Histologic features and cytologic techniques that aid pathologic stage assessment of colonic adenocarcinoma. Am J Surg Pathol. 2013;37:1252-1258. [PMID: 23774176 DOI: 10.1097/pas.0b013e3182960e7c]

[Prognostic factors: Degree of subserosal invasion, tumor-serosal distance and subserosal elastic boundary invasion in colonic adenocarcinoma]

The aim was to study the prognostic impact of tumor infiltration of the subserosa in colonic adenocarcinoma, by evaluating the degree of tumor infiltration in the subserosa (DISS), tumor-serosa distance (DTS), and invasion of the elastic boundary of the subserosa (ILE) after elastic fiber staining.

MATERIAL AND METHODS

All patients operated on for colonic adenocarcinoma classified as pT3 without lymph node or visceral metastasis operated on at the CHU d'Amiens between 2004 and 2017 were included. All slides were reviewed by 2 pathologists. Bivariate and subgroup analyses were performed according to the presence of a DISS≤5mm or>5mm, a DTS≤1mm or>1mm and the presence or absence of an ILE. These statistical analyses were then correlated with the 5-year survival.

RESULTS

One hundred and one patients were included in the study. We performed elastic fiber staining on an average of 2 tumor blocks per case and 39.6% of patients had invasion of the elastic boundary. However, bivariate and subgroup analyses showed no statistically significant association between DISS, DTS or ILE and 5-year survival.

CONCLUSION

None of these three histopathological criteria proved to have prognostic value in our series, contrary to some results in the literature. However, as these data are subject to a number of confounding factors, we do not recommend that pathologists specify these different criteria in their reports.

Prognostic and Predictive Determinants of Colorectal Cancer: A Comprehensive Review

Colorectal cancer (CRC) remains a significant global health burden, necessitating a thorough understanding of prognostic and predictive factors to enhance patient outcomes. This systematic review aims to comprehensively evaluate prognostic and predictive determinants in CRC, encompassing both traditional and emerging biomarkers. A systematic search of major electronic databases was conducted to identify relevant studies published from 1995 up to 2024. Eligible articles were critically appraised, and data extraction was performed according to predefined criteria. The prognostic determinants examined included clinicopathological features such as tumor stage, grade, and lymph node involvement, as well as molecular biomarkers including RAS, BRAF, and MSI status. Predictive determinants encompassed biomarkers influencing response to targeted therapies and immunotherapy, such as HER2 and Immunoscore. The review also explores novel prognostic and predictive markers, including tumor microenvironment characteristics and liquid biopsy-based biomarkers. Synthesizing evidence from diverse studies, this review provides insights into the prognostic and predictive landscape of CRC, highlighting the potential clinical implications of identified determinants. Understanding the multifaceted nature of prognostic and predictive factors in CRC is imperative for the advancement of personalized treatment strategies and improvement of patient outcomes.

The safety and effectiveness of prophylactic hyperthermic intraperitoneal chemotherapy in patients with pathological T3-4 locally advanced colon cancer

INTRODUCTION

The safety and effectiveness of prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) in pathological T3-4 locally advanced (pT3N + M0 and pT4NxM0) colon cancer (CC) patients with radical resection need further study.

METHODS

Clinical and pathological information of pT3-4 locally advanced CC patients who received radical surgery in our hospital from January 2018 to December 2020 were analyzed. The prognosis of patients was estimated using Cox proportional hazards regression analysis and Kaplan-Meier method.

RESULTS

Among 927 patients, 10.4% (96/927) received prophylactic HIPEC based on 5-FU, 4.6% (43/927) received prophylactic HIPEC based on lobaplatin, 85.0% (788/927) received conventional therapy. The incidence of metachronous peritoneal carcinomatosis (mPC) was 9.4%. Complications occurred in 32 patients (4.1%) in the conventional therapy group, 6 patients (6.3%) in the prophylactic HIPEC group based on 5-FU and 3 patients (7.0%) in the prophylactic HIPEC group based on lobaplatin within 30 days after surgery (5-FU vs. conventional therapy group, p = 0.464; Lobaplatin vs. conventional therapy group, p = 0.591). Multivariate Cox regression analysis revealed that prophylactic HIPEC based on either 5-FU or lobaplatin regimen could not effectively improve mPC-free survival (5-FU: p = 0.020, HR = 1.927, 95% CI, 1.111-3.343; Lobaplatin: p = 0.167, HR = 0.247, 95% CI, 0.034-1.796), overall survival (5-FU: p = 0.361, HR = 1.360, 95% CI, 0.703-2.634; Lobaplatin: p = 0.780, HR = 0.816, 95% CI, 0.195-3.416) and disease-free survival (5-FU: p = 0.525, HR = 1.149, 95% CI, 0.749-1.760; Lobaplatin: p = 0.117, HR = 0.488, 95% CI, 0.199-1.198).

CONCLUSION

Early prophylactic HIPEC based on 5-FU or lobaplatin subsequent to radical resection for patients with pT3-4 locally advanced CC is safe, but not effective in reducing the risk for mPC.

The clinical significance of elastic lamina invasion in patients with pStage II colorectal cancer: a notable prognostic indicator

BACKGROUND

Some colorectal cancers (CRCs) are clinically diagnosed as cT4a with　serosal invasion (SI). However, the cT4a is most often underdiagnosed pathologically as pT3 without SI by hematoxylin-eosin (H&E) staining alone. Using Elastica van Gieson (EVG) staining, some pT3 tumors invade the elastic lamina (EL), which extends just below the serosal layer. Recently, EL invasion (ELI) has been described as a poor prognostic factor for disease-free survival (DFS) and overall survival (OS) in patients with pStage II CRC. However, its clinicopathological significance remains unclear due to the limited number of studies and poor understanding of ELI.

