Omission of Adjuvant Chemotherapy Is Associated With Increased Mortality in Patients With T3N0 Colon Cancer With Inadequate Lymph Node Harvest

Adjuvant chemotherapy in stage 1 colon cancer: Patient characteristics and survival analysis from the national cancer database

BACKGROUND

A subset of patients in ACS-NCDB with stage-1 colon cancer received adjuvant chemotherapy (AC), in contrast to national guidelines. This study aimed to define this population and evaluate associations between AC and survival.

METHODS

Patients with T1-2N0 colon cancer from 2004 to 2016 were separated into AC and non-AC groups. Adverse pathological features (APF) included T2, poor differentiation, lymphovascular invasion, positive margin, and inadequate lymph nodes (<12). Cox proportional hazard models were used to estimate prognostic factors for overall survival (OS).

RESULTS

A total of 1745 of 139,857 patients (1.2 %) received AC. Receiving AC was associated with male sex (p = 0.02), uninsured (p < 0.01), low income (p = 0.02), or having ≥2 APFs (p < 0.001). In the total cohort, AC was associated with increased mortality (HR 1.14 [1.04-1.24] P < 0.01). On subset analysis, AC was associated with improved OS for patients with ≥2 APFs (log-rank P=<0.001), and decreased mortality when adjusted for covariates (HR 0.81 [0.69-0.95] P=<0.01). The most significant predictor of mortality was old age (HR 3.78 [3.67, 3.89] p ≤ 0.01), followed by higher Charlson Comorbidity Index (HR 1.73 [1.69, 1.76] (p ≤ 0.01), and higher APF score (HR 1.46 [1.42, 15.2] p ≤ 0.01).

CONCLUSION

AC was associated with decreased survival in the total cohort of stage 1 colon cancer patients, but was associated with improved survival for patients with multiple APFs.

A national evaluation of adjuvant chemotherapy in pT4N0M0 colon cancer from the National Cancer Database

BACKGROUND

T stage is a prognostic biomarker for overall survival in colon cancer and pathologic T4 disease is a high-risk characteristic. Adjuvant chemotherapy is recommended to improve overall survival in pT4N0M0, but compliance with guidelines is unknown. We aimed to evaluate adjuvant chemotherapy use and impact on overall survival in pT4N0M0 colon cancer.

METHODS

The National Cancer Database was reviewed for pT4N0M0 colon adenocarcinomas undergoing curative surgical resection (2010-2017). Cases were stratified into no adjuvant chemotherapy and adjuvant chemotherapy cohorts. Moderated multiple regression assessed factors associated with no AC. Kaplan-Meier and Cox regression assessed overall survival in propensity-score matched cohorts. The main outcome measures were adjuvant chemotherapy use, factors associated with adjuvant chemotherapy, and impact on overall survival.

RESULTS

Of 11 847 cases, 62.4% (n = 7391) received no adjuvant chemotherapy. With private insurance, comorbidities or income do not affect adjuvant chemotherapy use. Medicare cases with a Charlson-Deyo comorbidity index of 0 (odds ratio [OR] = 0.861, 95% confidence interval [CI] = 0.760 to 0.975; P = .019) and Medicare payors with high income (OR = 0.813, 95% CI = 0.690 to 0.959; P = .014) were associated with adjuvant chemotherapy. Medicaid Charlson-Deyo comorbidity index 0 (OR = 1.374, 95% CI = 1.125 to 1.679; P = .002) and uninsured Charlson-Deyo comorbidity index 0 (OR = 1.351, 95% CI = 1.120 to 1.629; P = .002) were associated with no adjuvant chemotherapy. Adjuvant chemotherapy was associated with improved 5-year overall survival (71.7% vs 56.4%; P < .001; adjusted hazard ratio = 0.543, 95% CI = 0.499 to 0.590; P < .001).

CONCLUSION

Although adjuvant chemotherapy is associated with improved overall survival, compliance is low. There is a complex relationship between payor, income, comorbidity, and adjuvant chemotherapy receipt. Medicare patients with no comorbidities or higher income have better adjuvant chemotherapy use. With private insurance, adjuvant chemotherapy compliance is not affected by comorbidities or income, whereas Medicaid and uninsured patients with no comorbidities have poor compliance. Future work could target these disparities for equitable care.

