To count and how to count, that is the question: interobserver and intraobserver variability among pathologists in lymph node counting

What is your count? An observational study of lymph node counting in 2,028 colorectal cancer resections

BACKGROUND

Lymph node status and lymph node count (LNC) are predictors of colorectal cancer outcome. Under-sampling of lymph nodes may lead to clinically relevant stage migration.

METHODS

Colorectal cancer (CRC) cases with a synoptic report, accessioned 2012-2020 at a regional laboratory, were extracted and retrospectively studied. LNC, positive lymph node count (PLNC), tumour deposits present (TDpos), and 'y' (staging) prefix (YS) were retrieved and tabulated by pathologist using custom software. Statistical analyses were done with R.

DATA AND RESULTS

The cohort had 2,543 CRC resections. Seventeen pathologists interpreted >50 cases (range: 56-356) each and collectively saw 2,074. After cases with unavailable data were purged, 2,028 cases remained with 43,996 lymph nodes, of which 2,637/43,996 were positive. 368 cases had a 'y' prefix, and 379 had TDpos. The 17 pathologists' median LNC/case was 19.0 (range: 14.0-24.0), and the mean PLNC per case was 1.4 (range: 1.0-2.0). Kruskal-Wallis rank sum tests showed there were differences in LNC (p<0.001) among pathologists; however, PLNC did not show this association (p = 0.2917). T-tests showed that mean LNC (p<0.001) and PLNC (p<0.035) differed between YS. 138 of 2,028 cases had less than the 12 LNC target. Logistic regression revealed a strong association between meeting the LNC target and pathologist (p<0.001) but TDpos was non-predictive (p = 0.4736).

CONCLUSIONS

Positive lymph node call rate has a good consistency in the laboratory; however, lymph node count varies significantly between pathologists. Standardized counting criteria are needed to improve uniformity and could be aided by synoptic reporting data.

Prognostic Value of Lymph Node Ratio in Patients with Uterine Carcinosarcoma

Uterine carcinosarcoma is a rare high-grade endometrial cancer. Controversy has surrounded a number of aspects in the diagnosis and management of this unique clinicopathological entity, including the efficacy of adjuvant therapy, which has been questioned. An unusual surgico-pathological parameter with prognostic significance in a number of tumour sites is the lymph node ratio (LNR). The availability of data in this respect has been scarce in the literature. The primary aim of this collaborative study was to evaluate the prognostic value of LNR in patients with uterine carcinosarcoma. LNR is a recognized lymph node metric used to stratify prognosis in a variety of malignancies. In this European multinational retrospective study, 93 women with uterine carcinosarcoma were included in the final analysis. We used t-tests and ANOVA for comparison between quantitative variables between the groups, and chi-square tests for qualitative variables. A multivariate analysis using Cox regression analysis was performed to determine potential prognostic factors, including the LNR. Patients were grouped with respect to LNR in terms of 0%, 20% > 0% and >20%. The analysis revealed LNR to be a significant predictor of progression-free survival (HR 1.69, CI (1.12-2.55), p = 0.012) and overall survival (HR 1.71, CI (1.07-2.7), p = 0.024). However, LNR did not remain a significant prognostic factor on multivariate analysis. Due to limitations of the retrospective study, a prospective large multinational study, which takes into effect the most recent changes to clinical practice, is warranted to elucidate the value of the pathophysiological metrics of the lymphatic system associated with prognosis.

Lymph node level ratio as a predictor of survival in oral cavity squamous cell carcinoma

OBJECTIVE

To evaluate whether nodal yields and ratios based on level serves as prognostic indicators in patients with oral cavity squamous cell carcinoma undergoing neck dissection.

MATERIALS AND METHODS

A retrospective analysis of 342 patients with oral cavity squamous cell carcinoma treated surgically between 1998 and 2017 were included.Demographics and clinicopathologic data were collated. Disease specific survival and overall survival were analyzed via Kaplan-Meier method and log-rank test as well as univariable and multivariable Cox models.

RESULTS

Total nodal yield is associated with improved overall and disease specific survival (p < 0.01). Total positive nodal yield (p < 0.01), positive nodal ratio per level (p < 0.001), and identification of <4 lymph nodes/level (p < 0.001) are associated with worse disease specific survival and overall survival. A ratio of at least 4 lymph nodes/level dissected yields the maximal hazard ratio on for both disease specific and overall survival optimizes the Kaplan-Meier split between survival groups. After controlling for sex, age, margin status, disease stage, extranodal extension, perineural invasion, and lymphovascular invasion as fixed covariates in the Cox models, a nodal level ratio of 4 lymph nodes/level provides hazard ratio (95% CI) of 3.59 (1.69, 7.60); p < 0.0006) for disease free survival and 2.90 (1.54, 5.46; p < 0.001) for overall survival.

CONCLUSION

Nodal level ratio of < 4 lymph nodes/level is associated with worse disease specific and overall survival in oral cavity squamous cell carcinoma. This level-specific metric may prove useful qualitatively and in predicting survival in oral cavity cancer with broader utility to address variations in levels of neck dissection performed.

Urothelial Carcinoma: Update on Staging and Reporting, and Pathologic Changes Following Neoadjuvant Chemotherapies

Staging and reporting of cancers of the urinary tract have undergone major changes in the past decade to meet the needs for improved patient management. Substantial progress has been made. There, however, remain issues that require further clarity, including the substaging of pT1 tumors, grading and reporting of tumors with grade heterogeneity, and following NAC. Multi-institutional collaborative studies with prospective data will further inform the accurate diagnosis, staging, and reporting of these tumors, and in conjunction with genomic data will ultimately contribute to precision and personalized patient management.

Reassessment of the Optimal Number of Examined Lymph Nodes in Pancreatoduodenectomy for Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The aim of this study was to reappraise the optimal number of examined lymph nodes (ELNs) in pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

SUMMARY BACKGROUND DATA

The well-established threshold of 15 ELNs in PD for PDAC is optimized for detecting 1 positive node (PLN) per the previous 7th edition of the American Joint Committee on Cancer (AJCC) staging manual. In the framework of the 8th edition, where at least 4 PLN are needed for an N2 diagnosis, this threshold may be inadequate for accurate staging.

