title: Role of definitive radiation therapy in carcinoma of unknown primary in the abdomen and pelvis.
abstract: OBJECTIVE
  Carcinoma of unknown primary (CUP) in the abdomen and pelvis is a heterogeneous group of cancers with no standard treatment. Considered by many to be incurable, these patients are often treated with chemotherapy alone. In this study, we determined the effectiveness of radiation therapy in combination with chemotherapy in patients with CUP in the abdomen and pelvis.
  
  
  METHODS
  Medical records were reviewed for 37 patients with CUP treated with radiation therapy for disease located in the soft tissues and/or nodal basins of the abdomen and pelvis at the University of Texas M.D. Anderson Cancer between 2002 and 2009. All patients underwent chemotherapy, either before or concurrent with radiation therapy. Patients were selected for radiation therapy on the basis of histologic type, disease extent, and prior therapy response. Twenty patients underwent definitive radiation therapy (defined as radiation therapy targeting all known disease sites with at least 45 Gy) and 17 patients underwent palliative radiation therapy. Only 6 patients had surgical resection of their disease. Patient and treatment characteristics were extracted and the endpoints of local disease control, progression-free survival (PFS), overall survival (OS), and treatment-related toxicity incidence were analyzed.
  
  
  RESULTS
  The 2-year PFS and OS rates for the entire cohort were 32% and 57%, respectively. However, in patients treated with definitive radiation therapy, the rates were 48% and 76%, and 7 patients lived more than 3 years after treatment with no evidence of disease progression. Nevertheless, radiation-associated toxicity was significant in this cohort, as 40% experienced Grade 2 or higher late toxicities.
  
  
  CONCLUSIONS
  The use of definitive radiation therapy should be considered in selected patients with CUP in the soft tissues or nodal basins of the abdomen and pelvis.
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kelly
authors.forename: Prajnan
authors.initials: P
authors.lastname: Das
authors.forename: Gauri R
authors.initials: GR
authors.lastname: Varadhachary
authors.forename: Hiral P
authors.initials: HP
authors.lastname: Fontanilla
authors.forename: Sunil
authors.initials: S
authors.lastname: Krishnan
authors.forename: Marc E
authors.initials: ME
authors.lastname: Delclos
authors.forename: Anuja
authors.initials: A
authors.lastname: Jhingran
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Eifel
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Crane
mesh_terms: D000008:Abdominal Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D010166:Palliative Care; D010386:Pelvic Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D020266:Radiotherapy, Conformal / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D012983:Soft Tissue Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D015996:Survival Rate