Treatment strategies and drug resistance mechanisms in adenocarcinoma of different organs

Adenocarcinoma is a common type of malignant tumor, originating from glandular epithelial cells in various organs, such as pancreas, breast, lung, stomach, colon, rectus, and prostate. For patients who lose the opportunity for radical surgery, medication is available to provide potential clinical benefits. However, drug resistance is a big obstacle to obtain desired clinical prognosis. In this review, we provide a summary of treatment strategies and drug resistance mechanisms in adenocarcinoma of different organs, including pancreatic cancer, gastric adenocarcinoma, colorectal adenocarcinoma, lung adenocarcinoma, and prostate cancer. Although the underlying molecular mechanisms involved in drug resistance of adenocarcinoma vary from one organ to the other, there are several targets that are universal for drug resistance in adenocarcinoma, and targeting these molecules could potentially reverse drug resistance in the treatment of adenocarcinomas.

Lymph node retrieval colon cancer: Are we making the grade?

BACKGROUND

Adequate lymph node (LN) excision is imperative for pathologic staging and determination of adjuvant treatment.

METHODS

he 2004-2017 National Cancer Database (NCDB) was queried for curative colon cancer resections. Tumors were categorized by location: left, right, and transverse colon cancers. Adequate (12-20 LNs) vs. inadequate (<12 LNs) lymphadenectomy was examined and sub-analysis of <12 LNs, 12-20 LNs or >20 LNs. Primary outcome was predictors of inadequate lymph node retrieval.

RESULTS

Of 101,551 patients, 11.2% (11,439) had inadequate lymphadenectomy. The inadequate lymphadenectomy rate steadily decreased. On multivariable analysis, inadequate LN retrieval was associated with transverse (OR 1.49, CI [1.30-1.71]) and left colon cancers (OR 2.66, CI [2.42-2.93], whereas income >$63,333 had decreased likelihood of inadequate LN retrieval (OR 0.68, CI[0.56-0.82].

CONCLUSION

We are making the grade as NCDB data demonstrates a steady decrease in inadequate lymphadenectomy (2004-2017). There remain socioeconomic risk factors for inadequate lymphadenectomy that need to be addressed.

Multiple High-Risk Features for Stage II Colon Carcinoma Portends Worse Survival Than Stage III Disease

BACKGROUND

High-risk features in stage II colon cancer worsen survival and serve as an impetus for adjuvant chemotherapy. Limited data exist on the effect of multiple high-risk features on survival.

OBJECTIVE

The study aimed to compare the survival of 0, 1, or multiple high-risk features in stage II to stage III colon cancer.

DESIGN

Patients with stage II and III colon cancer diagnosed between 2010 and 2016 were identified using the Survival, Epidemiology, and End Results database. Patients with stage II colon cancer were then classified according to the presence of 0, 1, or 2 or more of the following high-risk features: pathologic T4, perineural invasion, fewer than 12 lymph nodes assessed, or poor histologic differentiation. Overall survival and cause-specific survival were calculated. Each group was then stratified on the basis of whether chemotherapy was given.

SETTINGS

This study used the Survival, Epidemiology, and End Results database (2010-2016).

PATIENTS

Patients who had stage II or III colon cancer were included.

MAIN OUTCOME MEASURES

The primary outcome measures were 5-year overall survival and cause-specific survival.

RESULTS

A total of 65,831 patients were studied. Of these, 18,056 patients with stage II cancer had 0 high-risk features, 9426 had 1 high-risk feature, and 3503 had 2 or more high-risk features. There were 34,842 patients diagnosed with stage III disease. The 5-year overall survival and cause-specific survival for patients with stage II cancer with 2 or more high-risk features (49.2%, 59.5%) were lower than those without high-risk features (74.9%, 90.7%), with 1 high-risk feature (67.1%, 82.4%), or stage III disease (59.1%, 68.1%; p < 0.05). Although chemotherapy is associated with improved cause-specific survival in stage III disease, it is associated with worse cause-specific survival in patients with stage II disease.

