Petrus Järvinen

Survival of patients with pseudomyxoma peritonei treated by serial debulking.

Aim  We evaluated the outcome of patients with pseudomyxoma peritonei (PMP) after traditional debulking. PMP is a clinical condition characterized by disseminated intraperitoneal mucinous tumours often accompanied by mucinous ascites derived usually from an appendiceal neoplasm. Patients with PMP have traditionally been treated by serial debulking, but aggressive cytoreduction followed by hyperthermic intraperitoneal chemotherapy is now advocated as standard treatment in PMP.

Genomic profile of pseudomyxoma peritonei analyzed using next‐generation sequencing and immunohistochemistry

Pseudomyxoma peritonei (PMP) is a relatively rare clinical syndrome characterized by neoplastic epithelial cells growing in the peritoneal cavity and secreting mucinous ascites. Our aim was to explore the molecular events behind this fatal but under‐investigated disease. We extracted DNA from 19 appendix‐derived PMP tumors and nine corresponding normal tissues, and analyzed the mutational hotspot areas of 48 cancer‐related genes by amplicon‐based next‐generation sequencing (NGS). Further, we analyzed the protein expression of V600E mutated BRAF, MLH1, MSH2, MSH6 and p53 from a larger set of PMP tumors (n = 74) using immunohistochemistry. With NGS, we detected activating somatic KRAS mutations in all of the tumors studied. GNAS was mutated in 63% of the tumors with no marked difference between low‐grade and high‐grade tumors. Only one (5.3%) tumor showed oncogenic PIK3CA mutation, one showed oncogenic AKT1 mutation, three (15.8%) showed SMAD4 mutations and none showed an APC mutation. P53 protein was aberrantly expressed in higher proportion of high‐grade tumors as compared with low‐grade ones (31.3 vs. 7.1%, respectively; p = 0.012) and aberrant expression was an independent factor for reduced overall survival (p = 0.002). BRAF V600E mutation was only found in one (1.4%) high‐grade tumor by immunohistochemistry (n = 74). All the studied tumors expressed mismatch repair proteins MLH1, MSH2 and MSH6. Our results indicate that KRAS mutations are evident in all and GNAS mutations in most of the PMPs, but BRAF V600E, PIK3CA and APC mutations are rare. Aberrantly expressed p53 is associated with high‐grade histology and reduced survival.

Hand-assisted laparoscopic versus open partial nephrectomy in patients with T1 renal tumor: Comparative perioperative, functional and oncological outcome

Abstract Objective: Studies comparing hand-assisted laparoscopic partial nephrectomy (HALPN) and open partial nephrectomy (OPN) for T1 kidney tumors are scarce. This study investigated the perioperative, functional and oncological outcomes of these methods. Materials and methods: A prospective institutional kidney tumor register was used to identify patients between January 2006 and May 2014 undergoing HALPN (n = 139) or OPN (n = 165) for tumors 7 cm or smaller with non-absolute indication for nephron-sparing surgery. The outcomes were compared using univariate and multivariate statistical methods. Results: HALPN and OPN groups were similar with regard to tumor characteristics but HALPN patients were 2 years younger (p = 0.001) and had less comorbidity. Fewer intraoperative complications were encountered in HALPN than in OPN patients (7.2% vs 12.7%, p = 0.043). HALPN patients had less all-grade postoperative 30 day complications than OPN patients (27% vs 41%, p = 0.037), but there was no significant difference in Clavien 3–5 complications. Glomerular filtration rate 3 months after operation was lower in the HALPN than in the OPN group (7.1 ± 12.7% vs 10.0 ± 12.4%, p = 0.054). There was no difference in overall survival or recurrence-free survival during the median follow-up of 35 months. Conclusions: HALPN is a feasible method to achieve equal perioperative, functional and oncological outcomes compared to OPN in patients with tumors 7 cm or smaller in diameter.

FEASIBILITY OF RADICAL CYTOREDUCTIVE SURGERY AND HYPERTHERMIC INTRAPERITONEAL CHEMOTHERAPY FOR PSEUDOMYXOMA PERITONEI OF APPENDICEAL ORIGIN

Background and Aims: We analyzed the feasibility of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with pseudomyxoma peritonei. Material and Methods: A prospective database comprised 90 consecutive patients with demonstrable pseudomyxoma peritonei collected during 48 months. These patients, referred to our unit for consideration for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, received both cytoreductive surgery and hyperthermic intraperitoneal chemotherapy if possible. We evaluated the factors associated with a successful procedure. Results: Hyperthermic intraperitoneal chemotherapy was successfully delivered to 56 of 90 patients (62%) with demonstrable pseudomyxoma peritonei. Tumor morphology of low grade (p = 0.013), age under 65 years (p = 0.004), and serum carcinoembryonic antigen level under 5.0 µg/L (p = 0.003) were associated with successful administration of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Mean peritoneal cancer index was lower (18.9 vs 32.6, p < 0.001) and age was younger (54.3 vs 61.6, p = 0.003) in patients who underwent hyperthermic intraperitoneal chemotherapy than in patients who did not. Four patients had complete cytoreductive surgery alone, and 20 patients underwent palliative debulking, but 10 were ineligible for this operation. Conclusions: Although the combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is currently suggested the standard practice for pseudomyxoma peritonei, not all patients are eligible for this protocol. In this study, hyperthermic intraperitoneal chemotherapy was suitable for 62% of patients with pseudomyxoma peritonei of appendiceal origin.

