IntroductionBreast cancer accounts for about 17 percent of all female noncutaneous malignancies, and it is estimated that worldwide in 1994 more than 850,000 new cases of breast cancer were diagnosed and about 250,000 people died. In 1995 in the United States, it is estimated that 183,400 new cases of breast cancer will be diagnosed and 46,240 people will die.
1Although these numbers seem staggering, a positive trend toward earlier diagnosis of breast cancer has occurred. About 75 percent of newly diagnosed breast cancers in 1993 were stage I or II, and about two thirds of all breast cancer were node negative.2 Stage I and II cancers are by convention grouped together as early-stage breast cancer, while in situ cancers are grouped separately.The treatment of operable primary breast cancer has also undergone a remarkable evolution in the past several decades. The standard operative procedure has changed from the radical mastectomy to the modified radical mastectomy, and the use of breast-conserving treatment is increasing. Radical mastectomy is no longer the only available option for potentially curative treatment of early-stage breast cancer.
Survival for Early-Stage Breast CancerSurvival for patients with early-stage breast cancer treated with mastectomy alone is excellent, but varies by stage and quantitative nodal involvement.3 A recent study by Rosen et al 4 provided longterm follow-up of patients treated primarily by modified radical mastectomy. Patients with small tumors and no lymph node involvement (stage I, tumor less than 1.0 cm in widest diameter) had a 10-year disease-free survival rate of 91 percent and a 20-year disease-free survival rate of 88 percent. When all patients with stage I lesions were included, the 10-year and 20-year disease-free survival rates were 83 and 79 percent, respectively. Thus, survival for these patients was excellent, and most attrition occurred within the first decade.Lymph node involvement, however, had a profound impact on survival. Patients with stage IIA cancer (T1N1) with one involved lymph node had a 10-year disease-free survival rate of 71 percent and a 20-year disease-free survival rate of 66 percent. If two to four lymph nodes were involved, 10-year and 20-year disease-free survival rates were 62 and 56 percent, respectively. For patients with more than four involved lymph nodes, 10-year and 20-year disease-free survival rates were 47 and 43 percent, respectively.The long-term survival rates in the paper by Adair et al 3 reflect the impact of local-regional care alone, primarily with mastectomy, in an era prior to adjuvant systemic therapy. The primary and often only therapy was radical mastectomy.C A C a n c e r J C l i n 1 9 9 5 ; 4 5 : 2 7 9 -2 8 8