Background: Radiation therapy is an important part of the complex treatment of breast cancer (BC). At present, due to the wide spread of organ-conserving operations, at I-II stages of breast cancer, there is a tendency to an increase in the value of ionizing radiation.

One of the important indicators of the successful breast cancer treatment is the improvement of the long-term treatment results.

The standard scheme of radiation therapy (RT) is the use of a single dose by 2 Gy to a total dose by 50 Gy to the breast region. But it should be remembered that RT can give different side effects.

It is necessary to develop acceptable treatment regimens to achieve better local control with a minimal risk of toxic effects in normal tissues to improve the effectiveness of complex treatment

The aim of our study is comparison of the long-term treatment results at patients with breast cancer after surgical treatment who received the hypofractionated radiotherapy (HFRT) using the 2.7 Gy regimen per fraction up to a total dose of 43.2 Gy with the total group of patients receiving the traditional regimen of RT.

Methods: Study design is non-randomized clinical trial. From 2014 to 2017 years, 160 women with breast cancers were treated by the hypofractionated radiation therapy after surgical operations. The rates of local / locoregional recurrence from the start of breast cancer treatment to the progression of the process, as well as the presence of distant metastases were evaluated. The timing of the distant metastases development ranged from 2 to 30 months from the start of treatment.Mann-Whitney U test was used for comparing long-term treatment results between patients treated with hypofractionation and traditional radiotherapy. A p value of ˂0.05 was taken as significant. The whole analysis was performed with SPSS ver.20 software.

Results: It was designated that for a 30-month follow-up period, the indices of local and ipsilateral recurrences of BC were the same in both groups at the recurrence frequency assessment. And the parameters of the 30-month non-metastatic survival in the study groups were almost identical and amounted to 98.4 ± 2.4% and 95.8 ± 2.22%, respectively, without statistical differences (p = 0.81).

Conclusions: Assessment of long-term results made it possible to conclude that life expectancy at prolongation of breast cancer depends on the presence of many factors. Because of that there are all new methods to diagnose and treat breast cancer. One of these method is the improvement of RT regimens by hypofractionation of the total dose.

Key words: radiation therapy, breast cancer, hypofractionation, long-term results, recurrence.

Yеvgeniya O. Kossymbayeva, http://orcid.org/0000-0003-2893-0384

Tasbolat A. Adylkhanov, http://orcid.org/0000-0002-9092-5060

Ainur S. Baissalbayeva, http://orcid.org/0000-0002-7092-7448

Almagul S. Zhabagina, http://orcid.org/0000-0001-8956-6286

Daniyar T. Raissov, http://orcid.org/0000-0002-3872-1263


Oncology and radiology department,

Semey State Medical University, Semey, Kazakhstan.

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Kossymbayeva Yе.O., Adylkhanov T.A., Baissalbayeva A.S., Zhabagina A.S., Raissov D.T. Long-term treatment results for breast cancer patients depending on adjuvant regimes of radiation therapy. Nauka i Zdravookhranenie [Science & Healthcare]. 2017, 6, pp. 67-77.