Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

Progress in refining the clinical management of cancer of unknown primary in the molecular era

Abstract

Cancer of unknown primary (CUP) is an enigmatic disease entity encompassing heterogeneous malignancies without a detectable primary tumour, despite a thorough diagnostic workup. A minority of patients with CUP (15–20%) can be assigned a putative primary tissue of origin according to clinical and histopathological findings and typically have a more favourable prognosis with the use of corresponding tumour type-specific therapies. Thus, the majority of patients with CUP have disease that cannot be assigned to a culprit primary tumour, are treated with empirical chemotherapy and have a poor prognosis. In the molecular era, the use of (epi)genomic or transcriptomic CUP classifiers and DNA or RNA sequencing offers two, sometimes overlapping, therapeutic strategies: tumour type-specific therapy and biomarker-guided therapy. Published data reveal that the accuracy of site-of-origin predictions made using CUP classifiers ranges between 54% and 98% when compared with the assignment made according to the recommended clinicopathological criteria. These advances have led to promising results in non-randomized prospective studies evaluating the efficacy of tumour type-specific therapy; however, the favourable outcomes were not confirmed in randomized controlled studies comparing this approach with standard empirical chemotherapy. Currently, the evidence supporting the use of biomarker-guided therapies is limited to case reports and small case series. In this Review, we discuss the clinical management of CUP in the era of precision medicine. We focus on the advances in understanding the biology of CUP, the implications for the diagnosis and classification of CUP according to the tissue of origin and the shift away from empirical therapy towards tailored therapy.

Key points

  • Cancer of unknown primary (CUP) is a clinically well-recognized, but biologically enigmatic, disease entity that encompasses a heterogeneous group of metastatic cancers without an identifiable primary tumour, despite extensive investigations.

  • The current era is witnessing a decrease in the proportion of patients with cancer who are diagnosed with CUP to 1–2%, in comparison to 3–5% in the early 1990s.

  • The recommended diagnostic workup includes a thorough physical examination, basic blood analyses, evaluation of tumour biomarkers (guided by the clinical scenario) and CT scans of the thorax, abdomen and pelvis.

  • Multiple assays have been developed to predict the putative tissue of origin by alignment with prominent molecular profiles established for cancers with a known primary.

  • Together with the overall clinical picture and results of pathology investigations, molecular profiling of CUP can have therapeutic implications by guiding treatment decisions according to the putative primary tumour type and the detection of potential driver mutations.

  • The design of future prospective randomized trials should address the minority of patients that present with targetable mutations, especially driver mutations, based on the findings of molecular analyses and the predicted primary tumour type.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: The development and dissemination of CUP.
Fig. 2: Proposed algorithm for the diagnosis and management of CUP.

Similar content being viewed by others

References

  1. Fizazi, K. et al. Cancers of unknown primary site: ESMO clinical practice guidelines for diagnosis, treatment and follow-up. Ann. Oncol. 26 (Suppl. 5), v133–v138 (2015).

    PubMed  Google Scholar 

  2. Shu, X., Sundquist, K., Sundquist, J. & Hemminki, K. Time trends in incidence, causes of death, and survival of cancer of unknown primary in Sweden. Eur. J. Cancer Prev. 21, 281–288 (2012).

    PubMed  Google Scholar 

  3. Urban, D., Rao, A., Bressel, M., Lawrence, Y. R. & Mileshkin, L. Cancer of unknown primary: a population-based analysis of temporal change and socioeconomic disparities. Br. J. Cancer 109, 1318–1324 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  4. Brewster, D. H., Lang, J., Bhatti, L. A., Thomson, C. S. & Oien, K. A. Descriptive epidemiology of cancer of unknown primary site in Scotland, 1961–2010. Cancer Epidemiol. 38, 227–234 (2014).

    PubMed  Google Scholar 

  5. Randén, M., Rutqvist, L.-E. & Johansson, H. Cancer patients without a known primary: incidence and survival trends in Sweden 1960–2007. Acta Oncol. 48, 915–920 (2009).

    PubMed  Google Scholar 

  6. Levi, F., Te, V. C., Erler, G., Randimbison, L. & La Vecchia, C. Epidemiology of unknown primary tumours. Eur. J. Cancer 38, 1810–1812 (2002).

    CAS  PubMed  Google Scholar 

  7. Rassy, E. & Pavlidis, N. The currently declining incidence of cancer of unknown primary. Cancer Epidemiol. 61, 139–141 (2019).

    PubMed  Google Scholar 

  8. Bochtler, T. & Krämer, A. Does cancer of unknown primary (CUP) truly exist as a distinct cancer entity? Front Oncol. 9, 402 (2019).

