In 2005 all the health care regions in Sweden joined the National Swedish Kidney Cancer Register (NSKCR). The intention of the NSKCR is to get reliable data regarding the health care offered to patients with renal cell carcinoma (RCC) and to support research on the subject. Other important aims for the NSKCR include the evaluation of the adherence to the national guidelines for RCC [
Sweden is divided into six health care regions, each consisting of two to seven counties, in total 21. Since January 2005, all the health care regions participate in the registration of patients in the NSKCR. All health care regions have their own local cancer register located in their Regional Cancer Center. The Regional Cancer Center of Stockholm-Gotland is responsible for the coordination of the regional registers to the NSKCR. The NSKCR is governed by a steering committee comprised of a urologist and a medical oncologist from each health care region as well as a national representative for histopathology.
All patients in Sweden with newly diagnosed RCC are reported to the respective health care region’s cancer register. It is compulsory for health care providers to report all newly detected cancer patients to the register. The regional RCC-registries are regularly cross-linked with the regional cancer registries and missing patients can be identified and searched for. The identification of patients is efficient because every Swedish citizen has a personal identity number (PIN) [
The patients of the NSKCR constitute a compiled clinical material of virtually all patients with newly diagnosed RCC in Sweden and are more thoroughly described in earlier publications [
Descriptive statistics are provided in tables. Statistical tests were calculated using two-tailed
A validation of the register was made in 2009. Ten per cent of the registered patients from 2009 were sampled and data from the medical records was compared with the data that had been reported to the NSKCR. A mismatch regarding tumor size and grade was found in some of the patients. In order to correct this problem, alterations in the layout of the reporting module was made. It is no longer possible to enter an erroneous stage due to control of the input of data. If an erroneous stage is reported or if tumor size is reported as <1 cm or >15 cm, a validation question will occur during data entry. We plan to do repeated validations.
In order to increase the quality of care for patients with RCC and to allow for benchmarking, a number of quality indicators were measured in the NSKCR. Target levels of these quality indicators were set yearly and changed as appropriate. Some examples of quality indicators are the coverage of the register, the proportion of patients undergoing chest CT, partial nephrectomy, laparoscopic surgery, and centralization to high volume hospitals.
A total of 8556 patients with newly diagnosed RCC were registered in the NSKCR between 2005 and 2013. This represents a coverage of 99% as compared to the Swedish Cancer Registry. Patients and cancer characteristics of the patients registered in the NSKCR are shown in Table
Patient and cancer characteristics in patients with RCC registered in the NSKCR from 2005 to 2013.
Number of patients (%) | ||
---|---|---|
Total number of patients | 8556 (100%) | |
|
||
Gender | Male | 5256 (61%) |
Female | 3300 (39%) | |
|
||
Age at diagnosis | Median 67 yrs |
|
|
||
Stage | T0 | 3 (0%) |
T1a | 2511 (29%) | |
T1b | 2007 (23%) | |
T2 | 1506 (18%) | |
T3 | 2017 (24%) | |
T4 | 287 (3%) | |
Tx | 213 (2%) | |
Missing data | 12 (0%) | |
|
||
Fuhrman grade |
G1 | 926 (12%) |
G2 | 3496 (44%) | |
G3 | 2072 (26%) | |
G4 | 705 (9%) | |
GX | 657 (8%) | |
Missing data | 178 (2%) | |
|
||
Histopathology |
Clear cell | 6298 (78%) |
Papillary | 957 (12%) | |
Chromophobe | 399 (5%) | |
Collecting duct | 33 (0.4%) | |
Not possible to classify | 156 (2%) | |
Other kidney cancers | 147 (2%) | |
Missing data | 44 (1%) |
During the period we found a significant trend towards more incidental detection. In 2005, 43%, versus 48% in 2008 and in 2013 55%, of the patients were incidentally detected (
Variation of tumor size (mean and range) at the time of diagnosis (mm) in 2005–2013.
The recommended work-up for all patients with newly detected RCC included a chest CT for the evaluation of pulmonary metastases. The proportion of patients who underwent chest CT increased from 59% in 2005 to 90% in 2013 (
Metastatic disease (mRCC) at presentation was found in 5%, 9%, 21%, 37%, and 60% in patients with RCC stages T1a, T1b, T2, T3, and T4, respectively [
Percentage of patients diagnosed with metastatic renal cell carcinoma at primary diagnosis in relation to the total number of patients by year of diagnosis.
The patients who were diagnosed with nonmetastatic RCC during 2005–2007 and treated with curative intention were followed up after five years. During the five years of follow-up, 20% of the patients suffered a recurrence. The most common location of recurrence was lung, followed by bone, lymph nodes, and liver.
