We know it’s important to remove breast cancers before they can spread. But is it helpful to remove the initial dominant tumor (also called the primary tumor) in cases where the cancer has already spread? Does leaving primary cancer in place pose a significant danger, or is removing it a case of “closing the barn door after the horse has already escaped?”
Until recently, no good data existed to answer the question one way or the other. A review of the collected histories of patients with breast cancer seemed to indicate benefit. It was thought that perhaps the primary tumor secreted chemicals or hormones that helped the distant metastatic tumors grow. Or perhaps the primary tumor, usually the largest single clump of cancer cells, might be the biggest source of metastases (and removing might slow down the appearance of new metastases).
But last month at the San Antonio Breast Conference, two separate randomized controlled trials (one 350-patient trial from India, the second a 325-patient trial from Turkey) showed no benefit from removing the primary tumor in patients who presented to the doctor with widespread disease. The same issue is the subject of an ongoing study in the United States through the Eastern Cooperative Oncology Group(ECOG) (it’s just under halfway completed, having accrued 152 of its targeted 368 patients). Most experts at the San Antonio Conference agreed that the studies from India and Turkey are very relevant to patients in the United States.
I’ll be curious to see if this news affects the ECOG trial in progress, given the declining enthusiasm for the idea.