After removing duplicates in Endnote and Covidence, 2145 studies were screened against their title and abstract. Overall, 71 studies were included for full-text reading, which resulted in eight studies eligible for inclusion. Two additional studies were identified as relevant when the search was rerun in September 2021. Details are presented in Fig. 1.
The eight studies included in the narrative synthesis were published from 2001 to 2021. Four studies were published between 2001 and 2007 [14,15,16,17], and four of the most recent studies from 2019 to 2021 [18,19,20,21]. Three studies included patients treated from 1985 to 1999 [14,15,16], and five studies included patients treated from 2004 to 2018 [17,18,19,20,21]. Three studies recruited patients from Japan [15, 17, 21], and one study recruited patients from China , USA , Italy , Netherlands , and Canada , respectively. All studies included reported QoL measures, and half of the studies included baseline QoL assessments [17, 19,20,21]. Seven studies reported complications due to treatment [14, 15, 17, 19,20,21]. Six studies focused on PN [14,15,16, 18, 20, 21], while the remaining two studies reported ablative therapies, including one percutaneous radiofrequency ablation (RFA) , and one both percutaneous cryoablation (PCA) and laparoscopic cryoablation (LCA) . The latter study pooled PCA and LCA into one group, which was labeled as cryoablation (CA) of stage T1 RCC.
QoL outcomes were assessed using a variety of instruments. The validated 36-Item Short Form Health Survey (SF-36) was the most frequently used questionnaire and was used in four of the studies included in this analysis [14, 17,18,19], and SF-8 was used in one study . Other measurement tools included the Impact of Events Scale (IES) , General Health Questionnaire (G.H.Q.) , Hospital Anxiety Depression Scale (H.A.D.S) , Social Problem Questionnaire (S.P.Q.) , Functional Assessment of Cancer Therapy-Kidney Symptom Index-15 (FKSI-15) , the European Organisation for Research and Treatment of Cancer Quality-of-life Questionnaire Core 30 (EORTC QlQ C-30) , and EQ-5D-5L .
Complications were narratively described in four studies [14, 15, 17, 20], and three studies used the Clavien-Dindo classification to assess complications [18, 19, 21]. Only one study explicitly described the time of assessment of complications . Study characteristics are shown in detail in Table 2.
QoL quality of life, PN partial nephrectomy, SF-36 36-Item Short Form Health Survey, IES the Impact of Events Scale, NSS nephron sparing surgery, EORTC QLQ C30 the European Organisation for Research and Treatment of Cancer Quality-of-life Questionnaire Core 30, G.H.Q. General Health Questionnaire, H.A.D.S Hospital Anxiety Depression Scale, S.P.Q. Social Problem Questionnaire, RN radical nephrectomy, HRQoL health-related quality of life, RFA radiofrequency ablation, LRN laparoscopic radical nephrectomy, LPN laparoscopic partial nephrectomy, LLPN laser-assisted laparoscopic partial nephrectomy, SRM small renal masses, PCA percutaneous cryoablation, LCA laparoscopic cryoablation, OPN open partial nephrectomy, SRM small renal masses, RAPN robot-assisted partial nephrectomy, BP bodily pain, RE role limitations because of physical health problems, MH mental health, MCS mental health component summary
We adjusted question six of the CASP checklist for cohort studies with regard to follow-up, given that we included four cross-sectional studies, by adding the option of entering “not applicable” (n/a) to the response choices . Overall, we found that all observational studies included in our analysis had a clearly focused objective and recruited patients in an acceptable way. Two studies did not account for possible confounding factors in the study design or analysis [17, 21], and one of them was unclear whether the follow-up of subjects was complete, as no data on response rate or subjects lost to follow-up were presented . We applied “Can’t tell” to five studies with regard to the applicability of the results to the local population [14,15,16,17, 21], mainly due to cultural differences and the age of the publication, due to the rapid developments in surgical treatment for RCC and NSS . The only RCT study included received a “yes” to all questions in the CASP Randomized Controlled Trials Checklist . In Table 3, we present details of the quality assessment.