LIMITATIONS

This study being a retrospective database analysis is the main limitation. Also, lymphovascular invasion, margin status, and clinical obstruction or perforation were absent from the dataset.

CONCLUSIONS

Multiple high-risk features in stage II colon cancer predict worse survival than lymph node metastasis. Chemotherapy is associated with adverse cause-specific survival in patients with stage II disease. Further study into this group should focus on the type and duration of adjuvant therapy and biological features of these tumors. See Video Abstract at http://links.lww.com/DCR/B929 .

MLTIPLES CARACTERSTICAS DE ALTO RIESGO PARA EL CARCINOMA DE COLON EN ESTADIO II PRESAGIAN PEOR SUPERVIVENCIA QUE LA ENFERMEDAD EN ESTADIO III

ANTECEDENTES:Las características de alto riesgo en el cáncer de colon en estadio II empeoran la supervivencia y sirven como impulso para la quimioterapia adyuvante. Existen datos limitados sobre el efecto de múltiples características de alto riesgo en la supervivencia.OBJETIVO:Comparar la supervivencia de cero, una o múltiples características de alto riesgo en el cáncer de colon en estadio II con la enfermedad en estadio III.DISEÑO:Los pacientes con cáncer de colon en estadio II y III diagnosticados entre 2010 y 2016 se identificaron mediante la base de datos de supervivencia, epidemiología y resultados finales. Luego, los pacientes en etapa II se clasificaron según la presencia de cero, 1 o 2+ de las siguientes características de alto riesgo: T4 patológico, invasión perineural, menos de 12 ganglios linfáticos evaluados (< 12 ganglios linfáticos) o mala diferenciación histológica. Se calculó la supervivencia observada y específica de la causa. Luego, cada grupo se estratificó en función de si se administró quimioterapia.ESCENARIO:Este estudio utilizó la base de datos de supervivencia, epidemiología y resultados finales, 2010-2016.PACIENTES:Los pacientes tenían cáncer de colon en estadio II o III.PRINCIPALES MEDIDAS DE RESULTADO:La medida principal fue la supervivencia observada a 5 años y la supervivencia por causa específica.RESULTADOS:Se estudiaron un total de 65,831 pacientes. 18,056 pacientes estaban en estadio II sin características de alto riesgo, 9.426 con 1 característica de alto riesgo y 3.503 con 2+ características de alto riesgo. Hubo 34.842 pacientes a los que se les diagnosticó enfermedad en estadio III. La supervivencia observada a los 5 años y la supervivencia específica de la causa para los pacientes con cáncer en estadio II con 2+ características de alto riesgo (49.2 %, 59.5 %) fueron más bajas, en comparación con aquellos sin características de alto riesgo (74.9 %, 90.7 %), con 1 característica de alto riesgo (67.1 %, 82.4 %) o enfermedad en estadio III (59.1 %, 68.1 %) (p < 0.05). Si bien la quimioterapia se asocia con una mejor supervivencia por causa específica en la enfermedad en estadio III, se asocia con una peor supervivencia por causa específica en pacientes con enfermedad en estadio II.LIMITACIONES:Este es un análisis de base de datos retrospectivo. La invasión linfovascular, el estado de los márgenes y la obstrucción o perforación clínicas estaban ausentes en la base de datos.CONCLUSIONES:Múltiples características de alto riesgo en el cáncer de colon en estadio II predicen una peor supervivencia que la metástasis en los ganglios linfáticos. La quimioterapia se asocia con una supervivencia específica de causa adversa en pacientes con enfermedad en estadio II. El estudio adicional de este grupo deberá centrarse en el tipo y la duración de la terapia adyuvante y las características biológicas de estos tumores. Consulte Video Resumen en http://links.lww.com/DCR/B929 . (Traducción-Dr. Jorge Silva Velazco ).

