Mourão et al. BMC Urology (2020) 20:85 https://doi.org/10.1186/s12894-020-00649-8 RESEARCH ARTICLE Open Access Small renal masses in Latin-American population: characteristics and prognostic factors for survival, recurrence and metastasis – a multi-institutional study from LARCG database Thiago Camelo Mourão1* , Diego Abreu2, Gustavo F. Carvalhal3, Guillermo Gueglio4, Walter H. da Costa1, Vinicius Fernando Calsavara5, Luis Meza-Montoya6, Rubén G. Bengió7, Carlos Scorticati8, Ricardo Castillejos-Molina9, Francisco Rodríguez-Covarrubias9, Ana María Autran-Gómez10, José Gadu Campos-Salcedo11, Alejandro Nolazco12, Carlos Ameri13, Hamilton Zampolli14, Raúl Langenhin15, Diego Muguruza15, Marcos Tobias Machado14,16, Pablo Mingote17, Jorge Clavijo18, Lucas Nogueira19, Omar Clark20, Agustín R. Rovegno21, Fernando P. Secin22, Ricardo Decia2, Gustavo C. Guimarães23, Sidney Glina16,24, Oscar Rodríguez-Faba25, Joan Palou25 and Stenio C. Zequi1,26 Abstract Background: To evaluate demographic, clinical and pathological characteristics of small renal masses (SRM) (≤ 4 cm) in a Latin-American population provided by LARCG (Latin-American Renal Cancer Group) and analyze predictors of survival, recurrence and metastasis. Methods: A multi-institutional retrospective cohort study of 1523 patients submitted to surgical treatment for non- metastatic SRM from 1979 to 2016. Comparisons between radical (RN) or partial nephrectomy (PN) and young or elderly patients were performed. Kaplan-Meier curves and log-rank tests estimated 10-year overall survival. Predictors of local recurrence or metastasis were analyzed by a multivariable logistic regression model. Results: PN and RN were performed in 897 (66%) and 461 (34%) patients. A proportional increase of PN cases from 48.5% (1979–2009) to 75% (after 2009) was evidenced. Stratifying by age, elderly patients (≥ 65 years) had better 10- year OS rates when submitted to PN (83.5%), than RN (54.5%), p = 0.044. This disparity was not evidenced in younger patients. On multivariable model, bilaterality, extracapsular extension and ASA (American Society of Anesthesiologists) classification ≥3 were predictors of local recurrence. We did not identify significant predictors for distant metastasis in our series. (Continued on next page) * Correspondence: thiagocmourao@gmail.com 1 A.C. Camargo Cancer Center, Rua Antônio Prudente 211, Liberdade, São Paulo 01509-010, Brazil Full list of author information is available at the end of the article © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Mourão et al. BMC Urology (2020) 20:85 Page 2 of 9 (Continued from previous page) Conclusions: PN is performed in Latin-America in a similar proportion to developed areas and it has been increasing in the last years. Even in elderly individuals, if good functional status, sufficiently fit to surgery, and favorable tumor characteristics, they should be encouraged to perform PN. Intending to an earlier diagnosis of recurrence or distant metastasis, SRM cases with unfavorable characteristics should have a more rigorous follow-up routine. Keywords: Kidney cancer, Nephron-sparing surgery, Latin America, Renal cell carcinoma, Nephrectomy Background 1979 to 2016 in Argentina, Bolivia, Brazil, Chile, Comprehensive approach of renal cell carcinoma (RCC) Mexico, Peru, Uruguay, and two Spanish centers. In- is a priority in the main cancer centers. Increasing trend stitutional Review Board of Fundação Antônio Pru- in incidence, particularly of incidentally detected small dente approved this protocol (number 2.478.489, renal masses (SRM), has not been clearly associated to a CAAE: 71749917.3.0000.5432/January 30th. 2018) and significant decrease in global mortality. According to the the study did not interfere with the treatment or SEER (Surveillance, Epidemiology, and End Results) follow-up of the patients. database, the estimated number of new cases of RCC in the United States in 2019 is 73,820. RCC represents about 4% of all new cancer cases and about 2.5% of all Study population and variables definition cancer deaths [1–3]. We selected patients with renal tumors up to 4 cm on Latin America (LA) represents a large area with about pathological reports and no evidence of distant