Results of individual studies
Quality of life
Shinohara et al. and Ficarra et al. found higher scores of QoL after PN compared to RN [15, 16], whereas Clark et al. found no differences in the SF-36 domains between mandatory PN vs. elective PN vs. RN . However, Clark et al. found that self-reported remaining renal parenchyma correlated positively with several QoL domains . In four studies with a longitudinal design, Onishi et al., Sandbergen et al., Breau et al., and Watanabe et al. presented changes over time from baseline measurements [17, 19,20,21]. Sandbergen et al. reported a small decrease in QoL at one month compared to baseline with regard to the “role-physical functioning and social functioning” after CA regardless of LCA or PCA, whereas Onishi et al. reported no changes in any SF-36 domains 1 week after RFA, compared to baseline. However, they presented figures indicating decreased QoL scores for “bodily pain” and “role-emotional functioning” 1 week after RFA compared to baseline. Furthermore, Onishi et al. report a gradual increase in all SF-36 domains up to 24 weeks after RFA. Watanabe et al. showed similar results regarding all QoL scores after robot-assisted PN (RAPN). Sandbergen et al. found that all patients recovered to baseline QoL values 12 months after PCA and LCA. Likewise, Breau et al. found no significant change in levels of global health 12 months after open PN (OPN). Wang et al. reported no statistically significant differences in any of the SF-36 domains between laser-assisted partial nephrectomy (LLPN) and laparoscopic partial nephrectomy (LPN) 12 months after treatment . A summary of key findings is provided in Table 2.
There was substantial heterogeneity in measurement tools and time-periods of measurement in the included studies. Five out of eight studies used the SF-36 questionnaire, or a subset thereof, to assess QoL [14, 17, 19, 21]. Wang et al., Sandbergen et al., and Watanabe et al. used the SF-36 or SF-8 12 months after treatment [18, 19, 21]. Sandbergen et al. and Watanabe et al. reported their results on graphs, making comparisons difficult [19, 21]. Clark et al. used SF-36 with a follow-up of 39 ± 23 months and do not show results stratified by treatment type . Onishi et al. used SF-36 at 1 week, 1 month, 3 months, and 6 months after treatment and reported graphical results of differences in values from baseline . The two remaining studies included in our analysis used other QoL measurement tools. Therefore, a comparison was not possible.
All studies reported complications after treatment except for one . Sandbergen et al., Wang et al., and Watanabe et al. reported complications that were graded according to the Clavien-Dindo classification [18, 19, 21], and the remaining authors presented narrative descriptions of peri- and/or postoperative complications [14, 15, 17, 20]. Only Sandbergen et al. reported the timing of postoperative complications explicitly within 90 days . Wang et al. reported a minor complication rate of 8.3% after LLPN and 13.9% after LPN, respectively , and Watanabe et al. reported a 14% complication rate after RAPN . Shinohara et al. reported a 20% complication rate after OPN, consisting of two patients with minor complications and one patient who required permanent dialysis 5 years postoperatively . Breau et al. reported up to 17% complications after OPN , whereas Clark et al., assessed self-reported complications, with 16.8% of their respondents reporting complications and 83.2% reporting no major complications . The two studies on ablative therapies, including percutaneous RFA , LCA, and PCA , reported no major surgical or postoperative complications, but found a minor complication rate of 12.5% grade 1–2 complications, based on the Clavien-Dindo classification, following PCA and LCA.
Synthesis of results
In the eight studies that assessed QoL outcomes after NSS of stage T1 RCC, a total of 491 patients received PN, 24 patients received CA, and 20 patients received RFA. The seven studies that assessed post-treatment complications included 435 patients who were assessed after PN, 24 patients after CA, and 20 patients after RFA. Comparison of QoL outcomes across the eight studies was not possible due to the lack of exact QoL results presented in the individual studies, and the lack of separate data for NSS. QoL results were descriptively reported or reported on graphs, which did not allow for data extraction for comparison or meta-analysis. In half of the studies regarding PN (n= 150), PN was compared to RN in the original studies and in a retrospective design. Across these studies, we found higher, post-treatment scores of QoL after PN compared to RN. In the prospective studies of PN, we found that QoL increased or returned to baseline levels. No studies were identified that compared PN to ablative therapies for stage T1 RCC. One study showed a small decrease in QoL at the short-term follow-up after CA, but found that patients returned to baseline levels of QoL at the mid-term follow-up. With regard to RFA, one study reported no decrease in QoL after treatment and a gradual increase during a follow-up of 24 weeks. Our analysis of the eight included studies found a complication rate up to 20% after PN, up to 12.5% after CA, and no complications reported after RFA.
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