Expression of CEA, CA19-9, CA125, and EpCAM in pseudomyxoma peritonei

Pseudomyxoma peritonei is a fatal clinical syndrome with mucinous tumor cells disseminated into peritoneal cavity and secreting abundant mucinous ascites. The serum tumor markers CEA, CA19-9, and CA125 are used to monitor pseudomyxoma peritonei remission, but their expression at tissue level has not been well characterized. Herein, we analyzed expression of these proteins and the adenocarcinoma marker EpCAM in 92 appendix-derived pseudomyxoma peritonei tumors by immunohistochemistry. All tumors were found to ubiquitously express CEA and EpCAM. In the majority of the tumors (94.6%), CEA showed polarized immunostaining, but in 5 aggressive high-grade tumors containing numerous signet ring cells, a nonpolarized staining was detected. We found preoperative CEA serum values to correlate with peritoneal cancer index. However, the serum values of the advanced cases with nonpolarized staining pattern were normal, and the patients died within 5 years after diagnosis. Thus, serum CEA measurements did not reflect aggressiveness of these tumors. CA19-9 showed strong immunopositivity in most of the tumors (91.3%), and mutated enzyme FUT3 was demonstrated from the cases showing negative or weak staining. CA125 was infrequently expressed by tumor cells (focal staining in 6.5% of the cases), but in most of the cases (79.3%), adjacent nonneoplastic mesothelial cells showed immunopositivity. As a conclusion, CEA and EpCAM are invariably expressed by pseudomyxoma peritonei tumor cells and could be exploited to targeted therapies against this malignancy.

Contemporary treatment of renal tumors: a questionnaire survey in the Nordic countries (the NORENCA-I study)

Abstract Objective: The five Nordic countries comprise 25 million people, and have similar treatment traditions and healthcare systems. To take advantage of these similarities, a collaborative group (Nordic Renal Cancer Group, NORENCA) was founded in 2015. Materials and methods: A questionnaire of 17 questions on renal tumor management and surgical education was designed and sent to 91 institutions performing renal tumor surgery in 2015. The response rate was 68% (62 hospitals), including 28 academic, 25 central and nine district hospitals. Hospital volume was defined as low (LVH: < 20 operations), intermediate (IVH: 20–49 operations), high (HVH: 50–99) and very high (VHVH: ≥ 100). Descriptive statistics were performed. Results: Fifteen centers were LVH, 16 IVH, 21 HVH and 10 VHVH. Of all 3828 kidney tumor treatments, 55% were radical nephrectomies (RNs), 37% partial nephrectomies (PNs) and 8% thermoablations. For RN and PN, the percentages of open, laparoscopic and robotic approaches were 47%, 40%, 13% and 47%, 20%, 33%, respectively. The mean complication rate (Clavien–Dindo 3–5) was 4.9%, and 30 day mortality (TDM) was 0.5%. The median length of hospital stay was 4 days. Training with a simulator, black box or animal laboratory was possible in 48%, 74% and 21% of institutions, respectively. Conclusions: Despite some differences between countries, the data suggest an overall general common Nordic treatment attitude for renal tumors. Furthermore, the data demonstrate high adherence to international standards, with a high proportion of PN and acceptable rates for major complications and TDM.

Multiple components of PKA and TGF-β pathways are mutated in pseudomyxoma peritonei

Pseudomyxoma peritonei (PMP) is a subtype of mucinous adenocarcinoma mainly restricted to the peritoneal cavity and most commonly originating from the appendix. The genetic background of PMP is poorly understood and no targeted treatments are currently available for this fatal disease. While RAS signaling pathway is affected in most if not all PMP cases and over half of them also have a mutation in the GNAS gene, other genetic alterations and affected pathways are, to a large degree, poorly known. In this study, we sequenced whole coding genome of nine PMP tumors and paired normal tissues in order to identify additional, commonly mutated genes and signaling pathways affected in PMP. These exome sequencing results were validated with an ultra-deep amplicon sequencing method, leading to 14 validated variants. The validated results contain seven genes that contribute to the protein kinase A (PKA) pathway. PKA pathway, which also contains GNAS, is a major player of overproduction of mucin, which is the characteristic feature of PMP. In addition to PKA pathway, we identified mutations in six genes that belong to the transforming growth factor beta (TGF-β) pathway, which is a key regulator of cell proliferation. Since either GNAS mutation or an alternative mutation in the PKA pathway was identified in 8/9 patients, inhibition of the PKA pathway might reduce mucin production in most of the PMP patients and potentially suppress disease progression.