    PubMed  PubMed Central  Google Scholar 

  9. Bochtler, T. et al. Comparative genetic profiling aids diagnosis and clinical decision making in challenging cases of CUP syndrome. Int. J. Cancer 145, 2963–2973 (2019).

    CAS  PubMed  Google Scholar 

  10. Rassy, E., Kattan, J. & Pavlidis, N. Familial cancer of unknown primary. Int. J. Clin. Oncol. 24, 1328–1331 (2019).

    PubMed  Google Scholar 

  11. Conway, A.-M. et al. Molecular characterisation and liquid biomarkers in carcinoma of unknown primary (CUP): taking the ‘U’ out of ‘CUP’. Br. J. Cancer 120, 141–153 (2019).

    CAS  PubMed  Google Scholar 

  12. Schreiber, R. D., Old, L. J. & Smyth, M. J. Cancer immunoediting: integrating immunity’s roles in cancer suppression and promotion. Science 331, 1565–1570 (2011).

    CAS  PubMed  Google Scholar 

  13. Pavlidis, N. & Pentheroudakis, G. Cancer of unknown primary site. Lancet 379, 1428–1435 (2012).

    PubMed  Google Scholar 

  14. Rassy, E., Assi, T., Kattan, J. & Pavlidis, N. Paraneoplastic syndromes in cancers of unknown primary: an unknown field for oncologists. Bull Cancer 106, 590–603 (2019).

    PubMed  Google Scholar 

  15. Vikeså, J. et al. Cancers of unknown primary origin (CUP) are characterized by chromosomal instability (CIN) compared to metastasis of known origin. BMC Cancer 15, 151 (2015).

    PubMed  PubMed Central  Google Scholar 

  16. Pavlidis, N., Briasoulis, E., Hainsworth, J. & Greco, F. A. Diagnostic and therapeutic management of cancer of an unknown primary. Eur. J. Cancer 39, 1990–2005 (2003).

    CAS  PubMed  Google Scholar 

  17. Pavlidis, N. & Fizazi, K. Carcinoma of unknown primary (CUP). Crit. Rev. Oncol. Hematol. 69, 271–278 (2009).

    PubMed  Google Scholar 

  18. Pentheroudakis, G., Briasoulis, E. & Pavlidis, N. Cancer of unknown primary site: missing primary or missing biology? Oncologist 12, 418–425 (2007).

    CAS  PubMed  Google Scholar 

  19. Hemminki, K., Bevier, M., Sundquist, J. & Hemminki, A. Cancer of unknown primary (CUP): does cause of death and family history implicate hidden phenotypically changed primaries? Ann. Oncol. 23, 2720–2724 (2012).

    CAS  PubMed  Google Scholar 

  20. Hemminki, K., Sundquist, K., Sundquist, J., Hemminki, A. & Ji, J. Location of metastases in cancer of unknown primary are not random and signal familial clustering. Sci. Rep. 6, 22891 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  21. Rassy, E. et al. The role of site-specific therapy for cancers of unknown of primary: a meta-analysis. Eur. J. Cancer 127, 118–122 (2020).

    PubMed  Google Scholar 

  22. Hainsworth, J. D. et al. Molecular gene expression profiling to predict the tissue of origin and direct site-specific therapy in patients with carcinoma of unknown primary site: a prospective trial of the Sarah Cannon research institute. J. Clin. Oncol. 31, 217–223 (2013).

    CAS  PubMed  Google Scholar 

  23. Moran, S. et al. Epigenetic profiling to classify cancer of unknown primary: a multicentre, retrospective analysis. Lancet Oncol. 17, 1386–1395 (2016).

    PubMed  Google Scholar 

  24. Gross-Goupil, M. et al. Identifying the primary site using gene expression profiling in patients with carcinoma of an unknown primary (CUP): a feasibility study from the GEFCAPI. Onkologie 35, 54–55 (2012).

    PubMed  Google Scholar 

  25. Rassy, E. & Pavlidis, N. The current evidence for a biomarker-based approach in cancer of unknown primary. Cancer Treat. Rev. 67, 21–28 (2018).

    PubMed  Google Scholar 

  26. Hayashi, H. et al. Randomized phase II trial comparing site-specific treatment based on gene expression profiling with carboplatin and paclitaxel for patients with cancer of unknown primary site. J. Clin. Oncol. 37, 570–579 (2019).

