title: Meningeal carcinomatosis underdiagnosis and overestimation: incidence in a large consecutive and unselected population of breast cancer patients.
abstract: BACKGROUND
  The incidence of meningeal carcinomatosis appears to be higher than in the past due to advances in neuro-imaging diagnostic techniques and improvements in cancer survival. Among solid tumors, breast cancer is the cancer most commonly associated with meningeal carcinomatosis, with an incidence rate of between 0.8 and 16%. Aim of this study has been i) to evaluate the incidence of meningeal carcinomatosis in a continuous breast cancer unselected series treated in a dedicated Breast Unit and ii) to define the clinico-pathological and molecular parameters associated with meningeal carcinomatosis development.
  
  
  METHODS
  A retrospective series of 1915 consecutive patients surgically treated for breast cancer between 1998 and 2010 was collected. Clinico-pathological data were recorded from medical charts and pathological reports, including the date of development of symptomatic meningeal carcinomatosis. Meningeal carcinomatosis incidence was determined at both 5- and 10-year follow-ups.
  
  
  RESULTS
  Three patients in the first 5 years of follow-up and six patients in 10 years of follow-up developed meningeal carcinomatosis. An incidence rate of 5.44 per 10,000 patients (95% CI: 1.75-16.9) was observed, with a 5-year risk of 0.3%. At 10-year follow up, the rate increased to 7.55 per 10,000 patients (95% CI: 3.39-16.8). In a univariate analysis, young age, tumor size larger than 15 mm, histological grade 3, more than three metastatic lymph nodes, negative estrogen receptor, positive HER2 and high proliferative index were significantly associated with meningeal carcinomatosis development.
  
  
  CONCLUSIONS
  In an unselected breast cancer population, meningeal carcinomatosis is a rare event that is associated with adverse prognostic factors. Meningeal carcinomatosis incidence is overestimated when recorded in biased/high-risk selected breast cancer patients and should not be considered to accurately reflect the overall breast cancer population.
authors.affiliation: Division of Medical Oncology, University of Turin Medical School, Fondazione del Piemonte per l'Oncologia-Institute for Cancer Research and Treatment of Candiolo, Strada Provinciale 142 km 3,95, 10060, Candiolo, Turin, Italy. gloria.mittica@ircc.it.
authors.forename: Gloria
authors.initials: G
authors.lastname: Mittica
authors.affiliation: Department of Medical Sciences, University of Turin, Via Santena 7, 10126, Turin, Italy. rebesenetta@gmail.com.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Senetta
authors.affiliation: Department of Medical Sciences, University of Turin, Via Santena 7, 10126, Turin, Italy. lorenzo.richiardi@unito.it.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Richiardi
authors.affiliation: Department of Neuro-Oncology, University and City of Health and Science Hospital, Via Cherasco 15, 10126, Turin, Italy. rudarob@hotmail.com.
authors.forename: Roberta
authors.initials: R
authors.lastname: Rudà
authors.affiliation: Department of Medical Sciences, University of Turin, Via Santena 7, 10126, Turin, Italy. renato.coda@unito.it.
authors.forename: Renato
authors.initials: R
authors.lastname: Coda
authors.affiliation: Department of Medical Sciences, University of Turin, Via Santena 7, 10126, Turin, Italy. isabella.castellano@unito.it.
authors.forename: Isabella
authors.initials: I
authors.lastname: Castellano
authors.affiliation: Department of Medical Sciences, University of Turin, Via Santena 7, 10126, Turin, Italy. anna.sapino@unito.it.
authors.forename: Anna
authors.initials: A
authors.lastname: Sapino
authors.affiliation: Department of Medical Sciences, University of Turin, Via Santena 7, 10126, Turin, Italy. paola.cassoni@unito.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Cassoni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000150:complications / Q000601:surgery*; D005260:Female; D006801:Humans; D015994:Incidence; D055756:Meningeal Carcinomatosis / Q000175:diagnosis* / Q000453:epidemiology*; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult