The subgroup of patients with breast cancer have a low risk of an extremely low probability of cancer recurrence after organasohranyayuschey breast surgery. Radiation therapy further reduces the risk of the disease returning. This data is a 12-year prospective randomized study in which cases of recurrence after treatment of non-invasive ductal carcinoma in situ low risk were studied (DCIS,) were presented at the 60th Annual Meeting of the American Society for Radiation Oncology.
Patients with DCIS «good risks" as defined by the research team only by a mammogram or by chance during a breast biopsy, have a very low risk of recurrence 12 years after breast-conserving surgery. Those patients who underwent radiotherapy full chest and took tamoxifen had the lowest relapse rates. But even those participants who did not receive any treatment after surgery, have not experienced any life-threatening consequences.
"The number of relapses in patients treated with radiotherapy, was extremely low. Radiation therapy reduced the likelihood of a return of the disease by more than 70%," the researchers noted.
None of the tumors that recurred, posed no danger to patients life.
DCIS - a cancer of cells lining the milk ducts of the breast. He is about 25% of all new cases of breast cancer (60,000 cases) diagnosed in the US each year. For the treatment of diseases lumpectomy is performed in combination with radiotherapy.
The study involved 629 patients, mean age 58 years, of which 76% of women were postmenopausal. The average size of the pathological tumor was 0.60 cm, the median observation time - 12.4 years. Patients were randomized into two groups: the first group took additional radiotherapy (of which 58% had taken tamoxifen), and the second was not exposed to additional irradiation (of which 65% had taken tamoxifen).
After 12 years, the cumulative incidence of local recurrence of 2.8% for patients of the first group and 11.4% for patients from the second group. The cumulative incidence of invasive local recurrence was 1.5% for those undergoing radiation therapy and 5.8% for those who failed radiotherapy.
Multivariate analysis showed that only those who have received treatment with ionizing radiation and tamoxifen, experienced a decrease local recurrence. Neither age nor pathological size of the tumor were not significant for predicting local recurrence or invasive local recurrence. There were no significant differences between the two groups in survival, disease-free survival and holding mastectomy.