The impact of variant classification on the clinical management of hereditary cancer syndromes

PURPOSE

The reclassification of genetic variants poses a significant challenge for laboratories and clinicians. Variant review has resulted in the reclassification of variants of unknown significance as well as the reclassification of previously established pathogenic and likely pathogenic variants. These reclassifications have the potential to alter the clinical management of patients with hereditary cancer syndromes.

METHODS

Results were reviewed for 1694 patients seen for hereditary cancer evaluation between August 2012 and May 2017 to determine the frequency and types of variant reclassification. Patients with reclassifications with high potential for impact were monitored for alterations in organ surveillance, prophylactic surgery, and cascade testing.

RESULTS

One hundred forty-two variants were reclassified representing 124/1694 (7.3%) patients; 11.3% of reclassifications (16/142) had a high potential for clinical impact with 94% (15/16) altering clinical management of patients with 56% (9/16) changing multiple areas of management.

CONCLUSION

While reclassifications are rare, the impact on clinical management is profound. In many cases, patients with downgraded pathogenic/likely pathogenic variants had years of unnecessary organ surveillance and underwent unneeded surgical intervention. In addition, cascade testing misidentified those at risk for developing cancers, thereby altering the management across generations. The frequency and types of alterations to clinical management highlight the need for timely variant reclassification.

Improving attendance to genetic counselling services for gynaecological oncology patients

Background

Gynaecological cancers may be the sentinel malignancy in women who carry a mutation in BRCA1 or 2, a mis-match repair gene causing Lynch Syndrome or other genes. Despite published guidelines for referral to a genetics service, a substantial number of women do not attend for the recommended genetic assessment. The study aims to determine the outcomes of systematic follow-up of patients diagnosed with ovarian or endometrial cancer from Gynaecologic-oncology multidisciplinary meetings who were deemed appropriate for genetics assessment.

Methods

Women newly diagnosed with gynaecological cancer at the Royal Hospital for Women between 2010 and 2014 (cohort1) and 2015-2016 (cohort 2) who were identified as suitable for genetics assessment were checked against the New South Wales/Australian Capital Territory genetic database. The doctors of non-attenders were contacted regarding suitability for re-referral, and patients who were still suitable for genetics assessment were contacted by mail. Attendance was again checked against the genetics database.

Results

Among 462 patients in cohort 1, flagged for genetic assessment, 167 had not consulted a genetic service at initial audit conducted in 2014. 86 (18.6%) women whose referral was pending clarification of family history and/or immunohistochemistry did not require further genetic assessment. Letters were sent to 40 women. 7 women (1.5%) attended hereditary cancer clinic in the following 6 months.The audit conducted in 2016 identified 148 patients (cohort 2) appropriate for genetic assessment at diagnosis. 66 (44.6%) had been seen by a genetics service, 51 (34.5%) whose referral was pending additional information did not require further genetic assessment. Letters were sent to 15 women, of whom 9 (6.1%) attended genetics within 6 months.

Conclusions

To improve the effectiveness of guidelines for the genetic referral of women newly diagnosed with ovarian cancer, clinicians need to obtain a thorough family history at diagnosis; arrange for reflex MMR IHC according to guidelines; offer BRCA or panel testing to all women with non-mucinous ovarian cancer prior to discharge and systematically follow up all women referred to genetics at the post-op visit.