A correlation study affecting survival in patients after radical colon cancer surgery: A retrospective study

The objective of this study was to explore the relevant factors affecting the 5-year survival rate of patients after radical colon cancer surgery, and to provide some basis for improving the quality of life and prognosis of colon cancer patients. The clinical data of 116 colon cancer patients who underwent treatment in our hospital from January 2017 to December 2017 were retrospectively selected. Using the date of performing surgical treatment as the starting point and the completion of 5 years after surgery or patient death as the end point, all patients were followed up by telephone to count the 5-year survival rate and analyze the influence of each factor with the prognosis of colon cancer patients. Of the 116 patients, 14 patients were lost to follow-up. Of the 102 patients with complete follow-up, 33 patients were died, with an overall 5-year survival rate of 67.6%. After univariate analysis, it was found that distant metastasis (χ2 = 10.493, P = .001), lymph node metastasis (χ2 = 25.145, P < .001), depth of muscle infiltration (χ2 = 14.929, P < .001), alcohol consumption (χ2 = 15.263, P < .001), and preoperative obstruction (χ2 = 9.555, P = .002) were significantly associated with the prognosis of colon cancer patients. Multivariate logistic analysis showed that distant metastasis (odds ratio [OR]: 1.932, 95% confidence intervals [CI]: 1.272-2.934, P = .002), lymph node metastasis (OR: 1.219, 95% CI: 1.091-1.362, P < .001), and obstruction (OR: 1.970, 95% CI: 1.300-2.990, P < .001) were significant independent risk factors affecting the prognosis in patients after radical colon cancer surgery. In summary, preoperative obstruction, lymph node metastasis, and distant metastasis are independent factors influencing 5-year survival rate after radical colon cancer surgery. Patients with risk factors should be followed up more closely and reasonable postoperative adjuvant chemotherapy regimens should be used to improve long-term survival.

Phenolic Phytochemicals for Prevention and Treatment of Colorectal Cancer: A Critical Evaluation of In Vivo Studies

Colorectal cancer (CRC) is the third most diagnosed and second leading cause of cancer-related death worldwide. Limitations with existing treatment regimens have demanded the search for better treatment options. Different phytochemicals with promising anti-CRC activities have been reported, with the molecular mechanism of actions still emerging. This review aims to summarize recent progress on the study of natural phenolic compounds in ameliorating CRC using in vivo models. This review followed the guidelines of the Preferred Reporting Items for Systematic Reporting and Meta-Analysis. Information on the relevant topic was gathered by searching the PubMed, Scopus, ScienceDirect, and Web of Science databases using keywords, such as "colorectal cancer" AND "phenolic compounds", "colorectal cancer" AND "polyphenol", "colorectal cancer" AND "phenolic acids", "colorectal cancer" AND "flavonoids", "colorectal cancer" AND "stilbene", and "colorectal cancer" AND "lignan" from the reputed peer-reviewed journals published over the last 20 years. Publications that incorporated in vivo experimental designs and produced statistically significant results were considered for this review. Many of these polyphenols demonstrate anti-CRC activities by inhibiting key cellular factors. This inhibition has been demonstrated by antiapoptotic effects, antiproliferative effects, or by upregulating factors responsible for cell cycle arrest or cell death in various in vivo CRC models. Numerous studies from independent laboratories have highlighted different plant phenolic compounds for their anti-CRC activities. While promising anti-CRC activity in many of these agents has created interest in this area, in-depth mechanistic and well-designed clinical studies are needed to support the therapeutic use of these compounds for the prevention and treatment of CRC.

Correlation between lymph node size on pathology and metastatic disease in right-sided colon cancer: A retrospective review

BACKGROUND

Identification of positive lymph nodes in colon cancer can significantly impact treatment. Few studies have examined the role of lymph node size in staging and prognosis. This study evaluated the relationship between lymph node size and lymph node metastases in right-sided colon cancer.

METHODS

Retrospective chart review was performed for patients undergoing colectomy for right-sided colon cancer from 2015 to 2020 across a single multi-hospital health system. Patients under age 18 or who did not have invasive adenocarcinoma upon pathological examination were excluded. Primary endpoints assessed lymph node size and lymph node metastases. 572 patients were stratified by lymph node size; lymph nodes ≥5 mm (n = 308) were characterized as enlarged.