    CAS  PubMed  Google Scholar 

  27. Fizazi, K. et al. A phase III trial of empiric chemotherapy with cisplatin and gemcitabine or systemic treatment tailored by molecular gene expression analysis in patients with carcinomas of an unknown primary (CUP) site (GEFCAPI 04) [abstract LBA15_PR]. Ann. Oncol. 30 (Suppl. 5), v851–v934 (2019).

    Google Scholar 

  28. Losa, F. et al. SEOM clinical guideline on unknown primary cancer (2017). Clin. Transl. Oncol. 20, 89–96 (2018).

    CAS  PubMed  Google Scholar 

  29. NICE. Metastatic malignant disease of unknown primary origin in adults: diagnosis and management. Clinical guideline. https://www.nice.org.uk/guidance/cg104/resources/metastatic-malignant-disease-of-unknown-primary-origin-in-adults-diagnosis-and-management-pdf-35109328970437 (2010).

  30. NCCN. Occult primary (cancer of unknown primary (CUP)) version 2.2020 https://www.nccn.org/professionals/physician_gls/pdf/occult.pdf. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) (2020).

  31. Pentheroudakis, G. & Pavlidis, N. in Wick metastatic carcinomas of unknown origin (ed. Mark, R) 165–175 (Demos Medical Publishing, 2008).

  32. Hainsworth, J. D. & Greco, F. A. Gene expression profiling in patients with carcinoma of unknown primary site: from translational research to standard of care. Virchows Arch. 464, 393–402 (2014).

    CAS  PubMed  Google Scholar 

  33. Kwee, T. C. & Kwee, R. M. Combined FDG-PET/CT for the detection of unknown primary tumors: systematic review and meta-analysis. Eur. Radiol. 19, 731–744 (2009).

    PubMed  Google Scholar 

  34. Rassy, E., Kattan, J. & Pavlidis, N. A new entity of abdominal squamous cell carcinoma of unknown primary. Eur. J. Clin. Invest. 49, e13111 (2019).

    PubMed  Google Scholar 

  35. Rassy, E., Nicolai, P. & Pavlidis, N. Comprehensive management of HPV-related squamous cell carcinoma of the head and neck of unknown primary. Head Neck 41, 3700–3711 (2019).

    PubMed  Google Scholar 

  36. Rassy, E. et al. New rising entities in cancer of unknown primary: is there a real therapeutic benefit? Crit. Rev. Oncol. Hematol. 147, 102882 (2020).

    PubMed  Google Scholar 

  37. Varadhachary, G. R. et al. Carcinoma of unknown primary with gastrointestinal profile: immunohistochemistry and survival data for this favorable subset. Int. J. Clin. Oncol. 19, 479–484 (2014).

    CAS  PubMed  Google Scholar 

  38. Lazaridis, G., Pentheroudakis, G., Fountzilas, G. & Pavlidis, N. Liver metastases from cancer of unknown primary (CUPL): a retrospective analysis of presentation, management and prognosis in 49 patients and systematic review of the literature. Cancer Treat. Rev. 34, 693–700 (2008).

    PubMed  Google Scholar 

  39. Golfinopoulos, V. et al. Comparative survival with diverse chemotherapy regimens for cancer of unknown primary site: multiple-treatments meta-analysis. Cancer Treat. Rev. 35, 570–573 (2009).

    CAS  PubMed  Google Scholar 

  40. Hess, K. R., Abbruzzese, M. C., Lenzi, R., Raber, M. N. & Abbruzzese, J. L. Classification and regression tree analysis of 1000 consecutive patients with unknown primary carcinoma. Clin. Cancer Res. 5, 3403–3410 (1999).

    CAS  PubMed  Google Scholar 

  41. Greco, F. A. et al. Gemcitabine, carboplatin, and paclitaxel for patients with carcinoma of unknown primary site: a Minnie Pearl Cancer Research Network study. J. Clin. Oncol. 20, 1651–1656 (2002).

    CAS  PubMed  Google Scholar 

  42. Huebner, G. et al. Paclitaxel and carboplatin vs gemcitabine and vinorelbine in patients with adeno- or undifferentiated carcinoma of unknown primary: a randomised prospective phase II trial. Br. J. Cancer 100, 44–49 (2009).

    CAS  PubMed  Google Scholar 

  43. Hemminki, K., Bevier, M., Hemminki, A. & Sundquist, J. Survival in cancer of unknown primary site: population-based analysis by site and histology. Ann. Oncol. 23, 1854–1863 (2012).

    CAS  PubMed  Google Scholar 

  44. Jones, W. et al. Cancers of unknown primary diagnosed during hospitalization: a population-based study. BMC Cancer 17, 85 (2017).

