The role of primary tumor resection in colorectal cancer patients with asymptomatic, synchronous unresectable metastasis: Study protocol for a randomized controlled trial

A Review on Emerging Techniques for Diagnosis of Colorectal Cancer

Common detection methods in practice for diagnosing colorectal cancer (CRC) are painful and invasive leading to less participation of individuals for CRC diagnosis. Whereas, improved or enhanced imaging systems and other minimally invasive techniques with shorter detection times deliver greater detail and less discomfort in individuals. Thus, this review is a summary of the diagnostic tests, ranging from the simple potential use in developing a flexible CRC treatment to the patient's potential benefits in receiving less invasive procedures and the advanced treatments that might provide a better assessment for the diagnosis of CRC and reduce the mortality related to CRC.

An Updated Review on Molecular Biomarkers in Diagnosis and Therapy of Colorectal Cancer

Colorectal cancer is one of the most common cancer types worldwide. Since colorectal cancer takes time to develop, its incidence and mortality can be treated effectively if it is detected in its early stages. As a result, non-invasive or invasive biomarkers play an essential role in the early diagnosis of colorectal cancer. Many experimental studies have been carried out to assess genetic, epigenetic, or protein markers in feces, serum, and tissue. It may be possible to find biomarkers that will help with the diagnosis of colorectal cancer by identifying the genes, RNAs, and/or proteins indicative of cancer growth. Recent advancements in the molecular subtypes of colorectal cancer, DNA methylation, microRNAs, long noncoding RNAs, exosomes, and their involvement in colorectal cancer have led to the discovery of novel biomarkers. In small-scale investigations, most biomarkers appear promising. However, large-scale clinical trials are required to validate their effectiveness before routine clinical implementation. Hence, this review focuses on small-scale investigations and results of big data analysis that may provide an overview of the biomarkers for the diagnosis, therapy, and prognosis of colorectal cancer.

Palliative resection of the primary tumour improves survival in incurable metastatic colorectal cancer

BACKGROUND

Studies show conflicting results on whether primary tumour resection (PTR) in metastatic colorectal cancer (mCRC) prolongs survival. The aim of this study was to analyse prognostic factors and the effects of PTR on overall survival (OS) in mCRC patients.

METHODS

In this population-based cohort study, factors associated with PTR and OS were assessed in 188 mCRC patients with mCRC treated with palliative chemotherapy between 2008 and 2019. The Chi-square test and Mann-Whitney U-test were used to assess factors associated with PTR. The log-rank test was used to compare Kaplan-Meier estimates for OS. Cox regression was used to identify factors predicting OS.

RESULTS

Patients undergoing PTR had significantly better performance status, fewer metastatic sites, lower CEA levels, and more often had left-sided CRC than patients not undergoing PTR. OS was longer in palliative mCRC patients undergoing PTR (P < 0.01) and PTR was an independent variable in the Cox regression analysis (P < 0.05). Median OS was 22.9 ± 1.9 months for the PTR group and 14.5 ± 1.5 months for the non-operated group. Poor performance status and liver metastases were significantly associated with poor prognosis.

CONCLUSION

This study shows that PTR had a positive effect on OS and may be considered in patients suitable for surgery. PTR was offered to palliative mCRC patients with prognostic factors associated with better prognosis.

Development and validation of a nomogram to predict which patients with colorectal cancer liver metastases would benefit from primary tumor resection

PURPOSE

The use of primary tumor resection (PTR) in the treatment of colorectal cancer liver metastases (CRLM) patients has become increasingly controversial. Our goal is to establish a nomogram to screen for the candidates that would benefit from PTR in CRLM patients.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was searched for 8366 patients with colorectal liver cancer metastases (CRLM) from 2010 to 2015. Overall survival (OS) rates were calculated using the Kaplan-Meier curve. After propensity score matching (PSM), predictors were analyzed by logistic regression analysis, and a nomogram was created to predict for survival benefit of PTR using R software.

RESULTS

After PSM, there were 814 patients in both PTR group and non-PTR group, respectively. The median OS time in the PTR group was 26 months (95%CI = 23.33 ~ 28.67) and the median OS time in the non-PTR group was 15 months (95%CI = 13.36 ~ 16.64). The Cox regression analysis found that PTR was an independent predictive factor (HR = 0.46, 0.41 ~ 0.52) for OS. Additionally, logistic regression was used to study the factors impacting PTR benefit, and the results showed that CEA (P = 0.016), chemotherapy (P < 0.001), N stage (P < 0.001), histological grade (P < 0.001), and lung metastasis (P = 0.001) are independent predictive factors affecting the therapeutic outcome of PTR in patients with CRLM. The developed nomogram displayed good discriminative ability in predicting the beneficial probability of PTR surgery, with the area under the curve (AUC) values of 0.801 in training set and 0.739 in validation set respectively.

CONCLUSION

We developed a nomogram that predicts the survival benefits of PTR in CRLM patients with relatively high accuracy, and quantifies the predictive factors for PTR-related benefits.

Whether Patients With Stage Ⅱ/Ⅲ Colorectal Cancer Benefit From Adjuvant Chemotherapy: A Modeling Analysis of Literature Aggregate Data

Objective: This study used model analysis to clarify the benefits and risks of postoperative adjuvant chemotherapy compared with surgery alone in patients with stage II/III colorectal cancer.