OBJECTIVE

This study investigated the association between the ELI and patient prognosis.

METHODS

After 1982, pathological diagnosis was routinely performed using H&E and EVG staining methods, and long-term follow up was performed until 2016. All clinicopathological features including ELI were prospectively registered into our computer and 569 patients with pStage II CRC were collected from the database. Based on the ELI status, pT3 was divided into three pathological categories: pT3ELI - was defined as pT3a, pT3ELI + as pT3b and unidentified EL (pT3EL -) as pT3u.

RESULTS

Using H&E staining alone, gross cT4a was most often pathologically underdiagnosed as pT3 (93.8%) and very rarely as pT4a, resulting in a large diagnostic discrepancy. Using EVG staining, 60.7% of the cT4a tumors were diagnosed as pT3b. The 10-year DFS and OS rates were similar for pT3a and pT3u patients. However, the 10-year DFS and OS rates of pT3b patients were significantly lower than those of pT3a patients (75.6% vs. 95.6%, p < 0.0001 and 58.4% vs. 70.6%, p = 0.0024, respectively) but did not differ from those of pT4a patients (70.6%, p = 0.5799 and 52.0%, p = 0.1116, respectively). Multivariate analysis revealed that the ELI was the strongest independent risk factor for recurrence and CRC-specific death (p < 0.0001).

CONCLUSIONS

A better understanding of the ELI allows us to reconsider the diagnostic discrepancy of serosal invasion, i.e., pT3b should be considered pT4a. The ELI-based subclassification of pT3 is expected to be incorporated into the TNM staging system in the future. The ELI is a notable prognostic indicator in patients with pStage II CRC.

Identification of an Objective Cut-Off Point to Define the Clinical Stage T4a in Colon Cancer

Introduction: The current state of pathology practice and the variability in diagnosing pT4a colon cancer have been underexplored in existing studies. Our objective was to establish a specific cutoff point to distinguish between the pathological stages of pT3 and pT4a in colon cancer. Methods: We conducted a cross-sectional study involving pT3 and pT4 (pN0-2, cM0) colon cancers, measuring the distance to the serosa. Patients were categorized and analyzed based on this distance and the peritoneal reaction, with the aim being to ascertain their prognostic implications. Results: A total of 384 patients were analyzed. Patients with a distance between the invading front of cancer and the serosa ≥ 1 mm without a peritoneal reaction exhibited a median survival of 118 months, contrasting the amount of 70 months for those with <1 mm plus peritoneal reaction. Only lengths <1 mm with peritoneal reaction showed a significant correlation with mortality (p < 0.001). Conclusion: Our study revealed that patients in whom neoplastic cells were less than 1 mm from the serosal surface, accompanied by a peritoneal reaction (hemorrhage, inflammation, neovascularization, fibrin), had significantly lower survival rates compared to those with more than 1 mm distance and without peritoneal response (70 vs. 118 months, p < 0.001). Hence, such cases should be considered within the pT4a stage.

The development and implementation of pathological parameters and molecular testing impact prognosis of colorectal adenocarcinoma

Objective

This study aims to analyze how changes in pathological diagnosis practice and molecular detection technology have affected clinical outcomes for colorectal cancer (CRC) patients in Fudan University Shanghai Cancer Center (FUSCC).

Methods

This retrospective cohort study analyzed 21,141 pathologically confirmed CRC cases diagnosed at FUSCC from 2008 to 2020. Patients were divided into five groups for different analytical purposes: (1) the before vs. since 2014 groups to analyze the influence of the changes in the classification criteria of pT3 and pT4 staging on the survival of patients; (2) the partial vs. total mesorectal excision (TME) groups to analyze whether evaluation of completeness of the mesorectum have impact on the survival of patients; (3) the tumor deposit (TD)(+)N0 vs. TD(+)N1c groups to analyze the influence of the changes in the pN staging on the survival of patients with positive TD and negative regional lymph node metastasis (LNM); (4) the before vs. since 2013 groups to analyze the influence of the changes in the testing process of deficient mismatch repair on the survival of patients; and (5) the groups with vs. without RAS/BRAF gene mutation testing to analyze the influence of these testing on the survival of patients. Patients' clinicopathological parameters, including age at diagnosis, sex, tumor size, location, differentiation, mucinous subtype, TD, lymphovascular invasion, perineural invasion, tumor depth, LNM and distant metastasis, and tumor-node-metastasis (TNM) stage, were compared between groups. Kaplan-Meier analysis with log rank method was performed for patients' overall survival (OS) and disease-free survival (DFS) analyses.

Results

In pathological reports, there were three parameter changes that impacted patient outcomes. Firstly, changes in the pT staging criteria led to a shift of the ratio of patients with stage pT3 to stage pT4 from 1: 110.9 to 1: 0.26. In comparison to patients admitted before 2014 (n = 4,754), a significant difference in prognosis between pT3 and pT4 stages was observed since 2014 (n = 9,965). Secondly, we began to evaluate the completeness of the mesorectum since 2016. As a result, 91.0% of patients with low rectal cancer underwent TME (n = 4,111) surgery, and patients with TME had significantly better OS compared with partial mesorectal excision (PME, n = 409). Thirdly, we began to stage TD (+) LNM (-) as N1c since 2017. The results showed that N1c (n = 127) but not N0 (n = 39) can improve the prognosis of patients without LNM and distal metastasis. In molecular testing, there have been three and five iterations of updates regarding mismatch repair (MMR)/microsatellite instability (MSI) status and RAS/BRAF gene mutation detection, respectively. The standardization of MMR status testing has sharply decreased the proportion of deficient MMR (dMMR) patients (from 32.5% to 7.4%) since 2013. The prognosis of patients underwent MMR status testing since 2013 (n = 867) were significantly better than patients before 2013 (n = 1,313). In addition, detection of RAS/BRAF gene mutation status (n = 5,041) resulted in better DFS but not OS, for patients with stage I-III disease (n = 16,557).

