Table 4. AS patient characteristics for selection for entry into AS.
| Study | Selection process |
Mean age (yrs) | Mean size of tumour (cm) | CCI grade | Baseline kidney function | Histology | Comment on patient selection | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| All patients |
AS patients |
All patients |
AS patients |
All patients |
AS patients |
All patients |
AS patients |
All patients |
AS patients |
|||||||
| University of Michigan† (15) | Retrospective analysis of prospectively entered SRM database | 60 | 63 | 2.9 | 2.3 | CCI ≥2 48% |
CCI ≥2 45% |
eGFR ≤60 mL/min 22% |
eGFR ≤60 mL/min 21% |
37% had RMB in treatment group |
41% had RMB | The combination of tumour size <3 cm, performance status ≥2 and endophytic lesion were most predictive of AS | ||||
| Fox Chase Cancer Center (16) | Retrospective analysis of prospectively entered kidney tumour database | 63 | 71 | 3 | 2.6 | CCI ≥3 27% |
CCI ≥3 55% | CKD stage ≥3 22% |
CKD stage ≥3 37% |
n/r | n/r | Characteristics associated with use of AS included CCI 1-2, CCI ≥3, solitary kidney, bilateral disease | ||||
| NCDB (17) | Retrospective sample | 60.1 | 70.6 | 2.6 | 2.6 | CCI ≥3 3.4% |
CCI ≥3 5.7% | n/r | n/r | n/r | n/r | Increasing age associated with more likely to be managed with ablation or AS | ||||
| Cleveland Clinic (18) | Retrospective analysis of prospectively entered kidney tumour database | 79* | 81* | 3.3* | 2.3* | CCI ≥2 42% |
CCI ≥2 65% | CKD stage ≥3 45% |
CKD stage ≥3 54% |
RCC 39%; Benign 21%; Other cancer 20%; Unknown 20% | RCC 1.9%; Benign 3.8%; Unknown 94% | Patients on AS were older and had greater comorbidity | ||||
| University of Toronto (19) | Prospective AS cohort | n/a | 74 | n/a | 2.3* | n/a | n/r | n/a | n/r | n/a | 7/82 had RMB; 2/7 RCC; 5/7 inadequate samples | Eligibility criteria: renal mass ≤7 cm, not surgical candidates due to advanced age, significant comorbidities or patient refusal | ||||
| DISSRM, 2015† (20) | Prospective registry | 62* | 71* | 2.5* | 1.9* | CCI 1-3 37% |
CCI 1-3 51% |
CKD 7.3% |
CKD 9.9% |
3.6% had RMB in intervention group of which: oncocytoma 20%; RCC 70%; Non diagnostic 10% | 9.4% had RMB of which: Oncocytoma 43%; RCC 29%; Non-diagnostic 24% |
AS patients were older, had worse ECOG scores, total comorbidities and cardiovascular comorbidities, with tumours more likely to be multiple, smaller or bilateral | ||||
| Canada (22) | Prospective non-comparative clinical trial of AS | n/a | 73 | n/a | 2.1 | n/a | n/r | n/a | n/r | n/r | All trial patients asked to undergo RMB |
Eligibility criteria: T1a renal mass on imaging, deemed by physician to be unfit for surgery due to advanced age, comorbidity or refusal of other treatment | ||||
| Oxford, 2012† (23) | Retrospective analysis of local cancer database | 62.1 | 71.9 | 2.6 | 2.3 | n/r | n/r | n/r | n/r | n/r | 7/71 had RMB of which: 2/7 RCC; 2/7Oncocytoma; 3/7 Non-diagnostic | AS patients were significantly older. No significant difference in tumour size between AS and treatment groups (RN and PN) | ||||
| Haifa (25) | Retrospective analysis of AS cohort | n/a | 68 | n/a | 1.9 | n/a | Mean CCI =4.5 |
n/a | n/r | n/a | n/r | Inclusion criteria for AS: risk factors for end stage renal disease, multiple major medical comorbidities, patient preference | ||||
| University of Michigan, 2016 (26) | Retrospective analysis of AS cohort | n/a | 66 | n/a | 2.0 | n/a | ECOG 0 60%, ECOG 1 21%, ECOG 2 14% | n/a | eGFR m/min Mean 74.6 |
n/a | 51/118 had RMB of which: Benign 37%; Malignant 35%; Non-diagnostic 28% | No specific inclusion criteria for AS enrolment mentioned | ||||
| Pusan National University (27) |
Prospective AS cohort | n/a | 64 | n/a | 1.8 | n/a | CCI ≥3 19% | n/a | n/r | n/a | 32% | No specific inclusion criteria for AS enrolment mentioned | ||||
| Tayside (28) | Prospective AS cohort | n/a | 69.8 | n/a | 2.2 | n/a | Median number of comorbidities =2 |
n/a | eGFR ≤60ml/min 35% |
n/a | n/r | No specific criteria for management with AS mentioned | ||||
| MD Anderson (30) |
Prospective AS cohort | n/a | 68.5 | n/a | 1.74 | n/a | Mean CCI =5.8 | n/a | Mean eGFR mL/min =72.4 | n/a | 45% had RMB of which: RCC 50%; Benign 36%; Non-diagnostic 10% |
AS was recommended for elderly patients with significant comorbidities, for those undergoing active non-RCC-related cancer treatment, or for patients refusing surgery | ||||
AS, active surveillance; CCI, Charlson comorbidity index; CKD, chronic kidney disease; PI, primary intervention; PN, partial nephrectomy; RN, radical nephrectomy; SRM, small renal mass. *median value instead of mean; †comparator group is patient receiving primary intervention rather than all patients.