title: Predictors of growth kinetics and outcomes in small renal masses (SRM ≤4 cm in size): Tayside Active Surveillance Cohort (TASC) Study.
abstract: OBJECTIVE
  To determine outcomes of small renal masses (≤4 cm) on active surveillance and explore factors which can influence their growth.
  
  
  METHODS
  Two hundred twenty six patients between January 2007 and December 2014 were analysed using cross-linked methodology of healthcare data and independent review. Cancer specific and non-specific survival were the primary outcomes. Growth kinetics, factors influencing growth and need for interventions were secondary outcomes.
  
  
  RESULTS
  101 (64.4%) solid and 4 (5.9%) cystic SRMs showed growth. 43 (19.02%) of SRMs required treatment interventions. Seven patients (7/158; 4.4%) died due to renal cancer at a median follow-up of 21.7 (SD 10.6, min 6-42) months, all in solid category. Independent review of serial radiological imaging of these seven cases showed two patients had subtle metastatic disease at the initial presentation, and 5 of the 7 did not adhere to recommended imaging regime. 33 (33/158; 20.8%) died due to other causes including non-renal cancers (14/158; 8.8%). Multivariate analyses showed that lower eGFR at baseline, co-morbidities and tumour location were independently associated with growth in size.
  
  
  CONCLUSIONS
  A higher cancer-specific mortality was seen in the present study compared to the reported literature. Independent critical review of imaging of cases with poor outcome underscored the importance of adherence to a robust protocol including follow up. Comorbid conditions had a significant impact on growth and overall survival of patients with SRMs.
authors.affiliation: Academic Section of Urology, Division of Cancer Research, School of Medicine, Ninewells Hospital, Dundee, UK.
authors.forename: C
authors.initials: C
authors.lastname: Paterson
authors.affiliation: Academic Section of Urology, Division of Cancer Research, School of Medicine, Ninewells Hospital, Dundee, UK.
authors.forename: C
authors.initials: C
authors.lastname: Yew-Fung
authors.affiliation: Academic Section of Urology, Division of Cancer Research, School of Medicine, Ninewells Hospital, Dundee, UK.
authors.forename: C
authors.initials: C
authors.lastname: Sweeney
authors.affiliation: Academic Section of Urology, Division of Cancer Research, School of Medicine, Ninewells Hospital, Dundee, UK.
authors.forename: M
authors.initials: M
authors.lastname: Szewczyk-Bieda
authors.affiliation: Academic Section of Urology, Division of Cancer Research, School of Medicine, Ninewells Hospital, Dundee, UK.
authors.forename: S
authors.initials: S
authors.lastname: Lang
authors.affiliation: Academic Section of Urology, Division of Cancer Research, School of Medicine, Ninewells Hospital, Dundee, UK. Electronic address: g.nabi@dundee.ac.uk.
authors.forename: G
authors.initials: G
authors.lastname: Nabi
mesh_terms: D000328:Adult; D000368:Aged; D015897:Comorbidity; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D007700:Kinetics; D011159:Population Surveillance; D012606:Scotland; D015996:Survival Rate
keywords: Active surveillance; Co-morbidities; Growth patterns; Outcomes; Small renal masses