Prognostic value of preoperative radiological staging assessed by computed tomography in patients with nonmetastatic colon cancer

Neoadjuvant Chemotherapy With Oxaliplatin and Fluoropyrimidine Versus Upfront Surgery for Locally Advanced Colon Cancer: The Randomized, Phase III OPTICAL Trial

PURPOSE

The role of neoadjuvant chemotherapy (NAC) in colon cancer remains unclear. This trial investigated whether 3 months of modified infusional fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) or capecitabine and oxaliplatin (CAPOX) as NAC could improve outcomes in patients with locally advanced colon cancer versus upfront surgery.

PATIENTS AND METHODS

OPTICAL was a randomized, phase III trial in patients with clinically staged locally advanced colon cancer (T3 with extramural spread into the mesocolic fat ≥5 mm or T4). Patients were randomly assigned 1:1 to receive six preoperative cycles of mFOLFOX6 or four cycles of CAPOX, followed by surgery and adjuvant chemotherapy (NAC group), or immediate surgery and the physician's choice of adjuvant chemotherapy (upfront surgery group). The primary end point was 3-year disease-free survival (DFS) assessed in the modified intention-to-treat (mITT) population.

RESULTS

Between January 2016 and April 2021, of the 752 patients enrolled, 744 patients were included in the mITT analysis (371 in the NAC group; 373 in the upfront surgery group). At a median follow-up of 48.0 months (IQR, 46.0-50.1), 3-year DFS rates were 82.1% in the NAC group and 77.5% in the upfront surgery group (stratified hazard ratio [HR], 0.74 [95% CI, 0.54 to 1.03]). The R0 resection was achieved in 98% of patients who underwent surgery in both groups. Compared with upfront surgery, NAC resulted in a 7% pathologic complete response rate (pCR), significantly lower rates of advanced tumor staging (pT3-4: 77% v 94%), lymph node metastasis (pN1-2: 31% v 46%), and potentially improved overall survival (stratified HR, 0.44 [95% CI, 0.25 to 0.77]).

CONCLUSION

NAC with mFOLFOX6 or CAPOX did not show a significant DFS benefit. However, this neoadjuvant approach was safe, resulted in substantial pathologic downstaging, and appears to be a viable therapeutic option for locally advanced colon cancer.

The ELECLA trial: A multicentre randomised control trial on outcomes of neoadjuvant treatment on locally advanced colon cancer

BACKGROUND

Colon cancer (CC) is a public health concern with increasing incidence in younger populations. Treatment for locally advanced CC (LACC) involves oncological surgery and adjuvant chemotherapy (AC) to reduce recurrence and improve overall survival (OS). Neoadjuvant chemotherapy (NAC) is a novel approach for the treatment of LACC, and research is underway to explore its potential benefit in terms of survival. This trial will assess the efficacy of NAC in LACC.

METHODS

This is a multicentre randomised, parallel-group, open label controlled clinical trial. Participants will be selected based on homogenous inclusion criteria and randomly assigned to two treatment groups: NAC, surgery, and AC or surgery followed by AC. The primary aim of this study is to evaluate the 2-year progression-free survival (PFS), with secondary outcomes including 5-year PFS, 2- and 5-year OS, toxicity, radiological and pathological response, morbidity, and mortality.

DISCUSSION

The results of this study will determine whether NAC induces a clinical and histological tumour response in patients with CCLA and if this treatment sequence improves survival without increasing morbidity and mortality.

REGISTRATION NUMBER

NCT04188158.

The diagnostic accuracy of local staging in colon cancer based on computed tomography (CT): evaluating the role of extramural venous invasion and tumour deposits

PURPOSE

The shift from adjuvant to neoadjuvant treatment in colon cancer demands the radiological selection of patients for systemic therapy. The aim of this study was to evaluate the accuracy of the CT-based TNM stage and high-risk features, including extramural venous invasion (EMVI) and tumour deposits, in the identification of patients with histopathological advanced disease, currently considered for neoadjuvant treatment (T3-4 disease).

METHODS

All consecutive patients surgically treated for non-metastatic colon cancer between January 2018 and January 2020 in a referral centre for colorectal cancer were identified retrospectively. All tumours were staged on CT according to the TNM classification system. Additionally, the presence of EMVI and tumour deposits on CT was evaluated. The histopathological TNM classification was used as reference standard.

RESULTS

A total of 176 patients were included. Histopathological T3-4 colon cancer was present in 85.0% of the patients with CT-detected T3-4 disease. Histopathological T3-4 colon cancer was present in 96.4% of the patients with CT-detected T3-4 colon cancer in the presence of both CT-detected EMVI and CT-detected tumour deposits. Histopathological T0-2 colon cancer was present in 50.8% of the patients with CT-detected T0-2 disease, and in 32.4% of the patients without CT-detected EMVI and tumour deposits.

CONCLUSION

The diagnostic accuracy of CT-based staging was comparable with previous studies. The presence of high-risk features on CT increased the probability of histopathological T3-4 colon cancer. However, a substantial part of the patients without CT-detected EMVI and tumour deposits was diagnosed with histopathological T3-4 disease. Hence, more accurate selection criteria are required to correctly identify patients with locally advanced disease.