    PubMed  PubMed Central  Google Scholar 

  45. Hemminki, K., Pavlidis, N., Tsilidis, K. K., Sundquist, K. & Ji, J. Age-dependent metastatic spread and survival: cancer of unknown primary as a model. Sci. Rep. 6, 23725 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  46. Pavlidis, N., Rassy, E. & Smith-Gagen, J. Cancer of unknown primary: incidence rates, risk factors and survival among adolescents and young adults. Int. J. Cancer 146, 1490–1498 (2019).

    PubMed  Google Scholar 

  47. Rassy, E., Assi, T. & Pavlidis, N. Exploring the biological hallmarks of cancer of unknown primary: where do we stand today? Br. J. Cancer 122, 1124–1132 (2020).

    PubMed  Google Scholar 

  48. Frost, P. Unknown primary tumors: an example of accelerated (type 2) tumor progression. Basic. Life Sci. 57, 233–237 (1991).

    CAS  PubMed  Google Scholar 

  49. Brabletz, T., Jung, A., Spaderna, S., Hlubek, F. & Kirchner, T. Opinion: migrating cancer stem cells — an integrated concept of malignant tumour progression. Nat. Rev. Cancer 5, 744–749 (2005).

    CAS  PubMed  Google Scholar 

  50. Scadden, D. T. The stem-cell niche as an entity of action. Nature 441, 1075–1079 (2006).

    CAS  PubMed  Google Scholar 

  51. López-Lázaro, M. The migration ability of stem cells can explain the existence of cancer of unknown primary site. Rethinking metastasis. Oncoscience 2, 467–475 (2015).

    PubMed  PubMed Central  Google Scholar 

  52. Califano, J. et al. Unknown primary head and neck squamous cell carcinoma: molecular identification of the site of origin. J. Natl Cancer Inst. 91, 599–604 (1999).

    CAS  PubMed  Google Scholar 

  53. Suzuki, M., Mose, E. S., Montel, V. & Tarin, D. Dormant cancer cells retrieved from metastasis-free organs regain tumorigenic and metastatic potency. Am. J. Pathol. 169, 673–681 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  54. Tarin, D. Clinical and biological implications of the tumor microenvironment. Cancer Microenviron. 5, 95–112 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  55. Dasgupta, A., Lim, A. R. & Ghajar, C. M. Circulating and disseminated tumor cells: harbingers or initiators of metastasis? Mol. Oncol. 11, 40–61 (2017).

    PubMed  PubMed Central  Google Scholar 

  56. Stoyianni, A. et al. Immunohistochemical study of the epithelial–mesenchymal transition phenotype in cancer of unknown primary: incidence, correlations and prognostic utility. Anticancer Res. 32, 1273–1281 (2012).

    PubMed  Google Scholar 

  57. Stoyianni, A. et al. Insights into the epithelial mesenchymal transition phenotype in cancer of unknown primary from a global microRNA profiling study. Clin. Transl. Oncol. 16, 725–731 (2014).

    CAS  PubMed  Google Scholar 

  58. Kamposioras, K., Pentheroudakis, G. & Pavlidis, N. Exploring the biology of cancer of unknown primary: breakthroughs and drawbacks. Eur. J. Clin. Invest. 43, 491–500 (2013).

    CAS  PubMed  Google Scholar 

  59. Vanharanta, S. & Massagué, J. Origins of metastatic traits. Cancer Cell 24, 410–421 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  60. Lengauer, C., Kinzler, K. W. & Vogelstein, B. Genetic instabilities in human cancers. Nature 396, 643–649 (1998).

    CAS  PubMed  Google Scholar 

  61. Albertini, R. J., Nicklas, J. A., O’Neill, J. P. & Robison, S. H. In vivo somatic mutations in humans: measurement and analysis. Annu. Rev. Genet. 24, 305–326 (1990).

    CAS  PubMed  Google Scholar 

  62. Clynick, B. et al. Genetic characterisation of molecular targets in carcinoma of unknown primary. J. Transl. Med. 16, 185 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  63. Tothill, R. W. et al. Massively-parallel sequencing assists the diagnosis and guided treatment of cancers of unknown primary. J. Pathol. 231, 413–423 (2013).

    CAS  PubMed  Google Scholar 

  64. Gatalica, Z. et al. Comprehensive tumor profiling identifies numerous biomarkers of drug response in cancers of unknown primary site: analysis of 1806 cases. Oncotarget 5, 12440–12447 (2014).

    PubMed  PubMed Central  Google Scholar 

  65. Penson, A. et al. Development of genome-derived tumor type prediction to inform clinical cancer care. JAMA Oncol. 6, 84–91 (2020).