Methods: Clinical trials involving patients with stage II/III colorectal cancer who underwent surgery alone or those who received post-surgical adjuvant chemotherapy were searched in the PubMed and embase databases. By establishing a survival model, the overall survival (OS) and disease-free survival (DFS) of patients who underwent surgery alone or postoperative adjuvant chemotherapy were quantitatively analyzed to compare the differences between the two. In addition, the incidence of grade 3/4 adverse reactions in the adjuvant chemotherapy group was analyzed using the random effects model in the single-arm meta-analysis.

Results: A total of 34 studies containing 33,069 patients were included in the analysis. This study found that postoperative adjuvant chemotherapy can effectively improve the OS and DFS of patients with colorectal cancer. The median OS of the adjuvant chemotherapy group and the surgery-only group was 118.8 months (95% CI: 96.6, 146.6) and 74.6 months (95% CI: 57.8, 96.1) respectively; and median DFS was 86.3 months (95% CI: 67.6, 110.6) and 40.8 months (95% CI: 23.7, 69.6) in the adjuvant chemotherapy and surgery-only groups, respectively. Common grade 3/4 adverse reactions in the adjuvant chemotherapy group include diarrhea, stomatitis, leukopenia, and nausea or vomiting, with an incidence of approximately 3%–6%.

Conclusion: Patients with mid-stage colorectal cancer can benefit significantly from postoperative adjuvant chemotherapy. This study provides the necessary quantitative information for decision-making regarding the benefits and risks of receiving adjuvant chemotherapy after resection in patients with colorectal cancer.

Inoperable de novo metastatic colorectal cancer with primary tumour in situ: Evaluating discordant responses to upfront systemic therapy of the primary tumours and metastatic sites and complications arising from primary tumours (experiences from an Irish Cancer Centre)

Systemic therapy is the mainstay of treatment for de novo metastatic colorectal cancer (mCRC). Heterogeneity between primary tumours and metastases may lead to discordant responses to systemic therapy at these sites. The aim of the present study was to examine these discrepancies and to evaluate the rates of complications arising from the primary tumour and the strategies employed to manage these complications. Electronic medical records were screened for patients eligible for data analysis between January 1st, 2014 and December 31st, 2019. All patients diagnosed with de novo mCRC with primary tumour in situ at the time of initial systemic therapy were included in data analysis. Responses in primary tumour and metastatic sites (according to the Response Evaluation Criteria In Solid Tumours v1.1), discrepancies in these responses and rates of complications arising from primary tumours were assessed along with patient, pathological or molecular factors that may be associated with these discrepant responses or primary tumour complications. A total of 50 patients were identified (median age, 62 years). Right-colon, left-colon and rectal primary tumours comprised 34, 44 and 22% of CRC cases, respectively. All patients received 5-fluorouracil-based chemotherapy (either alone or in combination with oxaliplatin or irinotecan). Disease response (DR), stable disease (SD) and progressive disease (PD) were observed as the first response to systemic therapy in 24, 62 and 12% of primary tumours and in 36, 18 and 44% of metastatic sites, respectively. Only 36% of patients demonstrated concordant responses between the primary tumours and metastases, while the remaining 62% demonstrated discordant responses between the primary tumour and distant metastases (22% had DR with SD; 36% had DR or SD with PD; and 4% had PD with SD in the primary tumour and metastases, respectively). Restaging images were not available for 2% of the patients. Approximately 30% of patients developed complications from primary tumours, including bowel obstruction (6.12%), perforation (6%), rectal pain (6%) and rectal bleeding (10%). Approximately 10% of patients underwent palliative stoma creation. Additionally, 12% required palliative radiotherapy to the primary tumour (due to localized complications arising from the tumour). Discordant responses to systemic therapy between primary tumours and metastases occurred in 60% of patients with de novo mCRC (with primary tumour in situ at the time of first systemic therapy). The observations of the present study have potential implications for molecular tissue analysis to help guide systemic therapy. Tissue from metastatic sites may be preferable to confirm biomarker status in mCRC based on this study.

Nomogram to Predict the Occurrence and Prognosis of Distant Metastasis in T1N0 Colon Cancer: A SEER Data-Based Study

Purpose

Distant metastasis (DM) is relatively rare in T1 colon cancer (CC) patients, especially in those with negative lymph node metastasis. The aim of this study was to explore the main clinical factors and build nomogram for predicting the occurrence and prognosis of DM in T1N0 colon cancer patients.

Methods

Patients with T1N0 stage CC were collected from the Surveillance, Epidemiology, and End Result (SEER) database. All patients were divided into development and validation cohorts with the 3:1 ratio. Logistic regressions were performed to analyze the clinical risk factors for DM. Cox regression model was used to identify potential prognostic factors for patients with DM. The performance of nomogram was evaluated by concordance index (C-index), calibration curves, receiver operating characteristic (ROC) curves and decision curve analyses (DCAs). Based on cancer-specific survival (CSS), Kaplan-Meier curves were generated and analyzed using Log rank tests.

Results

A total of 6770 patients were enrolled in this study, including 428 patients (6.3%) with DM. Age, size, grade, CEA were independent risk factors associated with DM. Age, grade, CEA, surgery and chemotherapy were independent prognostic factors for CSS. Nomograms were applied and C-index, calibration curves, ROC curves and DCA curves proved good discrimination, calibration and clinical practicability of the nomogram in predicting the occurrence and prognosis of DM in T1N0 CC patients. In the DM nomogram, the AUCs for development and validation cohort were 0.901 (95% CI = 0.879-0.922) and 0.899 (95% CI=0.865-0.940), respectively. The calibration curves (development cohort: S: p = 0.712; validation cohort: S: p = 0.681) showed the relatively satisfactory prediction accuracy. Similarly, the AUCs of the nomogram at 1-, 2-, and 3-year were 0.763 (95% CI=0.744-0.782), 0.794 (95% CI=0.775-0.813), and 0.822 (95% CI=0.803-0.841) for the development cohort, and 0.785 (95% CI=0.754-0.816), 0.748 (95% CI=0.717-0.779) and 0.896 (95% CI=0.865-0.927) for the validation cohort in the CSS nomogram. The C-indices of the development and validation cohort were 0.718 (95% CI=0.639-0.737) and 0.712 (95% CI=0.681-0.743).