Prognostic Significance of Enlarged Lymph Nodes in Stage II Colorectal Cancer

BACKGROUND

Many studies have reported a correlation between lymph node metastasis and prognosis in patients with colorectal cancer. However, the clinical significance of enlarged lymph nodes for prognosis has scarcely been explored.

OBJECTIVE

This study aimed to assess the clinical significance of enlarged lymph nodes in stage II colorectal cancer.

DESIGN

This is a multicenter retrospective observational study with a median follow-up period of 66.8 months.

SETTINGS

Patients' medical records were retrospectively collected from the Japanese Study Group for Postoperative Follow-up of Colorectal Cancer database.

PATIENTS

This study included 2212 patients with stage II colorectal cancer who underwent surgical resection between January 2009 and December 2012. Patients were classified into the enlarged lymph node and nonenlarged lymph node groups and their data were compared.

MAIN OUTCOME MEASURES

Clinicopathological characteristics and prognoses of the 2 groups were compared. The main outcomes measured were recurrence-free survival and overall survival.

RESULTS

The enlarged lymph node group showed significantly better overall survival and recurrence-free survival in pT4b cases but not in pT3 or pT4a cases. In pT4b cases, an enlarged lymph node (HR, 0.53; 95% CI, 0.29-0.98) was an independent prognostic factor for longer recurrence-free survival, whereas a rectal lesion (HR, 3.46; 95% CI, 1.90-6.29) was an independent prognostic factor for shorter recurrence-free survival. An enlarged lymph node was associated with a lower distant recurrence rate (HR, 0.49; 95% CI, 0.26-0.92) and a tendency to correlate with better overall survival (HR, 0.50; 95% CI, 0.22-1.14).

LIMITATIONS

The retrospective design may have increased the risk of selection bias. Inadequate information regarding enlarged lymph nodes is another study limitation.

CONCLUSIONS

This study showed that enlarged lymph nodes are associated with a favorable prognosis in patients with pT4b stage II colorectal cancer. See Video Abstract at http://links.lww.com/DCR/C246 .

IMPORTANCIA PRONSTICA DE LOS GANGLIOS LINFTICOS AGRANDADOS EN EL CNCER COLORRECTAL EN ESTADIO II

ANTECEDENTES:Muchos estudios han informado una correlación entre la metástasis en los ganglios linfáticos y el pronóstico en pacientes con cáncer colorrectal. Sin embargo, apenas se ha explorado la importancia clínica de los ganglios linfáticos agrandados para el pronóstico.OBJETIVO:El objetivo fue evaluar la importancia clínica de los ganglios linfáticos agrandados en el cáncer colorrectal en estadio II.DISEÑO:Este es un estudio observacional retrospectivo multicéntrico con una mediana de seguimiento de 66,8 meses.CONFIGURACIÓN:Los registros médicos de los pacientes se recopilaron retrospectivamente de la base de datos del Grupo de estudio japonés para el seguimiento posoperatorio del cáncer colorrectal.PACIENTES:Incluimos 2212 pacientes con cáncer colorrectal en estadio II que se sometieron a resección quirúrgica entre enero de 2009 y diciembre de 2012. Los pacientes se clasificaron en grupos de ganglios linfáticos agrandados y no agrandados y se compararon sus datos.PRINCIPALES MEDIDAS DE RESULTADO:Se compararon las características clinicopatológicas y los pronósticos de los dos grupos. Los principales resultados medidos fueron la supervivencia sin recurrencia y la supervivencia general.RESULTADOS:El grupo de ganglios linfáticos agrandados mostró una supervivencia general significativamente mejor y una supervivencia libre de recurrencia en los casos pT4b, pero no en los casos pT3 ni pT4a. En los casos de pT4b, el agrandamiento de los ganglios linfáticos (CRI, 0,53; IC 95 %, 0,29-0,98) fue un factor pronóstico independiente para una supervivencia sin recidiva más prolongada, mientras que la lesión rectal (CRI, 3,46; IC 95%, 1,90-6,29) fue un factor pronóstico independiente para RFS más cortos. Los ganglios linfáticos agrandados se relacionaron con una tasa más baja de recurrencia a distancia (CRI, 0,49; IC 95%, 0,26-0,92) y una tendencia a correlacionarse con una mejor supervivencia general (CRI, 0,50; IC 95%, 0,22-1,14).LIMITACIONES:El diseño retrospectivo puede haber aumentado el riesgo de sesgo de selección. La información inadecuada sobre el agrandamiento de los ganglios linfáticos es otra limitación del estudio.CONCLUSIONES:Este estudio mostró que los ganglios linfáticos agrandados están asociados con un pronóstico favorable en pacientes con cáncer colorrectal pT4b en estadio II. Consulte Video Resumen en http://links.lww.com/DCR/C246 . ( Traducción - Dr. Mauricio Santamaria ).

A randomized phase II study comparing preoperative mFOLFOX6 versus FOLFOXIRI for locally advanced colon cancer: JCOG2006

The prognosis of locally advanced colon cancer (LACC) with surgical resection followed only by adjuvant chemotherapy is poor. Preoperative chemotherapy for LACC patients with risk factors such as cT4bN+ or cT3-4aN2-3 has attracted attention. Here, the authors describe the rationale and design of JCOG2006, a randomized phase II study comparing preoperative chemotherapy with mFOLFOX6 versus FOLFOXIRI for LACC. Their efficacy and safety are evaluated and a determination of which is the more promising treatment will be conducted in a subsequent phase III trial. A total of 86 patients will be accrued from 44 institutions over 2 years. The primary end point is the proportion of patients with a Tumor Regression Score of 0-2, and secondary end points include overall survival, response rate and adverse events. Clinical Trial Registration: jRCTs031210365 (https://jrct.niph.go.jp/).

