O.V. Morov1,2, R.Sh. Khasanov2, T.M. Safiullin1,3
1Republican Clinical Oncology Dispensary of Ministry of Healthcare of Tatarstan Republic named after prof. M.Z. Sigal, Kazan
2Kazan State Medical Academy ― Branch Campus of the FSBEI FPE RMACPE MOH Russia, Kazan
3Kazan State Medical University, Kazan
Morov Oleg V. ― Cand. of Sci. (Med.), radiation oncologist, head of day hospital department №2 of the Republican Clinical Oncology Dispensary of Ministry of Healthcare of Tatarstan Republic named after prof. M.Z. Sigal
29 Sibirskiy trakt, Kazan, 420029, Russian Federation, tel.: (843) 233-86-31, +7-987-269-33-96, e-mail: morvaks@mail.ru, ORCID ID: 0009-0008-9241-6703
Abstract
The purpose of the study was to study the long-term results of the treatment of localized prostate cancer by the method of low dose rate brachytherapy. The age of patients was to 63 years [58-68], the median of the level PSA was to 7.9 ng/ml [5,8-10,2]. Groups of low, intermediate and high risk included 238 (47,8%), 230 (46,2%) and 30 (6%) patients, respectively. 147 patients (29,5%) were treated in combination with external beam radiation therapy. 60% of patients received androgenic deprivation therapy.
Material and methods. In the period from 2008 to 2022, 498 men with localized prostate cancer received low dose rate brachytherapy with permanent implantation of sources I-125. The survival assessment was calculated according to the Kaplan-Meyer method. Analysis of patient survival was calculated according to the Cox-regression method. The indicator of biochemical relapse was determined by the classification of Phoenix (Nadir + 2).
Results. Median surveillance was 6.4 years [3,7-9,3]. During the observation period, 74 people died (14.3%), including 6 people from prostate cancer (1,2%). Biochemical, local and regional relapses were diagnosed in 32 (6,4%), 4 (0,8%) and 7 (1,4%) patients, respectively. Distant metastases were implemented in 10 patients (2%). The indicators of 14-year survival without biochemical relapse, the disease-specific and total survival were 89,2%, 97,2% and 66,1%, respectively. The risk of biochemical relapse in patients with intermediate risk was 2,654 times higher (HR=2,654; 95%CI: 1,171–6,013; p=0,019) compared to patients of low risk. Risk factors of death were distant metastases (HR=10,548; 95%CI: 3.377–32.945; p=0,001), second primary tumors (HR=5,381; 95%CI: 1,148–25,223; p=0,033) and an age (HR=1,093; 95%CI: 1,053-1,135; p<0,001). The second primary tumors developed in 51 patients (10,2%). In the structure of the causes of death, second primary tumors were to 20,3%. Late genitourinal and gastrointestinal toxicity of the grade 2 and higher (RTOG) was established in 1,4% and 4% of patients, respectively.
Conclusion. The low dose brachytherapy is an effective method of treating localized prostate cancer, which provides good oncological results and acceptable quality of life. Dispensary monitoring of patients should include an assessment of the risks of the development of second primary malignant tumors.
Key words: prostate cancer, brachytherapy, external beam radiation therapy, long-term results, survival, multiple primary tumors, second primary malignant tumors.