Treatment of clinical T1 rectal cancer in the Netherlands; a population-based overview of clinical practice.

INTRODUCTION: Local excision is increasingly used as an alternative treatment for radical surgery in patients with early stage clinical T1 (cT1) rectal cancer. This study provides an overview of incidence, staging accuracy and treatment strategies in patients with cT1 rectal cancer in the Netherlands. MATERIALS AND METHODS: Patients with cT1 rectal cancer diagnosed between 2005 and 2018 were included from the Netherlands Cancer Registry. An overview per time period (2005-2009, 2010-2014 and 2015-2018) of the incidence and various treatment strategies used, e.g. local excision (LE) or major resection, with/without neoadjuvant treatment (NAT), were given and trends over time were analysed using the Chi Square for Trend test. In addition, accuracy of tumour staging was described, compared and analysed over time. RESULTS: In total, 3033 patients with cT1 rectal cancer were diagnosed. The incidence of cT1 increased from 540 patients in 2005-2009 to 1643 patients in 2015-2018. There was a significant increased use of LE. In cT1N0/X patients, 9.2% received NAT, 25.5% were treated by total mesorectal excision (TME) and 11.4% received a completion TME (cTME) following prior LE. Overall accuracy in tumour staging (cT1 = pT1) was 77.3%, yet significantly worse in cN1/2 patients, as compared to cN0 patients (44.8% vs 77.9%, respectively, p < 0.001). CONCLUSION: Over time, there was an increase in the incidence of cT1 tumours. Both the use of neoadjuvant therapy and TME surgery in clinically node negative patients decreased significantly. Clinical accuracy in T1 tumour staging improved over time, but remained significantly worse in clinical node positive patients.

Validation of a clinicopathological and gene expression profile model for sentinel lymph node metastasis in primary cutaneous melanoma.

BACKGROUND: The Clinicopathological and Gene Expression Profile (CP-GEP) model was developed to accurately identify patients with T1-T3 primary cutaneous melanoma at low risk for nodal metastasis. OBJECTIVES: To validate the CP-GEP model in an independent Dutch cohort of patients with melanoma. METHODS: Patients (aged ≥ 18 years) with primary cutaneous melanoma who underwent sentinel lymph node biopsy (SLNB) between 2007 and 2017 at the Erasmus Medical Centre Cancer Institute were eligible. The CP-GEP model combines clinicopathological features (age and Breslow thickness) with the expression of eight target genes involved in melanoma metastasis (ITGB3, PLAT, SERPINE2, GDF15, TGFBR1, LOXL4, CXCL8 and MLANA). Using the pathology result of SLNB as the gold standard, performance measures of the CP-GEP model were calculated, resulting in CP-GEP high risk or low risk for nodal metastasis. RESULTS: In total, 210 patients were included in the study. Most patients presented with T2 (n = 94, 45%) or T3 (n = 70, 33%) melanoma. Of all patients, 27% (n = 56) had a positive SLNB, with nodal metastasis in 0%, 30%, 54% and 16% of patients with T1, T2, T3 and T4 melanoma, respectively. Overall, the CP-GEP model had a negative predictive value (NPV) of 90·5% [95% confidence interval (CI) 77·9-96.2], with an NPV of 100% (95% CI 72·2-100) in T1, 89·3% (95% CI 72·8-96·3) in T2 and 75·0% (95% CI 30·1-95·4) in T3 melanomas. The CP-GEP indicated high risk in all T4 melanomas. CONCLUSIONS: The CP-GEP model is a noninvasive and validated tool that accurately identified patients with primary cutaneous melanoma at low risk for nodal metastasis. In this validation cohort, the CP-GEP model has shown the potential to reduce SLNB procedures in patients with melanoma.

Treatment of melanoma of unknown primary in the era of immunotherapy and targeted therapy: A Dutch population-based study.

