Overview: Therapeutic Biomarkers in Cancer - Therapeutic Biomarkers in Cancer - page 18

this approach is highly effective in HER2-positive breast cancer, given
the fact that not all patients benefit from a taxane, using a biomarker
for taxanes may further increase efficacy or add additional benefit.
Recently, pAkt-S473 has been identified as a predictive factor for
paclitaxel chemotherapy benefit in node-positive breast cancer. It
would be legitimate to use both pAkt and HER2 for selecting patients
to receive trastuzumab in combination with taxane chemotherapy
although this approach remains to be evaluated.

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Rational use of multiple biomarkers in the context of targeted and
chemotherapy regimens hold promise towards a more personalized
medicine. The deployment of this approach potentially increases
the odds for patients to benefit from therapy and avoid unnecessary
toxicity from exposure to an ineffective or unnecessary treatment.

Table 1.3 Therapeutic biomarker categories based on therapy types

Chemotherapy
plus targeted
therapy

Targeted
therapy Biomarker Chemotherapy

c-Kit expression or
mutations

+++

BCR-ABL fusion gene
(Ph+)

+++

BCR-ABL/T315I
mutation

+++

BRAF V600E
mutation

+++

BRCA dysfunction ++ ++ ++

DPD deficiency ++

EGFR expression or
gene mutations

+++

EML4-ALK fusion
gene

+++

ER and/or PR + +++

HER2 overexpression
or gene amplification

++ +++ ++