A new study has reported that early stage breast cancer patients with three positive nodes experience reduced cause-specific survival compared with those with one or two involved nodes. Previous studies often have placed patients with one to three positive lymph nodes into a single group. The study initially included 5,996 breast cancer patients whose records were available for analysis from the Saskatchewan, Canada provincial registry between 1981 and 1995. Since the reliability of the nodal assessment depends on the number of lymph nodes assessed, only the 755 patients with Stage T1-T2 disease and at least eight nodes examined were evaluated further for overall survival and cause-specific survival.
Women with one or two positive nodes were found to have similar long-term survival, but those with three positive nodes had a different trend toward worse survival. The breast cancer-specific survival rates of patients with one, two, and three positive nodes at five years were 89.4%, 82.0%, and 81.3%. At 10 years, the survival rates were 78.87%, 72.9%, and 62.1% for one, two and three nodes. At 15 years, the rates were 72.7%. 69.0%, and 55.6%. In contradiction with other studies, the use of radiotherapy was not found to confer any apparent survival benefit. The authors conclude that patients with one or two positive nodes had similar breast cancer-specific survival. However, those with three positive nodes experienced significantly reduced survival compared to those with one or two involved nodes.
Comments regarding axillary lymph node studies
We present studies such as the one above because we want to provide those breast cancer patients and survivors who want it with information concerning prognois. However, this study and the other two newly published studies below are hampered by unavoidable flaws. They are of necessity retrospective and lack controls. Also, women selected for extensive lymph node dissection may possess other attribuites (such as young age or postmenopausal obesity) which would tend to reduce favorable long-term outcomes, thereby heightening the apparent association between number of positive lymph nodes and unfavorable prognosis.
Perhaps more problematic is that the studies may leave the impression in some readers that more is better with respect to axillary lymph node dissection. This is not the case. The sentinel lymph node procedure, in which extensive axillary lymph node dissection is only undertaken if cancer is found in the sentinel node, is the established standard of care and has been shown to be effective in staging breast cancer and determining appropriate adjuvant treatment. Axillary node dissection causes permanent damage to the arm and often results in lymphedema, which can become chronic and have a deterimental impact on quality of life. Therefore, axillary node dissection is to be avoided if it is not necessary.