 years and for DBCG 82a 3 1/3 years. The curves for recurrence-free survival and survival were found to be congruent in the two protocols. The recurrence-free survival after five years was 70% and 55% after ten years. Survival was 87% after five years and 70% after ten years. Local recurrence developed in 12.7% and 1.1% had distant recurrences simultaneously. Local recurrence was distributed with 60% in the scar or thoracic wall, 33% in the axilla and 7% in the clavicular lymph nodes. Distant recurrence alone developed in 11.4%. The time curves for development of local or distant recurrences were practically congruent. Local recurrence developed in 3.8% of the patients per annum during the first four years and after that in 1.5% per annum. Distant recurrence was found in 3.5% per annum in the first four years and after that in 1.8% per annum. The survival was significantly different after local and distant recurrence. Patients with tumours of grade 1 anaplasia had better prognoses than patient with grade 2 og 3 tumours as regards recurrence-free survival and survival. Multivariate analysis revealed that age under 40 years and anaplasia grad were significant prognostic variables for the parameters: distant recurrence and local recurrence. In addition, the number of lymph nodes in the operation specimen was a prognostic variable for local recurrence.