    Google Scholar 

  66. Centeno, B. A. et al. Hybrid model integrating immunohistochemistry and expression profiling for the classification of carcinomas of unknown primary site. J. Mol. Diagn. 12, 476–486 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  67. Pavlidis, N. Forty years experience of treating cancer of unknown primary. Acta Oncol. 46, 592–601 (2007).

    PubMed  Google Scholar 

  68. Kim, C. S. et al. Survival outcome differences based on treatments used and knowledge of the primary tumour site for patients with cancer of unknown and known primary in Ontario. Curr. Oncol. 25, 307–316 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  69. Daud, A. I. Removing the unknown from the carcinoma of unknown primary. J. Clin. Oncol. 31, 174–175 (2012).

    PubMed  Google Scholar 

  70. Greco, F. A. & Hainsworth, J. D. Renal cell carcinoma presenting as carcinoma of unknown primary site: recognition of a treatable patient subset. Clin. Genitourin. Cancer 16, e893–e898 (2018).

    PubMed  Google Scholar 

  71. Overby, A., Duval, L., Ladekarl, M., Laursen, B. E. & Donskov, F. Carcinoma of unknown primary site (CUP) with metastatic renal-cell carcinoma (mRCC) histologic and immunohistochemical characteristics (CUP-mRCC): results from consecutive patients treated with targeted therapy and review of literature. Clin. Genitourin. Cancer 17, e32–e37 (2019).

    PubMed  Google Scholar 

  72. Thamcharoen, N. & Chaiwiriyawong, W. Papillary renal cell carcinoma presented with supraclavicular lymph node metastasis without renal primary lesion. World J. Oncol. 4, 50–53 (2013).

    PubMed  PubMed Central  Google Scholar 

  73. Honda, A. et al. Successful control of carcinoma of unknown primary with axitinib, a novel molecular-targeted agent: a case report. Chemotherapy 60, 342–345 (2014).

    CAS  PubMed  Google Scholar 

  74. Escudier, B. Combination therapy as first-line treatment in metastatic renal-cell carcinoma. N. Engl. J. Med. 380, 1176–1178 (2019).

    PubMed  Google Scholar 

  75. Michielin, O., van Akkooi, A., Ascierto, P., Dummer, R. & Keilholz, U. Cutaneous melanoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann. Oncol. 30, 1884–1901 (2019).

    CAS  PubMed  Google Scholar 

  76. Simile, M. M. et al. Targeted therapies in cholangiocarcinoma: emerging evidence from clinical trials. Medicina 55, 42 (2019).

    PubMed Central  Google Scholar 

  77. Jardim, D. L. et al. Impact of a biomarker-based strategy on oncology drug development: a meta-analysis of clinical trials leading to FDA approval. J. Natl Cancer Inst. 107, djv253 (2015).

    PubMed  Google Scholar 

  78. Schwaederle, M. et al. Impact of precision medicine in diverse cancers: a meta-analysis of phase II clinical trials. J. Clin. Oncol. 33, 3817–3825 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  79. Hoadley, K. A. et al. Multiplatform analysis of 12 cancer types reveals molecular classification within and across tissues of origin. Cell 158, 929–944 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  80. Kandoth, C. et al. Mutational landscape and significance across 12 major cancer types. Nature 502, 333–339 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  81. Bogenberger, J. M., DeLeon, T. T., Arora, M., Ahn, D. H. & Borad, M. J. Emerging role of precision medicine in biliary tract cancers. NPJ Precis. Onc. 2, 21 (2018).

    Google Scholar 

  82. Brown, N. A., Aisner, D. L. & Oxnard, G. R. Precision medicine in non-small cell lung cancer: current standards in pathology and biomarker interpretation. Am. Soc. Clin. Oncol. Educ. Book 38, 708–715 (2018).

    PubMed  Google Scholar 

  83. Guler, I., Askan, G., Klostergaard, J. & Sahin, I. H. Precision medicine for metastatic colorectal cancer: an evolving era. Expert Rev. Gastroenterol. Hepatol. 13, 919–931 (2019).

    CAS  PubMed  Google Scholar 

  84. Binder, C., Matthes, K. L., Korol, D., Rohrmann, S. & Moch, H. Cancer of unknown primary — epidemiological trends and relevance of comprehensive genomic profiling. Cancer Med. 7, 4814–4824 (2018).