METHODS

Patients who underwent upfront PD at 2 academic institutions between 2000 and 2016 were analyzed. The optimal ELN threshold was defined as the cut-point associated with a 95% probability of identifying at least 4 PLNs in N2 patients. The results were validated addressing the N-status distribution and stage migration.

RESULTS

Overall, 1218 patients were included. The median number of ELN was 26 (IQR 17-37). ELN was independently associated with N2-status (OR 1.27, P < 0.001). The estimated optimal threshold of ELN was 28. This cut-point enabled improved detection of N2 patients and stage III disease (58% vs 37%, P = 0.001). The median survival was 28.6 months. There was an improved survival in N0/N1 patients when ELN exceeded 28, suggesting a stage migration effect (47 vs 29 months, adjusted HR 0.649, P < 0.001). In N2 patients, this threshold was not associated with survival on multivariable analysis.

CONCLUSION

Examining at least 28 LN in PD for PDAC ensures optimal staging through improved detection of N2/stage III disease. This may have relevant implications for benchmarking processes and quality implementation.

Deep learning-based approach to the characterization and quantification of histopathology in mouse models of colitis

Inflammatory bowel disease (IBD) is a chronic immune-mediated disease of the gastrointestinal tract. While therapies exist, response can be limited within the patient population. Researchers have thus studied mouse models of colitis to further understand pathogenesis and identify new treatment targets. Flow cytometry and RNA-sequencing can phenotype immune populations with single-cell resolution but provide no spatial context. Spatial context may be particularly important in colitis mouse models, due to the simultaneous presence of colonic regions that are involved or uninvolved with disease. These regions can be identified on hematoxylin and eosin (H&E)-stained colonic tissue slides based on the presence of abnormal or normal histology. However, detection of such regions requires expert interpretation by pathologists. This can be a tedious process that may be difficult to perform consistently across experiments. To this end, we trained a deep learning model to detect ‘Involved’ and ‘Uninvolved’ regions from H&E-stained colonic tissue slides. Our model was trained on specimens from controls and three mouse models of colitis–the dextran sodium sulfate (DSS) chemical induction model, the recently established intestinal epithelium-specific, inducible Klf5^ΔIND (Villin-CreER^T2;Klf5^fl/fl) genetic model, and one that combines both induction methods. Image patches predicted to be ‘Involved’ and ‘Uninvolved’ were extracted across mice to cluster and identify histological classes. We quantified the proportion of ‘Uninvolved’ patches and ‘Involved’ patch classes in murine swiss-rolled colons. Furthermore, we trained linear determinant analysis classifiers on these patch proportions to predict mouse model and clinical score bins in a prospectively treated cohort of mice. Such a pipeline has the potential to reveal histological links and improve synergy between various colitis mouse model studies to identify new therapeutic targets and pathophysiological mechanisms.

Multiplexed imaging and automated signal quantification in formalin-fixed paraffin-embedded tissues by ChipCytometry

Deciphering the spatial composition of cells in tissues is essential for detailed understanding of biological processes in health and disease. Recent technological advances enabled the assessment of the enormous complexity of tissue-derived parameters by highly multiplexed tissue imaging (HMTI), but elaborate machinery and data analyses are required. This severely limits broad applicability of HMTI. Here we demonstrate for the first time the application of ChipCytometry technology, which has unique features for widespread use, on formalin-fixed paraffin-embedded samples, the most commonly used storage technique of clinically relevant patient specimens worldwide. The excellent staining quality permits workflows for automated quantification of signal intensities, which we further optimized to compensate signal spillover from neighboring cells. In combination with the high number of validated markers, the reported platform can be used from unbiased analyses of tissue composition to detection of phenotypically complex rare cells, and can be easily implemented in both routine research and clinical pathology.

Intra-abdominal lymph node flaps in lymphedema therapy: An anatomical guide to donor site selection

BACKGROUND

Secondary lymphedema is a leading sequela of cancer surgery and radiotherapy. The microsurgical transfer of lymph node flaps (LNFs) to affected limbs can improve the symptoms. The intra-abdominal cavity contains an abundant heterogenic source. The aim of this study is to aid selection among intra-abdominal LNFs.

METHODS

Eight LNFs were harvested in a microsurgical fashion at five sites in 16 cadavers: gastroepiploic, jejunal, ileal, ileocolic, and appendicular. These flaps were compared regarding size, weight, arterial diameter, and lymph node (LN) count after histologic verification.

RESULTS

One hundred and sixteen flaps were harvested. The exposed area correlated with the flap weight and volume (r²  = 0.86, r = 0.9). While gastroepiploic LNFs (geLNFs) showed the highest median weight of 99 ml, the jejunal LNFs (jLNFs) had the highest density with 3.8 LNs per 10 ml. The most reliable jLNF was 60 cm from the ligament of Treitz. Three or more LNs were contained in 94% of the jejunal, 88% of the ileal/ileocolic, and 63% of the omental LNs. The ileocolic LNF had the largest arterial diameter of 3 mm, yet the smallest volume.

CONCLUSIONS

jLNF and ileal LNF provide a reliable, high LN density for simultaneous, smaller recipient sites. geLNFs are more suitable for larger recipient sites.

Updated pathology reporting standards for bladder cancer: biopsies, transurethral resections and radical cystectomies

Aim

Optimal management of bladder cancer requires an accurate, standardised and timely pathological diagnosis, and close communication between surgeons and pathologists. Here, we provide an update on pathology reporting standards of transurethral resections of the bladder and cystectomies.

Methods

We reviewed recent literature, focusing on developments between 2013 and 2021.