Conclusion

The population-based nomogram could help clinicians predict the occurrence and prognosis of DM in T1N0 CC patients and provide a reference to perform appropriate metastatic screening plans and rational therapeutic options for the special population.

Impact of Primary Tumor Resection on Mortality in Patients with Stage IV Colorectal Cancer with Unresectable Metastases: A Multicenter Retrospective Cohort Study

BACKGROUND

Primary tumor resection (PTR) before commencing systemic chemotherapy in patients with stage IV colorectal cancer and unresectable metastases (mCRC) remains controversial. This study aimed to assess whether PTR before systemic chemotherapy is associated with mortality in mCRC patients, after adjusting for confounding factors, such as the severity of the primary tumor and metastatic lesions.

METHODS

We analyzed hospital-based cancer registries from nine designated cancer hospitals in Fukushima Prefecture, Japan. Patients were divided into two groups (PTR and non-PTR), based on whether PTR was performed as initial therapy for mCRC or not. The primary outcome was all-cause mortality. Kaplan-Meier survival analysis was performed, and survival estimates were compared using the log-rank test. Adjusted hazard ratios were calculated using Cox regression to adjust for confounding factors. All tests were two-sided; P-values < 0.05 were considered statistically significant.

RESULTS

Between 2008 and 2015, 616 mCRC patients were included (PTR: 414 [67.2%]; non-PTR: 202 [32.8%]). The median follow-up time was 18.0 (interquartile range [IQR]: 8.4-29.7) months, and 492 patients (79.9%) died during the study period. Median overall survival in the PTR and non-PTR groups was 23.9 (IQR: 12.2-39.9) and 12.3 (IQR: 6.2-23.8) months, respectively (P < 0.001, log-rank test). PTR was significantly associated with improved overall survival (adjusted hazard ratio: 0.51; 95% confidence interval: 0.42-0.64, P < 0.001).

CONCLUSIONS

PTR before systemic chemotherapy in patients with mCRC was associated with improved survival.

Impact of postoperative complications after primary tumor resection on survival in patients with incurable stage IV colorectal cancer: A multicenter retrospective cohort study

AIMS

Primary tumor resection for patients with incurable stage IV colorectal cancer can prevent tumor-related complications but may cause postoperative complications. Postoperative complications delay the administration of chemotherapy and can lead to the spread of malignancy. However, the impact of postoperative complications after primary tumor resection on survival in patients with incurable stage IV colorectal cancer remains unclear. Therefore, this study aimed to investigate how postoperative complications after primary tumor resection affect survival in this patient group.

METHODS

We reviewed data on 966 patients with stage IV colorectal cancer who underwent palliative primary tumor resection between January 2006 and December 2007. We examined the association between major complications (National Cancer Institute Common Terminology Criteria for Adverse Events v3.0 grade 3 or more) and overall survival using Cox proportional hazard model and explored risk factors associated with major complications using multivariable logistic regression analysis.

RESULTS

Ninety-three patients (9.6%) had major complications. The 2-year overall survival rate was 32.7% in the group with major complications and 50.3% in the group with no major complications. Patients with major complications had a significantly poorer prognosis than those without major complications (hazard ratio: 1.62; 95% confidence interval: 1.21-2.18; P < .01). Male, rectal tumor, and open surgery were identified to be risk factors for major complications.

CONCLUSIONS

Postoperative complications after primary tumor resection was associated with decreased long-term survival in patients with incurable stage IV colorectal cancer.

The Impact of Primary Tumor Resection on Survival in Asymptomatic Colorectal Cancer Patients With Unresectable Metastases

Purpose

This study was conducted to evaluate the effectiveness of primary tumor resection (PTR) in asymptomatic colorectal cancer (CRC) patients with unresectable metastases using the inverse probability of treatment weighting (IPTW) method to minimize selection bias.

Methods

We selected 146 patients diagnosed with stage IV CRC with unresectable metastasis between 2001 and 2018 from our institutional database. In a multivariate logistic regression model using the patients’ baseline covariates associated with PTR, we applied the IPTW method based on a propensity score and performed a weighted Cox proportional regression analysis to estimate survival according to PTR.

Results

Upfront PTR was performed in 98 patients, and no significant differences in baseline factors were detected. The upweighted median survival of the PTR group was 18 months and that of the non-PTR group was 15 months (P = 0.15). After applying the IPTW, the PTR was still insignificant in the univariate Cox regression (hazard ratio [HR], 0.26; 95% confidence interval [CI], 0.5–1.21). However, in the multivariate weighted Cox regression with adjustment for other covariates, the PTR showed a significantly decreased risk of cancer-related death (HR, 0.61; 95% CI, 0.40–0.94).

Conclusion

In this study, we showed that asymptomatic CRC patients with unresectable metastases could gain a survival benefit from upfront PTR by analysis with the IPTW method. However, randomized controlled trials are mandatory.

Primary Tumor-Related Complications and Salvage Outcomes in Patients with Metastatic Rectal Cancer and an Untreated Primary Tumor

BACKGROUND

For rectal cancer with unresectable metastases, current practice favors omitting interventions directed at the primary tumor in asymptomatic patients.

