Spectrum and management of breast cancer patients with variant of uncertain significance mutations at a tertiary care centre in North India.

BACKGROUND

The spectrum and significance of Variants of Uncertain Significance (VUS) mutations in breast cancer predisposition genes is poorly defined in the Indian population.

METHODS

All new female breast cancer patients from 1 March 2019 to 28 February 2020 were screened. Those providing informed consent and without previous genetic testing were recruited. Multigene panel testing (107 genes) by next-generation sequencing was performed for all patients. Descriptive statistics was used to describe the spectrum of VUS mutations.

RESULTS

Out of 236 patients recruited in the study, a VUS was detected in 89 patients (37.71%). VUS pathogenic ratio was 2.02. A total of 121 different VUS mutations in 40 different genes were detected. Fourteen patients (15.7%) had a VUS in high penetrance genes and 36 VUS mutations (29.8%) were detected in one of the genes involved in homologous recombination repair pathway. No therapeutic interventions were done based on VUS.

CONCLUSIONS

In this large prospective study of genetic determinants of breast cancer from India, a high prevalence of VUS (37.71%) was detected with 15.7% patients having a VUS in high penetrance genes. More evidence needs to be generated from larger multicentric studies to better understand the implications of these genetic variants and enable their reclassification.