Discussion

This molecular tumor board case describes a patient with metastatic breast cancer who survived for 10 years after diagnosis
Her disease course was notable for disease biology that evolved over time

It is not uncommon for these markers to change over time in patients receiving ongoing treatment; it is therefore valuable to obtain repeat biopsies of metastatic foci periodically
Evolving results may influence systemic treatment recommendations
Her initial treatment included a combination of cytotoxic and endocrine therapies
After HER-2 amplification was demonstrated, HER-2-targeted agents were utilized
When repeat biopsy showed non-amplification of HER-2, she resumed cytotoxic therapy alone
Ultimately, genomic profiling revealed the following alterations:

PIK3CA

PTEN

TP53

TLE3

AR/ER/HER2

CHEK

In November 2017, ASCO TAPUR expanded to offer pembrolizumab to patients with metastatic breast cancer and a high tumor mutation burden
This offered a non-cytotoxic option to this heavily pretreated patient with chemo- and endocrine-resistant disease
She ultimately received 2 cycles of treatment, achieving stable disease per RECIST criteria
She continued to experience significant fatigue and general debilitation
Four months after enrolling in the clinical trial, she elected to pursue comfort-based care alone
The patient enrolled in hospice care and passed away shortly thereafter, nearly 10 years after her initial diagnosis

References:

Metastatic breast cancer