Long-term survival in node-positive breast cancer treated by locoregional therapy alone

To investigate the long-term survival rate of node-positive (pN+) breast cancer treated by locoregional therapy alone, we made an attempt to identify all such patients followed up for at least 15 years after treatment in a defined geographical area (city of Turku, Southwestern Finland) and time period (1945-79) using the files of the local hospitals and the Finnish Cancer Registry. The clinical and autopsy records and histological slides of 1172 women diagnosed with breast cancer in the city were reviewed. From this cohort we identified 339 women with unilateral node-positive breast cancer treated with locoregional therapy without systemic adjuvant therapy. The relative survival rate of the cohort compared with the general female population matched for age and year of follow-up was calculated. The 15- and 30-year survival rates corrected for known intercurrent deaths were 26% (95% CI, 21-31%) and 21% (16-26%) respectively, and the relative survival rates 23% and 21% respectively. None of the patients with pN2 disease survived for 15 years, whereas the 30-year corrected survival rate in pN1 disease was 24% (18-30%). Women with pT1N1M0 cancer had as high as 59% (43-75%) 15-year survival rate corrected for intercurrent deaths. A trend for improving survival was found by the decade of diagnosis. The results indicate that a considerable proportion of women with pN1 breast carcinoma treated with locoregional therapy alone become 30-year survivors and are probably cured. Adequate locoregional treatment is mandatory in the care of node-positive breast cancer.