Conclusion

Over the past few decades, updates in elements in pathological reports, as well as the development of standardized tests for MMR/MSI status and RAS/BRAF gene mutations have significantly improved patient outcomes.

Clinical and Histopathologic Features of 35 Patients Treated for Colorectal Peritoneal Metastases Who Survived 5 Years

BACKGROUND

Currently, patients with a limited extent of peritoneal metastases from colon and rectal cancer are treated by cytoreductive surgery combined with perioperative chemotherapy performed at experienced centers.

OBJECTIVE

To statistically evaluate features that may impact survival of ≥5 years. These data are used in the risk/benefit analyses performed by the multidisciplinary team.

DESIGN

This was a retrospective review of a prospective database.

SETTINGS

This single-institution study was conducted at an academic center.

PATIENTS

All patients who had biopsy-proven colon or rectal peritoneal metastases treated by systemic chemotherapy, complete cytoreductive surgery, and perioperative surgery were included.

MAIN OUTCOME MEASURES

The primary outcomes measured were the clinical-, histologic-, and treatment-related features that had an impact on 5-year survival.

RESULTS

From 131 patients who had complete cytoreduction, 35 patients (26.7%) were identified as 5-year survivors. The median survival time was 27 months. The median age was 50.5 (range, 25-80) years. By univariant analysis, an absence of lymph node involvement at the time of primary colorectal cancer resection (HR 1.899 [95% CI, 1.064-3.388]; p = 0.03), complete or near-complete response to neoadjuvant chemotherapy (HR 0.251 [95% CI, 0.092-0.684]; p = 0.007), peritoneal cancer index ≤17 (HR 0.509 [95% CI, 0.329-0.788]; p = 0.002), complete visible resection of disease indicated by the completeness of cytoreduction score of 0 (HR 0.412 [95% CI, 0.224-0.756]; p = 0.004), and well-differentiated tumor (HR 0.34 [95% CI, 0.157-0.737]; p = 0.006) were significantly associated with ≥5 years survival.

LIMITATIONS

Limitations include its retrospective nature, unmeasured confounders, and data from a single institution.

CONCLUSIONS

The tumor biology as revealed by lymph node status and tumor differentiation plus extent of disease as measured by the response to neoadjuvant chemotherapy, peritoneal cancer index, and no visible residual disease indicated a favorable outcome. See Video Abstract at http://links.lww.com/DCR/C62 .

CARACTERSTICAS CLNICAS E HISTOPATOLGICAS EN PACIENTES TRATADOS POR METASTASIS PERITONEALES DE ORGEN COLORECTAL Y QUE SOBREVIVIERON AOS

ANTECEDENTES:Actualmente, los pacientes con extensión limitada de metástasis peritoneales de orígen colorectal son tratados mediante cirugía citorreductora asociada con una quimioterapia peri-peratoria realizadas en centros experimentados.OBJETIVO:Estúdio y evaluación estadística de las características que puedan impactar en la sobrevida de los pacientes a 5 años o más. Se utilizaron estos datos en el análisis de riesgo /beneficio realizados por un equipo multidisciplinario.DISEÑO:Revisión retrospectiva de una base de datos prospectiva.AJUSTES:Estudio realizado en una sola institución académica.PACIENTES:Todos aquellos que presentaban metástasis peritoneales de orígen colorectal, comprobadas por biopsia y tratadas con quimioterapia sistémica, cirugía peri-operatoria y citorreductora completas.MEDIDAS DE RESULTADO PRINCIPALES:Las medidads de resultados primarios fueron las características clínicas, histológicas y relacionadas con el tratamiento que tuvieron un impacto en la sobrevida a 5 años.RESULTADOS:De 131 pacientes que tuvieron una cirugía de citorreducción completa, 35 pacientes (26, 7%) fueron identificados como sobrevivientes a 5 años. La mediana de sobrevida fué de 27 meses. Se identificarion 16 varones. La mediana de edad fue de 50, 5 años con un rango de 25 a 80 años. Según análisis univariante, la ausencia de compromiso de los ganglios linfáticos en el momento de la resección del cáncer colorrectal primario (HR 1,899 (1,064, 3,388) p = 0,03), la respuesta completa o casi completa al tratamiento neoadyuvante con quimioterapia (HR 0,251 (0,092, 0,684) p = 0,007), el índice de cáncer peritoneal ≤17 (HR 0,509 (0,329, 0,788) p = 0,002), la resección completa y visible de la enfermedad indicada por la puntuación de citorreducción de 0 (HR 0,412 (0,224), 0,756) p = 0,004) y los tumores bien diferenciados (HR 0,34 (0,157, 0,737) p = 0,006) se asociaron significativamente con 5 o más años de sobrevida.LIMITACIONES:El estudio se encontró limitado por su naturaleza retrospectiva, por la no medida de factores de confusión y por los datos provenientes de una sola institución.CONCLUSIONES:La biología tumoral demostrada según el estado de los ganglios linfáticos y la diferenciación tumoral, agregada a la extensión de la enfermedad medida por la respuesta a la quimioterapia neoadyuvante, el índice de cáncer peritoneal y la ausencia visible de enfermedad residual, demostraron un resultado favorable. Consulte Video Resumen en http://links.lww.com/DCR/C62(Traducción-Dr. Xavier Delgadillo ).