A Clinicopathological Feature-Based Nomogram for Predicting the Likelihood of D3 Lymph Node Metastasis in Right-Sided Colon Cancer Patients

BACKGROUND

Despite advancements in treating right-sided colon cancer patients, the ideal scope of lymphadenectomy remains controversial.

OBJECTIVE

Our objective was to investigate the likelihood of D3 lymph node metastasis in right-sided colon cancer patients and develop a clinicopathological feature-based nomogram for D3 lymphadenectomy.

DESIGN

We retrospectively analyzed 286 right-sided colon cancer patients who underwent D3 lymphadenectomy. The patients were divided into 2 groups based on whether D3 lymph node metastasis was positive. Then, univariable and multivariable logistic regression analyses were performed to obtain independent risk factors for predicting D3 lymph node metastasis. Moreover, we performed receiver operating characteristic curve analyses to evaluate the predictive power of the model.

SETTING

This study was conducted at Nanfang Hospital of Southern Medical University in China.

PATIENTS

A total of 286 consecutive patients who underwent right hemicolectomy and D3 lymphadenectomy as a primary treatment for right-sided colon cancer between January 2016 and December 2019 were enrolled in this study.

MAIN OUTCOME MEASURES

The primary measures were independent risk factors for predicting D3 lymph node metastasis in right-sided colon cancer.

RESULTS

The D3 lymph node metastasis rate in right-sided colon cancer patients was 16.1% (46/286). D3 lymphadenectasis on CT, lymphatic invasion, and T4 tumors were filtered out as independent risk factors for D3 lymph node metastasis according to the multivariable logistic regression analysis. We established a nomogram that predicted D3 lymph node metastasis of right-sided colon cancer on the combination of the 3 factors with an area under the curve of 0.717 (95% CI, 0.629-0.806).

LIMITATIONS

This was a retrospective study from a single center.

CONCLUSIONS

We developed a valuable clinicopathological feature-based nomogram to predict the incidence of D3 lymph node metastasis in right-sided colon cancer patients. Patients with D3 lymphadenectasis on CT, preoperative T4 tumors, and lymphatic invasion should undergo D3 lymphadenectomy. See Video Abstract at http://links.lww.com/DCR/B852 .

UN NOMOGRAMA BASADO EN CARACTERSTICAS CLNICOPATOLGICAS PARA PREDECIR LA PROBABILIDAD DE METSTASIS EN GANGLIOS LINFTICOS D EN PACIENTES CON CNCER DE COLON DERECHO

ANTECEDENTES:A pesar de los avances en el tratamiento de pacientes con cáncer de colon derecho, el ámbito ideal de la linfadenectomía sigue siendo controvertido.OBJETIVO:Investigar la probabilidad de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho y desarrollar un nomograma basado en características clínico-patológicas basado para la linfadenectomía D3.DISEÑO:Analizamos retrospectivamente a 286 pacientes con cáncer de colon derecho que se sometieron a linfadenectomía D3. Los pacientes se dividieron en dos grupos en función de si eran positivos para metástasis en los ganglios linfáticos D3. Luego, se realizaron análisis de regresión logística univariable y multivariable para obtener factores de riesgo independientes para predecir metástasis en los ganglios linfáticos D3. Además, realizamos análisis de las curvas de características operatorias del receptor para evaluar el poder predictivo del modelo.SEDE:Este estudio se realizó en el Hospital Nanfang de la Universidad Médica del Sur en China.PACIENTES:Un total de 286 pacientes consecutivos que se sometieron a hemicolectomía derecha y linfadenectomía D3 como tratamiento primario para el cáncer de colon derecho entre enero de 2016 y diciembre de 2019 se inscribieron en este estudio.PRINCIPALES MEDIDAS DE RESULTADO:Las medidas primarias fueron factores de riesgo independientes para predecir las metástasis en ganglios linfáticos D3 en el cáncer de colon derecho.RESULTADOS:La tasa de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon del lado derecho fue del 16,1% (46/286). El aumento de tamaño de ganglios D3 en la TC, la invasión linfática y los tumores T4 se filtraron como factores de riesgo independientes de metástasis en los ganglios linfáticos D3 de acuerdo con el análisis de regresión logística multivariable. Establecimos un nomograma que predijo metástasis en los ganglios linfáticos D3 del cáncer de colon derecho en la combinación de los tres factores con un área bajo la curva de 0,717 (IC del 95%, 0,629-0,806).LIMITACIONES:Este fue un estudio retrospectivo de un solo centro.CONCLUSIONES:Desarrollamos un valioso nomograma basado en características clínico-patológicas para predecir la incidencia de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho. Los pacientes con crecimiento de ganglios D3 en TC, tumores con clasificación preoperatoria T4 e invasión linfática, deben ser sometidos a linfadenectomía D3. Consulte Video Resumen en http://links.lww.com/DCR/B852 . (Traducción-Dr. Juan Carlos Reyes ).

