title: Sentinel lymph node status in vulval cancer: systematic reviews of test accuracy and decision-analytic model-based economic evaluation.
abstract: BACKGROUND
  Vulval cancer causes 3-5% of all gynaecological malignancies and requires surgical removal and inguinofemoral lymphadenectomy (IFL). Complications affect > 50% of patients, including groin wound infection, lymphoedema and cellulitis. A sentinel lymph node (SLN) is the first groin node with the highest probability of malignancy. SLN biopsy would be useful if it could accurately identify patients in whom cancer has spread to the groin, without removing all groin nodes. SLNs can be identified by isosulfan blue dye and/or technetium-99 ((99m)Tc) radioactive tracer during lymphoscintigraphy. The blue dye/(99m)Tc procedure only detects SLN, not metastases - this requires histological examination, which can include ultrastaging and staining with conventional haematoxylin and eosin (H&E) or immunohistochemistry.
  
  
  OBJECTIVE
  To determine the test accuracy and cost-effectiveness of the SLN biopsy with (99m)Tc and/or blue dye compared with IFL or clinical follow-up for test negatives in vulval cancer, through systematic reviews and economic evaluation.
  
  
  METHODS
  Standard medical databases, including MEDLINE, EMBASE, Science Citation Index and The Cochrane Library, medical search gateways, reference lists of review articles and included studies were searched to January 2011.
  
  
  METHODS
  For accuracy and effectiveness, standard methods were used and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches were to January 2011, with no language restrictions. Meta-analyses were carried out with Meta-Disc version 1.4 (Javier Zamora, Madrid, Spain) for accuracy; none was appropriate for effectiveness. The economic evaluation from a NHS perspective used a decision-tree model in DATA TreeAge Pro Healthcare 2001 (TreeAge Software, Inc., Williamstown, MA, USA). Six options (blue dye with H&E, blue dye with ultrastaging, (99m)Tc with H&E, (99m)Tc with ultrastaging, blue dye/(99m)Tc with H&E, blue dye/(99m)Tc with ultrastaging) were compared with IFL. Deterministic and probabilistic sensitivity analyses were conducted.
  
  
  RESULTS
  For accuracy, of the 26 included studies, most evaluated (99m)Tc/blue dye combined. Four studies had clinical follow-up only for test negatives and five had clinical follow-up for all and IFL for test negatives. Numbers with no SLN found were difficult to distinguish from those with negative SLN biopsies. The largest group of 11 studies using (99m)Tc/blue dye, ultrastaging and immunohistochemistry had a pooled sensitivity of 95.6% [95% confidence interval (CI) 91.5% to 98.1%] and a specificity of 100% (95% CI 99.0% to 100%). Mean SLN detection rates were 94.6% for (99m)Tc, 68.7% for blue dye and 97.7% for both. One study measured global health status quality of life (QoL) and found no difference between SLN biopsy and IFL. One patient preference evaluation showed that 66% preferred IFL rather than a 5% false-negative rate from SLN biopsy. For effectiveness, of 14,038 references, one randomised controlled trial, three case-control studies and 13 case series were found. Approximately 50% died from vulval cancer and 50% from other causes during follow-ups. Recurrences were in the ratio of approximately 4 : 2 : 1 vulval, groin and distant, with more recurrences in node-positive patients. No studies reported QoL. For cost per death averted, IFL was less costly and more effective than strategies using SLN biopsy. For morbidity-free survival and long-term morbidity-free survival, (99m)Tc with ultrastaging was most cost-effective. Strategies with blue dye only and H&E only were never cost-effective. The incremental cost-effectiveness ratio for (99m)Tc with ultrastaging compared with IFL was £4300 per case of morbidity-free survival and £7100 per long-term morbidity-free survival.
  
  
  CONCLUSIONS
  The main limitations of this study include the lack of good-quality evidence on accuracy, effectiveness and QoL. A large project such as this takes time to publish, so the most recent studies are not included.
  
  
  CONCLUSIONS
  A sensitive and specific combined metastatic SLN detection test and information on generic QoL in vulval cancer is urgently required.
  
  
  BACKGROUND
  The National Institute for Health Research Health Technology Assessment programme.
authors: Centre for Primary Care and Public Health, Barts and The London School of Medicine and Dentistry, Queen Mary University of London Health Economics Research Group (HERG), Brunel University Unit of Health Economics, University of Birmingham Arcana Institute Departments of Gynaecology and Gynaecological Oncology, Addenbrooke's Hospital NHS Trust Department of Gynaecology, Barts Health NHS Trust Pan Birmingham Gynaecological Cancer Centre, Birmingham Women's Hospital NHS Foundation Trust, London Middlesex Birmingham Krakow Cambridge London Birmingham, UK UK UK Poland UK UK UK.
authors: C
authors: C
authors: Meads
authors: A
authors: A
authors: Sutton
authors: S
authors: S
authors: Małysiak
authors: M
authors: M
authors: Kowalska
authors: A
authors: A
authors: Zapalska
authors: E
authors: E
authors: Rogozinska
authors: P
authors: P
authors: Baldwin
authors: A
authors: A
authors: Rosenthal
authors: R
authors: R
authors: Ganesan
authors: E
authors: E
authors: Borowiack
authors: P
authors: P
authors: Barton
authors: T
authors: T
authors: Roberts
authors: S
authors: S
authors: Sundar
authors: K
authors: K
authors: Khan
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D007264:Inguinal Canal / Q000473:pathology / Q000601:surgery; D061305:Lymphoscintigraphy / Q000009:adverse effects / Q000191:economics / Q000379:methods; D008875:Middle Aged; D018803:Models, Economic; D010043:Outcome and Process Assessment, Health Care; D011183:Postoperative Complications / Q000191:economics / Q000209:etiology / Q000523:psychology; D011379:Prognosis; D011788:Quality of Life / Q000523:psychology*; D011878:Radiotherapy / Q000009:adverse effects / Q000191:economics / Q000523:psychology; D012008:Recurrence; D012394:Rosaniline Dyes / Q000009:adverse effects / Q000191:economics; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000009:adverse effects / Q000191:economics* / Q000379:methods; D016019:Survival Analysis; D016284:Technetium Tc 99m Pentetate / Q000009:adverse effects / Q000191:economics; D006113:United Kingdom / Q000453:epidemiology; D014844:Vulva / Q000528:radiation effects / Q000601:surgery; D014846:Vulvar Neoplasms / Q000191:economics* / Q000453:epidemiology / Q000473:pathology / Q000628:therapy
chemical_list: D012394:Rosaniline Dyes; D016284:Technetium Tc 99m Pentetate