TNM staging system of colorectal carcinoma: surgical pathology of the seventh edition

Prognostic Value of Venous Invasion Detected by Elastin Stain May Surpass Lymph Node Status in Colon Cancer

BACKGROUND

Venous invasion is a poor prognostic factor in colon cancer but is often underreported with significant variability.

OBJECTIVES

We aimed to determine the impact of an elastin stain on venous invasion detection in colon cancer and evaluate the value of venous invasion in predicting disease recurrence in combination with lymph node status and other prognostic factors.

DESIGN

This is a retrospective analysis of a prospectively collected database.

SETTING

This study was conducted at a tertiary cancer center.

PATIENTS

A total of 418 patients who underwent curative resection for stage I to III colon cancer and routinely adopted an elastin stain were evaluated.

MAIN OUTCOME MEASURES

Venous invasion detection rate after adopting elastin stain, prognostic factors influencing disease recurrences by multivariate Cox regression models, and survival were measured. The zones of lymph node metastasis were defined as LNZ1, LNZ2, and LNZ3, corresponding to metastases in the pericolic, intermediate, and apical nodes.

RESULTS

Venous invasion detection rate increased from 11.3% to 35.4% compared with the previous period in which only hematoxylin and eosin stain was performed. Cox regression analysis showed venous invasion (HR, 3.856; 95% CI, 1.249-11.910; p = 0.019) and lymph node metastases (HR, 3.156; 95% CI, 1.094-9.108; p = 0.034) in all stages and LNZ 2, 3 (HR, 2.649; 95% CI, 1.244-5.640; p = 0.012) in stage III to be significantly associated with poor disease-free survival. When stratifying all patients by these 3 factors, patients with stage III [LNZ1/venous invasion (-)] had disease-free survival comparable with stage I, but significantly better disease-free survival than those with stage II [venous invasion (+)] (p = 0.018). Patients with stage II [venous invasion (+)] had better disease-free survival by using adjuvant chemotherapy (p < 0.001).

LIMITATIONS

This study was limited by its retrospective design.

CONCLUSION

Elastin stain contributed to a considerable increase in venous invasion detection. Venous invasion can be a powerful predictor of poor disease-free survival beyond lymph node metastases when limited to the pericolic area and is useful for deciding the use of adjuvant chemotherapy in stage II colon cancer. See Video Abstract at http://links.lww.com/DCR/B573.

EL VALOR PRONSTICO DE LA INVASIN VENOSA DETECTADA POR LA TINCIN DE ELASTINA PUEDE SUPERAR EL ESTADO DE LOS GANGLIOS LINFTICOS EN EL CNCER DE COLON

ANTECEDENTES:Invasión venosa (IV) es un factor de mal pronóstico en el cáncer de colon, que frecuentemente no se informa con una variabilidad significativa.OBJETIVOS:Nuestro objetivo fue determinar el impacto de tinción de elastina en la detección de IV en el cáncer de colon y evaluar el valor de IV en la predicción de la recurrencia de la enfermedad en combinación con el estado de los ganglios linfáticos y otros factores pronósticos.DISEÑO:Este es un análisis retrospectivo de una base de datos recopilada prospectivamente.ENTORNO CLINICO:Este estudio se realizó en un centro oncológico de referencia de tercer nivel.PACIENTES:Se valoraron un total de 418 pacientes sometidos a resección curativa por cáncer de colon en estadio I-III utilizando de manera rutinaria una tinción de elastina.PRINCIPALES MEDIDAS DE VALORACION:Se midieron la tasa de detección de IV después de adoptar la tinción de elastina, los factores de pronóstico que influyen en las recurrencias de la enfermedad mediante modelos de regresión de Cox multivariados y la supervivencia. La zona de metástasis ganglionares se definió como, LNZ1, LNZ2 y LNZ3, correspondientes a las metástasis en los ganglios pericólicos, intermedios y apicales, respectivamente.RESULTADOS:La tasa de detección de IV aumentó de 11,3% a 35,4% en comparación con el período anterior en el que solo se realizó tinción con hematoxilina y eosina. El análisis de regresión de Cox mostró VI (razón de riesgo, 3.856; intervalo de confianza [IC] del 95%, 1.249-11.910, p = 0.019) y metástasis en los ganglios linfáticos (razón de riesgo, 3.156; IC del 95%, 1.094-9.108, p = 0.034) en todos los estadios y LNZ 2, 3 (cociente de riesgo, 2.649; IC del 95%, 1.244-5.640, p = 0.012) en el estadio III se asociaron significativamente con una pobre supervivencia libre de enfermedad. Al estratificar a todos los pacientes según estos tres factores, los pacientes con estadio III [LNZ1 / VI (-)] tuvieron una sobrevivencia sin enfermedad (SSE) comparable con el estadio I, pero una supervivencia libre de enfermedad significativamente mejor que aquellos con estadio II [VI (+)] (p = 0,018). Pacientes en estadío II [VI (+)] tuvieron una mejor supervivencia sin enfermedad mediante el uso de quimioterapia adyuvante (p <0,001).LIMITACIONES:Estudio limitado por su diseño retrospectivo.CONCLUSIÓN:La tinción de elastina contribuyó a un aumento considerable en la detección de IV. IV puede ser un poderoso predictor de supervivencia sin enfermedad deficiente más allá de las metástasis de los ganglios linfáticos cuando se limita al área pericólica y es útil para decidir el uso de quimioterapia adyuvante en el cáncer de colon en estadío II. Consulte Video Resumen en http://links.lww.com/DCR/B573. (Traducción-Dr. Adrian Ortega).

