PIK3CA

Across TCGA pan-cancer cohorts, PIK3CA RNA differs between tumor and matched normal tissue in 8 of 18 cancer types tested, making tumor–normal expression one of PIK3CA’s most consistent transcriptional readouts.

The strongest signal is observed in head and neck squamous cell carcinoma (HNSC), where PIK3CA RNA is more highly expressed in tumor relative to normal tissue. In most cancer types PIK3CA is over-expressed in tumor, although a few such as BRCA and UCEC show the opposite, repressed pattern.

HNSC, LUSC, and BRCA are the cancer types where PIK3CA tumor–normal differential expression is most reproducible.

RNA tumor vs normal associations by lineage

Ranked by sampling consensus. Fold-change is the tumor-versus-normal difference in PIK3CA RNA (log₂); positive values indicate higher expression in tumor. p-values are from the differential-expression test.

Lineage	Gender	Stage	Fold-change	p	Sampling consensus
HNSC	All	IV	+1.137	<.001	12	view →
LUSC	All	All	+0.716	<.001	6	view →
BRCA	All	III,IV	−0.576	<.001	6	view →
LIHC	All	All	+0.357	.001	6	view →
CHOL	Male	All	+1.414	<.001	5	view →
UCEC	All	All	−0.712	.001	2	view →
THCA	All	All	−0.286	.016	2	view →
ESCA	Female	All	+0.570	.020	1	view →

Pink = over-expressed in tumor, green = repressed in tumor. Showing the 8 strongest of 8 lineages.

PIK3CA–HNSC

Open the HNSC breakdown →