Results

Published reporting standards developed by pathology organizations have improved diagnosis and treatment. Tumor sub-staging and subtyping has gained increased attention. Lymph nodes continue to be an area of debate, and their staging has seen minor modifications. Several tasks, particularly regarding specimen preparation (“grossing”), are not yet standardized and offer opportunity for improvement. Molecular classification is rapidly evolving, but currently has only limited impact on management.

Conclusion

Pathological reporting of bladder cancer is continuously evolving and remains challenging in some areas. This review provides an overview of recent major developments, with a particular focus on published reporting standards.

Variation in Lymph Node Yield After Radical Cystectomy

OBJECTIVES

To test the hypothesis that lymph node yield will vary by pathology assistant (PA) in patients undergoing radical cystectomy (RC) with pelvic lymph node dissection (PLND).

METHODS

This is a single-institution retrospective review that included patients who underwent an RC with PLND for bladder cancer from January 1, 2007, to January 1, 2018. Predicted mean lymph node counts were generated using multivariable regression analysis.

RESULTS

In a total of 430 patients who underwent RC with PLND, the median lymph node count (interquartile range) was 15.0 (11.0-21.0). The frequency of the limits of lymphadenectomy was as follows: external iliac, internal iliac, and obturator (true pelvis) (33.3%); true pelvis plus common iliac to the level of the aortic bifurcation (47.9%); and inferior mesenteric artery (18.8%). On descriptive analysis, there were differences in lymph node yield when evaluating the following variables: level of dissection, clinical stage, neoadjuvant chemotherapy, surgical approach, surgeon, pathologist, and PA (P < .05). On multivariable analysis, adjusted lymph node counts varied between surgeons, pathologists, clinical stage, and level of dissection but not by PA (P = .18).

CONCLUSIONS

Lymph node yield after RC varies on several known levels, including surgeon, extent of lymphadenectomy, clinical stage, and pathologist. This study found no significant variation in lymph node yield according to PA.

Association of lymph node yield with overall survival in patients with pathologically node negative prostate cancer

We investigated the association between lymph node yield (LNY) with overall survival (OS) and post-radical prostatectomy (RP) secondary treatments among men with pathologically node negative (pN0) prostate cancer. We reviewed the National Cancer Database for men with Gleason Grade Group 2 or higher prostate cancer treated with RP and had pathologically node-negative disease. LNY was modeled as a continuous and categorical variable grouped by quartiles of LNY. Secondary treatment was defined as the use of radiation or systemic therapy post-RP. Multivariable Cox proportional hazards and logistic regression models were used to test for an association of LNY with OS and secondary treatments, respectively. We identified 89,416 men with pN0 prostate cancer treated with RP from 2010-2015. LNY was associated with improved OS when modeled as a categorical and continuous variable. The third (6-9 nodes) and fourth (≥10 nodes) quartiles of LNY were associated with improved OS (HR 0.87, 95% CI 0.79-0.96, P = 0.006 and HR 0.88, 95% CI 0.79-0.98, P= 0.017, respectively) when compared with the lowest quartile of LNY (≤3 nodes) and the hazard of death decreased by 1% for each benign lymph node removed (HR 0.99, 95% CI 0.98-0.99, P= 0.022). Additionally, categorical and continuous LNY was associated with significantly less use of post-RP secondary treatments. Removal of additional negative lymph nodes was associated with improved OS and less secondary treatments in patients with pN0 prostate cancer. These data suggest that removing a higher quantity of lymph nodes provides more accurate staging and prognosis.

Pathological reporting of cystectomy lymph nodes: a retrospective analysis of experience in Paris

Purpose

Pathological evaluation of pelvic lymph node (LN) dissection (PLND) is important for management of cystectomy patients. However, challenges such as unclear interobserver variability of LN counting remain. Here, we assess interobserver variability of LN measures and their clinical utility, with a focus on variant histology.

Methods

We retrieved radical cystectomy cases with PLND between 2010 and 2016 and reevaluated pathological parameters; number of total and metastatic LN, LN density (LND), length of metastatic LN and metastases, extranodal extension (ENE).

Results

We report 96 patients: median age of 71a, 34 cases pN+, 36 cases with any extent of variant histology, median follow-up 10 months. Perivesical LN were only rarely identified, but frequently metastatic (4/9). Variant histology (34 cases) frequently exhibited LN metastasis (53% of pN+ cases). Interobserver variance was poor for total LN (kappa = 0.167), excellent for positive LN (0.85) and pN staging (0.96), and mediocre for LND (0.53). ROC analysis suggests that both LND and the sum of LN metastasis length may predict outcome (AUC 0.83 and 0.75, respectively).

Conclusion

Our study confirms the notion of LND as a prognostic measure, but cautions due to strong interobserver variance of LN counts. The sum length of LN metastases could be a measure that is independent of LN counts. We find that microscopically identified perivesical LN merit particular attention. In summary, our study highlights current challenges in pathological reporting of PLND, confirms previous observations and forms a basis for further studies.

Does Timing of Robotic Esophagectomy Adoption Impact Short-Term Postoperative Outcomes?

BACKGROUND

Robotic esophagectomies are increasingly common and are reported to have superior outcomes compared with an open approach; however, it is unclear if all institutions can achieve such outcomes. We hypothesize that early adopters of robotic technique would have improved short-term outcomes.

METHODS

The National Cancer Database (2010-2016) was used to identify robotic esophagectomies. Early adopters were defined as programs which performed robotic esophagectomies in 2010-2011, late adopters in 2012-2013. Outcomes of esophagectomies performed between 2014 and 2016 were compared and included length of stay, number of lymph nodes evaluated, readmission, conversion rate, and 90-day mortality. Multivariable regressions, accounting for robotic esophagectomy volume, were used to control for confounding factors.

