Poster Display session

55P - Evolution of Genetic Testing after Ovarian Cancer (OC) diagnosis

Session Name
Poster Display session (ID 10)
Speakers
  • Ana Teresa Lopes Bruno (Lisbon, Portugal)
Date
Thu, 23.02.2023
Time
13:00 - 13:45
Room
Exhibition and Poster area

Abstract

Background

Circa 25% of all OC are heritable, mainly associated with BRCA1/2 genes. Due to BRCA1/2impact on carcinogenesis, prevention and treatment, all cases of OC (excluding mucinous) are candidates for genetic testing, even without family history. We analyzed genetic testing after OC diagnosis since 2014.

Methods

Identification of OC patients tested under the Breast/Ovarian/Prostate program (2014-2022) and analysis of referrals after primary diagnosis and access to testing. The subgroup of OC patients observed between November 2021 and October 2022, which included candidates for olaparib maintenance after primary treatment, is described.

Results

488 OC patients consented on germinal testing. Most of cases were HGSOC (n=347, 71%). Detection rate was 18.0%. Variant distribution: BRCA1-27; BRCA2- 34 BRCA2 (8 c.156_157insAlu, a founder variant); RAD51C-10; RAD51D-10; CHEK2-3; ATM-2, MUTYHand BARD1 (one each). After November 2021, from 61 OC women, 45 stage were III/IV and 34 had high grade disease (HGD), 27 of them under primary treatment. Five of 27 (18,5%) tested positive for BRCA1(2), BRCA2(2), ATM (1) and 1 patient had a somatic BRCA1variant. All these are under olaparib primary maintenance.

After OC diagnosis, median delay of testing referral was 3.6 years (5days-30years) between 2014-2022, 5yrs (5days-23years) between 2014-2016, 4years (22days-9.6years) between 2017-2019, and 2.7yrs (16days-30years) between 2020-2022. This delay decreased in 2022, significantly for HGOC patientss under primary treatment (177 d) (p<0.05). For this subgroup most women were tested at diagnosis, after surgery or during primary CT, but 6 (22%) patients were only identified after primary treatment was completed.

Medium delay for test reporting (2014-2022) was 176 days (12-524days). While a trend for reduction was observed after 2017, this was not significant (p=0.6). For the past year, median delay was 92 days and for the high grade subgroup under primary treatment 71 (22-141) days.

Conclusions

Referral delays after OC diagnosis reflect broadening of testing criteria after 2014. Patients should be tested early after diagnosis, to avoid cases without information regarding the possibility of maintenance after primary treatment. Other findings reinforce the role of BRCA2 in OC in Portugal.

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