OBJECTIVE

This study aimed to determine the proportion of patients with primary tumor-related complications, characterize salvage outcomes, and measure survival in patients with metastatic rectal cancer who did not undergo upfront intervention for their primary tumor.

DESIGN

This is a retrospective analysis.

SETTING

This study was conducted at a comprehensive cancer center.

PATIENTS

Patients who presented between January 1, 2008, and December 31, 2015, with synchronous stage IV rectal cancer, an unresected primary tumor, and no prior primary tumor-directed intervention were selected.

MAIN OUTCOME MEASURES

The main outcome measured was the rate of primary tumor-related complications in the cohort that did not receive any primary tumor-directed intervention. The Kaplan-Meier method and Cox regression analysis were used to determine whether complications are associated with survival.

RESULTS

The cohort comprised 358 patients with a median age of 56 years (22-92). Median follow-up was 26 months (range, 1-93 months). Among the 168 patients (46.9%) who eventually underwent elective resection of the primary tumor, the surgery was performed with curative intent in 66 patients (18.4%) and preemptive intent in 102 patients (28.5%). Of the 190 patients who did not undergo an upfront or elective intervention for the primary tumor, 68 (35.8%) experienced complications. Nonsurgical intervention for complications was attempted in 34 patients with an overall success rate of 61.8% (21/34). Surgical intervention was performed in 47 patients (including 13 patients for whom nonsurgical intervention failed): diversion in 26 patients and resection in 21 patients. Of those 47 patients, 42 (89.4%) ended up with a colostomy or ileostomy.

LIMITATIONS

This study was conducted at a single center.

CONCLUSION

A significant proportion of patients with metastatic rectal cancer and untreated primary tumor experience primary tumor-related complications. These patients should be followed closely, and preemptive intervention (resection, diversion, or radiation) should be considered if the primary tumor progresses despite systemic therapy. See Video Abstract at http://links.lww.com/DCR/B400. COMPLICACIONES RELACIONADAS CON EL TUMOR PRIMARIO Y RESULTADOS DE RESCATE EN PACIENTES CON CÁNCER DE RECTO METASTÁSICO Y UN TUMOR PRIMARIO NO TRATADO: Para el cáncer de recto con metástasis no resecables, la práctica actual favorece la omisión de las intervenciones dirigidas al tumor primario en pacientes asintomáticos.Determinar la proporción de pacientes con complicaciones relacionadas con el tumor primario, caracterizar los resultados de rescate y medir la supervivencia en pacientes con cáncer rectal metastásico que no se sometieron a una intervención inicial para su tumor primario.Análisis retrospectivo.Centro oncológico integral.Pacientes que se presentaron entre el 1 de enero de 2008 y el 31 de diciembre de 2015 con cáncer de recto en estadio IV sincrónico, un tumor primario no resecado y sin intervención previa dirigida al tumor primario.Tasa de complicaciones relacionadas con el tumor primario en la cohorte que no recibió ninguna intervención dirigida al tumor primario. Se utilizó el método de Kaplan-Meier y el análisis de regresión de Cox para determinar si las complicaciones están asociadas con la supervivencia.La cohorte estuvo compuesta por 358 pacientes con una mediana de edad de 56 años (22-92). La mediana de seguimiento fue de 26 meses (rango, 1 a 93 meses). Entre los 168 pacientes (46,9%) que finalmente se sometieron a resección electiva del tumor primario, la cirugía se realizó con intención curativa en 66 pacientes (18,4%) y con intención preventiva en 102 pacientes (28,5%). De los 190 pacientes que no se sometieron a una intervención inicial o electiva para el tumor primario, 68 (35,8%) experimentaron complicaciones. Se intentó una intervención no quirúrgica para las complicaciones en 34 pacientes con una tasa de éxito global del 61,8% (21 de 34). La intervención quirúrgica se realizó en 47 pacientes (incluidos 13 pacientes en los que falló la intervención no quirúrgica): derivación en 26 pacientes y resección en 21 pacientes. De esos 47 pacientes, 42 (89,4%) terminaron con una colostomía o ileostomía.Único centro.Una proporción significativa de pacientes con cáncer de recto metastásico y primario no tratado experimentan complicaciones relacionadas con el tumor primario. Se debe hacer un seguimiento estrecho de estos pacientes y considerar la posibilidad de una intervención preventiva (resección, derivación o radiación) si el tumor primario progresa a pesar de la terapia sistémica. Consulte Video Resumen en http://links.lww.com/DCR/B400.

The Role of Primary Tumor Resection in Colorectal Cancer Patients with Asymptomatic, Synchronous, Unresectable Metastasis: A Multicenter Randomized Controlled Trial

We aimed to assess the survival benefits of primary tumor resection (PTR) followed by chemotherapy in patients with asymptomatic stage IV colorectal cancer with asymptomatic, synchronous, unresectable metastases compared to those of upfront chemotherapy alone. This was an open-label, prospective, randomized controlled trial (ClnicalTrials.gov Identifier: NCT01978249). From May 2013 to April 2016, 48 patients (PTR, n = 26; upfront chemotherapy, n = 22) diagnosed with asymptomatic colorectal cancer with unresectable metastases in 12 tertiary hospitals were randomized (1:1). The primary endpoint was two-year overall survival. The secondary endpoints were primary tumor-related complications, PTR-related complications, and rate of conversion to resectable status. The two-year cancer-specific survival was significantly higher in the PTR group than in the upfront chemotherapy group (72.3% vs. 47.1%; p = 0.049). However, the two-year overall survival rate was not significantly different between the PTR and upfront chemotherapy groups (69.5% vs. 44.8%, p = 0.058). The primary tumor-related complication rate was 22.7%. The PTR-related complication rate was 19.2%, with a major complication rate of 3.8%. The rates of conversion to resectable status were 15.3% and 18.2% in the PTR and upfront chemotherapy groups. While PTR followed by chemotherapy resulted in better two-year cancer-specific survival than upfront chemotherapy, the improvement in the two-year overall survival was not significant.

