Abstract P4-10-13: Screening and risk reducing surgeries for patients at high risk for breast and ovarian cancer at an integrated care setting

Background: Current US guidelines recommend more intensive screening and preventive strategies for patients with a known pathogenic germline mutation or a high lifetime risk based on breast cancer risk prediction models. The American Cancer Society, for example, recommends that yearly mammogram alternating with MRI screening should be considered as early as 30 years old in women with a lifetime breast cancer risk of > 20%. Furthermore, NCCN recommends that BRCA1/2 mutation carriers consider additional risk-reducing strategies, including bilateral mastectomy, bilateral oophorectomy at age 35, or post-child bearing, and hormonal chemoprevention. It is unclear what the uptake of screening and risk reducing strategies are after an HRBROC assessment and recommendations by Genetics at an integrated care setting.

Methods: We retrospectively studied female patients diagnosed as high risk for breast and ovarian cancer (HRBOC) (regardless of prior cancer) and/or tested for BRCA mutations by a genetic counselor or physician geneticist at Kaiser Permanente Mid-Atlantic States (KPMAS) Genetics clinics between 2005-2016. We identified cancer diagnoses, mammogram and MRI screening, mastectomies and oophorectomies with ICD diagnosis or CPT procedure codes during the study period. We defined prophylactic mastectomy or prophylactic oophorectomy as occurring either 180 days prior to, or without a diagnosis of breast or ovarian cancer respectively. We assessed screening with a mammogram or MRI, post Genetics visit for patients 30-75yrs old at time of HRBOC dx, and had no breast cancer prior to, or within 180 days, of the Genetics visit.

Results: Our cohort included 813 women with a HRBOC diagnosis, with a median 51 yrs of age at diagnosis, 45% White, 38% Black and 15% other race. Since genetics services for cancer at KPMAS were established recently, 98% of visits occurred after 1-1-2013. Table 1 shows the distribution of cancer diagnoses and surgeries pre and post Genetics visit. 249 Breast cancer-free patients were screened post Genetic visit between mid-2013-2016: 159 (64%) had at least 1 screening test, 68 had two to three and only 3 women had four to six screening tests. The median time to the latest screen after HRBOC dx was 14.4 mo, (range 2 days to 39 mo). Post-Genetics screening frequency did not differ by race.

Conclusion: The majority of women visited Genetics after a diagnosis of breast or ovarian cancer. Patients received prophylactic oophorectomies more often than prophylactic mastectomies. Screening in cancer free patients with a HRBROC diagnosis appears to be limited to 1-3 screens post diagnostic visit. Our findings suggest that earlier detection of patients at high risk for breast and ovarian cancer and closer monitoring is needed.

Table 1.Cancer diagnoses and Surgeries Pre and Post Genetics Visit for HRBROC (2004-2016) (N=813) pre-Geneticspost-GeneticsTotalBreast Cancer diagnosed51314527Post cancer Mastectomy3198327Prophylactic Mastectomy314Ovarian Cancer diagnosed55257Post cancer oophorectomy40343Prophylactic oophorectomy632689

Citation Format: Ter-Minassian M, Visvanathan K, Jefferson CR, Schaeffer ML, Suwannarat P. Screening and risk reducing surgeries for patients at high risk for breast and ovarian cancer at an integrated care setting [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-10-13.

Molecular analysis of the iduronate-2-sulfatase gene in Thai patients with Hunter syndrome

Molecular defects in the gene encoding the enzyme iduronate-2-sulfatase (IDS) result in Hunter disease (mucopolysaccharidosis type II, MPS II). To determine the molecular basis of MPS II in Thailand, the IDS gene was analysed in 20 Thai patients with Hunter syndrome from 18 unrelated families. A total of 19 different mutations, including 9 missense mutations, 3 nonsense mutations, 3 splice site alterations, 1 deletion, 2 indels, and 1 rearrangement were identified, 8 of which were novel (p.R101C, p.D148V, p.G224A, p.K227E, p.E254X, p.W337X, c.440_442delinsTT and c.720_731delinsTTTCAGATGTTCTCCCCAG). Evaluation of the IDS activity of two hemizygous variants identified in the same patient, p.R101C and p.R468Q, by expression of IDS with the individual mutations in COS 7 cells indicated that only the p.R468Q mutation affected IDS protein activity. Two exonic mutations, c.257C>T (p.P86L) and c.418G>A, were found to activate multiple cryptic splice sites, resulting in aberrantly spliced transcripts. Thus, MPS II in Thailand is caused by a diverse set of defects affecting both IDS protein production and activity.

Molecular characterization of type 3 (neuronopathic) Gaucher disease in Thai patients

Gaucher disease is an autosomal recessive lysosomal storage disorder due to deficiency of the lysosomal enzyme glucocerebrosidase. Three clinical phenotypes, type 1, nonneuronopathic; and types 2 and 3, acute and subacute neuronopathic are recognized. The incidence of Gaucher disease in the Thai population is unknown, but likely under-diagnosed. We performed molecular analysis in four patients, from three sibships, with type 3 Gaucher disease. Four mutant glucocerebrosidase (GBA) alleles were identified including two novel splice site mutations, IVS6-1G>C and IVS9-3C>G; both are predicted to result in truncated protein products, p.F255fsX256, and p.K464fsX487 and p.S463fsX480, respectively. One patient, homozygous for the L444P point mutation, had a "Norbottnian-like" phenotype, with more severe visceral involvement, kyphosis, barreled chest, and no neurological involvement other than supranuclear gaze palsy. These molecular studies of neuronopathic Gaucher disease will provide additional genotype-phenotype correlation particularly in non-Caucasian population.

Mitochondrial DNA mutations in a patient with sex reversal and clinical features consistent with Fraser syndrome

We describe a 20-year-old 46,XY woman, with clinical findings of Fraser syndrome and three mitochondrial DNA (mtDNA) mutations of Leber hereditary optic neuropathy. The patient had microphthalmia, blindness, widely spaced nipples, bifid ureter, syndactyly of the toes, and mental retardation. Sonography showed the presence of a uterus and intra-abdominal gonads. The proband was screened for mtDNA mutations because of chronic gastrointestinal pseudo-obstruction, urinary tract dysmotility, seizures, mental retardation and persistent macrocytosis, as well as the intermittent elevation of methylmalonic acid. Analysis of point mutations by multiplex polymerase chain reaction and allele-specific oligonucleotide dot-blot hybridization revealed three homoplasmic mtDNA mutations, T14484C, T4216C, and T3394C. This represents a unique case with sex reversal, Fraser-like syndrome, and mitochondrial disease.