Prognostic value of elastic lamina staining in patients with stage III colon cancer

OBJECTIVE

The objectives of this study were to analyze the difference between the preoperative radiological and postoperative pathological stages of colorectal cancer (CRC) and explore the feasibility of elastic lamina invasion (ELI) as a prognostic marker for patients with stage III colon cancer.

METHODS

A total of 105 consecutive patients underwent radical surgery (R0 resection) for stage III colon cancer at the Cancer Hospital of China Medical University between January 2015 and December 2017. Clinicopathological features, including radiological stage and elastic lamina staining, were analyzed for prognostic significance in stage III colon cancer.

RESULTS

A total of 105 patients with stage III colon cancer who met the criteria and had complete data available were included. The median follow-up period of survivors was 41 months. During the follow-up period, 33 (31.4%) patients experienced recurrence after radical resection, and the 3-year disease-free survival (DFS) rate was 64.8%. The consistency between preoperative radiological and postoperative pathological staging was poor (κ = 0.232, P < 0.001). The accuracy of ≤ T2 stage diagnoses was 97.1% (102/105), that of T3 stage was 60.9% (64/105), that of T4a stage was 68.6% (72/105) and that of T4b stage was 91.4% (96/105). The DFS rate of T3 ELI (+) patients was significantly lower than that of both T3 ELI (-) patients (P = 0.000) and pT4a patients (P = 0.013). The DFS rate of T3 ELI (-) patients was significantly higher than that of pT4b patients (P=0.018). T3 ELI (+) (HR (Hazard ratio), 8.444 [95% CI, 1.736-41.067]; P = 0.008), T4b (HR, 57.727[95% CI, 5.547-600.754]; P = 0.001), N2 stage (HR, 10.629 [95% CI, 3.858-29.286]; P < 0.001), stage III (HR, 0.136 [95% CI, 0.31-0.589]; P = 0.008) and perineural invasion (PNI) (HR, 8.393 [95% CI, 2.094-33.637]; P = 0.003) were independent risk factors for postoperative recurrence of stage III colon cancer.

CONCLUSIONS

The consistency between preoperative radiological and postoperative pathological staging was poor, especially for tumors located in the ascending colon and descending colon. Elastic lamina staining is expected to become a stratified indicator of recurrence risk for patients with stage III colon cancer and a guide for individualized adjuvant chemotherapy, thus improving patient prognosis.

Accurate staging of non-metastatic colon cancer with CT: the importance of training and practice for experienced radiologists and analysis of incorrectly staged cases

PURPOSE

To investigate whether locoregional staging of colon cancer by experienced radiologists can be improved by training and feedback to minimize the risk of over-staging into the context of patient selection for neoadjuvant therapy and to identify potential pitfalls of CT staging by characterizing pathologic traits of tumors that remain challenging for radiologists.

METHODS

Forty-five cases of stage I-III colon cancer were included in this retrospective study. Five experienced radiologists evaluated the CTs; 5 baseline scans followed by 4 sequential batches of 10 scans. All radiologists were trained after baseline scoring and 2 radiologists received feedback. The learning curve, diagnostic performance, reader confidence, and reading time were evaluated with pathologic staging as reference. Pathology reports and H&E slides of challenging cases were reviewed to identify potential pitfalls.

RESULTS

Diagnostic performance in distinguishing T1-2 vs. T3-4 improved significantly after training and with increasing number of reviewed cases. Inaccurate staging was more frequently related to under-staging rather than over-staging. Risk of over-staging was minimized to 7% in batch 3-4. N-staging remained unreliable with an overall accuracy of 61%. Pathologic review identified two tumor characteristics causing under-staging for T-stage in 5/7 cases: (1) very limited invasive part beyond the muscularis propria and (2) mucinous composition of the invading part.

CONCLUSION

The high accuracy and specificity of T-staging reached in our study indicate that sufficient training and practice of experienced radiologists can ensure high validity for CT staging in colon cancer to safely use neoadjuvant therapy without significant risk of over-treatment, while N-staging remained unreliable.

Tumor size measured by multidetector CT in resectable colon cancer: correlation with regional lymph node metastasis and N stage

Background

Lymph node metastasis (LNM) is a risk factor for poor long-term outcomes and a prognostic factor for disease-free survival in colon cancer. Preoperative lymph node status evaluation remains a challenge. The purpose of this study is to determine whether tumor size measured by multidetector computed tomography (MDCT) could be used to predict LNM and N stage in colon cancer.

Material and methods

One hundred six patients with colon cancer who underwent radical surgery within 1 week of MDCT scan were enrolled. Tumor size including tumor length (Tlen), tumor maximum diameter (Tdia), tumor maximum cross-sectional area (Tare), and tumor volume (Tvol) were measured to be correlated with pathologic LNM and N stage using univariate logistic regression analysis, multivariate logistic analysis, and receiver operating characteristic (ROC) curve analysis.