A randomized controlled trial comparing primary tumour resection plus chemotherapy with chemotherapy alone in incurable stage IV colorectal cancer: JCOG1007 (iPACS study)

It is controversial whether chemotherapy with or without primary tumour resection is effective for the patients with incurable Stage IV colorectal cancer. A randomized controlled trial, initiated in Japan in 2012, is being conducted to evaluate the survival benefit and safety of primary tumour resection plus chemotherapy compared with chemotherapy alone in asymptomatic Stage IV colorectal cancer patients with unresectable metastatic disease. Patients are randomly assigned to either chemotherapy alone or primary tumour resection followed by chemotherapy. The primary endpoint is overall survival. Secondary endpoints are progression-free survival, incidence of adverse events, proportion of patients with R0 resection and proportion of palliative surgery for the chemotherapy-alone group. This trial was registered in June 2012 with the UMIN Clinical Trials Registry as UMIN000008147 [http://www.umin.ac.jp/ctr/index-j.htm]. In December 2017, the study protocol was amended for reducing sample size. A total of 280 patients will be enrolled over the course of 8.5 years.

The outcome of primary tumor resection in the unresectable stage IV colorectal cancer patients who received the bevacizumab-containing chemotherapy

Primary tumor resection (PTR) for unresectable metastatic colorectal cancer (mCRC) patients has been documented to be associated with postoperative hyper-neovascularization and enhanced growth of metastases, which may be prevented by bevacizumab. This study aimed to investigate the survival outcome of PTR in patients who received palliative bevacizumab-containing chemotherapy (BCT).From January 2006 to December 2018, medical records of 240 mCRC patients who received palliative BCT at a single tertiary colorectal cancer center were retrospectively reviewed. Patients were classified into three groups: PTR-a (PTR before BCT, n = 60), PTR-b (PTR during BCT, n = 17), and BCT-only group (n = 163). Resectable mCRCs or recurrent diseases were excluded, and the end-point was overall survival (OS) rate.Three groups had similar age, cell differentiation, location of the primary tumor, and the number of metastatic organs. More than two-thirds of patients who received PTR experienced disease-progressions (PD) during their postoperative chemotherapy-free time (PTR-a vs PTR-b; 66.7% vs 76.5%, P = .170), but OS was not inferior to the BCT-only group (PTR-a vs BCT-only; HR 0.477 [95% CI 0.302-0.754], P = .002/PTR-b vs BCT-only; HR 0.77 [95% CI 0.406-1.462], P = .425). The postoperative chemotherapy-free time was similar between PTR-a and PTR-b (median 32.0 [14-98] days vs 41.0 [18-71] days, P = .142), but non-obstructive indications (perforation, bleeding, pain) were the more frequent in the PTR-b than PTR-a. Young age, the number of BCT, and PTR-a were the independent factors for OS.The efficacy of the PTR for unresectable mCRC has been controversial, but this study demonstrated that PTR should be considered for the unresectable mCRC patients regardless before and during BCT.

Short-term Outcomes After Upfront Chemotherapy Followed by Curative Surgery in Metastatic Colon Cancer: A Comparison With Upfront Surgery Patients

Purpose

Upfront systemic chemotherapy with target agents has been recommended for patients with stage IV colon cancer. Some with partial response are considered for curative resection. There is high risk of developing postoperative complications following upfront systemic chemotherapy. We aimed to evaluate short-term perioperative outcomes of curative surgery after upfront chemotherapy in comparison with upfront surgery in patients with metastatic colon cancer.

Methods

Between January 2010 and October 2015, 146 patients (80 in the surgery first group, 66 in the upfront chemotherapy group) who underwent surgical resection before or after systemic chemotherapy for metastatic colon cancer were included in the present study. All decisions for treatment were made through a multidisciplinary team. Postoperative clinical outcomes and complications were analyzed to compare the groups.

Results

There was no difference between the 2 groups in terms of postoperative clinical outcomes. Overall complication rates were not different between the groups (surgery first group: 46.3% vs. upfront chemotherapy group: 60.6%; P = 0.084). When classified according to the Clavien-Dindo method, there was no difference between the 2 groups in terms of major complications (grade 3 or more) (surgery first group: 18.9% vs. upfront chemotherapy group: 27.5%; P = 0.374).

Conclusion

There was no significant increase in major postoperative complications in metastatic colon cancer patients who received upfront chemotherapy followed by curative surgery. Careful patient selection and treatment planning are important.

A systematic analysis highlighting deficiencies in reported outcomes for patients with stage IV colorectal cancer undergoing palliative resection of the primary tumour

BACKGROUND

Management of the primary tumour in the presence of unresectable metastatic colorectal cancer (mCRC) is controversial. The role of primary tumour resection (PTR) has been investigated by a number of retrospective cohort studies, with a number on going randomised controlled trials. The aim of this study was to identify the clinical and patient-reported outcomes currently reported in studies that evaluate the role of PTR in mCRC.