RESULTS

All surgical specimens examined had adequate number of lymph nodes for staging. 33.9% of all specimens examined contained lymph node metastases. Patients with enlarged lymph nodes were significantly more likely to have lymph node metastases than those with normal-sized lymph nodes (p < 0.001). Enlarged lymph nodes were associated with advanced nodal staging.

CONCLUSIONS

Patients with enlarged nodes were significantly more likely to have lymph node metastases than those with normal-sized lymph nodes. Further research to analyze these enlarged lymph nodes on radiologic imaging is warranted to determine the role of radiographic assessment of lymph node size during pre-operative staging.

Can clinicopathologic high-risk features in T3N0 colon cancer be reliable prognostic factors?

Purpose

The purpose of this study was to assess the reliability and prognostic significance of the high-risk feature (HRF) in patients with T3N0 colon cancer.

Methods

We included 1,205 patients with pT3N0 colon cancer treated with curative radical resection between 2012 and 2016. HRF was defined as lymphovascular invasion, perineural invasion, poorly/undifferentiated histology, margin involvement, and preoperative obstruction. We investigated the relationships between the number and type of HRF and recurrence-free survival (RFS) and overall survival (OS), as well as the effect of adjuvant treatment.

Results

A total of 751 of the patients (62.3%) had more than 1 HRF and 515 of the patients (42.7%) underwent adjuvant treatment. Patients who had more than 2 HRFs had a significantly worse 5-year RFS and OS compared to patients who had neither HRF nor even one HRF. According to the findings of the multivariate analysis, the presence of multiple HRFs was a risk factor for a lower RFS and OS. When the quantity and type of HRF were taken into consideration in the multivariate analysis, adjuvant chemotherapy was not found to be linked with RFS or OS in patients with pT3N0 colon cancer.

Conclusion

In the present study, adjuvant treatment based on the current guideline of treatment indication was unable to enhance the prognosis of patients with pT3N0 colon cancer. The role of adjuvant treatment in T3N0 colon cancer must be examined with the HRF count in mind.

Impact on inadequate lymph node harvest on survival in T4N0 colorectal cancer: A would-be medical center experience in Taiwan

Insufficient lymph node harvest (< 12) may lead to incorrect classification of stage I and II disease. Many studies have indicated a poor prognosis with inadequate lymph node harvest in stages I to III, but few studies have demonstrated the relationship between low lymph node harvest and T4 disease. This study aimed to identify the influence of insufficient number of lymph nodes harvested on survival in T4N0 colorectal cancer. We enrolled patients with T4N0 colorectal cancer who underwent radical resection between 2010 and 2016. A total of 155 patients were divided into 2 groups; 142 patients had ≥ 12 harvested lymph nodes, and the other 13 had < 12 lymph nodes. All patients were followed up for at least 5 years. The primary outcome was the impact of the number of lymph nodes harvested on disease-free survival and overall survival, which were investigated using Kaplan-Meier survival techniques. There were no significant differences in recurrence rate, emergent or elective surgery, laparoscopic or open surgery, or chemotherapy between the 2 groups. Kaplan-Meier analyses showed no statistical differences in 5-year disease-free survival (P = .886) and 5-year overall survival (P = .832) between the groups. There were no significant differences in disease-free survival and overall survival between patients with adequate (≥ 12) and inadequate (< 12) lymph node harvest in T4N0 colorectal cancers.