RESULTS

There were 37 early adopters and 35 late adopters. Between 2014 and 2016, 683 robotic esophagectomies were performed: 446 (65.3%) by early adopters and 237 (34.7%) by late adopters. Early adopters were more likely to be academic programs (96.2 versus 72.8%, P < 0.01). Other clinical and demographic variables were similar. Late adopters were found to have decreased a number of lymph nodes evaluated (coefficient -2.407, P = 0.004) compared with early adopters. There were no significant differences in length of stay, readmissions, rate of positive margins, conversion from robotic to open, or 90-day mortality.

CONCLUSIONS

When accounting for robotic esophagectomy volume, late adoption of robotic esophagectomy was associated with a reduced lymph node harvest, but other postoperative outcomes were similar. These data suggest that programs can safely start new robotic esophagectomy programs, but must ensure an adequate case load.

Impact of Lymph Node Yield in Patients Undergoing Total Laryngectomy and Neck Dissection

OBJECTIVES

To determine the impact of lymph node yield (LNY) in patients undergoing neck dissection at the time of total laryngectomy (TL). To determine the impact of radiation therapy (RT) on LNY.

METHODS

Retrospective review of LNY and clinical outcomes in 232 patients undergoing primary or salvage total laryngectomy (TL) with ND.

RESULTS

Preoperative RT significantly decreased mean LNY from 31.7 to 23.9 nodes (P < .001). In primary TL patients, age (P < .001) and positive margins (P = .044) were associated with decreased OS. In salvage TL patients, only positive margins was associated with poorer OS (P = .009). No LNY cutoff provided significant OS or DFS benefit.

CONCLUSIONS

Radiotherapy significantly reduces LNY in patients undergoing TL and ND. Within a single institution cohort, positive margins, but not LNY, is associated with survival in both primary and salvage TL patients.Level of Evidence: 4.

Clinical markers of morbidity, mortality and survival in bladder cancer patients treated with radical cystectomy. A systematic review

Context: Radical cystectomy and pelvic lymph node dissection (RC and PLND) are an essential part of the treatment paradigm in high risk bladder cancer. However, these patients have high rates of morbidity and mortality related both to the treatment and to the disease.Objective: To provide overview of current literature about clinical markers that can be used to predict and improve BC-patient outcomes at the time of RC and PLND and to study if they are properly validated.Evidence acquisition: A systematic literature search was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria between January 1990 and October 2018 to identify English written original and review articles relevant to this topic. Prospective and retrospective studies were included.Evidence synthesis: There are several risk factors identified from non-randomised trials that can be improved before surgery to reduce perioperative mortality and morbidity. These include poor nutritional status, anaemia, renal function and smoking. Preoperative nomograms have also been developed to help decision-making and to inform patients about the risks of surgery. They can be used to estimate risk of postoperative mortality after RC and PLND with accuracy varying from 70 to 86%. These nomograms are largely based on retrospective data. Likewise, nomograms developed to calculate estimates about patient's overall and cancer specific survival have the same limitations.Conclusion: Clinical markers to predict morbidity, mortality and survival in patients with bladder cancer treated with RC and PLND may help to improve patient outcomes and treatment decision-making, but available data come from small retrospective trials and have not been properly validated. Prospective, multi-centre studies are needed to implement and disseminate predictive clinical markers and nomograms such that they can be utilised in treatment decision-making in daily practice.

Handling and reporting of pelvic lymphadenectomy specimens in prostate and bladder cancer: a web-based survey by the European Network of Uropathology

AIMS

Pathological evaluation of lymphadenectomy specimens plays a pivotal role in accurate lymph node (LN) staging. Guidelines standardising the gross handling and reporting of pelvic LN dissection (PLND) in prostate (PCa) and bladder (BCa) cancer are currently lacking. This study aimed to establish current practice patterns of PLND evaluation among pathologists.

METHODS AND RESULTS

A web-based survey was circulated to all members of the European Network of Uropathology (ENUP), comprising 29 questions focusing on the macroscopic handling, LN enumeration and reporting of PLND in PCa and BCa. Two hundred and eighty responses were received from pathologists throughout 23 countries. Only LNs palpable at grossing were submitted by 58%, while 39% routinely embedded the entire specimen. Average LN yield from PLND was ≥10 LNs in 56% and <10 LNs in 44%. Serial section(s) and immunohistochemistry were routinely performed on LN blocks by 42% and <1% of respondents, respectively. To designate a LN microscopically, 91% required a capsule/subcapsular sinus. In pN+ cases, 72% reported the size of the largest metastatic deposit and 94% reported extranodal extension. Isolated tumour cells were interpreted as pN1 by 77%. Deposits identified in fat without associated lymphoid tissue were reported as tumour deposits (pN0) by 36% and replaced LNs (pN+) by 27%. LNs identified in periprostatic fat were included in the PLND LN count by 69%.

CONCLUSION

This study highlights variations in practice with respect to the gross sampling and microscopic evaluation of PLND in urological malignancies. A consensus protocol may provide a framework for more consistent and standardised reporting of PLND specimens.

Does lymphadenectomy improve survival in patients with intermediate risk endometrial cancer? A multicentric study from the FRANCOGYN Research Group

Objective

The role of lymphadenectomy in intermediate risk endometrial cancer remains uncertain. We evaluated the impact of lymphadenectomy on overall survival and relapse-free survival for patients with intermediate risk endometrial cancer.

Methods

We retrospectively reviewed patients from the FRANCOGYN database with intermediate risk endometrial cancer, based on pre-operative and post-operative criteria (type 1, grade 1–2 tumors with deep (> 50%) myometrial invasion and no lymphovascular space invasion), who received primary surgical treatment between November 2002 and August 2013. We compared overall survival and relapse-free survival between staged and unstaged patients.

Results

From 1235 screened patients, we selected 108 patients with intermediate risk endometrial cancer. Eighty-two (75.9%) patients underwent nodal staging (consisting of pelvic +/- para-aortic lymphadenectomy). Among them, 35 (32.4%) had lymph node disease. The median follow-up was 25 months (range 0.4 to 155.0). The overall survival rates were 82.5% for patients staged (CI 64.2 to 91.9) vs 77.9 % for unstaged patients (CI 35.4 to 94.2) (P = 0.73). The relapse-free survival rates were 68.9% for staged patients (CI 51.2 to 81.3) vs 68.8% for unstaged patients (CI 29.1 to 89.3) (P=0.67).