METHODS

Literature searches were performed in MEDLINE (via OvidSP) (1966-June 2017), EMBASE (via OvidSP) and the Cochrane Library using terms related to colorectal cancer and primary tumour resection. All studies documenting outcomes following palliative PTR were included. Eligible articles were assessed using the Risk of Bias In Non-Randomised Studies of Intervention (ROBINS-I) tool.

RESULTS

Of 11,209 studies screened, 59 non-randomised studies reporting outcomes on 331,157 patients were included. Patient characteristics regarding performance status and co-morbidity were recorded in 26 (44.1%) and 17 (28.8%) studies. The chemotherapy regime used was reported in 27 (45.8%) studies. The operative setting and the operative approach was reported in 42 (71%) and 14 (23.7%) studies. Post-operative mortality and morbidity were reported in 33 (55.9%) and 35 (59.3%) studies. Overall survival was reported in 49 (83.1%) studies, with 5 different definitions identified. Quality of life was only reported in 1 (1.7%) study.

CONCLUSION

This study demonstrates significant heterogeneity in the selection and definition of outcomes reported following PTR in mCRC. There is significant heterogeneity with a significant under-reporting of important outcomes such as treatment related adverse events and patient reported outcomes.

Survival outcomes following primary tumor resection for patients with incurable metastatic colorectal carcinoma: Experience from a single institution

OBJECTIVE

Palliative primary tumor resection (PTR) has been used for preventing and treating tumor-related complications. We aimed to determine whether PTR can increase overall survival (OS) in patients with unresectable metastatic colorectal cancer (CRC).

METHODS

A retrospective review of a prospectively collected database in a single center was performed. Patients diagnosed with metastatic CRC from January 2004 to December 2014 were included. Patients who had attained curative resection or had disease recurrence were excluded. All patients were discussed at a multidisciplinary tumor board where subsequent treatment decisions were made.

RESULTS

Altogether 408 patients were analyzed. Of these 145 received PTR with palliative chemotherapy (PC; group A), 110 received PC only (group B), 52 received PTR only (group C), while 101 received neither PTR nor PC (group D). Undergoing PTR led to statistically significant improvement in OS (22.7 months vs 12.1 months vs 6.9 months vs 2.7 months, P < 0.001). We performed subgroup analyses to control for potential confounders and found that the influence of PTR on OS persisted. With multivariate analysis, the predictors of poor OS were no PTR (hazards ratio [HR] 2.32, 95% confidence interval [CI] 1.82-2.96, P < 0.001), no PC (HR 4.25, 95% CI 3.27-5.33, P < 0.001) and the presence of peritoneal metastases (HR 1.37, 95% CI 1.06-1.78, P = 0.018). Diversion surgery did not lead to a statistical difference in OS.

CONCLUSIONS

The absences of PTR and PC, and peritoneal metastases are independently associated with decreased OS in patients with unresectable metastatic CRC. Randomized controlled trials are needed to verify this observation.

Modern-day palliative chemotherapy for metastatic colorectal cancer: does colonic resection affect survival?

BACKGROUND

Patients with metastatic colorectal cancer (mCRC) with surgically incurable metastases would be recommended for palliative chemotherapy (PC). The role of surgical intervention is debatable with no conclusive evidence for routine primary tumour resection (PTR) or stoma creation. We aimed to study if surgical intervention conferred a survival benefit in patients with mCRC who received upfront systemic therapy.

METHODS

A retrospective review of a prospectively collected database in a single centre was performed. Patients diagnosed with mCRC from January 2004 to December 2014 were included. We excluded patients who had an upfront surgical intervention, had no treatment with systemic therapy or had attained curative resection. The decision for surgery was based on the outcome of a multidisciplinary tumour board. Demographic, clinicopathological, treatment and follow-up data were collected. Univariate and multivariate analyses were performed.

RESULTS

Out of 408 patients with mCRC with incurable metastases, we analysed 124 patients who had upfront PC. Twenty-nine had PC + PTR (group A), 10 had PC + stoma (group B) and 85 had PC only (group C). Undergoing PTR led to significant improvement in overall survival (OS; 30.8 versus 13.4 versus 11.0 months, P < 0.001). With multivariate analysis, undergoing PTR and receiving biologics were independent good prognostic variables. Surgical resection was safe with minimal complications.

CONCLUSIONS

PTR was found to increase OS while stoma creation had no impact on OS. The benefits and safety of undergoing PTR may be a result of selection bias. Further prospective studies are required to confirm the observations of this study.

Primary tumor sidedness is an independent prognostic marker for survival in metastatic colorectal cancer: Results from a large retrospective cohort with mutational analysis

Recent reports demonstrate inferior outcomes associated with primary right‐sided vs left‐sided colorectal tumors in patients with metastatic colorectal cancer (mCRC). We sought to describe our experience with mCRC patients on whom we have molecular data to determine whether primary tumor sidedness was an independent prognostic marker for overall survival (OS). mCRC patients with documented primary tumor sidedness who received mutational profiling between 2009 and 2014 were identified (n = 367, median follow‐up 30.4 months). Mutational profiling for >150 mutations across commonly mutated cancer genes including RAS, PIK3CA, BRAF, and PTEN as well as treatment data, including receipt of a biologic agent, were collected. Univariable/multivariable models were used to analyze relationships between collected data and OS. Among 367 patients, sidedness breakdown was as follows: 234 left (64%), 133 right (36%). 56% were male, with a median age at diagnosis of 57 (range 24‐89). A total of 143 patients had RAS mutations. Five‐year OS was 41%, median OS was 54 months (range 1‐149). Five‐year OS for left‐ vs right‐sided tumors was 46% vs 24% (P < .0001). On univariable analysis, among both RAS wildtype and mutant tumors, left‐sided tumors continued to have improved OS vs right‐sided tumors (HR: 0.49, 95% CI: 0.34‐0.69 RAS wildtype; HR: 0.61, 95% CI: 0.40‐0.95 RAS mutant). Left‐sidedness was an important prognostic factor for OS among RAS wildtype patients despite treatment with or without a biologic agent (P < .05). Left‐sidedness remained significant for improved OS on multivariable analysis (P < .0001). Left‐sided primary tumor remained most important prognostic factor for OS, even when adjusting for mutational status and receipt of biologic agent.

