February 23, 2011 1 Comment
According to a study reported in the Journal of the American Medical Association, a randomized clinical trial that compared axillary lymph node removal to no lymph node removal in patients with node-positive breast cancer, there was no advantage for the more aggressive lymph node removal in terms of survival. The study reported by principal investigator Armando Giuliano has created a stir in the surgical, radiation and medical oncologic communities.
But, in the global scheme of breast cancer management, it really should not have.
The history of breast cancer management is one of diminishing returns. In the beginning of the turn of the last century, breast cancer was managed by the Halsted radical mastectomy. This procedure removed the breast, lymph nodes and pectoral muscle, skeletonizing the chest wall. Following that, Hagenson, Crile and other early pioneers documented the equivalence of the Halsted technique and the modified radical mastectomy. Decades later, Veronese at the National Cancer Institute of Italy proved that a quadrantectomy was equivalent to a modified radical mastectomy. This gave rise to the lumpectomy and finally the lumpectomy with sentinel lymph node dissection.
What we have learned, painfully, is that breast cancers have a trajectory all their own. Those tumors with a propensity for dissemination are likely to progress despite aggressive surgery and the associated morbidity and disfigurement while those tumors unlikely to recur cannot possibly benefit from more therapy. To some degree the outcome was independent of the aggressiveness of the surgery.
For years, tumor biologists have recognized that the process of dissemination and metastasis can begin when some cancers are less than 1/8 cm3 in volume — well below the level able to be detected by most diagnostic tools. What Dr. Giuliano’s study has shown us is that cancer biology determines the cancer outcome. The scalpel blade, however sharp, is a blunt instrument in the management of micro-metastatic disease. The cure of this and other solid tumor malignancies will increasingly depend upon effective systemic therapies and judicious use of local measures. Recognizing the fundamental role of systemic management, optimization of drug selection becomes only that much more important.