Repeat multiparametric MRI in prostate cancer patients on active surveillance

Introduction This study was conducted to describe the changes in repeat multiparametric MRI (mpMRI) occurring in prostate cancer (PCa) patients during active surveillance (AS), and to study possible associations between mpMRI-related parameters in predicting prostate biopsy (Bx) Gleason score (GS) upgrading >3+3 and protocol-based treatment change (TC). Materials and methods The study cohort consisted of 76 AS patients with GS 3+3 PCa and at least two consecutive mpMRIs of the prostate performed between 2006–2015. Patients were followed according to the Prostate Cancer Research International Active Surveillance (PRIAS) protocol and an additional mpMRI. The primary end points were GS upgrading (GU) (>3+3) in protocol-based Bxs and protocol-based TC. Results Out of 76 patients, 53 (69%) had progression (PIRADS upgrade, size increase or new lesion[s]), while 18 (24%) had radiologically stable disease, and 5 (7%) had regression (PIRADS or size decrease, disappearance of lesion[s]) in repeat mpMRIs during AS. PIRADS scores of 4–5 in the initial mpMRI were associated with GU (p = 0.008) and protocol-based TC (p = 0.009). Tumour progression on repeat mpMRIs was associated with TC (p = 0.045) but not with GU (p = 1.00). PIRADS scores of 4–5 predict GU (sensitivity 0.80 [95% confidence interval (CI); 0.51–0.95, specificity 0.62 [95% CI; 0.52–0.77]) with PPV and NPV values of 0.34 (95% CI; 0.21–0.55) and 0.93 (95% CI; 0.80–0.98), respectively. Conclusion mpMRI is a useful tool not only to select but also to monitor PCa patients on AS.

Carbonic anhydrase II: a novel biomarker for pseudomyxoma peritonei

Altered expression of carbonic anhydrase (CA) II is associated with human carcinogenesis. We analysed CA II protein expression in 89 patients with pseudomyxoma peritonei (PMP) and correlated its association against survival. We determined the expression of CA II by immunohistochemistry and then scored the staining results. The correlations of CA II expression with Peritoneal Cancer Index (PCI) and tumour grade were examined. The effect of CA II and tumour grade on survival was investigated. Positive CA II expression was found in 58 patients (65%) and absent in 31 patients (35%). High‐grade (HG) morphology was associated with a loss of CA II expression (p = 0.048). The mean CA II immunostaining intensity score was 1.00 ± 1.1 (median 1, range 0–3) for HG morphology and 1.54 ± 1.1 (median 2, range 0–3) for low‐grade (LG) morphology. The 5‐year overall survival (OS) for those patients with CA II expression was 80% and 59% for those without (p < 0.001). The 5‐year OS rates for those patients with HG morphology and positive CA II expression was 72% and 31% for those with negative CA II expression (p = 0.044). This study suggests that the expression of CA II acts as independent prognostic biomarker for survival in PMP.

Renal Tumor Invasion Depth and Diameter are the Two Most Accurate Anatomical Features Regarding the Choice of Radical Versus Partial Nephrectomy

Background and Aims: To evaluate simple tumor characteristics (renal tumor diameter and parenchymal invasion depth) compared with more complex classifications, that is, Renal Tumor Invasion Index (RTII) and Preoperative Aspects and Dimensions Used for an Anatomical classification, in predicting the type of nephrectomy (radical vs partial) performed. Material and Methods: A total of 915 patients who had undergone either partial nephrectomy (n = 388, 42%) or radical nephrectomy (n = 527, 58%) were identified from the Helsinki University Hospital kidney tumor database between 1 January 2006 and 31 December 2014. Tumor maximum diameter and depth of invasion into the parenchyma were estimated from computed tomography or magnetic resonance imaging images and compared with Preoperative Aspects and Dimensions Used for an Anatomical and Renal Tumor Invasion Index. Logistic regression and receiver operating curves were used to compare the parameters at predicting the type of nephrectomy. Results and conclusion: All the anatomical variables of receiver operating curve/area under the curve analyses were significant predictors for the type of nephrectomy. Parenchymal invasion (area under the curve 0.91; 95% confidence interval, 0.89–0.93), RTII (area under the curve 0.91; 95% confidence interval, 0.89–0.93), and diameter (area under the curve 0.91; 95% confidence interval, 0.89–0.93) performed significantly better than Preoperative Aspects and Dimensions Used for an Anatomical classification (area under the curve 0.88; 95% confidence interval, 0.85–0.89). In multivariable analysis, invasion depth was the best predictor of nephrectomy type (percentage correct, 85.6%). Addition of one anatomic parameter into the model of non-anatomical cofactors improved the accuracy of the model significantly, but the addition of more parameters did not. Parenchymal invasion depth and tumor diameter are the most accurate anatomical features for predicting the nephrectomy type. All potential anatomical classification systems should be tested against these two simple characteristics.