Not only is the notion of"early" muddled, but the question of what is being detected is also difficult to grasp.36 Nearly one third of the women with tumors undetected by mammogram have positive Iymph nodes--a sign that the disease is already systemic.37 Mammography fails to detect one fifth of all cancers; in women under 50, it misses as much as 40%.38 Unfortunately, having a clear mammogram does not mean that a woman is cancer-free. But because many cases are visualized by mammography, the current recommendation is that, especially for women over 50, it is a useful tool--particularly when a qualified technician uses a reliable mammography machine with a skilled radiologist interpreting the results. As counterintuitive as it sounds, radiologists Samuel Hellman and Jay Harris39 assert that
"[d]etection of cancer at an earlier stage does not necessarily imply an improved cure rate."
Axillary Node Dissection
Axillary node dissection is another procedure that is no longer routinely justified, yet remains firmly entrenched. Halsted was wrong: cancer does not spread in an orderly fashion via the Iymph system, node by node. Whether nodes are positive or negative does not necessarily foretell whether an individual woman will have a survival advantage. An early hypothesis posited that the presence of malignancy in the Iymph nodes served as a marker for who should receive chemotherapy. But new studies have shown that it is not an accurate prognostic measure. In 1986, Hellman and Harris39 reported the following: "Twenty-five percent of patients without axillary Iymph-node involvement develop metastases while 25 percent of those with axillary Iymph-node metastases never develop distant metastases." Thirty-eight percent of women with negative Iymph nodes die of the disease, which demonstrates that the positive or negative status of these nodes does not provide reliable prognostic information.
Harvard surgeon Blake Cady urges that "[w]e need to move beyond the latest dogma and convention regarding routine axillary dissection for established functionally equivalent goals" (note 13). In a book called Important Advances in Oncology 1996, Cady writes a chapter titled "Is Axillary Node Dissection Necessary in Routine Management of Breast Cancer? No." Surgeon Peter Deckers suggests that "[w]ithin the next decade, axillary dissection will be extinct."33(p363) Again, it is the cellular biology that is most crucial in determining prognosis and treatment, and this is now the focus of current research. But there is a lag time between the incorporation of new information and the dispatch of old habits.
Fisher's Protocol B-04 study established that axillary node dissection does not provide survival benefit. When further treatment was dependent on whether the nodes show malignancy, then node dissection was perceived to be a useful procedure. Today, however, we have many biological markers that provide information equivalent to positive or negative node status, rendering this procedure obsolete. If these markers suggest that a tumor is aggressive, women will receive chemotherapy regardless of the status of their axillary nodes. The medical school dictum applies: "If the results of a test do not change what you do, do not do the test." So why does it continue as routine procedure? Again, one suspects a lag between habit and the adoption of the newer logical thinking. When queried, many oncologists say, "I just feel more comfortable knowing about the nodes." But unless there is good justification for axillary node dissection, it should be questioned because it does harm.