Conclusion

Systematic nodal staging does not appear to improve overall survival and relapse-free survival for patients with IR EC but could provide information to tailor adjuvant therapy. Sentinel lymph node dissection may be an effective and less invasive alternative staging technique and should provide a future alternative for this population.

Sentinel lymph node biopsy in endometrial cancer-Feasibility, safety and lymphatic complications

OBJECTIVE

To compare the rate of lymphatic complications in women with endometrial cancer undergoing sentinel lymph node biopsy versus a full pelvic and infrarenal paraaortic lymphadenectomy, and to examine the overall feasibility and safety of the former.

METHODS

A prospective study of 188 patients with endometrial cancer planned for robotic surgery. Indocyanine green was used to identify the sentinel lymph nodes. In low-risk patients the lymphadenectomy was restricted to removal of sentinel lymph nodes whereas in high-risk patients also a full lymphadenectomy was performed. The impact of the extent of the lymphadenectomy on the rate of complications was evaluated.

RESULTS

The bilateral detection rate of sentinel lymph nodes was 96% after cervical tracer injection. No intraoperative complication was associated with the sentinel lymph node biopsy per se. Compared with hysterectomy alone, the additional average operative time for removal of sentinel lymph nodes was 33min whereas 91min were saved compared with a full pelvic and paraaortic lymphadenectomy. Sentinel lymph node biopsy alone resulted in a lower incidence of leg lymphedema than infrarenal paraaortic and pelvic lymphadenectomy (1.3% vs 18.1%, p=0.0003).

CONCLUSION

The high feasibility, the absence of intraoperative complications and the low risk of lymphatic complications supports implementing detection of sentinel lymph nodes in low-risk endometrial cancer patients. Given that available preliminary data on sensitivity and false negative rates in high-risk patients are confirmed in further studies, we also believe that the reduction in lymphatic complications and operative time strongly motivates the sentinel lymph node concept in high-risk endometrial cancer.

Changes in treatment and outcome of oesophageal cancer in Denmark between 2004 and 2013

Background

Since 2003, care for patients with oesophageal cancer has been centralized in a few dedicated centres in Denmark. The aim of this study was to assess changes in the treatment and outcome of patients registered in a nationwide database.

Methods

All patients diagnosed with oesophageal cancer or cancer of the gastro-oesophageal junction who underwent oesophagectomy in Denmark between 2004 and 2013, and who were registered in the Danish clinical database of carcinomas in the oesophagus, gastro-oesophageal junction and stomach (DECV database) were included. Quality-of-care indicators, including number of lymph nodes removed, anastomotic leak rate, 30- and 90-day mortality, and 2- and 5-year overall survival, were assessed. To compare quality-of-care indicators over time, the relative risk (RR) was calculated using a multivariable log binomial regression model.

Results

Some 6178 patients were included, of whom 1728 underwent oesophagectomy. The overall number of patients with 15 or more lymph nodes in the resection specimen increased from 38·1 per cent in 2004 to 88·7 per cent in 2013. The anastomotic leak rate decreased from 14·8 to 7·6 per cent (RR 0·66, 95 per cent c.i. 0·43 to 1·01). The 30-day mortality rate decreased from 4·5 to 1·7 per cent (RR 0·51, 0·22 to 1·15) and the 90-day mortality rate from 11·0 to 2·9 per cent (RR 0·46, 0·26 to 0·82). There were no statistically significant changes in 2- or 5-year survival rates over time.

Conclusion

Indicators of quality of care have improved since the centralization of oesophageal cancer treatment in Denmark.

Institutional variants for lymph node counts after pancreatic resections

BACKGROUND

Lymph node (LN) counts from pancreatectomy are postulated as quality metric for surgical therapy of pancreatic malignancy.

METHODS

Prospectively collected data from a single surgeon's pancreatectomy experience were analyzed for predictors of LN counts.

RESULTS

Of 315 consecutive patients (54% female, median age: 65, range 18-88), 239 had a proven cancer diagnosis (76%). Operations included pancreatoduodenectomy (69%), distal pancreatectomy (26%), total pancreatectomy (1%) and others (4%). Patients were treated in 4 different tertiary cancer center settings (Institution A: 11%; B: 46%; C: 27%; D: 16%) with consistent regional dissection standards. Mean total LN counts differed between institutions for malignancies (A: 18, B: 13, C: 26, D: 26, p < 0.0001) and benign diseases (p = 0.003). At least 15 LNs were reported in 63% of cancer patients (institution range: 34-92%, p < 0.0001).

CONCLUSIONS

Pathologic processing should be standardized if LN numbers are to be adopted as quality metric for pancreatic cancer resections.

Development, validation and clinical application of Pelvic Lymphadenectomy Assessment and Completion Evaluation: intraoperative assessment of lymph node dissection after robot-assisted radical cystectomy for bladder cancer

OBJECTIVES

To develop a scoring tool, Pelvic Lymphadenectomy Appropriateness and Completion Evaluation (PLACE), to assess the intraoperative completeness and appropriateness of pelvic lymph node dissection (PLND) following robot-assisted radical cystectomy (RARC).

PATIENTS, SUBJECTS AND METHODS

A panel of 11 open and robotic surgeons developed the content and structure of PLACE. The PLND template was divided into three zones. In all, 21 de-identified videos of bilateral robot-assisted PLNDs were assessed by the 11 experts using PLACE to determine inter-rater reliability. Lymph node (LN) clearance was defined as the proportion of cleared LNs from all PLACE zones. We investigated the correlation between LN clearance and LN count. Then, we compared the LN count of 18 prospective PLNDs using PLACE with our retrospective series performed using the extended template (No PLACE).