Results

The inter- and intraobserver reproducibility of Tlen (intraclass correlation coefficient [ICC] = 0.94, 0.95, respectively), Tdia (ICC = 0.81, 0.93, respectively), Tare (ICC = 0.97, 0.91, respectively), and Tvol (ICC = 0.99, 0.99, respectively) parameters measurement are excellent. Univariate logistic regression analysis showed that there were significant differences in Tlen, Tdia, Tare, and Tvol between positive and negative LNM (p < 0.001, 0.001, < 0.001, < 0.001, respectively). Multivariate logistic regression analysis revealed that Tvol was independent risk factor for predicting LNM (odds ratio, 1.082; 95% confidence interval for odds ratio, 1.039, 1.127, p<0.001). Tlen, Tdia, Tare, and Tvol could distinguish N0 from N1 stage (p < 0.001, 0.041, < 0.001, < 0.001, respectively), N0 from N2 (all p < 0.001), N0 from N1-2 (p < 0.001, 0.001, < 0.001, < 0.001, respectively), and N0-1 from N2 (p < 0.001, 0.001, < 0.001, < 0.001, respectively). The area under the ROC curve (AUC) was higher for Tvol than that of Tlen, Tdia, and Tare in identifying LNM (AUC = 0.83, 0.82, 0.69, 0.79), and distinguishing N0 from N1 stage (AUC = 0.79, 0.78, 0.63, 0.74), N0 from N2 stage (AUC = 0.92, 0.89, 0.80, 0.89, respectively), and N0-1 from N2 stage (AUC = 0.84, 0.79, 0.76, 0.83, respectively).

Conclusion

Tumor size was correlated with regional LNM in resectable colon cancer. In particularly, Tvol showed the most potential for noninvasive preoperative prediction of regional LNM and N stage.

Neoadjuvant chemotherapy in locally advanced colon cancer: a systematic review

BACKGROUND

Preoperative or neoadjuvant chemotherapy (NAC) has emerged as a novel alternative to treat locally advanced colon cancer (LACC), as in other gastrointestinal malignancies. However, evidence of its efficacy and safety has not yet been gathered in the literature. The aim of the present study was to perform an extensive review of the scientific evidence for NAC in patients with LACC.

METHODS

PubMed, EMBASE, MEDLINE and Cochrane Library were searched for a systematic review of the literature from 2010 to 2019. Six eligible studies were included, with a total of 27,937 patients, 1232 of them (4.4%) treated with NAC. There were only one randomized controlled trial, three phase II non-randomized single arm studies and two retrospective studies.

RESULTS

The baseline computed tomography scan showed that most of patients had a T3 tumor. The completion rate of the planned neoadjuvant treatment ranged from 52.5 to 93.8%. Between 97.2 and 100% of patients had the scheduled surgery. The median tumor volume reduction after NAC ranged from 62.5 to 63.7%. The anastomotic leak rate in the NAC group ranged from 0 to 7%, with no cases of postoperative mortality. There was major pathological tumor regression in 4-34.7% of cases. Between 84 and 100% of NAC patients had R0-surgery. Survival after NAC seems to be encouraging although significant improvement has only been proven in T4b tumours.

CONCLUSIONS

According to our systematic review, the NAC may be a safe and effective emerging therapeutic alternative for treating LACC. This approach, which is still being tested, increases the reliance on accurate radiological staging.

T4 Colon Cancer - Current Management

Colorectal cancer is the third most often encountered type of cancer and represents the third leading cause of cancer related deaths, on both sexes. One of the most important prognostic parameters is the tumor’s stage at the time of the diagnosis. T4 cancers represent advanced tumors associated with penetration of the visceral peritoneum (T4a) and/or direct invasion in adjacent structures (T4b). Preoperative diagnosis is influenced by the inability of the existent imaging modalities to accurately differentiate the true invasion from the simple, inflammatory adherence to the neighboring structures. As a consequence surgical treatment must follow the principle of en bloc resection; however the ability of achieving an R0 resection depends on the tumor location, invaded organ, and the type of the surgical procedure required. Neoadjuvant treatment for advanced colon cancer it may be very difficult to be applied. This review is focused on preoperative workup, therapeutic strategies and subsequent results in advanced T4 colon cancers.

Staging with computed tomography of patients with colon cancer

PURPOSE

Accurate staging of colonic cancer is important for patient stratification. We aimed to correlate the diagnostic accuracy of preoperative computed tomography (CT) with final histopathology as reference standard.

METHODS

Data was collected retrospectively on 615 consecutive patients operated for colonic cancer. Evaluation was based upon T-stage. Patients were stratified into high-risk and low-risk groups, based on the extent of tumor invasion beyond the proper muscle layer of more or less than 5 mm. The Kendall tau correlation coefficient was used to calculate concordance between radiological (r)T-stage obtained at CT imaging and pathological (p)T-stage from the final pathology.

RESULTS

In total, 501 patients were included. We found no significant differences in the Kendall tau values for diagnostic measures between the groups at the 95% confidence interval (CI) level: 49% (95% CI, 43-55) for all individuals, 48% (95% CI, 40-56) for screened individuals, and 47% (95% CI, 37-56) for non-screened individuals. The overall sensitivity and specificity for all individuals in identifying high-risk tumors on CT was 65% (95% CI, 56-73) and 89% (95% CI, 85-92). The risk of ending up in the high-risk group due to overstaging among all individuals was calculated as the number needed to harm 11.7 (95% CI, 9-16).

CONCLUSIONS

There is basis for improvement of CT-based preoperative staging of patients with colorectal cancer. Supplementary modalities may be needed for correct staging of patients preoperatively, especially in relation to stratification of patients into neoadjuvant treatments or tailored therapy in patients with early cancers.