Incidence of extramural venous invasion in colorectal carcinoma as determined at the invasive tumor front and its prognostic impact

Extramural venous invasion (EMVI) is prognostic for colorectal cancer; however, veins are only detected partially by normal perpendicular preparation. Therefore, reported findings are conflicting and standardization is required. A total of 239 resection specimens were examined by tangential preparation of the extramural veins at the invasive tumor front. Average follow-up was 39 months. The relationship of EMVI to metachronous hematogenic metastasis (MHM) was evaluated. With this method, a high prevalence of EMVI beginning in stage II is apparent. In stage I, 66% of patients with EMVI developed MHM; in stage II, 25%; and in stage III, 49%. In stage III, the number of tumor-invaded veins is crucial. In the absence of detection of EMVI, MHM occurred in 1 of 29 patients in stage II and in 2 of 13 patients in early stage III. By tangential sectioning at the invasive tumor front, we found a high incidence of EMVI beginning in stage II, which increases with tumor stage. Especially in stages II and III, the correct determination of absent EMVI has a high negative predictive value for MHM. In stage I, EMVI defines a patient group with increased risk for MHM. The quantification of EMVI is an important issue for standardization.

Increased Expression of Thymosin β4 Is Independently Correlated with Hypoxia Inducible Factor-1α (HIF-1α) and Worse Clinical Outcome in Human Colorectal Cancer

Background

Thymosin β₄ is a multi-functional hormone-like polypeptide, being involved in cell migration, angiogenesis, and tumor metastasis. This study was undertaken to clarify the clinicopathologic implications of thymosin β₄ expression in human colorectal cancers (CRCs).

Methods

We investigated tissue sections from 143 patients with CRC by immunohistochemistry. In addition, we evaluated the expression patterns and the clinico-pathological significance of thymosin β₄ expression in association with hypoxia inducible factor-1α (HIF-1α) expression in the CRC series.

Results

High expression of thymosin β₄ was significantly correlated with lymphovascular invasion, invasion depth, regional lymph node metastasis, distant metastasis, and TNM stage. Patients with high expression of thymosin β₄ showed poor recurrence-free survival (p = .001) and poor overall survival (p = .005) on multivariate analysis. We also found that thymosin β₄ and HIF-1α were overexpressed and that thymosin β₄ expression increased in parallel with HIF-1α expression in CRC.

Conclusions

A high expression level of thymosin β₄ indicates poor clinical outcomes and may be a useful prognostic factor in CRC. Thymosin β₄ is functionally related with HIF-1α and may be a potentially valuable biomarker and possible therapeutic target for CRC.

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.

Staging colorectal cancer with the TNM 7th: The presumption of innocence when applying the M category

One of the main changes of the current TNM-7 is the elimination of the category MX, since it has been a source of ambiguity and misinterpretation, especially by pathologists. Therefore the ultimate staging would be better performed by the patient’s clinician who can classify the disease M0 (no distant metastasis) or M1 (presence of distant metastasis), having access to the completeness of data resulting from clinical examination, imaging workup and pathology report. However this important change doesn’t take into account the diagnostic value and the challenge of small indeterminate visceral lesions encountered, in particular, during radiological staging of patients with colorectal cancer. In this article the diagnosis of these lesions with multiple imaging modalities, their frequency, significance and relevance to staging and disease management are described in a multidisciplinary way. In particular the interplay between clinical, radiological and pathological staging, which are usually conducted independently, is discussed. The integrated approach shows that there are both advantages and disadvantages to abandoning the MX category. To avoid ambiguity arising both by applying and interpreting MX category for stage assigning, its abandoning seems reasonable. The recognition of the importance of small lesion characterization raises the need for applying a separate category; therefore a proposal for their categorization is put forward. By using the proposed categorization the lack of consideration for indeterminate visceral lesions with the current staging system will be overcome, also optimizing tailored follow-up.

Impact of lymph node retrieval on surgical outcomes in colorectal cancers

BACKGROUND

Adequacy of lymph node sampling is fundamental to the accuracy of nodal status (N-status) assessment in colorectal cancers (CRCs). This study aimed to determine the minimum sampling number to achieve reliable prognosis and to look for any association between the positive lymph node ratio (LNR) and overall survival (OS). Pathological reports of 533 stages I-III CRC patients who underwent curative resection during the period from January 1998 to December 2007 were retrospectively reviewed with regard to the number of lymph nodes obtained for pathological diagnosis (nLN) and number of positive nodes.

RESULTS

The median nLN was 10 nodes and the mean number of positive nodes was 1.7 nodes. On the N-status attribution plot, the cut-off point where the converging curves turned parallel was at 12 nodes. This cut-off was supported by the significant difference in OS between cases with nLN ≥ 12 (5-year OS 73.0%) and those with nLN < 12 (5-year OS 62.7%), (P-value < 0.01). Multivariate analysis showed that both nLN-12 and LNR were independent factors predicting survival probability.

CONCLUSION

Our data emphasize the importance of lymph node harvesting during the surgical resection of CRCs. In addition, LNR is a strong independent factor associated with CRC survival.