A total of 76% patients with RCC were treated with a curative intention. In the patients diagnosed in 2005–2011 radical nephrectomy (RN) was the most common treatment (74%) followed by partial nephrectomy (PN, 23%) and minimally invasive treatments such as cryotherapy and radiofrequency ablation were performed in 2% of the cases [
An increased use of laparoscopic technique was noted during the years of work with the NSKCR. The laparoscopic approach was increasingly used both for RNs and PNs. The proportion of RNs laparoscopically performed increased from 6% in 2005 to 17% in 2010. During 2009–2013, 14% of the PNs were performed by laparoscopic technique and robotic assisted surgery was used in nearly one-third of these cases.
During the last decade there has been a clear trend of an increasing proportion of patients with RCC that have been treated at large volume hospitals (>25 nephrectomies per year, Figure
Number of nephrectomies in large volume hospitals (>25 nephrectomies per year) as compared to medium (6–25 nephrectomies per year) and small volume hospitals (≤5 nephrectomies per year).
The survival at five years for the whole cohort of patients with RCC was 70%. We found no difference in relative survival between men and women. The relative survival was strongly connected to T and M stage. The relative survival at five years for patients with RCC M0 was 85% and for patients with RCC M1 20% [
The NSKCR has been in operation for a decade and virtually all patients with newly detected RCC in Sweden are registered. The register is continuously expanding and data is maturing. Several manuscripts emanating from the NSKCR are published ([
Publications based on data from the NSKCR.
Reference | Journal | Year | Topic | Main findings |
---|---|---|---|---|
Guðmundsson et al. [ |
European Urology | 2011 | Metastatic potential in small renal tumors | Even small tumors (1-2 cm) have a malignant potential |
|
||||
Thorstenson et al. [ |
Scandinavian Journal of Urology | 2014 | Tumor characteristics and surgical treatment | A significant decrease in tumor size and metastatic disease at presentation |
|
||||
Ljungberg et al. [ |
Scandinavian Journal of Urology | 2014 | Surgical treatment of T1c tumours | Partial nephrectomy was underutilized in 2005–2011 (23% underwent PN) |
|
||||
Thorstenson et al. [ |
Scandinavian Journal of Urology (in press) | 2015 | The impact of quality indicators on the compliance to guidelines for RCC | Quality indicators in the NSKCR increased the compliance to the national guidelines for RCC |
The proportion of patients undergoing preoperative chest CT is continuously increasing during this last decade in Sweden. The registration itself, including the yearly reports from the NSKCR, probably stimulates stronger adherence to the national guidelines of RCC [
In order to minimize errors due to misclassification one important aim for the NSKCR is to maintain histopathology reports that follow the Swedish recommendations [
PNs and laparoscopically performed RNs have become more widely used over the last decade. More than half of the patients with tumors ≤4 cm underwent PNs in 2012. This is the recommended treatment for T1a tumors in both the national and the EAU guidelines [
The strength of this material is that it includes virtually all patients diagnosed with RCC in Sweden. The data is truly population based and the risk for selection bias can be ignored. The data registration is performed prospectively and the data are continuously validated at the registration centers and thereby the likelihood of erroneous data is reduced.
Until now, there has been no specific information on patients with mRCC receiving systemic therapy. However, from now on there is an oncologic module which records oncological treatments. We also intend to include patient reported outcome measures (PROM) as well as a detailed registration of surgical variables and surgical complications occurring within 90 days.
In conclusion, we find a continuous trend of early detection and migration towards less advanced tumors at presentation in patients diagnosed with of RCC in Sweden during the last decade. An increasing proportion of the patients undergo laparoscopic- and nephron-sparing procedures.
The authors alone are responsible for the content and writing of the paper.
The authors report no conflict of interests.
The members of the NSKCR are Börje Ljungberg (chairman), Stina Christensen, Britt-Inger Dahlin, Peter Elfving, Ulrika Harmenberg, Benny Holmström, Annika Håkansson, Åsa Jellvert, Per Lindblad, Magnus Lindskog, Sven Lundstam, Ann-Helén Scherman-Plogell, Andreas Thorstenson, Emma Ulvskog, and Janos Vasko. The study was supported by grants from Umeå University, and Lions Cancer Research Foundation, Umeå (BL), the Research Foundation at the Urology Department of Sahlgrenska University Hospital, the Foundation of Anna-Lisa and Bror Björnsson (SL), the Stockholm Cancer Society, and Capio S:t Görans Hospital (AT).