Recent updates in the surgical treatment of colorectal cancer

Because of recent advances in medical technology and new findings of clinical trials, treatment options for colorectal cancer are evolutionally changing, even in the last few years. Therefore, we need to update the treatment options and strategies so that patients can receive optimal and tailored treatment. The present review aimed to elucidate the recent global trends and update the surgical treatment strategies in colorectal cancer by citing the literature published in the last 2 years, namely 2016 and 2017. Although laparoscopic surgery is still considered the most common approach for the treatment of colorectal cancer, new surgical technologies such as transanal total mesorectal excision, robotic surgery, and laparoscopic lateral pelvic lymph node dissection are emerging. However, with the recent evidence, superiority of the laparoscopic approach to the open approach for rectal cancer seems to be controversial. Surgeons should notice the risk of adverse outcomes associated with unfounded and uncontrolled use of these novel techniques. Many promising results are accumulating in preoperative and postoperative treatment including chemotherapy, chemoradiotherapy, and targeted therapy. Development of new biomarkers seems to be essential for further improvement in the treatment outcomes of colorectal cancer patients.

Primary tumor location as a predictor of the benefit of palliative resection for colorectal cancer with unresectable metastasis

Background

It is still under debate that whether stage IV colorectal cancer patients with unresectable metastasis can benefit from primary tumor resection, especially for asymptomatic colorectal cancer patients. Retrospective studies have shown controversial results concerning the benefit from surgery. This retrospective study aims to evaluate whether the site of primary tumor is a predictor of palliative resection in asymptomatic stage IV colorectal cancer patients.

Methods

One hundred ninety-four patients with unresectable metastatic colorectal cancer were selected from Sun Yat-sen University Cancer Center Database in the period between January 2007 and December 2013. All information was carefully reviewed and collected, including the treatment, age, sex, carcinoembryonic antigen, site of tumor, histology, cancer antigen 199, number of liver metastases, and largest diameter of liver metastasis. The univariate and multivariate analyses were used to detect the relationship between primary tumor resection and overall survival of unresectable stage IV colorectal cancer patients.

Results

One hundred twenty-five received palliative resection, and 69 received only chemotherapy. Multivariate analysis indicated that primary tumor site was one of the independent factors (RR 0.569, P = 0.007) that influenced overall survival. For left-side colon cancer patients, primary tumor resection prolonged the median overall survival time for 8 months (palliative resection vs. no palliative resection: 22 vs. 14 months, P = 0.009); however, for right-side colon cancer patients, palliative resection showed no benefit (12 vs. 10 months, P = 0.910).

Conclusions

This study showed that left-side colon cancer patients might benefit from the primary tumor resection in terms of overall survival. This result should be further explored in a prospective study.

The influence of local therapy on the survival of patients with metastatic rectal cancer: a population-based, propensity-matched study

PURPOSE

This study was aimed to determine the effect of the local tumor therapy on patients' prognosis in the management of metastatic rectal cancer.

METHODS

Patients diagnosed with metastatic rectal cancer from 2004 to 2013 were selected from the SEER (Surveillance, Epidemiology, and End Results) database. Overall survival and cancer-specific survival were compared between the local treatment group and the nonlocal treatment group using Kaplan-Meier methods. Uni- and multivariate analyses were further performed to confirm or deny the results. The statistical approach of propensity score matching was conducted to avoid potential confounding factors.

RESULTS

Of 6867 patients included in this analysis, 3971 (57.8%) received local therapy to the primary tumor and 2896 (42.2%) did not receive. Both univariable and multivariable analysis showed local therapy continued to be associated with an improvement in OS (HR 0.532; 95% CI 0.503-0.563, p < 0.001 and HR 0.532; 95% CI 0.498-0.568, p < 0.001, respectively) and CSS (HR 0.527; 95% CI 0.497-0.559, p < 0.001 and HR 0.521; 95% CI 0.487-0.557, p < 0.001, respectively) in the unmatched cohorts. Further analysis showed patients underwent local tumor destruction or surgical resection had a better overall survival compared with those who did not undergo (p < 0.001). In the matched population, patients receiving local therapy had a better OS (HR 0.427; 95% CI 0.428-0.519, p < 0.001) and CSS (HR 0.462; 95% CI 0.418-0.511, p < 0.001) compared with those who did not receive.

CONCLUSIONS

Local therapy to the primary tumor may be associated with a better survival in patients with metastatic rectal cancer.

Asymptomatic primary tumour in incurable metastatic colorectal cancer: is there a role for surgical resection prior to systematic therapy or not?

INTRODUCTION

The role of the resection of asymptomatic primary colorectal cancer in patients with incurable disease is questionable.

AIM

To evaluate the impact of the resection of asymptomatic primary tumour on overall survival in patients with unresectable distant metastases.