The distribution of lymph node metastases and their size in colon cancer

PURPOSE

The purpose of this study is to clarify the optimal extent of lymph node dissection for colon cancer by evaluating the distributions of lymph node metastases and lymph node size according to tumor location and T stage.

METHODS

This study enrolled 662 patients who underwent curative resection for primary colon cancer between 2013 and 2015. Lymph node regions were classified into pericolic, intermediate, and main nodes. The short-axis diameter of each dissected lymph node was measured. The distributions of lymph node metastases and lymph node size were evaluated according to tumor location and T stage.

RESULTS

In the overall cohort, the incidence of metastases in pericolic nodes located more than 5 cm but no more than 10 cm from tumor and in pericolic nodes located more than 10 cm from tumor was 3.6 and 0.2%, respectively. More than 2% of patients with ≥ T2 tumor had metastases in main lymph nodes, and no patients with T1 tumor had metastases in main lymph nodes. Only 0.7% of patients with T1 tumor had lymph node metastases in pericolic nodes located more than 5 cm from the tumor. Both metastatic and non-metastatic lymph node sizes were significantly larger in right-sided colon cancer than in left-sided colon cancer, and both metastatic and non-metastatic lymph node sizes were significantly larger in ≥ T2 tumor than in T1 tumor.

CONCLUSION

It is necessary to resect 10 cm of normal bowel both proximal and distal to the tumor and to perform D3 lymph node dissection for ≥ T2 colon cancer.

Outcomes of laparoscopic surgery in pathologic T4 colon cancers compared to those of open surgery

INTRODUCTION

Despite the oncologic safety of laparoscopic surgery in colon cancer management, laparoscopy is not regarded as a standard treatment for T4 colon cancer. The aim of this study was to investigate the short-term and long-term oncologic outcomes of laparoscopic surgery in patients with locally advanced colon cancer.

MATERIAL AND METHOD

From March 2003 to June 2013, a total of 109 consecutive patients with proven pathologic T4 colon cancer were enrolled. These patients were divided into the laparoscopy group (LG, n = 52) and the open group (OG, n = 57). Perioperative and long-term oncologic outcomes were compared between the two groups.

RESULTS

In the LG, open conversion occurred in four patients (7.6%). Combined resection was less commonly performed in the LG (13.5%) than in the OG (36.8%, P = 0.005). Operation time was similar between the two groups. In the LG, blood loss (129 mL vs. 437 mL, P < 0.001) and overall complication rate (13.5 vs. 36.8%, P = 0.005) were lower and length of hospital stay was shorter (median 7 vs. 17 days, P < 0.001) than in the OG. The 5-year overall survival rate was 60.7% for the LG and 61.9% for the OG (P = 0.817). Local recurrence-free survival did not differ between the groups (88.9% in LG vs. 88.1% in OG, P = 0.725).

CONCLUSION

Considering the benefits of early recovery and similar oncologic outcomes, laparoscopic surgery in T4 colon cancer could be a viable option in selected patients.

Assessment and diagnostic accuracy of lymph node status to predict stage III colon cancer using computed tomography

Background

To study different imaging criteria for prediction of lymph node metastases (Stage III disease) in colon cancer using CT.

Methods

In a retrospective setting, 483 consecutive patients with histology proven colon cancer underwent elective primary resection during 2008–2011, a cohort of 119 patients were included. Contrast enhanced CT examinations, in portal-venous phase, were reviewed with assessment of the number of lymph nodes, their anatomical distribution, size, size ratio, internal heterogeneity, presence of irregular outer border and attenuation values. Sensitivity, specificity, PPV and NPV for each studied criteria for prediction of stage III disease was calculated.

Results

According to histopathology 80 patients were stage I-II and 39 were stage III. Of the studied CT-criteria for lymph node metastases per patient, internal heterogeneity in at least one lymph node resulted in the best performance with sensitivity, specificity, PPV and NPV of 79, 84, 70 and 89%, Odds ratio (OR) 20. Presence of irregular outer border resulted in a sensitivity, specificity, PPV and NPV of 59, 81, 61 and 82%, OR 6.2. If both internal heterogeneity and/or irregular outer border was used as a criterion this resulted in a sensitivity, specificity, PPV and NPV of 85, 75, 62 and 91%, OR 16.5. None of the size criteria used were predictive for stage III disease.

Conclusions

When performing preoperative CT in patients with colon cancer, the imaging criteria that allow best prediction of stage III disease on CT are either presence of at least one lymph node with internal heterogeneity or internal heterogeneity and/or irregular outer border. These criteria have to be validated in a prospective study.

Clinically suspected T4 colorectal cancer may be resected using a laparoscopic approach

Background

The role of laparoscopic resection in patients with clinically suspicious T4 colorectal cancer remains controversial. The aim of this study was to compare the long-term and oncologic outcomes of laparoscopic resection and the open approach in clinical T4 colorectal cancer.

Methods

Two hundred ninety-three consecutive patients undergoing curative surgery for colorectal cancer suspected to be T4 by computed tomography and/or magnetic resonance imaging were reviewed.