Postoperative circulating tumor DNA detection is associated with the risk of recurrence in patients resected for a stage II colorectal cancer

Circulating tumor DNA (ctDNA) is reported to be promising in localized colorectal cancer (CRC). The present study aimed to retrospectively evaluate the impact of ctDNA in patients with a resected stage II CRC from the PROGIGE 13 trial with available paired tumor and blood samples. A group of recurrent patients were matched one-to-one with nonrecurrent patients according to sex, tumor location, treatment sequence, and blood collection timing. CtDNA was analyzed by digital PCR according to NGS of tumors. Disease-free survival (DFS) and overall survival (OS) were analyzed based on ctDNA, and the risks of recurrence and death were determined. A total of 134 patients were included, with 67 patients in each group. At least one alteration was identified in 115/134 tumors. Postoperative ctDNA was detected in 10/111 (9.0%) informative samples and was detected more frequently in the recurrent group (16.7% versus 1.8%; p = 0.02). The median DFS of ctDNA+ versus ctDNA- patients was 16.8 versus 54 months (p = 0.002), respectively, and the median OS was 51.3 versus 69.5 months (p = 0.03), respectively. CtDNA was associated with recurrence (ORa = 11.13, p = 0.03) and death (HRa = 3.15, p = 0.01). In conclusion, the presence of postoperative ctDNA is associated with both recurrence and survival in stage II CRC.

Improved Accuracy of Lymph Node Staging and Long-Term Survival Benefit in Colorectal Cancer With Ex Vivo Arterial Methylene Blue Infiltration

Introduction:Ex vivo methylene blue (MB) injection into the main supplying arteries of the colorectal specimen after surgical removal is an uncomplicated technique to support lymph node harvest during pathological evaluation. The primary aim of this randomized, interventional, bicentric trial was to evaluate the impact of MB injection on lymph node yield, with secondary aims assessing the accuracy of lymph node staging and the effect on 5-year overall survival for patients undergoing resection of colorectal cancer.

Methods: In the study period between December 2013 and August 2015, 200 colorectal resections were performed at two independent onco-surgery centers of Hungary. Following surgical resection, each specimen was randomly assigned either to the control (standard pathological work-up) or to the MB staining group before formaldehyde fixation. Patient-level surgical and clinical data were retrieved from routinely collected clinical datasets. Survival status data were obtained from the National Health Insurance Fund of Hungary.

Results: A total of 162 specimens, 82 in the control and 80 in the MB groups, were included for analysis. Baseline characteristics were equally distributed among study groups, except for specimen length. Both the median of total number of lymph nodes retrieved (control 11 ± 8 [0–33] nodes vs. MB 14 ± 6 [0–42] nodes; p < 0.01), and the ratio of cases with at least 12 removed lymph nodes (36/82, 43.9% vs. 53/80, 66.3%; p < 0.01) were higher in the MB group. The rate of accurate lymph node staging was non-significantly improved. As for rectal cancer, nodal staging accuracy (16/31, 51.6% vs. 23/30, 76.7%; p = 0.04) and the proportion with minimum 12 lymph node retrieval (7/31, 22.6%, vs. 18/30, 60%; p < 0.01) was improved by MB injection. In Mantel–Cox regression, a statistically significant survival benefit with methylene blue injection at 5 years post-surgery was proven (51.2% vs. 68.8%; p = 0.04).

Conclusion: In our experience, postoperative ex vivo arterial methylene blue injection appears to be an uncomplicated technique, improving lymph node yield and decreasing the chance of insufficient nodal staging. The technique might also associate with a 5-year overall survival benefit.

A national evaluation of the predictors of compliance and survival from adjuvant chemotherapy in high-risk stage II colon cancer: A National Cancer Database (NCDB) analysis

BACKGROUND

Guidelines recommend adjuvant chemotherapy for stage II colon cancer with high-risk features, but there has been little study on compliance with guidelines. This work sought to evaluate compliance with adjuvant chemotherapy and factors associated with compliance in high-risk stage II colon cancer. This work's hypothesis was that compliance with adjuvant chemotherapy recommendations is low, but improves overall survival when used.

METHODS

The National Cancer Database was reviewed for stage II high-risk colon cancers that underwent curative resection from 2010 to 2017. The cases were stratified into adjuvant chemotherapy and no adjuvant chemotherapy cohorts. A multivariate logistic regression identified factors associated with adjuvant chemotherapy compliance. Propensity-score matching was performed to balance the cohorts and Kaplan-Meier analysis assessed overall survival. The main outcome measures were adjuvant chemotherapy compliance, factors associated with compliance, and overall survival in high-risk stage II colon cancer.