RESULTS

A significant reliability was achieved for all PLACE zones among the 11 raters for the 21 bilateral PLND videos. The median (interquartile range) for LN clearance was 468 (431-545). There was a significant positive correlation between LN clearance and LN count (R² = 0.70, P < 0.01). The PLACE group yielded similar LN counts when compared to the No PLACE group.

CONCLUSIONS

Pelvic Lymphadenectomy Appropriateness and Completion Evaluation is a structured intraoperative scoring system that can be used intraoperatively to measure and quantify PLND for quality control and to facilitate training during RARC.

Radical cystectomy: do we need standardization?

INTRODUCTION

The first series of radical cystectomy with a definition of surgical landmarks was published in 1949 and was characterized by a high perioperative mortality and a 5-year survival rate around 50%. Decades later, nevertheless many surgical progresses were made and the perioperative mortality dropped to 2,5%, this had not lead to an improvement of long term survival rates, also because a standardization of the procedure is still missing. Areas covered: Radical cystectomy is performed with different surgical techniques obmitting a standardization. The comparability of many studies is therefore difficult or havely compromised. A paragon with other diciplines was made emphazing that there high surgical quality is defined, measured and controlled. A systematic literature search was made selecting finally 76 article adressing this issue. Expert commentary: Surgical guidelines in uro-oncology are vague and a definition of surgical quality is missing. A view outside of the box could be very helpful. This is a plea for a change.

Does the gross prosector impact pT3 subclassification or lymph node counts in bladder cancer?

Gross prosector analysis of perivesicular adipose tumor invasion is the sole differentiator between pT3 substages, and gross evaluation is critical to lymph node identification. Gross prosector impact on pT3 subclassification and lymph node counts in cystectomy specimens resected for bladder cancer has not been previously analyzed. Both pT3 subclassification and total number of lymph nodes removed at radical cystectomy for bladder cancer are considered important components of the pathology report; however, both have controversial prognostic significance. Our objective was to assess the impact of the gross prosector on pT3 substaging and lymph node count. Pathology reports from 560 cystectomy cases performed for primary bladder cancer were reviewed. Educational interventions regarding cystectomy gross prosector documentation were conducted. Gross prosectors did not document the presence or absence of macroscopic perivesicular adipose invasion in 17% of cases. There was a decrease in the frequency of cases lacking documentation after educational intervention (33% to 5%, P<.01). Most pT3 cases lacking documentation were classified as pT3a (75%). The percentage of pT3 cases classified as pT3a decreased after intervention (68% to 35%, P<.01). Overcounting of lymph nodes by gross prosectors was more common than undercounting (22% versus 2%). Pathology residents and prosectors with lower caseloads had more uncounted lymph packets (P<.01). In conclusion, we demonstrated an impact of the gross prosector on pT3 substaging and lymph node counts within bladder cancer resection specimens. This novel variable may confound the relationship of these parameters upon oncologic outcomes and should be incorporated into quality assurance programs.

Does a Higher Cutoff Value of Lymph Node Retrieval Substantially Improve Survival in Patients With Advanced Gastric Cancer?-Time to Embrace a New Digit

BACKGROUND

The present study assessed the impact of the retrieval of >25 lymph nodes (LNs) on the survival outcome of patients with advanced gastric cancer after curative-intent gastrectomy.

PATIENTS AND METHODS

A total of 5,386 patients who had undergone curative gastrectomy for gastric cancer from 1994 to 2011 were enrolled. The clinicopathological parameters and overall survival (OS) were analyzed according to the number of LNs examined (≤15, n = 916; 16-25, n = 1,458; and >25, n = 3,012).

RESULTS

The percentage of patients with >25 LNs retrieved increased from 1994 to 2011. Patients in the LN >25 group were more likely to have undergone total gastrectomy and to have a larger tumor size, poorer tumor differentiation, and advanced T and N stages. Hospital mortality among the LN ≤15, LN 16-25, and LN >25 groups was 6.1%, 2.7%, and 1.7%, respectively (p < .0001). The LN >25 group consistently exhibited the most favorable OS, in particular, with stage II disease (p = .011) when OS was stratified according to tumor stage. Similarly, the LN >25 group had significantly better OS in all nodal stages (from N1 to N3b). The discrimination power of the lymph node ratio (LNR) for the LN ≤15, LN 16-25, and LN >25 groups was 483, 766, and 1,560, respectively. Multivariate analysis demonstrated that the LNR was the most important prognostic factor in the LN >25 group.

CONCLUSION

Retrieving more than 25 lymph nodes during curative-intent gastrectomy substantially improved survival and survival stratification of advanced gastric cancer without compromising patient safety. The Oncologist 2017;22:97-106Implications for Practice: D2 lymph node (LN) dissection is currently the standard of surgical management of gastric cancer, which is rarely audited by a third party. The present study, one of the largest surgical series worldwide, has shown that the traditionally recognized retrieval of ≥16 LNs during curative-intent gastrectomy might not be adequate in regions in which locally advanced gastric cancers predominate. The presented data show that retrieval of >25 LNs, which more greatly mimics D2 dissection, improves long-term outcomes and survival stratification without compromising patient safety.

Histological features associated with diagnostic agreement in atypical ductal hyperplasia of the breast: illustrative cases from the B-Path study

AIMS

This study examined the case-specific characteristics associated with interobserver diagnostic agreement in atypical ductal hyperplasia (ADH) of the breast.

METHODS AND RESULTS

Seventy-two test set cases with a consensus diagnosis of ADH from the B-Path study were evaluated. Cases were scored for 17 histological features, which were then correlated with the participant agreement with the consensus ADH diagnosis. Participating pathologists' perceptions of case difficulty, borderline features or whether they would obtain a second opinion were also examined for associations with agreement. Of the 2070 participant interpretations of the 72 consensus ADH cases, 48% were scored by participants as difficult and 45% as borderline between two diagnoses; the presence of both of these features was significantly associated with increased agreement (P < 0.001). A second opinion would have been obtained in 80% of interpretations, and this was associated with increased agreement (P < 0.001). Diagnostic agreement ranged from 10% to 89% on a case-by-case basis. Cases with papillary lesions, cribriform architecture and obvious cytological monotony were associated with higher agreement. Lower agreement rates were associated with solid or micropapillary architecture, borderline cytological monotony, or cases without a diagnostic area that was obvious on low power.

