Women who have a type of early breast cancer that is confined to the milk ducts have an equally good chance of successful recovery if the cancer recurs, regardless of how they were treated initially, according to a study presented at the 4th European Breast Cancer Conference in Hamburg, Germany.
Professor Dennis Holmes told the meeting in Hamburg that results from his study offered reassuring evidence to women with ductal carcinoma in situ (DCIS) that if they chose to have only the affected area of their breast removed (lumpectomy) rather than the whole breast removed (mastectomy), it would make no difference to their chances of surviving the disease. Even although there was a higher risk of the cancer recurring locally after conservation treatment than after a mastectomy, the women could still be treated successfully and the overall survival rates remained the same.
However, he said that this outcome was dependent on doctors keeping a close eye on the women after their treatment, with regular screenings, so that any recurrence of the breast cancer could be detected early while it was still small.
Holmes, an assistant professor of clinical surgery at the University of Southern California Keck School of Medicine, said that he and his colleagues had studied data from 1,136 patients who had been treated for DCIS and then followed up for ten years. Professor Melvin J. Silverstein led the team and data from both the Van Nuys Breast Center and USC were included.
Of the 1,136 patients, 286 had a lumpectomy and radiotherapy, 444 had a lumpectomy only, and 406 had a mastectomy.
After ten years, cancer had recurred in the same breast (local recurrence) in 18 percent (lumpectomy and radiotherapy), 30 percent (lumpectomy only) and 1.8 percent (mastectomy) of the women. The rate of distant metastases (recurrences in distant parts of the body) was 2, 1.2 and 1 percent respectively, while deaths from breast cancer were 2, 0.7 and 0 percent respectively.
Holmes said: "These results show that nearly all patients with DCIS whose cancer recurs can be treated successfully, whether or not DCIS recurs as new DCIS or invasive cancer. In the small sub-group of patients who develop invasive recurrences, the chances of surviving ten years are better than 90 percent - similar to patients diagnosed with small, node negative cancer.
"The ten-year rate of deaths from all causes and from breast cancer specifically is statistically similar across all three groups. Therefore, regardless of their initial treatment, the three groups of patients had similar rates of survival."
These successes had been gained through careful monitoring of patients after their initial treatment, he emphasized.
"At our institution, patients who have been treated for DCIS are screened closely for recurrences, regardless of the treatment they received. For patients treated by lumpectomy alone or lumpectomy plus radiotherapy, follow-up includes mammography of the treated breast twice a year for the first few years, followed by annual mammography. Any abnormality is evaluated with additional imaging and all suspicious finding are biopsied. More recently, we have used breast MRI to evaluate patients for recurrence. As a result of rigorous follow-up, invasive recurrences are more likely to be diagnosed when they are quite small and confined to the breast. When treated at this stage, survival rates are very good," explained Holmes.
The incidence of DCIS is increasing, mainly because of mammography screening programs, which are able to detect it before it has progressed to a more advanced stage when a woman might be able to feel a lump. Although DCIS is a very early form of breast cancer with an excellent prognosis, doctors and patients have often chosen the more aggressive option of mastectomy, because it carries the least chance of a recurrence. Holmes's findings are significant, since they show that the less aggressive option of a lumpectomy can be chosen in the knowledge that it does not affect a woman's overall chances of survival.
"As shown by other clinical trials comparing mastectomy to breast conservation therapy, mastectomy is associated with the lowest risk of local recurrence but provides no survival advantage when compared to breast conservation therapy. Our experience with DCIS supports this conclusion. We agree that mastectomy is the most complete treatment for DCIS in terms of minimizing the risk of local recurrence, but mastectomy is an undesirable option for many women who are willing to accept a higher risk of local recurrence as long as it does not place them at a higher risk of death," said Holmes.
SOURCE:
4th European Breast Cancer Conference, March 19, 2004, Hamburg, Germany
