Clinicians who treat patients with cancer tend to hold firm to the belief that removing, if possible, any tissue known to contain any cancer cells is important for maximizing a patient’s chance of survival. For patients with breast cancer, some advocate using ultrasensitive immunohistochemical techniques to determine whether cancer cells have spread to nearby “sentinel” lymph nodes in the axilla (armpit area). Women who are found by such testing to have these “micrometastases,” which are undetectable by conventional microscopic examination, are advised to undergo complete axillary lymph node dissection—removal of most of the lymph nodes under the arm—a procedure that may cause such complications as severe swelling of the arm.
In today’s JAMA, a new study reports that women with early-stage breast cancer who had evidence of these micrometastases in their axillary lymph nodes were as likely as those who did not to be alive more than 6 years later. These findings follow results published from another breast cancer treatment trial published earlier this year in JAMA showing that among women who had evidence of breast cancer spread to their axillary lymph nodes, those who had all of their axillary lymph nodes excised did not fare better than those who did not have the surgery.
news@JAMA spoke with Armando E. Giuliano, MD, of the John Wayne Cancer Institute at Saint John’s Health Center in Santa Monica, California, and lead author of the new JAMA study, about the study’s implications for patient care.
news@JAMA: Are these studies game changers? Do they suggest that most women with breast cancer found to have these micrometastases should not undergo surgical removal of axillary lymph nodes?
Dr Giuliano: These studies should change the way breast cancer is treated. The randomized trial of women with sentinel nodes involved with metastases showed no benefit from more radical axillary surgery after sentinel node biopsy for selected patients. The second study, looking at the prognostic significance of micrometastases, showed no adverse impact on survival of patients with small metastases in their sentinel nodes. This study, along with other recent studies, argues against the routine examination of sentinel nodes with immunohistochemistry and argues against basing more extensive treatment on these micrometastatic findings.
news@JAMA: Patients in both of the studies had breast cancer that had been classified as stage I or stage II breast cancer. What proportion of women in the United States with breast cancer have stage I or II disease?
Dr Giuliano: These represent the majority of patients who undergo surgery for breast cancer in the United States. Stage I breast cancers are small cancers with tumor-free nodes, whereas stage II cancers are larger or have involved nodes.
news@JAMA: Aside from surgical removal of the breast cancer itself—lumpectomy—what other treatments did these women get that may have an effect on survival and spread to the axillary lymph nodes?
Dr Giuliano: Aside from lumpectomy and sentinel node biopsy, it is important to remember that patients in these studies were treated with adjuvant systemic therapy—chemotherapy, hormonal therapy, or both. In addition, they had whole breast irradiation. These adjuvant treatments probably impacted not only survival but axillary recurrence rates.
news@JAMA: Is there a role for axillary lymph node dissection in any women with breast cancer? If so, for whom?
Dr Giuliano: Women who have clinically palpable metastases in lymph nodes should undergo axillary lymph node dissection. In addition, women treated with mastectomy, [preoperative] chemotherapy, accelerated partial breast irradiation, or radiation in the prone position still should have axillary lymph node dissection when lymph nodes are involved with tumor. The presence of micrometastases, however, should usually not warrant more aggressive therapy after lumpectomy.
news@JAMA: Should sentinel node sampling still be done for women with stage I/II breast cancer, given that your findings suggest that information gained from sentinel node sampling does not guide further treatment?
Dr Giuliano: Sentinel lymph node biopsy should still be performed for patients with early breast cancer as findings may change the use or type of adjuvant systemic therapy or reveal the need for axillary dissection. Sentinel node biopsy remains part of the standard management for early breast cancer.