    PubMed  PubMed Central  Google Scholar 

  85. Chakravarty, D. et al. OncoKB: a precision oncology knowledge base. JCO Precis. Oncol. 1, 1–16 (2017).

    Google Scholar 

  86. Mateo, J. et al. A framework to rank genomic alterations as targets for cancer precision medicine: the ESMO Scale for Clinical Actionability of molecular Targets (ESCAT). Ann. Oncol. 29, 1895–1902 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  87. Ross, J. S. et al. Comprehensive genomic profiling of carcinoma of unknown primary site: new routes to targeted therapies. JAMA Oncol. 1, 40–49 (2015).

    PubMed  Google Scholar 

  88. Löffler, H. et al. Molecular driver alterations and their clinical relevance in cancer of unknown primary site. Oncotarget 7, 44322–44329 (2016).

    PubMed  PubMed Central  Google Scholar 

  89. Kato, S. et al. Utility of genomic analysis in circulating tumor DNA from patients with carcinoma of unknown primary. Cancer Res. 77, 4238–4246 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  90. Varghese, A. M. et al. Clinical and molecular characterization of patients with cancer of unknown primary in the modern era. Ann. Oncol. 28, 3015–3021 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  91. Gatalica, Z., Xiu, J., Swensen, J. & Vranic, S. Comprehensive analysis of cancers of unknown primary for the biomarkers of response to immune checkpoint blockade therapy. Eur. J. Cancer 94, 179–186 (2018).

    PubMed  Google Scholar 

  92. Hainsworth, J. D. et al. Phase II trial of bevacizumab and erlotinib in carcinomas of unknown primary site: the Minnie Pearl Cancer Research Network. J. Clin. Oncol. 25, 1747–1752 (2007).

    CAS  PubMed  Google Scholar 

  93. Hainsworth, J. D. et al. Paclitaxel/carboplatin plus bevacizumab/erlotinib in the first-line treatment of patients with carcinoma of unknown primary site. Oncologist 14, 1189–1197 (2009).

    PubMed  Google Scholar 

  94. Dietlein, F. et al. Identification of cancer driver genes based on nucleotide context. Nat. Genet. 52, 208–218 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  95. Hainsworth, J. D., Lennington, W. J. & Greco, F. A. Overexpression of Her-2 in patients with poorly differentiated carcinoma or poorly differentiated adenocarcinoma of unknown primary site. J. Clin. Oncol. 18, 632–635 (2000).

    CAS  PubMed  Google Scholar 

  96. Massard, C. et al. Carcinoma of an unknown primary: are EGF receptor, Her-2/neu, and c-Kit tyrosine kinases potential targets for therapy? Br. J. Cancer 97, 857–861 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  97. Dova, L. et al. Targeting c-KIT, PDGFR in cancer of unknown primary: a screening study for molecular markers of benefit. J. Cancer Res. Clin. Oncol. 134, 697 (2008).

    CAS  PubMed  Google Scholar 

  98. Dova, L. et al. Global profiling of EGFR gene mutation, amplification, regulation and tissue protein expression in unknown primary carcinomas: to target or not to target? Clin. Exp. Metastasis 24, 79–86 (2007).

    CAS  PubMed  Google Scholar 

  99. Koo, J. S. & Kim, H. Hypoxia-related protein expression and its clinicopathologic implication in carcinoma of unknown primary. Tumour Biol. 32, 893–904 (2011).

    CAS  PubMed  Google Scholar 

  100. Pavlidis, N., Briassoulis, E., Bai, M., Fountzilas, G. & Agnantis, N. Overexpression of C-myc, Ras and C-erbB-2 oncoproteins in carcinoma of unknown primary origin. Anticancer Res. 15, 2563–2567 (1995).

    CAS  PubMed  Google Scholar 

  101. Mauri, G. et al. TRKA expression and NTRK1 gene copy number across solid tumours. J. Clin. Pathol. 71, 926–931 (2018).

    CAS  PubMed  Google Scholar 

  102. Krikelis, D. et al. Profiling immunohistochemical expression of NOTCH1-3, JAGGED1, cMET, and phospho-MAPK in 100 carcinomas of unknown primary. Clin. Exp. Metastasis 29, 603–614 (2012).

    CAS  PubMed  Google Scholar 

  103. Gatalica, Z. et al. Molecular profiling of cancers of unknown primary site (CUP): paradigm shift in management of CUP [abstract LBA39]. Eur. J. Cancer 49, S17 (2013).

    Google Scholar 

  104. Pentheroudakis, G. et al. Mutational profiling of the RAS, PI3K, MET and b-catenin pathways in cancer of unknown primary: a retrospective study of the Hellenic Cooperative Oncology Group. Clin. Exp. Metastasis 31, 761–769 (2014).

