NCI Definition: The spread of a malignant neoplasm from an unknown primary to another region remote from the primary site. [1]

Cancer of unknown primarys most frequently harbor alterations in TP53, KRAS, CDKN2A, KMT2D, and ARID1A [2].

Most Commonly Altered Genes in Cancer of Unknown Primary

TP53 Mutation, TP53 Missense, TP53 c.217-c.1178 Missense, KRAS Mutation, and KRAS Exon 2 Mutation are the most common alterations in cancer of unknown primary [2].

Top Alterations in Cancer of Unknown Primary

Disease Details

Unknown primary malignant neoplasm, cancer of unknown primary origin, occult primary tumor, Unknown primary malignant neoplasm (NOS), Metastatic Malignant Neoplasm of Unknown Primary, Cancer of Unknown Primary Site, Metastatic Malignant Neoplasm of Unknown Primary Origin, Metastatic Neoplasm of Unknown Primary Origin
Metastatic Malignant Neoplasm
Neuroendocrine Carcinoma, NOS, Undifferentiated Malignant Neoplasm, Carcinoma of Unknown Primary, Poorly Differentiated Carcinoma, NOS, Neuroendocrine Tumor, NOS, Acinar Cell Carcinoma, NOS, Cancer of Unknown Primary, NOS, Melanoma of Unknown Primary, and Mixed Cancer, NOS
OncoTree Name
Cancer of Unknown Primary
OncoTree Code


1. National Cancer Institute. NCI Thesaurus Version 18.11d. https://ncit.nci.nih.gov/ncitbrowser/ [2018-08-28]. [2018-09-21].

2. The AACR Project GENIE Consortium. AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discovery. 2017;7(8):818-831. Dataset Version 8. This dataset does not represent the totality of the genetic landscape; see paper for more information.

3. All assertions and clinical trial landscape data are curated from primary sources. You can read more about the curation process here.