Melanoma of unknown primary (MUP) may have a different biology to melanoma of known primary, but clinical trials of novel therapies (e.g., immune checkpoint or BRAF/MEK inhibitors) have not reported the outcomes in this population. We therefore evaluated the overall survival (OS) among patients with MUP in the era of novel therapy. Data for stage III or IV MUP were extracted from a nationwide database for the period 2003-2016, with classification based on the eighth edition of the American Joint Committee on Cancer criteria. The population was divided into pre- (2003-2010) and post- (2011-2016) novel therapy eras. Also, OS in the post-novel era was compared between patients with stage IV MUP by whether they received novel therapy. In total, 2028 of 65,110 patients (3.1%) were diagnosed with MUP. Metastatic sites were known in 1919 of 2028 patients, and most had stage IV disease (53.8%). For patients with stage III MUP, the 5-year OS rates were 48.5% and 50.2% in the pre- and post-novel eras, respectively (p = 0.948). For those with stage IV MUP, the median OS durations were unchanged in the pre-novel era and post-novel era when novel therapy was not used (both 4 months); however, OS improved to 11 months when novel therapy was used in the post-novel era (p < 0.001). In conclusion, more than half of the patients with MUP are diagnosed with stage IV and the introduction of novel therapy appears to have significantly improved the OS of these patients.

Development and validation of a nomogram to predict recurrence and melanoma-specific mortality in patients with negative sentinel lymph nodes.

BACKGROUND: Patients with melanoma and negative sentinel nodes (SNs) have varying outcomes, dependent on several prognostic factors. Considering all these factors in a prediction model might aid in identifying patients who could benefit from a personalized treatment strategy. The objective was to construct and validate a nomogram for recurrence and melanoma-specific mortality (MSM) in patients with melanoma and negative SNs. METHODS: A total of 3220 patients with negative SNs were identified from a cohort of 4124 patients from four EORTC Melanoma Group centres who underwent sentinel lymph node biopsy. Prognostic factors for recurrence and MSM were studied with Cox regression analysis. Significant factors were incorporated in the models. Performance was assessed by discrimination (c-index) and calibration in cross-validation across the four centres. A nomogram was developed for graphical presentation. RESULTS: There were 3180 eligible patients. The final prediction model for recurrence and the calibrated model for MSM included three independent prognostic factors: ulceration, anatomical location and Breslow thickness. The c-index was 0·74 for recurrence and 0·76 for the calibrated MSM model. Cross-validation across the four centres showed reasonable model performance. A nomogram was developed based on these models. One-third of the patients had a 5-year recurrence probability of 8·2 per cent or less, and one-third had a recurrence probability of 23·0 per cent or more. CONCLUSION: A nomogram for predicting recurrence and MSM in patients with melanoma and negative SNs was constructed and validated. It could provide personalized estimates useful for tailoring surveillance strategies (reduce or increase intensity), and selection of patients for adjuvant therapy or clinical trials.

Depletion of SMC5/6 sensitizes male germ cells to DNA damage.

The structural maintenance of chromosomes complex SMC5/6 is thought to be essential for DNA repair and chromosome segregation during mitosis and meiosis. To determine the requirements of the SMC5/6 complex during mouse spermatogenesis we combined a conditional knockout allele for Smc5, with four germ cell-specific Cre-recombinase transgenes, Ddx4-Cre, Stra8-Cre, Spo11-Cre, and Hspa2-Cre, to mutate Smc5 in spermatogonia, in spermatocytes before meiotic entry, during early meiotic stages, and during midmeiotic stages, respectively. Conditional mutation of Smc5 resulted in destabilization of the SMC5/6 complex. Despite this, we observed only mild defects in spermatogenesis. Mutation of Smc5 mediated by Ddx4-Cre and Stra8-Cre resulted in partial loss of preleptotene spermatocytes; however, spermatogenesis progresses and mice are fertile. Mutation of Smc5 via Spo11-Cre or Hspa2-Cre did not result in detectable defects of spermatogenesis. Upon exposure to gamma irradiation or etoposide treatment, each conditional Smc5 mutant demonstrated an increase in the number of enlarged round spermatids with multiple acrosomes and supernumerary chromosome content. We propose that the SMC5/6 complex is not acutely required for premeiotic DNA replication and meiotic progression during mouse spermatogenesis; however, when germ cells are challenged by exogenous DNA damage, the SMC5/6 complex ensures genome integrity, and thus, fertility.