    CAS  PubMed  Google Scholar 

  105. Stella, G. M. et al. MET mutations in cancers of unknown primary origin (CUPs). Hum. Mutat. 32, 44–50 (2011).

    CAS  PubMed  Google Scholar 

  106. Golfinopoulos, V. et al. Intracellular signalling via the AKT axis and downstream effectors is active and prognostically significant in cancer of unknown primary (CUP): a study of 100 CUP cases. Ann. Oncol. 23, 2725–2730 (2012).

    CAS  PubMed  Google Scholar 

  107. Pentheroudakis, G. et al. Immunohistochemical profiling of signalling pathways in cancer of unknown primary (CUP). Eur. J. Cancer 47, S184 (2011).

    Google Scholar 

  108. Briasoulis, E. et al. Bcl2 and p53 protein expression in metastatic carcinoma of unknown primary origin: biological and clinical implications. A Hellenic Co-operative Oncology Group study. Anticancer Res. 18, 1907–1914 (1998).

    CAS  PubMed  Google Scholar 

  109. van de Wouw, A. J., Jansen, R. L. H., Griffioen, A. W. & Hillen, H. F. P. Clinical and immunohistochemical analysis of patients with unknown primary tumour. A search for prognostic factors in UPT. Anticancer Res. 24, 297–301 (2004).

    PubMed  Google Scholar 

  110. Rashid, A. et al. Overexpression and prevalence of molecular markers in patients with cancer of unknown primary (CUP). J. Clin. Oncol. 24, 9683 (2005).

    Google Scholar 

  111. Karavasilis, V. et al. Angiogenesis in cancer of unknown primary: clinicopathological study of CD34, VEGF and TSP-1. BMC Cancer 5, 25 (2005).

    PubMed  PubMed Central  Google Scholar 

  112. Karavasilis, V. et al. Matrix metalloproteinases in carcinoma of unknown primary. Cancer 104, 2282–2287 (2005).

    CAS  PubMed  Google Scholar 

  113. Hemminki, K. et al. Germline genetics of cancer of unknown primary (CUP) and its specific subtypes. Oncotarget 7, 22140–22149 (2016).

    PubMed  PubMed Central  Google Scholar 

  114. Hedley, D. W., Leary, J. A. & Kirsten, F. Metastatic adenocarcinoma of unknown primary site: abnormalities of cellular DNA content and survival. Eur. J. Cancer Clin. Oncol. 21, 185–189 (1985).

    CAS  PubMed  Google Scholar 

  115. Tothill, R. W. et al. An expression-based site of origin diagnostic method designed for clinical application to cancer of unknown origin. Cancer Res. 65, 4031–4040 (2005).

    CAS  PubMed  Google Scholar 

  116. Horlings, H. M. et al. Gene expression profiling to identify the histogenetic origin of metastatic adenocarcinomas of unknown primary. J. Clin. Oncol. 26, 4435–4441 (2008).

    CAS  PubMed  Google Scholar 

  117. Bridgewater, J., van Laar, R., Floore, A. & Van’T Veer, L. Gene expression profiling may improve diagnosis in patients with carcinoma of unknown primary. Br. J. Cancer 98, 1425–1430 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  118. van Laar, R. K. et al. Implementation of a novel microarray-based diagnostic test for cancer of unknown primary. Int. J. Cancer 125, 1390–1397 (2009).

    PubMed  Google Scholar 

  119. Monzon, F. A., Medeiros, F., Lyons-Weiler, M. & Henner, W. D. Identification of tissue of origin in carcinoma of unknown primary with a microarray-based gene expression test. Diagn. Pathol. 5, 3 (2010).

    PubMed  PubMed Central  Google Scholar 

  120. Ades, F. et al. Comparison of a gene expression profiling strategy to standard clinical work-up for determination of tumour origin in cancer of unknown primary (CUP). J. Chemother 25, 239–246 (2013).

    CAS  PubMed  Google Scholar 

  121. Tothill, R. W. et al. Development and validation of a gene expression tumour classifier for cancer of unknown primary. Pathology 47, 7–12 (2015).

    CAS  PubMed  Google Scholar 

  122. Mileshkin, L. R. et al. Development of a histology-guided gene expression tumor classifier for cancer of unknown primary (CUP). J. Clin. Oncol. 32, 11108–11108 (2014).

    Google Scholar 

  123. Varadhachary, G. R. et al. Molecular profiling of carcinoma of unknown primary and correlation with clinical evaluation. J. Clin. Oncol. 26, 4442–4448 (2008).

    CAS  PubMed  Google Scholar 

  124. Greco, F. A., Lennington, W. J., Spigel, D. R. & Hainsworth, J. D. Molecular profiling diagnosis in unknown primary cancer: accuracy and ability to complement standard pathology. J. Natl Cancer Inst. 105, 782–790 (2013).