[Prognostic histological markers in colorectal cancer]

BACKGROUND

Colon carcinomas are among the most common malignant tumors worldwide. The critical evaluation of different therapy options is particularly relevant. On the one hand, colon carcinomas more often occur at an older age, on the other hand patients with colon carcinomas often live for decades after initial diagnosis - it is just as important to avoid overtreatment as it is to avoid undertreatment, which shortens the patient's life span. Prognostically effective biomarkers are decision-making tools. There are clinical, molecular, and histological prognostic markers-the latter are presented in this paper.

AIM OF THE WORK

To present the current state of knowledge on morphologically determinable prognostic markers in colon cancer.

MATERIALS AND METHOD

Literature search in PubMed and Medline.

CONCLUSIONS

In their daily work, pathologists identify highly relevant prognostic markers that are essential for therapeutic decisions. These markers must be communicated to the clinical colleague. The most important and longest-known prognostic markers are staging (TNM), including local resection status, lymph node involvement and number on the surgical specimen, vascular invasion, perineural sheath infiltration, and histomorphologic growth pattern determination (e.g., micropapillary colon carcinoma is associated with a very unfavorable prognosis). Recently, tumor budding has been added, which has practical applications especially in endoscopically applied pT1 carcinomas ("malignant polyps").

The measured distance between tumor cells and the peritoneal surface predicts the risk of peritoneal metastases and offers an objective means to differentiate between pT3 and pT4a colon cancer

Substantial variability exists in what pathologists consider as pT4a in colorectal cancer when tumor cells are within 1 mm of the free peritoneal surface. This study aimed to determine if the measured sub-millimeter distance between tumor cells and the free peritoneal surface would offer an objective means of stratifying patients according to the risk of developing peritoneal metastases. Histological slides of patients included in the COLOPEC trial, with resectable primary c/pT4N0-2M0 colon cancer, were centrally reassessed. Specific tumor morphological variables were collected, including distance from tumor to free peritoneal surface, measured in micrometers (µm). The primary outcome, 3-year peritoneal metastasis rate, was compared between four groups of patients stratified for relation of tumor cells to the peritoneum: 1) Full peritoneal penetration with tumor cells on the peritoneal surface, 2) 0-99 µm distance to the peritoneum, 3) 100-999 µm to the peritoneum, and 4) ≥1000 µm to the peritoneum, by using Kaplan-Meier analysis. In total, 189 cases were included in the present analysis. Cases with full peritoneal penetration (n = 89), 0-99 µm distance to the peritoneal surface (n = 34), 100-999 µm distance (n = 33), and ≥1000 µm distance (n = 33), showed significantly different 3-year peritoneal metastases rates of 25% vs 29% vs 6% vs 12%, respectively (Log Rank, p = 0.044). N-category did not influence the risk of peritoneal metastases in patients with a tumor distance beyond 100 µm, while only the N2 category seemed to result in an additive risk in patients with a distance of 0-99 µm. The findings of this study suggest that the measured shortest distance between tumor cells and the free peritoneal surface is useful as an objective means of stratifying patients according to the risk of developing peritoneal metastases. This simple measurement is practical and may help in providing a precise definition of pT4a. Trial registration: NCT02231086 (Clinicaltrials.gov).

Advances in the management of peritoneal malignancies

Peritoneal surface malignancies (PSMs) are usually associated with a poor prognosis. Nonetheless, in line with advances in the management of most abdominopelvic metastatic diseases, considerable progress has been made over the past decade. An improved understanding of disease biology has led to the more accurate prediction of neoplasia aggressiveness and the treatment response and has been reflected in the proposal of new classification systems. Achieving complete cytoreductive surgery remains the cornerstone of curative-intent treatment of PSMs. Alongside centralization in expert centres, enabling the delivery of multimodal and multidisciplinary strategies, preoperative management is a crucial step in order to select patients who are most likely to benefit from surgery. Depending on the specific PSM, the role of intraperitoneal chemotherapy and of perioperative systemic chemotherapy, in particular, in the neoadjuvant setting, is established in certain scenarios but questioned in several others, although more prospective data are required. In this Review, we describe advances in all aspects of the management of PSMs including disease biology, assessment and improvement of disease resectability, perioperative management, systemic therapy and pre-emptive management, and we speculate on future research directions.

Risk factors for metachronous peritoneal carcinomatosis after radical resection for patients with nonmetastatic pT3-4 colon cancer

BACKGROUND

Patients with nonmetastatic pT3-4 colon cancers are prone to develop metachronous peritoneal carcinomatosis (mPC). Risk factors for mPC and the influence of mutant kirsten rat sarcoma viral oncogene (KRAS)/neuroblastoma rat sarcoma (NRAS)/v-raf murine sarcoma viral oncogene homolog B1 (BRAF) and DNA mismatch repair (MMR) status on mPC remain to be described in these patients.

METHOD

All enrolled patients were identified from the prospectively collected colorectal cancer database of a tertiary referral hospital between 2013 and 2018. Multivariate analysis was used to identify risk factors associated with mPC.