CONCLUSIONS

The results of this study suggest that pathologists frequently recognize the challenge of ADH cases, with some cases being more prone to diagnostic variability. In addition, there are specific histological features associated with diagnostic agreement on ADH cases. Multiple example images from cases in this test set are provided to serve as educational illustrations of these challenges.

Lymph Node Yield in Colon Cancer: Individuals Can Make the Difference

AIM

To investigate the influence of individual surgeons and pathologists on examining an adequate (i.e. ≥10) number of lymph nodes in colon cancer resection specimens.

PATIENTS AND METHODS

The number of lymph nodes was evaluated in surgically treated patients for colon cancer at our hospital from 2008 through 2010, excluding patients who had received neo-adjuvant treatment. The patient group consisted of 156 patients with a median age of 73 (interquartile range (IQR) 63-82 years) and a median of 12 lymph nodes per patient (IQR 8-15). In 106 patients (67.9%), 10 or more nodes were histopathologically examined.

RESULTS

At univariate analysis, the examination of ≥10 nodes was influenced by tumour size (p = 0.05), tumour location (p = 0.015), type of resection (p = 0.034), individual surgeon (p = 0.023), and pathologist (p = 0.005). Neither individual surgeons nor pathologists did statistically and significantly influence the chance of finding an N+ status. Age (p = 0.044), type of resection (p = 0.007), individual surgeon (p = 0.012) and pathologist (p = 0.004) were independent prognostic factors in a multivariate model for finding ≥10 nodes.

CONCLUSION

Though cancer staging was not affected in this study, individual efforts by surgeons and pathologists play a critical role in achieving optimal lymph node yield through conventional methods.

Three-tiered nodal classification system for bladder cancer: a new proposal

ABSTRACT 

Aim: To evaluate a three-tiered prognostic stratification using one, two to five and >five positive lymph nodes (LNs) and this nodal staging system performs across different pelvic LN dissection (PLND) templates and adjuvant chemotherapy status. Methods: We evaluated 244 patients with positive LN urothelial cancer who underwent radical cystectomy and PLND between 2000 and 2011. Survival analyses utilizing the Kaplan-Meier method and log rank test were performed. Median follow-up was 55.3 months (range: 0.4–141). Multivariable Cox proportional hazards models were built to evaluate the prognostic stratification. Results: Extended PLND template was performed on 152 (62.3%) patients and standard on 92 (37.7%). The median number of LNs resected was 14 in the standard group vs 22 in the extended group (p < 0.01) and positive LNs was 2 vs 3 (p = 0.09), respectively. Stratification in patients with: one positive LN, two to five positive LNs or >five positive LNs lead to 5-year recurrence-free survival of: 48.6, 34.5 and 15.9% for each group, while the 5-year overall survival was: 43.0, 22.1 and 11.3%, respectively. Stratification in the three groups was also verified irrespective of PLND template and adjuvant chemotherapy. Two multivariable models confirmed the findings when controlling for demographic features and known pathologic risk factors. Conclusion: Three-tiered nodal classification system using the number of metastatic LNs (one, two to five and >five) stratifies patients with lymphatic disease into distinct prognostic groups.

Understanding diagnostic variability in breast pathology: lessons learned from an expert consensus review panel

AIMS

To gain a better understanding of the reasons for diagnostic variability, with the aim of reducing the phenomenon.

METHODS AND RESULTS

In preparation for a study on the interpretation of breast specimens (B-PATH), a panel of three experienced breast pathologists reviewed 336 cases to develop consensus reference diagnoses. After independent assessment, cases coded as diagnostically discordant were discussed at consensus meetings. By the use of qualitative data analysis techniques, transcripts of 16 h of consensus meetings for a subset of 201 cases were analysed. Diagnostic variability could be attributed to three overall root causes: (i) pathologist-related; (ii) diagnostic coding/study methodology-related; and (iii) specimen-related. Most pathologist-related root causes were attributable to professional differences in pathologists' opinions about whether the diagnostic criteria for a specific diagnosis were met, most frequently in cases of atypia. Diagnostic coding/study methodology-related root causes were primarily miscategorizations of descriptive text diagnoses, which led to the development of a standardized electronic diagnostic form (BPATH-Dx). Specimen-related root causes included artefacts, limited diagnostic material, and poor slide quality. After re-review and discussion, a consensus diagnosis could be assigned in all cases.

CONCLUSIONS

Diagnostic variability is related to multiple factors, but consensus conferences, standardized electronic reporting formats and comments on suboptimal specimen quality can be used to reduce diagnostic variability.

Lymph node-positive bladder cancer: surgical, pathologic, molecular and prognostic aspects

The presence of lymphatic metastasis is associated with markedly worse prognosis in patients with bladder cancer, although surgical resection and chemotherapy can still provide long-term survival for selected patients. The prognostic stratification of patients with positive lymph nodes has been broadly discussed in the current literature and a more extensive pelvic lymph node dissection and thorough pathologic assessment has been advocated. It is clear that stratification using the tumor node metastasis staging system is insufficient to adequately discriminate prognosis between patients with different lymph node involvement. Lymph node density and extranodal extension have been extensively investigated and appear to influence the prognosis of these patients. Molecular markers have been developed to improve the diagnosis of micrometastatic disease, and new targeted therapies have shown promising preclinical results and are now being tested in different clinical scenarios.

