Lymph node micrometastasis is not prognostically significant
Breast cancer patients frequently ask about the significance of lymph node micrometastasis. Micrometastases are sometimes called "occult" metastasis because they were not seen during routine lymph node staging. Patients may be first diagnosed as node-negative, but upon more refined inspection of the tissue after biopsy are reclassified as having lymph node micrometastasis.
What does this mean? Well, according to recent research, not much.
A new Journal of the American Medical Association (JAMA) study found no association between occult lymph node metastasis and overall survival. In the study, 3,326 sentinel lymph nodes which were considered negative after stain testing underwent further immunohistochemical testing. 349 were found to contain occult metastasis. The authors concluded, "Among women receiving breast-conserving therapy and SLN dissection, immunohistochemical evidence of SLN metastasis was not associated with overall survival over a median of 6.3 years. . ."
If sentinel lymph node micrometastasis is not prognostically significant, is immunohistochemical testing necessary? The Los Angeles Times and US News and World Report suggest not. In an interview with JAMA News, study author Armando E. Giuliano, MD noted,
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.
Dr. Giuliano clarified that while immunohistochemical testing may be unecessary, sentinel lymph node biopsies are still important. He said,
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.
Importantly, Dr. Giuliano notes that all women in the study were treated with breast conserving surgery, whole breast irradiation and systemic therapy - chemotherapy, hormone therapy or both. Micrometastatic lymph nodes may not require extra testing or treatment, but the standard of care for stage I or II breast cancer still applies.
Links to the study abstract and news stories may be found on the sentinel lymph node biopsy page of the LATESTBreastCancer.com website.
No scientific evidence to support mastectomy for multicentric breast cancer
The use of preoperative MRI has been associated with higher mastectomy rates. Just this year alone, studies in The Breast Journal (March 16), the Journal of Surgical Oncology (May 25) and Annals of Surgical Oncology (July 13) associated MRI use with higher mastectomy rates. Sometimes MRI reveals cancer in the opposite breast. Sometimes it reveals multicentric breast cancer in one breast.
Is a mastectomy necessary to treat multicentric breast tumors? A July 15 review in the Journal of the National Cancer Institute suggests not. After an "extensive examination" of the vast amount of material on the subject, the author concluded that aside from a large trial which demonstrated no statistically significant difference in disease-free survival or overall survival between lumpectomy and mastectomy, "there has been no information in any of the few recently conducted studies involving multicentricity to justify the current resurgence in mastectomy."
Links to all of these studies may be found on the mastectomy page of the LATESTBreastCancer.com website.
Please check back tomorrow for more breast cancer news and research updates from LATESTBreastCancer.com. Until then, all the latest news and research for any breast cancer test or treatment option may be found on our website anytime.
Micrometasis is a grey area for many women including myself. What to do on treatment options is a difficult decision. That you for this additional information since we seem to get lumped into the bigger group.
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