Results

Despite clinical suspicion of T4 disease in all cases, concordance with pathologic determination of T4 was only 37.9 %. Of the 71 patients in the laparoscopic group, four (5.6 %) were converted to the open technique. Patients in the laparoscopic group had significantly lower estimated blood loss (p < 0.001), fewer days to first flatus (p = 0.001), shorter length of hospital stay (p < 0.001), and fewer adverse events (14.1 % versus 31.5 %, p = 0.004). After a median follow-up of 36 months, 5-year disease-free survival was not significantly different between the two groups (81.8 % in laparoscopic versus 73.9 % in open surgery, p = 0.433). The clinical factors that predicted T4 staging on pathologic examination were found to be male sex (p = 0.038), preoperative carcinoembryonic antigen status (p = 0.021), clinical N status (p = 0.046), and clinical cancer perforation (p = 0.004).

Conclusions

Laparoscopic colorectal resection for T4 colorectal cancer has perioperative and long-term oncologic outcomes similar to those of the open approach when performed by an experienced surgeon.

Mid-term oncologic outcome of a novel approach for locally advanced colon cancer with neoadjuvant chemotherapy and surgery

PURPOSE

Neoadjuvant chemotherapy is being actively tested as an emerging alternative for the treatment of locally advanced colon cancer (LACC) patients, resembling its use in other gastrointestinal tumors. This study assesses the mid-term oncologic outcome of LACC patients treated with oxaliplatin and fluoropyrimidines-based preoperative chemotherapy followed by surgery.

METHODS AND PATIENTS

Patients with radiologically resectable LACC treated with neoadjuvant therapy between 2009 and 2014 were retrospectively analyzed. Radiological, metabolic, and pathological tumor response was assessed. Both postoperative complications, relapse-free survival (RFS), and overall survival (OS) were studied.

RESULTS

Sixty-five LACC patients who received treatment were included. Planned treatment was completed by 93.8 % of patients. All patients underwent surgery without delay. The median time between the start of chemotherapy and surgery was 71 days (65-82). No progressive disease was observed during preoperative treatment. A statistically significant tumor volume reduction of 62.5 % was achieved by CT scan (39.8-79.8) (p < 0.001). It was also observed a median reduction of 40.5 % (24.2-63.7 %) (p < 0.005) of SUV_max (Standard Uptake Value) by PET-CT scan. Complete pathologic response was achieved in 4.6 % of patients. Postoperative complications were observed in 15.4 % of patients, with no cases of mortality. After a median follow-up of 40.1 months, (p ₂₅-p ₇₅: 27.3-57.8) 3-5 year actuarial RFS was 88.9-85.6 %, respectively. Five-year actuarial OS was 95.3 %.

CONCLUSION

Preoperative chemotherapy in LACC patients is safe and able to induce major tumor regression. Survival times are encouraging, and further research seems warranted.

Accuracy of preoperative T and N staging in colon cancer--a national population-based study

AIM

To select patients for neoadjuvant therapy in colon cancer, there is a need to improve pre-therapeutic locoregional staging. There are now data showing that the TN stage can be adequately assessed by preoperative CT in dedicated centres. In Sweden the use of preoperative CT of the abdomen for staging of the primary tumour is increasing. The aim of this study was to determine to what extent the preoperatively reported radiological TN stage correlates with the histopathological TN stage in an entire population.

METHOD

Data were collected on the preoperative cTN stage according to the radiologist and postoperative pTN stage according to the pathologist on all patients operated on for colon cancer in Sweden 2007-2010. The correlation between cTN stage and pTN stage was calculated using kappa statistics.

RESULTS

T stage was compared in 4373 patients with cT and pT stage. The correlation coefficient was 0.44, indicating fair agreement. The cN and pN correlation coefficient was 0.28, indicating a slight correlation. There was no difference in correlation related to age, gender, tumour location, body mass index or emergent vs elective surgery. A slight difference was seen between different geographical regions.

CONCLUSION

Preoperative CT in an unselected population does not result in an accurate cTN staging as previously reported from dedicated centres. To achieve adequate preoperative cTN staging nationally, the education of radiologists and optimization of the radiological method will be necessary.

Accuracy of computed tomography in nodal staging of colon cancer patients

AIM

To predict node-positive disease in colon cancer using computed tomography (CT).

METHODS

American Joint Committee on Cancer stage I-III colon cancer patients who underwent curavtive-intent colectomy between 2007-2010 were identified at a single comprehensive cancer center. All patients had preoperative CT scans with original radiology reports from referring institutions. CT images underwent blinded secondary review by a surgeon and a dedicated abdominal radiologist at our institution to identify pericolonic lymph nodes (LNs). Comparison of outside CT reports to our independent imaging review was performed in order to highlight differences in detection in actual clinical practice. CT reviews were compared with final pathology. Results of the outside radiologist review, secondary radiologist review, and surgeon review were compared with the final pathologic exam to determine sensitivity, specificity, positive and negative predictive values, false positive and negative rates, and accuracy of each review. Exclusion criteria included evidence of metastatic disease on CT, rectal or appendiceal involvement, or absence of accompanying imaging from referring institutions.