RESULTS

Of the 1689 patients with nonmetastatic pT3-4 colon carcinoma, 8.4% (142/1689) progressed to mPC. Endoscopic obstruction (HR = 3.044, p < 0.001), elevated CA125 (HR = 1.795, p = 0.009), pT (T4a vs. T3, HR = 2.745, p < 0.001; T4b vs. T3, HR = 3.167, p = 0.001), pN (N1 vs. N0, HR = 2.592, p < 0.001; N2 vs. N0, HR = 4.049, p < 0.001), less than 12 lymph nodes harvested (HR = 2.588, p < 0.001), mucinous or signet ring cell carcinoma (HR = 1.648, p = 0.038), perineural invasion (HR = 1.984, p < 0.001), and adjuvant chemotherapy (HR = 1.522, p = 0.039) were strongly related to mPC but that mutant KRAS/NRAS/BRAF and MMR status was not associated with mPC.

CONCLUSION

This study identified the high-risk factors for mPC in patients with nonmetastatic pT3-4 colon carcinoma, and these factors should be considered in selective preventive therapy and close follow-up for patients subsequently deemed to have high risk for mPC.

Pathology and Prognosis of Colonic Adenocarcinomas With Intermediate Primary Tumor Stage Between pT2 and pT3

CONTEXT.—

Primary tumor stage (pT) is an important prognostic indicator in colonic adenocarcinomas; however, cases that have no muscle fibers beyond the advancing tumor edge but also show no extension beyond the apparent outer border of muscularis propria (termed pT2int), have not been previously studied.

OBJECTIVE.—

To address the clinicopathologic characteristics and prognosis of pT2int tumors.

DESIGN.—

We recharacterized 168 colon carcinomas and compared pT2int cases to bona fide pT2 and pT3 tumors.

RESULTS.—

In side-by-side analysis, 21 pT2int cases diverged from 29 pT2 tumors only in terms of larger size (P = .03), but they were less likely to show high-grade (P = .03), lymphovascular (P < .001), and extramural venous invasion (P = .04); discontinuous tumor deposits (P = .02); lymph node involvement (P = .001); and advanced stage (P = .001), compared with 118 pT3 tumors. Combining pT2int with pT2 cases (versus pT3) was a better independent predictor of negative lymph nodes in multivariate analysis (P = .04; odds ratio [OR], 3.96; CI, 1.09-14.42) and absent distant metastasis in univariate analysis (P = .04), compared with sorting pT2int with pT3 cases (versus pT2). Proportional hazards regression showed that pT2 and pT2int cases together were associated with better disease-free survival compared with pT3 tumors (P = .04; OR, 3.65; CI, 1.05-12.70). Kaplan-Meier analysis demonstrated that when pT2int were grouped with pT2 tumors, they were significantly less likely to show disease progression compared with pT3 (P = .002; log-rank test) and showed a trend toward better disease-specific survival (P = .06), during a mean patient follow-up of 44.9 months.

CONCLUSIONS.—

These data support the conclusion that pT2int carcinomas have clinicopathologic characteristics and are associated with patient outcomes more closely aligned with pT2 rather than pT3 tumors.

Peritoneal cytology as an indicator of peritoneal metastases in colorectal cancer

BACKGROUND

In the management of peritoneal metastases from colon and rectal cancer, the most favorable results are reported with an aggressive combined treatment on patients who have a small extent of the disease. A test to detect occult peritoneal metastases would greatly facilitate the management of this component of colorectal dissemination.

METHODS

Currently, the standard test by which to confirm the diagnosis of the peritoneal spread of colorectal cancer is peritoneal cytology. To study the utility of this test, we gathered information from patients with biopsy-proven peritoneal metastases. The clinical, histologic, and treatment-related features of these patients at the time of a cytoreductive surgery were statistically correlated with the results of the peritoneal cytology test.

RESULTS

Forty-nine patients with colorectal cancer peritoneal metastases and a peritoneal cytology determination at the time of a cytoreductive surgery were available for analysis. Twenty-eight patients (55.1%) had a positive test. Patients with a high peritoneal cancer index and mucinous histology were most likely to have positive peritoneal cytology.

CONCLUSION

Peritoneal cytology identified patients with mucinous histology and a large extent of disease but was consistently negative in patients who had a small extent of disease compatible with a favorable response to treatment.

Variability in Synoptic Reporting of Colorectal Cancer pT4a Category and Lymphovascular Invasion

CONTEXT.—

Serosal involvement (pT4a category) and lymphovascular invasion have prognostic significance in colorectal carcinoma, but are subject to interobserver variation in assessment.

OBJECTIVES.—

To provide the first large-scale assessment of interobserver variability in pT4a category and lymphovascular invasion reporting in real-world practice and to explore the impact of information from guidelines on variability in reporting these features.

DESIGN.—

Analysis of 1555 consecutive synoptic reports of colorectal carcinoma was performed using multivariate logistic regression. Interobserver variability before and after the presentation of guideline information was assessed using an image-based survey.

RESULTS.—

Significant differences in the odds of reporting pT4a versus pT3 category, detecting lymphovascular invasion of any type, and detecting large vessel invasion were identified among hospital sites and for individual pathologists compared with the median pathologist at the same site. Consistent with these results, interobserver agreement was only moderate in the image-based survey regarding T4a staging and lymphovascular invasion (all κ ≤ 0.57). The provision of information from guidelines did not tend to increase interobserver agreement in the survey, though responses in favor of using an elastic stain increased following recommendations for their use. However, when observers were provided with elastic-stained images, interobserver agreement remained only moderate (κ = 0.55).

CONCLUSIONS.—

Real-world reporting of pT4a category and lymphovascular invasion shows substantial variability at both local and regional levels. Our study underscores the need to address these features in quality initiatives, and provides a novel method through which existing synoptic data can be harnessed to monitor reporting patterns and provide individualized feedback.