Improved stratification of pT1 melanoma according to the 8th American Joint Committee on Cancer staging edition criteria: A Dutch population-based study.

INTRODUCTION: The 8th American Joint Committee on Cancer (AJCC) staging edition includes revisions regarding pT1 melanomas. We aimed to evaluate the expected impact of this edition on staging and survival in the Dutch pT1 melanoma population. METHODS: In total, 32,935 pT1 melanoma patients, whose data were retrieved from the Netherlands Cancer Registry between 2003 and 2015, were included in the study. Patients were stratified by the 6th AJCC edition (cohort 1: 2003-2009) and 7th edition (cohort 2: 2010-2015) and all reclassified according to the 8th edition. Stage migration, sentinel lymph node biopsy (SLNB) positivity rates and relative survival were analysed. Agreement between staging systems was calculated by Cohen's kappa coefficient. RESULTS: In cohort 2, restaging according to the 8th edition led to an increase of 7% in the total number of patients staged pT1b. The kappa score for agreement between the 6th and 8th edition was 0.15 and 0.25 for agreement between 7th and 8th edition. Restaging according to the 8th edition resulted in a higher SLNB positivity rate for pT1b patients than pT1a patients (8% versus 5%, p = 0.08). Relative survival curves were predominantly similar between the staging editions. CONCLUSIONS: Implementation of the 8th AJCC staging edition will presumably not have major impact on the total number of Dutch pT1b patients. Consequently, the number of patients eligible for SLNB would roughly remain similar. In terms of SLNB positivity, the selection of high-risk pT1 melanoma patients is likely to improve. In addition, the 8th edition criteria for pT1 melanoma seem more workable for pathologists.

Optimal extent of completion lymphadenectomy for patients with melanoma and a positive sentinel node in the groin.

BACKGROUND: The optimal extent of groin completion lymph node dissection (CLND) (inguinal or ilioinguinal dissection) in patients with melanoma is controversial. The aim of this study was to evaluate whether the extent of groin CLND after a positive sentinel node biopsy (SNB) is associated with improved outcome. METHODS: Data from all sentinel node-positive patients who underwent groin CLND at four tertiary melanoma referral centres were retrieved retrospectively. Baseline patient and tumour characteristics were collected for descriptive statistics, survival analyses and Cox proportional hazards regression analyses. RESULTS: In total, 255 patients were included, of whom 137 (53·7 per cent) underwent inguinal dissection and 118 (46·3 per cent) ilioinguinal dissection. The overall CLND positivity rate was 18·8 per cent; the inguinal positivity rate was 15·5 per cent and the pelvic positivity rate was 9·3 per cent. The pattern of recurrence, and 5-year melanoma-specific survival, disease-free survival and distant-metastasis free survival rates were similar for both dissection types, even for patients with a positive CLND result. Cox regression analysis showed that type of CLND was not associated with disease-free or melanoma-specific survival. CONCLUSION: There was no significant difference in recurrence pattern and survival rates between patients undergoing inguinal or ilioinguinal dissection after a positive SNB, even after stratification for a positive CLND result. An inguinal dissection is a safe first approach as CLND in patients with a positive SNB.

Treatment of extra-articular proximal and middle phalangeal fractures of the hand: a systematic review.