    CAS  PubMed  Google Scholar 

  125. Raghav, K. P. S., Poage, G. M., Schnabel, C. A. & Varadhachary, G. R. Resolving diagnostic uncertainty in bone-predominant metastases in cancer of unknown primary (CUP) using the 92-gene assay. J. Clin. Oncol. 36, 12064–12064 (2018).

    Google Scholar 

  126. Thompson, D. S. et al. Molecular tumor profiling (MTP) in cancer of unknown primary site (CUP): a complement to standard pathologic diagnosis. J. Clin. Oncol. 29, 10560–10560 (2011).

    Google Scholar 

  127. Ferracin, M. et al. MicroRNA profiling for the identification of cancers with unknown primary tissue-of-origin. J. Pathol. 225, 43–53 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  128. Varadhachary, G. R. et al. Prospective gene signature study using microRNA to identify the tissue of origin in patients with carcinoma of unknown primary. Clin. Cancer Res. 17, 4063–4070 (2011).

    CAS  PubMed  Google Scholar 

  129. Sanden, M. O. et al. Observational study of real world clinical performance of microRNA molecular profiling for cancer of unknown primary (CUP). J. Clin. Oncol. 31, e22173–e22173 (2013).

    Google Scholar 

  130. Fernandez, A. F. et al. A DNA methylation fingerprint of 1628 human samples. Genome Res. 22, 407–419 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  131. Mileshkin, L. R. et al. Clinical impact of tissue of origin testing and mutation profiling in the solving unknown primary cancer (SUPER) national prospective study: experience of the first two years. J. Clin. Oncol. 37, 3072–3072 (2019).

    Google Scholar 

  132. Culine, S. et al. Cisplatin in combination with either gemcitabine or irinotecan in carcinomas of unknown primary site: results of a randomized phase II study-trial for the French Study Group on carcinomas of unknown primary (GEFCAPI 01). J. Clin. Oncol. 21, 3479–3482 (2003).

    CAS  PubMed  Google Scholar 

  133. Greco, F. A. et al. Carcinoma of unknown primary site: phase II trials with docetaxel plus cisplatin or carboplatin. Ann. Oncol. 11, 211–215 (2000).

    CAS  PubMed  Google Scholar 

  134. Dowell, J. E., Garrett, A. M., Shyr, Y., Johnson, D. H. & Hande, K. R. A randomized phase II trial in patients with carcinoma of an unknown primary site. Cancer 91, 592–597 (2001).

    CAS  PubMed  Google Scholar 

  135. Briasoulis, E. et al. Multicenter phase-II trial of irinotecan plus oxaliplatin (IROX regimen) in patients with poor-prognosis cancer of unknown primary: a Hellenic Cooperative Oncology Group study. Cancer Chemother. Pharmacol. 62, 277–284 (2008).

    CAS  PubMed  Google Scholar 

  136. Schuette, K. et al. Phase II trial of capecitabine and oxaliplatin in patients with adeno- and undifferentiated carcinoma of unknown primary. Onkologie 32, 162–166 (2009).

    CAS  PubMed  Google Scholar 

  137. Møller, A. K. H., Pedersen, K. D., Abildgaard, J., Petersen, B. L. & Daugaard, G. Capecitabine and oxaliplatin as second-line treatment in patients with carcinoma of unknown primary site. Acta Oncol. 49, 431–435 (2010).

    PubMed  Google Scholar 

  138. Hainsworth, J. D. et al. Oxaliplatin and capecitabine in the treatment of patients with recurrent or refractory carcinoma of unknown primary site. Cancer 116, 2448–2454 (2010).

    CAS  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Contributions

The authors contributed equally to all aspects of the article.

Corresponding authors

Correspondence to Elie Rassy or Nicholas Pavlidis.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Reviewer information

Nature Reviews Clinical Oncology thanks Kari Hemminki, Kanwal Raghav and the other, anonymous, reviewer for their contribution to the peer review of this work.

Related links

OncoKB: https://www.oncokb.org/

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Rassy, E., Pavlidis, N. Progress in refining the clinical management of cancer of unknown primary in the molecular era. Nat Rev Clin Oncol 17, 541–554 (2020). https://doi.org/10.1038/s41571-020-0359-1

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41571-020-0359-1

This article is cited by

Search

Quick links

Nature Briefing: Cancer

Sign up for the Nature Briefing: Cancer newsletter — what matters in cancer research, free to your inbox weekly.

Get what matters in cancer research, free to your inbox weekly. Sign up for Nature Briefing: Cancer