metasta- 8.5% of the world population, most of them living in de- sis at presentation. We found 1523 patients with these veloping countries. GLOBOCAN estimated the RCC in- characteristics which were stratified by histologic sub- cidence and mortality in LA in 4.4/100,000 and 1.5/100, type criteria in clear cell, papillary, chromophobe or 000, respectively [4]. Recently, an elegant study sug- others (collecting duct carcinoma, TTFE3 gene, unclassi- gested that in 2030, LA countries (Brazil and Ecuador) fied and mixed histologies) and by surgical treatment: will experiment the highest burden of increase of new partial nephrectomy (PN) or RN. Firstly, we excluded cases in both genders [5]. RCC data in LA are scarce patients with benign histology and those with missing and, over time, miscegenation has impacted this popula- values for histologic subtype. Afterwards, non-surgical tion in a singular ethnicity, which could make unreliable management cases were excluded. extrapolating biomolecular profiles and guided therapies Demographic, clinical and pathological variables se- already stablished in developed world populations [6]. lected were age, gender, race, body mass index (BMI), Nephron-sparing surgery (NSS) is the standard of care smoking status, ECOG (Eastern Cooperative Oncology for SRM, providing equivalent oncological control and a Group) Performance Status, Karnofsky and ASA decrease in the non-cancer related mortality [7, 8]. (American Society of Anesthesiologists) classifications, Besides that, even with the improvement of minimally- symptoms at presentation, tumor size (≤ 3 cm or > 3 – invasive and robotic techniques, large series continue to 4 cm), positive surgical margins (PSM), nuclear Fuhrman evidence a high proportion of radical nephrectomy (RN) grade (low or high grade), intratumoral necrosis, sarco- in this setting [7, 9–11]. matoid component, extracapsular extension (ECE), Considering the paucity of information about RCC in multifocality or bilaterality, and admission period (before LA, the aims of this study were to review the LARCG or after 2009). Patients were considered symptomatic at (Latin-American Renal Cancer Group) database to presentation if they had hematuria, local pain, palpable evaluate demographic, clinical and pathologic features of mass, paraneoplastic syndrome, neurological symptoms, SRM in this population, correlating the impact in prog- acute onset varicocele and constitutional symptomatol- nosis and survival in comparison to literature. ogy. Nuclear grade was just established for clear cell and papillary RCC [12]. ECE was considered in cases pre- senting disease in perinephric fat, hilar fat and/or in Methods renal pelvis. Data source Follow-up was established from the date of surgery to This is a multi-institutional retrospective cohort study the date of death or to the latest follow-up. Treatment involving the registries from 28 institutions in LA and indications and follow-up routine were determined at Spain, members of LARCG [6]. Data were collected from the discretion of each center. Overall deaths considered patient charts and pathological reports from each insti- deaths due to the renal cancer and deaths from other tution with a total of 6039 cases of RCC operated from causes. Local recurrence was defined as recurrence in Mourão et al. BMC Urology (2020) 20:85 Page 3 of 9 the renal fossa after RN, and demonstration of recurrent (5 – 2500 mL), median warm ischemia time was 20 min, enhancement within the tumor bed or enhancing suspi- and median hospital stay was 4 days (1–37). cious lesion in the ipsilateral kidney after PN. The median follow-up time was 24 months (range: 0– Authors used a multiple imputation method only in 289). We reported 72 (4.7%) overall deaths and 30 variables with a limited proportion of missing data [13]. (2.0%) cancer-specific deaths. Local recurrence occurred The data were assumed to be missing completely at ran- in 49 (6.1%) from 804 cases and metastasis during dom (MCAR) and a method of predictive mean machine follow-up, in 10 (1.7%) from 588 evaluable cases. (PMM) was adopted [14]. Variables with more than 50% There were no significant differences in 10-year OS of missing data and non-attributable