The aim of the study was to systematically review the patient reported and functional outcomes of treatment for extra-articular proximal or middle phalangeal fractures of the hand in order to determine the best treatment options. The review methodology was registered with PROSPERO. A systematic literature search was conducted in electronic bibliographic databases. Two independent reviewers performed screening and data extraction. The evaluation of quality of the included studies was performed using the Structured Effectiveness Quality Evaluation scale. The initial search yielded 2354 studies. The full text manuscripts of 79 studies were evaluated of which 16 studies met the inclusion criteria. In total, 513 extra-articular proximal and middle phalangeal fractures of the hand were included of which 118 (23%) were treated non-operatively, 188 (37%) were treated by closed reduction internal fixation (CRIF) and 207 (40%) by open reduction internal fixation. It can be recommended that closed displaced extra-articular phalangeal fractures can be treated non-operatively, even fractures with an oblique or complex pattern, provided that closed reduction is possible and maintained. Conservative treatment is preferably performed with a cast/brace allowing free mobilization of the wrist. No definite conclusion could be drawn upon whether closed reduction with extra-articular K-wire pinning or transarticular pinning is superior; however, it might be suggested that extra-articular K-wire pinning is favoured. When open reduction is necessary for oblique or spiral extra-articular fractures, lag screw fixation is preferable to plate and screw fixation. But, similar recovery and functional results are achieved with transversally inserted K-wires compared to lag screw fixation. TYPE OF STUDY/LEVEL OF EVIDENCE: therapeutic III.

Vascular management during live donor nephrectomy: an online survey among transplant surgeons.

In 2006, a survey from the American Society of Transplant Surgeons disclosed significant and sometimes fatal hemorrhagic events in live donor nephrectomies (LDN) related to failure of clips, leading to the contraindication of the Weck® Hem-o-lok® clip for control of the renal artery during LDN. A survey regarding vascular control techniques, their perceived safety ratings and their failures was sent to 645 European Society for Organ Transplantation members who profiled their profession as "surgeon" and selected "kidney" as organ type. Two hundred forty-three (41%) members responded, of whom 171 (63.3%) independently perform LDN. Their responses were analyzed. For arterial and venous vascular control, the GIA™ and TA™stapler are used most frequently, and were rated the safest. Of the 121 reported hemorrhagic events, slippage and dislodgement of clips occurred at least 58 times, while stapler malfunction occurred at least 40 times. One donor death from hemorrhage related to clip dysfunction was reported. Hemorrhagic complications of LDN with fatal and non-fatal outcomes still occur. Strikingly, many surgeons do not use the vascular closing technique that they consider most safe. Failure of non-transfixion techniques is associated with greater risks for the donor. Control of major vessels in LDN must employ transfixion techniques for optimal donor safety.

Role for rodent Smc6 in pericentromeric heterochromatin domains during spermatogonial differentiation and meiosis.

Chromatin structure and function are for a large part determined by the six members of the structural maintenance of chromosomes (SMC) protein family, which form three heterodimeric complexes: Smc1/3 (cohesin), Smc2/4 (condensin) and Smc5/6. Each complex has distinct and important roles in chromatin dynamics, gene expression and differentiation. In yeast and Drosophila, Smc6 is involved in recombinational repair, restarting collapsed replication forks and prevention of recombination in repetitive sequences such as rDNA and pericentromeric heterochromatin. Although such DNA damage control mechanisms, as well as highly dynamic changes in chromatin composition and function, are essential for gametogenesis, knowledge on Smc6 function in mammalian systems is limited. We therefore have investigated the role of Smc6 during mammalian spermatogonial differentiation, meiosis and subsequent spermiogenesis. We found that, during mouse spermatogenesis, Smc6 functions as part of meiotic pericentromeric heterochromatin domains that are initiated when differentiating spermatogonia become irreversibly committed toward meiosis. To our knowledge, we are the first to provide insight into how commitment toward meiosis alters chromatin structure and dynamics, thereby setting apart differentiating spermatogonia from the undifferentiated spermatogonia, including the spermatogonial stem cells. Interestingly, Smc6 is not essential for spermatogonial mitosis, whereas Smc6-negative meiotic cells appear unable to finish their first meiotic division. Importantly, during meiosis, we find that DNA repair or recombination sites, marked by γH2AX or Rad51 respectively, do not co-localize with the pericentromeric heterochromatin domains where Smc6 is located. Considering the repetitive nature of these domains and that Smc6 has been previously shown to prevent recombination in repetitive sequences, we hypothesize that Smc6 has a role in the prevention of aberrant recombination events between pericentromeric regions during the first meiotic prophase that would otherwise cause chromosomal aberrations leading to apoptosis, meiotic arrest or aneuploidies.