Ex vivo dissection increases lymph node yield in oesophagogastric cancer

BACKGROUND

Retrieval and analysis of an adequate number of lymph nodes is critical for accurate staging of oesophageal and gastric cancer. Higher total node counts reported by pathologists are associated with improved survival. A prospective study was undertaken to understand the factors contributing to variability in lymph node counts after oesophagogastric cancer resections and to determine whether a novel strategy of ex vivo dissection of resected specimens into nodal stations improves node counts reported by pathologists.

METHODS

The study involved 88 patients with potentially curable oesophagogastric cancer undergoing radical resection. Lymph node counts were obtained from pathology reports and analysed in relation to multiple variables including the introduction of ex vivo dissection of nodal stations in theatre.

RESULTS

Higher lymph node counts were obtained with ex vivo dissection of nodal stations (median 19 versus 8, P < 0.01). Node counts also varied significantly with the reporting pathologist (median range 4 to 48, P = 0.02) which was independent of the level of experience of the pathologist (P = 0.67). Node counts were not affected by patient age (P = 0.26), gender (P = 0.50), operative approach (P = 0.50) or neoadjuvant therapy (P = 0.83).

CONCLUSIONS

Specimen handling is a significant factor in determining lymph node yield following radical oesophageal and gastric cancer resections. Ex vivo dissection of resected specimens into nodal stations improves node counts without alterations to surgical techniques. Ex vivo dissection should be considered routine.

Pelvic lymph node dissection in the context of radical cystectomy: a thorough insight into the connection between patient, surgeon, pathologist and treating institution

Pelvic lymph node dissection (PLND) in patients with bladder cancer varies widely in extent, technique employed, and pathological workup of specimens. The present paper provides an overview of the existing evidence regarding the effectiveness of PLND and elucidates the interactions between patient, surgeon, pathologist, and treating institution as well as their cumulative impact on the final postoperative lymph node (LN) staging. Bladder cancer patients undergoing radical cystectomy with extended PLND appear to have better oncologic outcomes compared to patients undergoing radical cystectomy and limited PLND. Attempts have been made to define and assess the quality of PLND according to the number of lymph nodes identified. However, lymph node counts depend on multiple factors such as patient characteristics, surgical template, pathological workup, and institutional policies; hence, meticulous PLND within a defined and uniformly applied extended template appears to be a better assurance of quality than absolute lymph node counts. Nevertheless, the prognosis of the patients can be partially predicted with findings from the histopathological evaluation of the PLND specimen, such as the number of positive lymph nodes, extracapsular extension, and size of the largest LN metastases. Therefore, particular prognostic parameters should be addressed within the pathological report to guide the urologist in terms of patient counseling.

Problematic issues in the staging of endometrial, cervical and vulval carcinomas

The International Federation of Gynecology and Obstetrics (FIGO) staging of tumours of the uterine corpus, cervix and vulva was revised in 2009. The greatest impact of the revised staging was on carcinomas of the uterine corpus. Uterine sarcomas are now staged separately. Changes to the staging system for vulvar carcinomas largely reflect the significance of lymph node status. Only minor amendments have been introduced for cervical carcinomas, which remain the only gynaecological tumours to be staged clinically. These revisions, based on recent evidence, require careful, more detailed assessment of several histological parameters at each anatomical site. The present review deals with the evidence and rationale underpinning the revisions, and includes practical guidance on tumour staging. This covers the assessment and measurement of myoinvasion and evaluation of cervical, parametrial, serosal and vaginal involvement in carcinomas of the uterine corpus; the identification and accurate measurement of stromal invasion in cervical and vulvar carcinomas; the assessment of unusual variants of carcinoma at each of these sites; and the assessment of lymph node involvement.

Inter- and intra-operator variability in the reading of indirect immunofluorescence assays for the serological diagnosis of scrub typhus and murine typhus

Inter- and intra-observer variation was examined among six microscopists who read 50 scrub typhus (ST) and murine typhus (MT) indirect immunofluorescence assay (IFA) immunoglobulin M (IgM) slides. Inter-observer agreement was moderate (κ = 0.45) for MT and fair (κ = 0.32) for ST, and was significantly correlated with experience (P = 0.03 and P = 0.004, respectively); κ-scores for intra-observer agreement between morning and afternoon readings (range = 0.35–0.86) were not correlated between years of experience for ST and MT IFAs (Spearman's ρ = 0.31, P = 0.54 and P = 0.14, respectively; P = 0.78). Storage at 4°C for 2 days showed a change from positive to negative in 20–32% of slides. Although the titers did not dramatically change after 14 days of storage, the final interpretation (positive to negative) did change in 36–50% of samples, and it, therefore, recommended that slides should be read as soon as possible after processing.

The complexity of the count: considerations regarding lymph node evaluation in colorectal carcinoma

In patients with colorectal carcinoma, studies have reported improved survival with increasing numbers of retrieved lymph nodes. These findings are puzzling, as increased node sampling was not correlated with significant change in disease staging. Although the physiologic processes underlying this correlation between number of lymph nodes sampled and survival remain unknown, the reported correlation has caused modifications to clinical and non-clinical practices. Herein, we review the literature and discuss potential etiologies responsible for the observed increased survival statistics. Literature regarding colorectal lymph node anatomy, molecular aspects of colorectal cancer, changes in tumor characteristics and utilization of lymph node sample numbers are evaluated. In addition, we present the mathematical concepts available for probabilistic prediction of diagnostic confidence based upon sample size. From evaluation of the aggregate literature, certain facts emerge which are not easily identified within the individual studies. Colorectal carcinoma appears to encompass a number of individual disease entities with different physiologic characteristics and likelihoods of metastasis. In addition, it appears the improved survival is likely multifactorial including effects from intrinsic tumor biology and tumor-host interactions along with ever changing clinical practices. Finally, because lymph node count is dependent on a number of variables and is correlated, but unlikely to be causally associated with survival, use of this number as a quality indicator is unwarranted. Based on statistical considerations, the current recommended goal of 12-15 recovered lymph nodes without evidence of metastatic disease provides approximately 80% negative predictive value for colorectal carcinoma metastasis.