Thorough cancer surgery may make radiation unnecessaryBMJ 1999; 318 doi: https://doi.org/10.1136/bmj.318.7195.1369 (Published 22 May 1999) Cite this as: BMJ 1999;318:1369
Women who undergo localised breast surgery for the removal of a common form of non-invasive breast carcinoma may have their need for follow up radiotherapy eliminated if surgeons remove an extra centimetre of tissue around the cancer, according to a new study (New England Journal of Medicine 1999;340:1455-61). Ductal carcinoma in situ, an abnormal growth of cells inside milk ducts that is non-invasive and unlikely to recur if completely excised, was studied.
Dr Melvin J Silverstein (at the University of Southern California School of Medicine) and colleagues followed 469 women with the cancer who were treated at two California facilities between 1972 and 1998. Just under half of them had no follow up radiotherapy.
Among women whose lumps were removed along with a 1 cm margin of tissue, about 97%had no recurrence of cancer. When used, radiotherapy did not reduce recurrence rates. The study found that radiotherapy benefited only women who had had 1 mm or less of extra tissue removed around the cancer.
Up to 80%of patients with ductal carcinoma in situ are eligible for lumpectomy rather than complete breast removal. Medical opinion has been divided on whether radiotherapy is necessary for all patients with this type of cancer who have chosen to have a lumpectomy.
The new findings suggest that there is a trade off: having more tissue removed might alter or disfigure the breast but may also eliminate or delay the need for follow up radiotherapy.
Dr Carolyn Kaelin, director of the Comprehensive Breast Health Center at Boston's Brigham and Women's Hospital, said that the pathologists taking part in the study had used a meticulous procedure to measure how much tissue was removed from around the cancer. But in cases in which this approach is not adopted hospitals may not feel confident advising women not to have radiotherapy.
In an accompanying editorial (New England Journal of Medicine 1999;340:1499-1500), Drs David L Page and Jean F Simpson of the Vanderbilt University School of Medicine in Nashville, Tennessee, said: “What the report does not establish is that the excised lesion should have a 1 cm margin in all cases of ductal carcinoma in situ that are amenable to cure by local excision.
“This conclusion would be as overly simplistic and restrictive as the paradigm it is replacing.”