characteristics (e.g., rates comparing patients with SRM ≤ 3 cm or > 3 cm. race, and histological subtype) were not submitted to the Similarly, OS rates were not different between patients imputation method. This method was used for the underwent PN or RN. The 5-year and 10-year OS rates following variables: perinephric fat invasion (24% of for SRM ≤ 3 cm were 95.1 and 80.3%, respectively. For missing data), smoking status (32% of missing data), SRM > 3 cm, 5-year and 10-year OS rates were 94.1 and intratumoral necrosis (41% of missing data), weight (42% 74.8%, respectively (Fig. 1-a). Patients underwent PN of missing data), and ECOG performance status (44% of presented the 5-year and 10-year OS of 96.9 and 88.8%, missing data). respectively; whereas RN cases achieved 93.2 and 74.2%, respectively (Fig. 1-b). Statistical analysis Stratifying by age, elderly patients (≥ 65 years) had bet- Continuous variables were expressed as mean, standard ter 10-year OS rates when submitted to PN (83.5%), deviation, median and interquartile range. Categorical than RN (54.5%), p = 0.044 (Fig. 2-b). This disparity was variables were expressed as absolute relative frequencies. not evidenced in younger patients (Fig. 2-a). Elderly They were compared with a Pearson’s chi-squared test group presented more comorbidities, ASA ≥ 3, larger or a Fisher’s exact test, when appropriate. Student’s t- SRM, and a higher proportion of RN than younger. A test was used to compare continuous variables. Kaplan- crosstab analysis considering younger and elderly pa- Meier curves and log-rank tests were used in 10-year tients is presented in Table 2. overall survival (OS) estimation, according age, tumor On univariable analysis, extracapsular extension (ECE), size and surgery performed. Considering that some ASA classification and bilaterality were associated with patients underwent the surgical treatment at a referral recurrence (data not shown). On multivariable model, center and then return to their communities, survival bilaterality, ECE and ASA classification ≥3 were signifi- analysis were performed only for patients with follow-up cant predictors of local recurrence. We did not identify ≥ 12 months. Univariable and multivariable logistic significant predictors for distant metastasis in our series regression analysis were used to predict independent fac- (Table 3). tors for local recurrence or distant metastasis. Related to these outcomes, it was considered the entire period, in- Discussion cluding all the patients regardless of the available follow- Several reports attempt to provide information regarding up time. The analysis was conducted using IBM predictive clinical, pathological and molecular factors in SPSS®software v.24 (IBM Corp. Armonk, NY, USA) and RCC leading to aggressive histology or unfavorable out- the packages R-Software v. 3.5 for graphical analysis. comes. Majority of published literature is provided from The significance level of the tests were fixed at 0.05. developed countries. After the propagation of cross- sectional images, incidence of SRM has increased world- Results wide, as we verified in LA. Some of them may present A total of 1008 cases had a defined malignant histologic adverse clinico-pathological features, potentially com- subtype, being 651 cases (64.6%) of clear cell RCC, 60 promising the oncological outcomes. NSS demonstrates (6%) of papillary RCC (types I and II), 238 (23.6%) of lower rates of chronic kidney disease or cardiovascular chromophobe RCC, and 59 (6%) of other histologies. PN events. However, there are some issues about onco- and RN were performed in 897 (66%) patients and 461 logical efficacy of PN in comparison to RN [8, 15, 16]. (34%), respectively. The proportion of PN cases in- In literature, benign SRM are found in 13 to 30% of creased from 48.5% (up to 2009) to almost 75% after that the cases and about 40% correspond to low aggressive- year. Table 1 summarizes the main clinical and patho- ness [17–19]. A recent study from Mexico, involving logical characteristics. elderly patients, reported 26% of pT1a [20]. Our series Regarding surgical aspects of PN cases, open and evidenced a similar proportion of pT1a cases (25.2%). minimally-invasive approaches (laparoscopic, retroperi- However, we were not able to report reliable data about toneoscopic or robot-assisted) were performed in 47.9 benign SRM, because many centers could have rejected and 50.4%, respectively. Median blood loss was 200 mL information of benign lesions in their database. Mourão et al. BMC Urology (2020) 20:85 Page 4 of 9 Table 1 Comparison of clinical and pathological data between Table 1 Comparison of clinical and pathological data between patients with small renal masses who performed partial or patients with small renal masses who performed partial or radical nephrectomy radical nephrectomy (Continued) Variable Partial Radical p Value * Variable Partial Radical p Value * Category Nephrectomy Nephrectomy Category Nephrectomy Nephrectomy (n = 897) (n = 461) (n = 897) (n = 461) Year of the surgery Sarcomatoid component n (%) Up to 2009 n (%) 225 (48.5) 239 (51.5) < 0.001 Yes 2 (0.6) 3 (1.2) 0.654 Since 2010 n (%) 637 (74.9) 214 (25.1) No 354 (99.4) 253 (98.8) Age (years) Tumoral necrosis n (%) Mean (SD) 57.9 (12.7) 61.2 (12.8) < 0.001 Yes 104 (11.6) 77 (16.7) 0.011 Median (Q1 - Q3) 59 (50–67) 63 (53–71) No 793 (88.4) 384 (83.3) BMI (Body Mass Index) Multifocality n (%) Mean (SD) 27.6 (4.8) 27.5 (4.9) 0.661 Yes 41 (5.0) 33 (7.7) 0.070 Median (Q1 – Q3) 26.9 (24.2–29.9) 26.7 (24.2–30) No 782 (95.0) 395 (92.3) Blood Transfusion n (%) 107 (12.6) 43 (10.5) 0.317 Locoregional recurrence n (%) Serum Creatinine - mg/dL Yes 19 (4.4%) 26 (7.2%) 0.126 Baseline - Mean (SD) 1.02 (0.61) 1.23 (1.23) 0.011 No 410 (95.6%) 334 (92.8%) Median (Q1 – Q3) 0.96 (0.86–1.1) 1.0 (0.8–1.2) * p-Value < 0.05 considered statistically significant. Pearson’s chi-squared test or Fisher’s exact test were used in categorical variables when appropriate. Post-operative - Mean (SD) 1.13 (0.51) 1.50 (1.50) 0.003 Student’s t-test was used in continuous variables Median (Q1 – Q3) 1.1 (0.9–1.3) 1.3 (1.1–1.5) Operation time – min The proportion of PN or RN in the surgical treatment Mean (SD) 174.4 (76.6) 197.3 (86.8) < 0.001 of SRM was clearly heterogeneous comparing this dec- Median (Q1 – Q3) 120 (90–180) 180 (120–240) ade with the first period of the study (up to 2009). This can be attributable to the development of minimally in- ECOG vasive techniques, the better expertise of the LA referral 0–1 n (%) 862 (96.1) 437 (94.8) 0.329 centers, and the stage migration with the raise of SRM ≥ 2 n (%) 35 (3.9) 24 (5.2) in the last years [21]. Sun et al. [22] described that PN Karnofsky for SRM increased from 4.7% in 1988 to 40.4% in 2008. ≤ 80 n (%) 74 (8.2) 46 (10) 0.336 A recent British study showed more than 90% of NSS > 80 n (%) 823 (91.8) 415 (90.0) performed in T1 tumors [10]. Cases with lower mean age and less comorbidities had PN performed more fre- ASA classification quently. Interestingly, the mean operation time in PN 1–2 n (%) 767 (85.5) 359 (77.9) 0.001 was significantly lower than in RN, maybe due to factors ≥ 3 n (%) 130 (14.5) 102 (22.1) related to the patients or to the participating centers Renal tumor (teaching hospitals or communitarian hospitals). Exophytic tumor 236 (62.8) 140 (37.2) < 0.001 From 1983 to 2002, overall mortality rose in patients Totally endophytic tumor 19 (26.0) 54 (74.0) with RCC in the USA. In tumors < 2 cm, this rise was 0.07 to 0.2 deaths per 100,000. In tumors between 2 and ≤ 3 cm 538 (74.8) 181 (25.2) < 0.001 4 cm, this rise was from 0.2 to 1.5 deaths per 100,000 US 3.1 - 4 cm 261 (53.0) 231 (47.0) population [23]. Considering only patients with at least Extracapsular extension n (%) 12-months of follow-up, our 5-year and 10-year OS were Yes 51 (6.9) 87 (20.8) < 0.001 94.7 and 81.3%, respectively. Tumor size in our SRM No 686 (93.1) 332 (79.2) casuistic did not affect the 10-year OS. Interestingly, Surgical Margins n (%) Jeon [19] pointed that in studies limited to small tumors, they may not find associations with size and favorable Positive 42 (4.7) 7 (1.6) 0.008 histologic features. Negative 844 (95.3) 422 (98.4) Considering that elderly people have more comorbidi- Nuclear grade ties and that RN can proportionate a higher risk of renal Low grade n (%) 685 (76.4) 330 (71.6) 0.064 dysfunction [20, 24], we found that NSS is associated High grade n (%) 212 (23.6) 131 (28.4) with a better 10-year OS in this population. Russel [25] analyzed patients ≥80 years of age and described a Mourão et al. BMC Urology (2020) 20:85 Page 5 of 9 Fig. 1 Kaplan-Meier curve for 10-year overall survival (OS) in evaluable patients according to the tumor size (a) and the surgical treatment (b) decreased RCC-specific mortality for tumors larger than OS and CSS in comparison with those patients < 70 3 cm submitted to surgery. A previous series from Mayo years [28]. Similarly to our study, elderly patients under- Clinic found also an association of RN for pT1a tumors went more frequently to RN than PN. Treatment deci- and a decreased OS, but particularly in younger patients sions favoring PN in selected SRM in elderly patients (< 66 years of age) [26]. Similarly, in a recent Cochrane should be discussed, particularly if we consider that ref- review, PN was associated with a reduced time-to-death erence centers have acquired expertise on minimally in- of any cause (HR: 1.50, 95%CI: 1.03–2.18) [27]. The ef- vasive techniques. fect of age on cancer-specific mortality was tested in a The benefits of regional or retroperitoneal lymphade- recent study. Elderly patients (≥ 70 years) evidenced lar- nectomy are controversial, particularly in small renal ger masses, a higher nuclear grade, and presented worse masses, that rarely present positive lymph nodes. The Mourão et al. BMC Urology (2020) 20:85 Page 6 of 9 Fig. 2 Kaplan-Meier curve for 10-year overall survival (OS) comparing patients submitted to PN or RN according to the group of age. a < 65 years b ≥ 65 years extent and number of retroperitoneal lymph nodes re- predictive of unfavorable pathology in cT1a cases. Other moved have no defined templates. Marchioni et al [29] recent study with SRM under AS described 2% of distant studied pT2-pT3 renal masses treated with RN and evi- metastasis during follow-up and associated non-black denced no gain in CSS related to the lymph nodes dis- race, male gender, high nuclear grade, clear cell subtype section (LND). In our study, LND was not analyzed and tumor size as independent predictors [31]. We were because it is not a routine procedure in SRM, even when able to find an association of ECE with local recurrence, it is treated with RN. but not with distant metastasis. ECE is a rare event in Ball et al. [30] described that male gender, tumor size SRM, due to this reason, we aggregated perinephric fat ≥3 cm and R.E.N.A.L. nephrometry score ≥ 8 are invasion, hilar fat invasion, and renal pelvis invasion in Mourão et al. BMC Urology (2020) 20:85 Page 7 of 9 Table 2 Comparison of clinical and surgical data between Table 2 Comparison of clinical and surgical data between younger (< 65 years) and elderly patients (≥ 65 years) with small younger (< 65 years) and elderly patients (≥ 65 years) with small renal masses renal masses (Continued) < 65 years ≥ 65 years p Value * < 65 years ≥ 65 years p Value * (n = 949) (n = 574) (n = 949) (n = 574) Gender ASA classification Male n (%) 644 (68.1) 378 (66.3) 0.496 1–2 n (%) 822 (86.6) 421 (73.3) < 0.001 Female n (%) 301 (31.9) 192 (33.7) ≥ 3 n (%) 127 (13.4) 153 (26.7) Comorbidities n (%) * p-Value < 0.05 considered statistically significant. Pearson’s chi-squared test or Fisher’s exact test were used in categorical variables when appropriate. Yes 552 (61.3) 387 (72.6) < 0.001 Student’s t-test was used in continuous variables No 349 (38.7) 146 (27.4) Hypertension n (%) 115 (18.0) 128 (37.8) < 0.001 this variable. This feature was seldom evidenced and it Obesity n (%) demonstrated an ominous factor in the follow-up of Yes 229 (24.9) 131 (23.6) 0.634 these patients. No 691 (75.1) 423 (76.4) Furthermore, bilaterality and ASA classification ≥3 as- sociated with local recurrence following surgery. Patients Smoking n (%) classified with ASA ≥ 3 can present more aggressive tu- Yes 339 (35.7) 190 (33.1) 0.324 mors [32, 33]. Usually, these patients have routine clin- No 610 (64.3) 384 (66.9) ical appointments and, probably, perform more image Symptomatic at presentation n (%) exams than fit people. We suggest that these patients Yes 442 (46.6) 260 (45.3) 0.666 can have earlier diagnosis of recurrence than others. No 507 (53.4) 314 (54.7) Regarding nephrometry, patients with totally endo- phytic tumors performed RN more than three times Serum Creatinine - mg/dL than patients with exophytic tumors (76% vs. 24%). Due Baseline - Mean (SD) 1.04 (0.81) 1.17 (0.92) 0.045 to the historic long-time design of this series, we have Median (Q1 – Q3) 0.96 (0.83–1.1) 1.0 (0.83–1.2) no confident data of nephrometry scores (e.g.: Post-operative - Mean (SD) 1.20 (0.79) 1.35 (1.22) 0.143 R.E.N.A.L.). We did not find differences between totally Median (Q1 – Q3) 1.1 (0.9–1.33) 1.2 (1.01–1.41) endophytic or exophytic tumors in OS neither in our re- Tumor size currence or distant metastasis analysis (data present in only 449 cases). ≤ 3 cm n (%) 487 (62.3) 255 (55.6) 0.023 There are limitations in our study, including the retro- > 3 cm n (%) 295 (37.7) 204 (44.4) spective design and heterogeneity of each center. Patho- Surgical treatment logic reports were provided by different pathologists and Partial Nephrectomy n (%) 602 (69.7) 295 (59.7) < 0.001 central pathology review was performed only in Brazilian Radical Nephrectomy n (%) 262 (30.3) 199 (40.3) cases (N = 244). Furthermore, the heterogeneity of the Histologic subtype different centers and the long period of this series could lead to a selection bias of the elderly patients underwent Clear cell n (%) 401 (64.8) 250 (64.3) 0.921 PN or RN. Proposed protocols regarding surgical ap- Non-clear cell n (%) 218 (35.2) 139 (35.7) proaches have been changed during the last decades. Nuclear grade n (%) Additionally, we did not include patients treated with Low grade 224 (23.6) 166 (28.9) 0.025 non-surgical approaches, such as active surveillance, High grade 725 (76.4) 408 (71.1) watchful waiting, or ablative treatments, which are pos- Extracapsular extension n (%) sible options in SRM, particularly in elderly or in pa- tients with multiple comorbidities. Due to the lack of Yes 81 (10.9) 60 (14.0) 0.140 data, we were not able to report the nephrometry score No 661 (89.1) 368 (86.0) of the cases. Related to the secondary outcomes for local ECOG recurrence and distant metastasis, we were unable to de- 0–1 n (%) 912 (96.1) 543 (94.6) 0.212 fine the exact moment of the event. Thus, a logistic re- ≥ 2 n (%) 37 (3.9) 31 (5.4) gression model was the most appropriate for the analysis Karnofsky of secondary outcomes, instead of a survival analysis. Fi- nally, the short median follow-up time of 24 months ≤ 80 n (%) 73 (7.7) 69 (12.0) 0.006 could be related to possible influences on survival out- > 80 n (%) 876 (92.3) 505 (88.0) comes. Despite these limitations, this study is one of the Mourão et al. BMC Urology (2020) 20:85 Page 8 of 9 Table 3 Multivariable logistic regression analysis of predictive factors for local recurrence (a) and metastasis during follow-up (b) (a) Variable Category OR 95% CI p Value * Signs and symptoms at diagnosis – 1.265 0.593–2.694 0.543 Bilaterality Bilateral tumors 5.936 2.104–16.746 0.001 Extracapsular extension 2.700 1.216–5.995 0.015 ASA classification ASA ≥ 3 3.380 1.643–6.957 0.001 (b) Variable Category OR 95% CI p Value * Gender Male 4.494 0.545–37.058 0.163 Bilaterality Bilateral tumors 2.112 0.235–18.954 0.504 Extracapsular extension 3.849 0.881–16.821 0.073 Histologic subtype Non-clear cell Ref. – – Clear Cell 2.464 0.484–12.531 0.277 * p-Value < 0.05 considered statistically significant largest known series of patients with small renal masses Funding in Latin America. Many of the involved institutions are No funding was obtained for this study. referral centers or teaching institutions. They tend to have skilled uropathologists, more detailed pathology re- Availability of data and materials The datasets generated and/or analyzed during the current study are not cords, and more available data about oncological out- publicly available due to containing information that could compromise comes. The results are important to recognize particular research participant privacy. features of SRM in LA and to counsel patients about ap- propriate decisions. Ethics approval and consent to participate All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national Conclusions research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Institutional