The median survival for this patient group is approximately 6-9 months, which is often a reflection of the more aggressive cancer types (1).
Approximately 20% of cases have characteristics that correspond to a slightly better prognosis. These include:
- women with papillary carcinomas in the peritoneum
- women with adenocarcinomas in axillary lymph nodes only
- low differentiated tumors with mid-line distribution only
- squamous epithelial carcinoma in cervical lymph nodes only
- adenocarcinomas with colon and rectal cancer profiles (CK20+, CK7-, CDX2+)
- neuroendocrine carcinomas
- men with sclerotic bone metastases and increased PSA
- very limited spreading
Liver metastases, metastases to multiple organs, and reduced health condition are poor prognostic factors, in addition to high LD and ALP, as well as low albumin and lymphopenia. In addition, men have a poorer prognosis than women (2,3).
Five-year relative survival for patients with cancer of unknown primary site, in percent, during the diagnosis period 1974–2013.
Source: Cancer Registry of Norway