Background. Different schools of thought regarding the natural history
of breast cancer and how it relates to the importance of local contro
l in affecting survival have generated controversy over the optimal tr
eatment of early breast cancer. Parting with traditional thinking that
some disease is localized, in which cases local control is important
for survival, another view of the natural history of the disease argue
s that local control is not of value to survival. This commentary will
review the evidence and attempt to evaluate the effect of modern adeq
uate local treatment on survival. Methods. A review of the pertinent l
iterature on the treatment of breast cancer and an analysis of recent
clinical trials and metaanalysis are presented. Results. Evaluation of
the recent literature and metaanalysis demonstrates that adequate loc
al regional treatment, especially radiation therapy in the treatment o
f breast cancer, does effect survival significantly. Conclusions. Resu
lts of modern effective local treatment of breast cancer substantiate
the claim that some breast cancer is localized. Data show that tumor s
ize, lymph node involvement, tumor grade, and other prognostic factors
are important predictors of whether a tumor is localized and therefor
e amenable to local treatment. Smaller tumors generally are most likel
y to be localized. Recent studies on modern irradiation techniques sho
w that adequate effective irradiation of localized disease, including
appropriate treatment of all nodal areas when needed and limited radia
tion to sensitive organs, can significantly improve survival and, in h
igh-risk patients, enhance the effect of systemic treatment in improvi
ng survival.