T3 versus T4a staging challenges in deeply invasive colonic adenocarcinomas and correlation with clinical outcomes

Despite the latest 8th edition American Joint Committee on Cancer Staging Manual guidelines, disagreement still exists among pathologists regarding staging deeply invasive colonic adenocarcinomas ≤1 mm to the serosal surface. In this retrospective study, 151 untreated colonic adenocarcinomas staged initially as either pT3 or pT4a and with available 5-year follow-up data were retrieved and re-categorized: Group 1 (38 cases): pT4a with tumor at the serosa; Group 2 (49 cases): tumor ≤1 mm from the serosa, with intervening reactive fibrosis (40/49) or inflammation (9/49); Group 3 (64 cases): pT3 tumor >1 mm from the serosa. Clinical outcomes were analyzed. Groups 1 and 2 tumors showed significantly lower 5-year recurrence-free survival and lower overall survival rates (log-rank p < 0.001 for both), when compared with Group 3 tumors. Even after adjusting for adjuvant therapy and nodal metastases, the proportional hazards ratios for the risk of death (p < 0.001) and risk of recurrence (p = 0.005) showed significantly higher risk in Groups 1 and 2 compared with Group 3. The synchronous nodal (p = 0.012) and metachronous distant metastases (p = 0.004) were also significantly more in Groups 1 and 2 versus Group 3. Colonic adenocarcinomas ≤1 mm from the serosal surface behaved more akin to "bona fide" pT4a tumors at the serosal surface in our study with regards to clinical outcomes. We recommend these tumors be staged as pT4a rather than pT3, as supported by outcome data in our study. We hope this will also ensure reproducibility and consistency in staging these tumors across institutions.

Reproducibility of AJCC Criteria for Classifying Deeply Invasive Colon Cancers Is Suboptimal for Consistent Cancer Staging

The eighth edition of the American Joint Committee on Cancer (AJCC) Staging Manual attempts to address ambiguity in the pT category assignment for colon cancer from prior editions. Despite modifications, the distinction between the pT3 and pT4a categories continues to be a source of diagnostic confusion. In this study, we assessed interobserver agreement among pathologists from different institutions in the application of AJCC eighth edition criteria for categorizing deeply invasive colonic adenocarcinomas. We identified morphologic patterns that produce diagnostic confusion. We assessed 47 colon cancers that closely approached the serosal surface. Six pathologists with interest in gastrointestinal pathology and 4 focused in other subspecialties classified each case as pT3 or pT4a, based on examination of low-magnification and high-magnification images of the most deeply invasive area. Interobserver agreement was assessed using Fleiss' κ. Cases displayed 3 morphologic patterns at the advancing tumor edge, namely, (1) continuous invasion through an inflammatory focus, (2) pushing border, and (3) infiltrative glands and cell clusters with serosal reaction. Gastrointestinal pathologists achieved slight (κ=0.21) or moderate (κ=0.46) and (κ=0.51) agreement in each category, whereas agreement among nongastrointestinal pathologist was fair (0.31) and (0.39), or moderate (0.57) for each category, respectively. In 10 (21%) cases, the distinction between pT3 and pT4a would have changed the overall clinical stage. We conclude that histologic criteria for serosal penetration is a persistent source of diagnostic ambiguity for gastrointestinal and general pathologists in the pT categorization of colon cancers. Clarification of these criteria will help ensure uniform reporting of pathologic and clinical stage.

Interobserver, intraobserver, and interlaboratory variability in reporting pT4a colon cancer

Clinical significance of the pT4 category in colon cancer is increasing with several therapeutic implications. The aim of this study was to evaluate variability in diagnosing pT4a colon cancer. Twelve pathologists classified 66 preselected scanned Hematoxylin/Eosin-stained slides with tumor cells at a distance of 25-1500 μm (n = 22), 0-25 μm (n = 22), or on (n = 22) the peritoneal surface. Inter- and intraobserver variability were calculated using Kappa statistics. For interlaboratory variability, pathology reports of pT3 and pT4a colon cancer were extracted from the Dutch Pathology Registry between 2012 and 2015. The proportion of pT4a (pT4a/(pT3+pT4a)) was compared between 33 laboratories. Potential risk of understaging was assessed by determining the average number of blocks taken from pT3 and pT4a N0-2M0 tumors with metachronous peritoneal metastasis. Interobserver variability among 12 pathologists was 0.50 (95%CI 0.41-0.60; moderate agreement). Intraobserver variability (8 pathologists) was 0.71 (substantial agreement). A total of 7745 reports with pT3 or pT4aN0-2M0 colon cancer from 33 laboratories were included for interlaboratory analysis. Median percentage of pT4a was 15.5% (range 3.2-24.6%). After adjustment for case mix, 8 labs diagnosed pT4a significantly less or more frequently than the median lab. Metachronous peritoneal metastases were histologically verified in 170 of 6629 pT3 and in 129 of 1116 pT4a tumors, with a mean number of blocks of 4.03(SD 1.51) and 4.78 (SD 1.76) taken from the primary tumors, respectively (p < 0.001). A substantial variability in diagnosing pT4a colon cancer exists, both at pathologist and laboratory level. Diagnosis of pT4a stage appears to be challenging and there is a need for standardizing assessment of this pathological entity.

