A new study published in the journal Cancer has confirmed not only the importance of a "clear margin" when a breast tumor is removed-i.e., the neighboring tissue is free from any residual cancer cells-but also its importance in predicting whether breast cancer will return.

During breast cancer surgery, the surgeon will remove not only the tumor itself but also a portion of the surrounding tissue. This tissue is then sent to a pathologist for immediate determination of the visual presence of cancer cells under a microscope. If cancer cells are seen, additional tissue is removed (reexcised) until the tissue margins are determined to be clear (cancer-free).

According to this new study, which builds upon the conclusions of earlier studies, the presence of cancer cells in the tissue immediately surrounding a tumor can be a major predictor of the likelihood of cancer recurrence. Dr. Andrew Neuschatz, a radiologist at the New England Medical Center in Boston, and colleagues studied tissue specimens from 253 women with ductal carcinoma in situ (DCIS) who underwent lumpectomy and subsequent reexcision. Their objective was to determine the probability that residual DCIS would be in the reexcised tissue based on the size of the original tumor, margin status, nuclear grade of the tumor, the presence of necrosis, the patient's age, and the extent of specimen processing (the number of sections/tissue volume).

They found that the width of the margin and the size of the original lesion were the most "significant predictors" of both the presence and amount of residual tumor-and thus the likelihood of disease recurrence.

While not new, their conclusions confirm several earlier studies that determined that the larger the margin of normal tissue around a breast cancer, and the smaller the cancer itself, the smaller the chance that there would be residual cells left behind-and therefore a smaller chance that the cancer would come back.

"The margin status of a DCIS lumpectomy specimen is the most important predictive factor for both the presence and amount of residual disease," they concluded. They suggested that this type of information could help women and their doctors decide on the type-or even need-for additional follow-up therapy.

SOURCE:
Cancer, April 1, 2002; 94:1917-1924