INFLUENCE OF MOLECULAR GENETIC CHARACTERISTICS ON THE PROGNOSIS OF NEWLY DIAGNOSED HIGH-GRADE III-IV STAGE SEROUS OVARIAN CANCER DEPENDING ON TREATMENT OPTIONS

V.N. Zhurman1,2

1Primorsky Regional Oncological Dispensary, Vladivostok

2Pacific State Medical University, Vladivostok

Zhurman Varvara N. — Cand. of Sci. (Med.), oncologist of the Primorsky Regional Oncological Dispensary

59 Russkaya Str., Vladivostok, 690105, Russian Federation, tel. +7-904-622-25-77, e-mail: varvara2007@yandex.ru, ORCID ID: 0000-0002-6927-3336

Abstract. Up to 13 000 cases of ovarian cancer are detected annually in Russia (10,17 per 100 000), ranking ninth in the structure of total oncological morbidity (4,4%) and third among gynecological tumors, after cancer of the endometrial cancer and cervical cancer. At the same time, high-grade serous ovarian cancer accounts for 70% of all of ovarian cancer cases.

The study was conducted in 398 patients with high-grade III-IV stage serous ovarian cancer treated at the Primorsky Regional Oncological Dispensary in the period from 2016 to 2022, aged 33-77 years, the median age was 53,5 years. Mutations in BRCA1/2 genes and homologous recombination deficiency were evaluated in histological samples of tumor tissue on paraffin blocks obtained intraoperatively and in biological material (blood) by next generation sequencing (NGS). A mutation in the BRCA1 gene was detected in 154/398 patients, in the BRCA2 gene — 16/398 patients, a deficiency of homologous recombination was detected in 6/23, a combination of BRCA1/2 mutation and a deficiency of homologous recombination was found in 4/23, no mutation in the BRCA1/2 genes was detected in 228/398 patients. The median age in the group of patients with a mutation in the BRCA1 gene was 52,3 years, with BRCA2 it was 61,5 years, in the absence of a mutation in the BRCA1/2 gene it was 53,2 years. When analyzing the treatment in patients with stage III-IV who received the first stage of neoadjuvant chemotherapy followed by interval cytoreductive surgery (ICR), the median overall survival and median progression-free survival were BRCA1/2+ 62,0 (±6,0) months and 16,0 (±2,84) months, BRCAneg 35,0 (±3,2) months and 15,0 (±1,5) months accordingly (fig. 3), which differs from the group of ovarian cancer patients who received primary cytoreductive surgery (PCR) at the first stage — the median of overall survival and median of progression-free survival was BRCA1/2+ 107,0 (±26,3) months and 26,0 (±2,1) months, BRCAneg 50,0 (±7,2) months and 19,0 (±1,4) months, respectively (fig. 4), the differences are statistically significant for BRCA1/2+ at p=0,01 and not significant for BRCAneg p>0,05.

Key words: BRCA 1/2, ovarian cancer, overall survival, progression-free survival, primary cytoreduction, interval cytoreduction.