Challenges with colorectal cancer staging: results of an international study

Challenges exist with standardized colorectal cancer reporting despite adoption of the American Joint Committee on Cancer-Staging Manual 8th edition. We performed this study to gauge current practice patterns among a diverse group of surgical pathologists. A web-based questionnaire depicting problematic issues and images related to colorectal carcinoma staging was circulated among 118 surgical pathologists and their responses were correlated with their geographic location (North America vs. Europe vs. others), nature of practice (academic vs. community), the sign-out model (gastrointestinal subspecialty vs. general surgical pathology), and years of professional experience. We found that a substantial number of practicing pathologists ignore recommended-staging criteria in specific settings, particularly with respect to assessment of advanced T stage. Tumors that communicated with the serosa through inflammatory foci were staged as pT3 (49%) or pT4a (51%) by nearly equal numbers of pathologists regardless of level of experience, the sign-out model, or geographic location. Only 65% assigned T stage and margin status based on extent of viable tumor in the neoadjuvant setting. One-third of pathologists, particularly those in Europe (p = 0.015), classified acellular mucin deposits as N1 disease when detected in treatment-naive cases. Nearly 50% of pathologists classified isolated tumor cells (i.e., deposits <0.2 mm) in lymph nodes as metastatic disease (i.e., pN1, p = 0.02). Our results suggest that pathologists ignore recommendations that are based on insufficient data and apply individualized criteria when faced with situations that are not addressed in the American Joint Committee on Cancer Staging Manual 8th edition. These variations in practice limit the ability to compare outcome data across different institutions and draw attention to areas that require further study.

Standardized Pathology Report for Colorectal Cancer, 2nd Edition

The first edition of the 'Standardized Pathology Report for Colorectal Cancer,' which was developed by the Gastrointestinal Pathology Study Group (GIP) of the Korean Society of Pathologists, was published 13 years ago. Meanwhile, there have been many changes in the pathologic diagnosis of colorectal cancer (CRC), pathologic findings included in the pathology report, and immunohistochemical and molecular pathology required for the diagnosis and treatment of colorectal cancer. In order to reflect these changes, we (GIP) decided to make the second edition of the report. The purpose of this standardized pathology report is to provide a practical protocol for Korean pathologists, which could help diagnose and treat CRC patients. This report consists of "standard data elements" and "conditional data elements." Basic pathologic findings and parts necessary for prognostication of CRC patients are classified as "standard data elements," while other prognostic factors and factors related to adjuvant therapy are classified as "conditional data elements" so that each institution could select the contents according to the characteristics of the institution. The Korean version is also provided separately so that Korean pathologists can easily understand and use this report. We hope that this report will be helpful in the daily practice of CRC diagnosis.

Detailed pathological analysis of the advancing edge of the tumour can effectively stratify clinical T4b colorectal cancer patients

AIMS

Pathological staging of colorectal cancers (CRCs) that involve adhesion to adjacent organs (clinical stages T4b, cT4b) is sometimes difficult because the morphology of the invasive front varies. To resolve this issue, we reviewed 492 surgically resected CRC samples, comprising 96 cT4b tumours and, for comparison, 335 typical pathological stages (p) T3 and 61 pT4a tumours.

METHODS AND RESULTS

Cases were subdivided into four groups according to the presence or absence of microscopic tumour invasion into the muscular wall of the adjacent organs and peritumoral abscess along invasive front. Those that directly invaded the wall of the adjacent organs without peritumoral abscess were associated with a significantly worse overall (OS) and recurrence-free survival (RFS) than the other three types of cT4b tumours. Those with peritumoral abscess showed similar prognosis to typical pT3 tumours, even when the advancing edge of the tumour invaded the wall of adjacent organs (staged as pT4b). Tumours showing fibrous adhesions without tumour cell invasion into the muscular wall of the adjacent organs showed a similar prognosis to typical pT3 tumours and showed a better prognosis than pT4a tumours.

CONCLUSION

Only CRCs with tumour cell invasion into the muscular wall of the adjacent organs should be classified as pT4b, and it might be better to avoid 'the presence of tumour cells in fibrous adhesion' to define pathological T4b CRCs. In addition, the presence of a peritumoral abscess should be recorded as a predictor of better prognosis.

A Review of Current Challenges in Colorectal Cancer Reporting

Context.—

Pathologic assessment of colorectal cancer resection specimens plays an important role in postsurgical management and prognostication in patients with colorectal cancer. Challenges exist in the evaluation and reporting of these specimens, either because of difficulties in applying existing guidelines or related to newer concepts.

Objective.—

To address challenging areas in colorectal cancer pathology and to provide an overview of the literature, current guidelines, and expert recommendations for the handling of colorectal cancer resection specimens in everyday practice.

Data Sources.—

PubMed (US National Library of Medicine, Bethesda, Maryland) literature review; reporting protocols of the College of American Pathologists, the Royal College of Pathologists of the United Kingdom, and the Japanese Society for Cancer of the Colon and Rectum; and classification manuals of the American Joint Committee on Cancer and the Union for International Cancer Control.

Conclusions.—

This review has addressed issues and challenges affecting quality of colorectal cancer pathology reporting. High-quality pathology reporting is essential for prognostication and management of patients with colorectal cancer.

Clinicopathological, genomic and immunological factors in colorectal cancer prognosis

BACKGROUND

Numerous factors affect the prognosis of colorectal cancer (CRC), many of which have long been identified, such as patient demographics and the multidisciplinary team. In more recent years, molecular and immunological biomarkers have been shown to have a significant influence on patient outcomes. Whilst some of these biomarkers still require ongoing validation, if proven to be worthwhile they may change our understanding and future management of CRC. The aim of this review was to identify the key prognosticators of CRC, including new molecular and immunological biomarkers, and outline how these might fit into the whole wider context for patients.

METHODS

Relevant references were identified through keyword searches of PubMed and Embase Ovid SP databases.

RESULTS

In recent years there have been numerous studies outlining molecular markers of prognosis in CRC. In particular, the Immunoscore® has been shown to hold strong prognostic value. Other molecular biomarkers are useful in guiding treatment decisions, such as mutation testing of genes in the epidermal growth factor receptor pathway. However, epidemiological studies continue to show that patient demographics are fundamental in predicting outcomes.