RESULTS

From 2007 to 2010, 64 stageI-III colon cancer patients met the eligibility criteria of our study. The mean age of the cohort was 68 years, and 26 (41%) patients were male and 38 (59%) patients were female. On final pathology, 26 of 64 (40.6%) patients had node-positive (LN+) disease and 38 of 64 (59.4%) patients had node-negative (LN-) disease. Outside radiologic review demonstrated sensitivity of 54% (14 of 26 patients) and specificity of 66% (25 of 38 patients) in predicting LN+ disease, whereas secondary radiologist review demonstrated 88% (23 of 26) sensitivity and 58% (22 of 38) specificity. On surgeon review, sensitivity was 69% (18 of 26) with 66% specificity (25 of 38). Secondary radiology review demonstrated the highest accuracy (70%) and the lowest false negative rate (12%), compared to the surgeon review at 67% accuracy and 31% false negative rate and the outside radiology review at 61% accuracy and 46% false negative rate.

CONCLUSION

CT LN staging of colon cancer has moderate accuracy, with administration of NCT based on CT potentially resulting in overtreatment. Active search for LN+ may improve sensitivity at the cost of specificity.

Positron emission tomography/computed tomography for optimized colon cancer staging and follow up

OBJECTIVES

Optimal management of colon cancer (CC) requires detailed assessment of extent of disease. This study prospectively investigates the diagnostic accuracy of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (PET/CT) for staging and detection of recurrence in primary CC.

MATERIAL AND METHODS

PET/CT for preoperative staging was performed in 66 prospectively included patients with primary CC. Diagnostic accuracy for PET/CT and CT was analyzed. In addition to routine follow up, 42 stages I-III CC patients had postoperative PET/CT examinations every 6 months for 2 years. Serological levels of tissue inhibitor of metalloproteinase-1 (TIMP-1), carcinoembryonic antigen, and liberated domain I of urokinase plasminogen activator receptor were analyzed.

RESULTS

Accuracy for tumor, nodal, and metastases staging by PET/CT were 82% (95% confidence interval [CI]: 70; 91), 66% (CI: 51; 78), and 89% (CI: 79; 96); for CT the accuracy was 77% (CI: 64; 87), 60% (CI: 46; 73), and 69% (CI: 57; 80). Cumulative relapse incidences for stages I-III CC at 6, 12, 18, and 24 months were 7.1% (CI: 0; 15); 14.3% (CI: 4; 25); 19% (CI: 7; 31), and 21.4% (CI: 9; 34). PET/CT diagnosed all relapses detected during the first 2 years. High preoperative TIMP-1 levels were associated with significant hazards toward risk of recurrence and shorter overall survival.

CONCLUSIONS

This study indicates PET/CT as a valuable tool for staging and follow up in CC. TIMP-1 provided prognostic information potentially useful in selection of patients for intensive follow up.

Pretreatment staging of colon cancer in the Swedish population

AIM

Preoperative staging of colon cancer according to Swedish national guidelines implies imaging evaluation of the primary tumour, liver and lungs. Failure to adhere to these guidelines results in negative scorings in the national registration system. In the present study we report the extent of compliance with these guidelines.

METHOD

Since 2007 clinical data on all patients diagnosed with colon cancer in Sweden have been collected in a national database. This includes information on pretherapeutic diagnostic imaging performed, pretherapeutic TNM stage and data on treatment and follow-up. All patients diagnosed with colon cancer in Sweden between 2007 and 2010 were included.

RESULTS

Nine thousand and eight-three patients (i.e. 60.5% of all patients) had a complete pretherapeutic radiological evaluation; 65.2% had a CT or MRI of the primary tumour, whereas over 80% had examinations of the liver and lungs. There were no difference related to sex, but more patients under 75 years had a complete evaluation. There were large differences between different regions; one region performed a complete evaluation of 78.3% of all patients. The proportion of patients examined increased from 53.9 to 65.0% during the study period. Elective cases were more frequently evaluated before treatment than those with an emergency presentation.

CONCLUSION

Most patients in Sweden had a complete pretreatment imaging evaluation of the colon cancer with geographical and time-dependent variations. Knowledge of the importance of these variations and correlation of pre- and postoperative TNM stage is warranted, and such studies are ongoing.

Preliminary outcome of a treatment strategy based on perioperative chemotherapy and surgery in patients with locally advanced colon cancer

AIM

Preoperative chemotherapy followed by radical surgery is an attractive treatment for locally advanced colon cancer (LACC) given the promising results of this approach in other locally advanced tumours. The study evaluates the outcome and treatment-related complications of perioperative oxaliplatin- and capecitabine-based chemotherapy and surgery for clinical Stage III colon cancer.

METHOD

Twenty-two consecutive patients with a CT-staged LACC were included. All were staged at baseline and before surgery. Surgery-related complications and oncological outcome were determined.

RESULTS

Toxicity was manageable, with 19/22 patients completing the planned chemotherapy protocol. The median time from initial diagnosis to surgery was 65.5 days. The median time from the end of chemotherapy to surgery was 22 days. After neoadjuvant treatment, tumour reduction of 69.5% was observed by CT scan and a 59.9% decrease of SUVmax (standard uptake value) was achieved on positron emission tomography/CT. No progressive disease was reported during preoperative chemotherapy and surgery was performed in all 22 patients. Four patients developed postoperative complications. After a median postoperative follow-up of 14.4 months, the actuarial overall and disease-free survival rates were 100 and 90%.

CONCLUSION

Neoadjuvant chemotherapy followed by surgery and chemotherapy for LACC is safe without apparent increase of early and medium-term complications.