Checking the margins is typically done during the lumpectomy, but analyzing the margins can take about a week, according to Breastcancer. Margins also are checked after surgical biopsy and mastectomy. A new standard published recently in the Journal of Clinical Oncology suggests that a 2-millimeter clean margin offers enough protections against the recurrence of ductal carcinoma in situ DCIS for women treated with lumpectomy and whole-breast radiation.
DCIS is the earliest form of cancer or stage 0 cancer. The guidelines were issued because of disagreement about how big clean margins should be.
About 1 in 3 women treated for DCIS has to have more surgery because doctors decide the margins should be bigger, Breastcancer.
Some doctors want 2 mm or more of normal tissue removed and others consider a 1-mm rim of health tissue or less to be enough of a clean margin.
Clean lumpectomy margins mean that no cancer cells can be seen in the outer edge of the removed tissue. The fact that metastasis did not occur in their model even months later, indicates the immune system destroyed the disseminated tumor cells rather than pushing them into a dormant state, Korkaya and his colleagues report in the journal Nature Communications. In contrast, when the primary tumor was not completely removed, the immune system appears to begin to support the tumor, which grows back faster and bigger than the original mass, and its disseminated tumor cells survive.
The scientists say what they found in their breast cancer model is likely true for other solid tumor types that can be surgically removed with no sign of cancer in adjacent tissue.
There actually has been a lot of contradictory information on the topic of what enables deadly metastasis. Retrospective studies in patients with breast cancer indicate that completely removing the primary tumor improves survival however mouse models indicate that removing primary tumors actually accelerates growth of the tumor cells that migrate out from the main tumor.
Inflammation, a normal response to surgery, also has been shown to both promote outgrowth of tumors and improve survival. To better understand what's happening at the molecular level, the scientists used models of both extremely aggressive breast cancer, like the triple negative breast cancer that occurs in women, and a less invasive breast cancer that would enable them to really hone in on the fate of disseminated breast cancer cells.
Within a week, mice with both types had disseminated tumor cells present in the lymph nodes that drain the breasts and in the lungs, both common sites for breast cancer spread. However the more aggressive cancer, quickly established a growing presence at the remote locations. As they expected, metastasis and death both occurred quickly in the more aggressive breast cancers.
But following successful surgery for the less aggressive cancer, they found again and again that the disseminated cancer cells did not just go dormant, but were cleared, apparently by the refocused immune response.
It was clear the immune response was key, because when they removed the front line attackers called cytotoxic T cells, the cancer more readily spread. The mice were even were able to fight off three subsequent tail injections of , cancer cells. They labeled the tumor cells they injected then watched them travel, like cells from the primary tumor, right to the lungs then continued to watch as the immune system eradicated them in a few days.
The positive results occurred weeks after the primary breast tumor was removed, suggesting the investigators write, that the immune system remembered the attacker.
In fact, six months later, the immune memory was still intact. Conversely, when a portion of the primary tumor was left behind, the immune system seemed to support the tumor, which grew bigger and faster than the original mass, disseminated cancer cells were better able to take up residence in other areas of the body and the mice soon died.
Our objective is to create the most effective individualized treatment plan for each patient to optimize outcomes, reduce the burden of treatment, and improve quality of life. No Ink on Tumor About five years ago, the Society of Surgical Oncology and the American Society for Radiation Oncology convened a multidisciplinary panel to develop a consensus guideline on the appropriate margin width for minimizing LR risk in patients with invasive cancer who are undergoing BCT and whole-breast radiation therapy.
Pilewskie M, Morrow M. Margins in breast cancer: how much is enough? Society of Surgical Oncology—American Society for Radiation Oncology consensus guideline on margins for breast-conserving surgery with whole-breast irradiation in stages I and II invasive breast cancer. J Clin Oncol. Society of Surgical Oncology—American Society for Radiation Oncology—American Society of Clinical Oncology consensus guideline on margins for breast-conserving surgery with whole-breast irradiation in ductal carcinoma in situ.
Pilewskie M, King TA. Age and molecular subtypes: impact on surgical decisions. J Surg Oncol. Ann Surg Oncol. Effect of margin width on local recurrence in triple negative breast cancer patients treated with breast-conserving therapy. Trends in reoperation after initial lumpectomy for breast cancer: addressing overtreatment in surgical management.
JAMA Oncol. Breast Cancer mortality after a diagnosis of ductal carcinoma in situ. Overview of the randomized trials of radiotherapy in ductal carcinoma in situ of the breast. J Natl Cancer Inst Monogr. Axillary dissection vs no axillary dissection in women with invasive breast cancer and sentinel node metastasis: a randomized clinical trial.
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