MATERIAL AND METHODS

Patients treated in the National Cancer Institute, Lithuania, in the period 2008-2012, were selected retrospectively. The main inclusion criteria were: metastatic colorectal cancer (mCRC), endoscopically and histologically confirmed adenocarcinoma, without any symptoms for urgent operation, and at least one cycle of palliative chemotherapy administered. Information on patients' age, gender, tumour histology, localization of the tumour, regional lymph node involvement, number of metastatic sites, surgery and systemic treatment was collected prospectively. Eligible patients for the study were divided into two groups according to the initial treatment - surgery (patients who underwent primary tumour resection) and chemotherapy (patients who received chemotherapy without surgery). The impact of initial treatment strategy, tumour size and site, regional lymph nodes, grade of differentiation of adenocarcinoma and application of biotherapy on overall cumulative survival was estimated using the Kaplan-Meier method. To compare survival between groups the log-rank test was used. Cox regression analysis was employed to assess the effects of variables on patient survival.

RESULTS

The study group consisted of 183 patients: 103 men and 80 women. The median age was 66 years (range: 37-91). There were no notable imbalances with regard to age, gender, number of metastatic sites, metastases (such as pulmonary, peritoneal, liver, metastases into non-regional lymph nodes and other metastases), the number of received cycles of chemotherapy, first line chemotherapy type or biological therapy. Only 27 (14.8%) patients received biological therapy and the majority of them (n = 25, 92.6%) were treated with bevacizumab. For surgically treated patients 1-year survival was 71.2% (95% CI: 62.1-78.5) and 5-year survival was 4.0% (95% CI: 1.0-10.5). In the chemotherapy group, survival rates were lower - 43.9% (95% CI: 31.4-55.7) and 1.7% (95% CI: 0.1-8.1), respectively. Better survival rates were in the palliative surgery group. Multivariate analysis using the Cox proportional hazards model revealed that the initial palliative surgery and the application of biological therapy were statistically significant independent prognostic factors for survival.

CONCLUSIONS

Our findings suggest that palliative resectional surgery for the primary tumour in patients with incurable mCRC improves survival. Of course, one can argue that patients in the surgery group were "less problematic". Prospective randomized trials are needed to delineate precisely the role of palliative surgery of the primary tumour in these patients.

From tumour heterogeneity to advances in precision treatment of colorectal cancer

In recent years, the high heterogeneity of colorectal cancer (CRC) has become evident. Hence, biomarkers need to be developed that enable the stratification of patients with CRC into different prognostic subgroups and in relation to response to therapies, according to the distinctive tumour biology. Currently, only RAS-mutation status is used routinely as a negative predictive marker to avoid treatment with anti-EGFR agents in patients with metastatic CRC, and mismatch-repair status can guide the use of adjuvant chemotherapy in patients with early stage colon cancer. Advances in molecular biology over the past decade have enabled a better understanding of the development of CRC, as well as the more-precise use of innovative targeted therapies for this disease, and include three fundamental achievements. First, the availability of large databases to capture and store the genomic landscape of patients with CRC, providing information on the genes that are frequently deregulated in CRC. Second, the possibility of using gene-expression profiling to differentiate the subtypes of CRC into prognostic groups. Third, results from highly sensitive next-generation sequencing analyses have led to an appreciation of the extensive intratumoural heterogeneity of CRC. Herein, we discuss these advances and place them into the clinical context, and present the novel targets and therapeutic opportunities that are on the horizon.

Observational Cohort Study of Patients With Metastatic Colorectal Cancer Initiating Chemotherapy in Combination With Bevacizumab (CONCERT)

BACKGROUND

The CONCERT study (observational cohort study of patients with metastatic colorectal cancer initiating chemotherapy in combination with bevacizumab) aimed to describe patient characteristics, bevacizumab use, its efficacy in terms of progression-free survival (PFS) and overall survival (OS), and its safety in patients with metastatic colorectal cancer (mCRC) treated in daily medical practice.

PATIENTS AND METHODS

CONCERT was an observational, prospective, multicenter, cohort study conducted in France. Patients with mCRC initiating bevacizumab combined with chemotherapy were included and followed up for ≤ 36 months.

RESULTS

Overall, 737 evaluable patients were assessed, and 71%, 21%, and 8% initiated bevacizumab as first-, second-, or third-line therapy or more, respectively. Their mean age was 64.5 years (range, 25-88 years), and 60% were men. Bevacizumab was mainly started at 5 mg/kg every 2 weeks (95%) and mostly combined with FOLFIRI (leucovorin, 5-fluorouracil, irinotecan; 68.0%) or FOLFOX (leucovorin, 5-fluorouracil, oxaliplatin; 22.0%). The median PFS was 10.4 months (95% confidence interval [CI], 9.6-11.3) in first-line, 8.5 months (95% CI, 7.0-9.2) in second-line, and 6.3 months (95% CI, 4.5-8.9) in third-line or beyond. The corresponding median OS was 25.3 months (95% CI, 21.5-28.6), 19.1 months (95% CI, 15.7-22.6), and 14.9 months (95% CI, 11.6-20.4). In first-line treatment, primary tumor resection and oxaliplatin-based chemotherapy were prognostic of a longer PFS. Eastern Cooperative Oncology Group performance status ≥ 2, > 1 metastatic sites, and intermediate or high risk using the Köhne prognostic index were associated with shorter PFS. The safety profile of bevacizumab combined with chemotherapy was comparable to that found by other observational studies of mCRC.

CONCLUSION

The efficacy and safety results of bevacizumab plus chemotherapy as first- and second-line treatment of mCRC in daily practice in the CONCERT observational, prospective study were in line with those from randomized clinical studies.