Review Board of RN is still overly done in the SRM setting in LA. How- Fundação Antônio Prudente approved this protocol (number 2.478.489, ever, NSS procedures are performed in a proportion CAAE: 71749917.3.0000.5432/January 30th. 2018). similar to developed areas and has been increasing in the last years. RN might be considered an overtreatment Consent for publication for many of these patients. Even in elderly individuals, if This study used secondary observational databases from existing health systems. No specific study-related informed consent was necessary from all good functional status, sufficiently fit to surgery, and individual participants included in the study. presenting favorable tumor characteristics, they should be encouraged to underwent PN. Posteriorly, a more in- Competing interests tense follow-up routine could be discussed in SRM cases The authors declare that they have no competing interests related to this with unfavorable characteristics, intend to an earlier research. diagnosis of recurrence or distant metastasis. Author details 1 A.C. Camargo Cancer Center, Rua Antônio Prudente 211, Liberdade, São Abbreviations Paulo 01509-010, Brazil. 2Pasteur Hospital, Montevideo, Uruguay. 3São Lucas ASA: American Society of Anesthesiologists; BMI: Body Mass Index; Hospital – PUCRS, Porto Alegre, Brazil. 4Italian Hospital, Buenos Aires, ECE: Extracapsular extension; ECOG: Eastern Cooperative Oncology Group; Argentina. 5Epidemiology and Statistics Department, International Research LA: Latin America; LND: Lymph nodes dissection; NSS: Nephron-sparing Center, A.C.Camargo Cancer Center, São Paulo, Brazil. 6Instituto Nacional de surgery; OS: Overall Survival; PN: Partial Nephrectomy; PSM: Positive surgical Enfermedades Neoplásicas, Lima, Peru. 7Urological Center Profesor Bengió, margins; RCC: Renal Cell Carcinoma; RN: Radical Nephrectomy; SRM: Small Cordoba, Argentina. 8Clinics Hospital José de San Martín, Buenos Aires, Renal Mass Argentina. 9Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCNSZ), Mexico City, Mexico. 10Jiménez Díaz Foundation, Madrid, Spain. 11Military Hospital, Mexico City, Mexico. 12British Hospital, Buenos Aires, Acknowledgments Argentina. 13German Hospital, Buenos Aires, Argentina. 14Instituto Arnaldo We would like to thank, in special, all participants of LARCG who contributed Vieira de Carvalho, São Paulo, Brazil. 15Corporación Médica de Paysandú to this database. (COMEPA), Paysandu, Uruguay. 16ABC Medical School, São Paulo, Brazil. 17 Policlinico Neuquén, Neuquen, Argentina. 18Clinics Hospital, Montevideo, Authors’ contributions Uruguay. 19Federal University of Minas Gerais, Belo Horizonte, Brazil. 20Military TCM was involved in data analysis and manuscript writing; GFC, GG, WHC, Hospital, Montevideo, Uruguay. 21Centro de Educación Médica e LM, RB, CS, RC, FR, AMA, JG, AN, CA, HZ, RL, DM, MTM, PM, JC, LN, OC, AR, Investigaciones Clínicas (CEMIC), Buenos Aires, Argentina. 22San Lázaro FPS, RD, GCG, SG, ORF, JP were involved in data collection and project Foundation and FUNDES, Buenos Aires, Argentina. 23Surgical Oncology development; VFC was involved in statistical analysis; DA was involved in Coordinator at Beneficencia Portuguesa Hospital, São Paulo, Brazil. 24Ipiranga group and database coordination. SCZ was involved in the idealization of Hospital, São Paulo, Brazil. 25Puigvert Foundation, Barcelona, Spain. 26National the study, data collection, project development, and manuscript revision. Institute for Science and Technology in Oncogenomics and Therapeutic Manuscript was approved by the authors. Innovation, AC Camargo Cancer Center, São Paulo, Brazil. Mourão et al. BMC Urology (2020) 20:85 Page 9 of 9 Received: 7 April 2019 Accepted: 19 June 2020 21. Secin FP, Castillo OA, Rozanec JJ, et al. American Confederation of Urology (CAU) experience in minimally invasive partial nephrectomy. World J Urol. 2017;35:57–65 https://doi.org/10.1007/s00345-016-1837-z. 22. Sun M, Abdollah F, Bianchi M, et al. Treatment Management of Small Renal References Masses in the 21st century: a paradigm shift. Ann Surg Oncol. 2012;19:2380– 1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. 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