CONCLUSION

Current strategies for managing CRC are strongly dependent on clinicopathological staging, although molecular testing is increasingly being implemented into routine clinical practice. As immunological biomarkers are further validated, their testing may also become routine. To obtain clinically useful information from new biomarkers, it is important to implement them into a model that includes all underlying fundamental factors, as this will enable the best possible outcomes and deliver true precision medicine.

Persistent Problems in Colorectal Cancer Reporting

Tumor stage, as determined by the Tumor, Node, Metastasis (TNM) staging system, is the single most influential factor determining treatment decisions and outcome among patients with colorectal cancer. Several stage-related elements in pathology reports consistently pose diagnostic challenges: recognition of serosal penetration by tumor (ie, pT3 vs pT4a), evaluation of regional lymph nodes, distinction between tumor deposits and effaced lymph nodes, and assessment of tumor stage in the neoadjuvant setting. This article discusses each of these issues in detail and provides practical tips regarding colorectal cancer staging.

Locally Advanced Colorectal Cancer: True Peritoneal Tumor Penetration is Associated with Peritoneal Metastases

BACKGROUND

Findings show T4 colorectal cancer (CRC) to be a risk factor for the development of peritoneal metastases (PM). Heterogeneity regarding peritoneal involvement of T4 tumors might explain the wide range of reported PM incidences (8-50%). Hyperplastic and mesothelial inflammatory reactions complicate evaluation of the exact primary tumor involvement of the peritoneal layer. This retrospective cohort study aimed to assess the association between either inflammatory peritoneal reaction or peritoneal involvement of the primary tumor and the risk of PM.

METHODS

Since 2010, pathologists at UZ Leuven have systematically categorized peritoneal involvement in peritoneal reaction with tumor less than 1 mm from the peritoneal surface or true peritoneal penetration. All patients undergoing resection of CRC between January 2010 and July 2013 who fulfilled either of these pathologic criteria were included in this study.

RESULTS

The study enrolled 159 CRC patients. Peritoneal reaction with tumor less than 1 mm from the peritoneal surface was present in 43 patients and true peritoneal penetration in 116 patients. Overall, 29 patients (18%) had synchronous PM, and 30 patients (23%) had metachronous PM. In the multivariable analysis, true peritoneal penetration, in contrast to peritoneal reaction with tumor less than 1 mm from the peritoneum, was associated with greater risk of PM (odds ratio [OR], 2.518; range, 1.038-6.111; p = 0.041) and lymph node involvement (N1: OR, 1.572; range, 0.651-3.797 vs N2: OR, 4.046; range, 1.549-10.569; p = 0.014).

CONCLUSION

Histologically confirmed true peritoneal penetration by CRC, rather than inflammatory peritoneal reaction constitutes a high risk for PM. With evolving treatment strategies that aim to treat PM in an earlier phase, identification of high-risk patients becomes highly important clinically.

Serosal surfaces, mucin pools, and deposits, oh my: challenges in staging colorectal carcinoma

Colorectal carcinoma is the third most common cancer in the United States. Proper and standardized pathologic staging is vital for prognostic assessment and impacts therapeutic decisions. The Tumor Node Metastasis (TNM) staging system was developed by the American Joint Committee on Cancer (AJCC) to be a data-driven, evidence-based staging system providing an accurate prediction of outcome. The AJCC 7th edition (2010) included several changes clarifying some issues and leading to new controversies. We aim to address selected challenging issues in tumor T staging, neoadjuvant treatment effects in rectal cancer, and definition of lymph node vs tumor deposit. Serosal involvement in colorectal cancer is staged as T4, which is associated with decreased survival and may impact additional therapy decisions. Although careful sampling and sectioning are helpful, challenges remain in interpretation of tumor within 1 mm of serosal surface with a reaction. Elastic stain as a surrogate marker for serosal invasion has been studied, but its usefulness remains unclear. Some unique issues in rectal cancer include the presence of serosa in proximal but not in distal tumors and post-neoadjuvant effects. Tumor should be staged based on tumor cells rather than acellular mucin pools. Additionally, tumor response should be graded only in primary tumor but not in lymph nodes or metastatic sites. The distinction between tumor deposits and lymph nodes has been modified in AJCC TNM from using size in the 5th edition, to the round contour in the 6th edition, to only features of residual lymph node architecture in the 7th edition. Interobserver variability remains but tumor deposits should be documented when present. The number of deposits should not be added to the total number of positive lymph nodes, and the N1c designation should only be used in cases without any positive lymph nodes. Future clarification will likely evolve as more data become available.

Controversies in the pathological assessment of colorectal cancer

Pathologic assessment of colorectal cancer specimens plays an essential role in patient management, informing prognosis and contributing to therapeutic decision making. The tumor-node-metastasis (TNM) staging system is a key component of the colorectal cancer pathology report and provides important prognostic information. However there is significant variation in outcome of patients within the same tumor stage. Many other histological features such as tumor budding, vascular invasion, perineural invasion, tumor grade and rectal tumor regression grade that may be of prognostic value are not part of TNM staging. Assessment of extramural tumor deposits and peritoneal involvement contributes to TNM staging but there are some difficulties with the definition of both of these features. Controversies in colorectal cancer pathology reporting include the subjective nature of some of the elements assessed, poor reporting rates and reproducibility and the need for standardized examination protocols and reporting. Molecular pathology is becoming increasingly important in prognostication and prediction of response to targeted therapies but accurate morphology still has a key role to play in colorectal cancer pathology reporting.