RESULTS

A total of 52,609 patients were evaluated, and 23.2% received adjuvant chemotherapy. The factors associated with noncompliance included older age (odds ratio 0.919; 95% confidence interval 0.915-0.922; P < .001), Medicaid (odds ratio 0.720; 95% confidence interval 0.623-0.832; P < .001) payor, greater comorbidities (odds ratio 0.423; 95% confidence interval 0.334-0.530; P < .001), and residing in the Midwest (odds ratio 0.898; 95% confidence interval 0.812-0.994; P = .037). All of the known high-risk features were significantly independently associated with compliance. In a matched cohort, adjuvant chemotherapy significantly improved the 5-year overall survival (78.1% vs 66.6%; P < .001).

CONCLUSION

Nationally, there is low compliance with adjuvant chemotherapy in high-risk stage II colon cancer. Despite the low compliance, adjuvant chemotherapy was associated with improved overall survival. Demographic variables were associated with poor compliance, whereas tumor factors were associated with increased compliance. These results highlighted the disparities in care and opportunities to improve outcomes in high-risk stage II colon cancer.

Landscape of Immunotherapy Options for Colorectal Cancer: Current Knowledge and Future Perspectives beyond Immune Checkpoint Blockade

Colorectal cancer is the third most prevalent malignancy in Western countries and a major cause of death despite recent improvements in screening programs and early detection methods. In the last decade, a growing effort has been put into better understanding how the immune system interacts with cancer cells. Even if treatments with immune checkpoint inhibitors (anti-PD1, anti-PD-L1, anti-CTLA4) were proven effective for several cancer types, the benefit for colorectal cancer patients is still limited. However, a subset of patients with deficient mismatch repair (dMMR)/microsatellite-instability-high (MSI-H) metastatic colorectal cancer has been observed to have a prolonged benefit to immune checkpoint inhibitors. As a result, pembrolizumab and nivolumab +/− ipilimumab recently obtained the Food and Drug Administration approval. This review aims to highlight the body of knowledge on immunotherapy in the colorectal cancer setting, discussing the potential mechanisms of resistance and future strategies to extend its use.

Adjuvant Therapy for Stage II Colon Cancer: ASCO Guideline Update

PURPOSE

To develop recommendations for adjuvant therapy for patients with resected stage II colon cancer.

METHODS

ASCO convened an Expert Panel to conduct a systematic review of relevant studies and develop recommendations for clinical practice.

RESULTS

Twenty-one observational studies and six randomized controlled trials met the systematic review inclusion criteria.

RECOMMENDATIONS

Adjuvant chemotherapy (ACT) is not routinely recommended for patients with stage II colon cancer who are not in a high-risk subgroup. Patients with T4 tumors are at higher risk of recurrence and should be offered ACT, whereas patients with other high-risk factors, including sampling of fewer than 12 lymph nodes in the surgical specimen, perineural or lymphatic invasion, poorly or undifferentiated tumor grade, intestinal obstruction, tumor perforation, or grade BD3 tumor budding, may be offered ACT. The addition of oxaliplatin to fluoropyrimidine-based ACT is not routinely recommended, but may be offered as a result of shared decision making. Patients with mismatch repair deficiency/microsatellite instability tumors should not be routinely offered ACT; if the combination of mismatch repair deficiency/microsatellite instability and high-risk factors results in a decision to offer ACT, oxaliplatin-containing chemotherapy is recommended. Duration of oxaliplatin-containing chemotherapy is also addressed, with recommendations for 3 or 6 months of treatment with capecitabine and oxaliplatin or fluorouracil, leucovorin, and oxaliplatin, with decision making informed by key evidence of 5-year disease-free survival in each treatment subgroup and the rate of adverse events, including peripheral neuropathy.Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines.

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

CONTEXT.—

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

OBJECTIVE.—

To address the clinicopathologic characteristics and prognosis of pT2int tumors.

DESIGN.—

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

RESULTS.—

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

CONCLUSIONS.—

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

Association of Adherence to Quality Metrics with Recurrence or Mortality among Veterans with Colorectal Cancer

BACKGROUND

The National Comprehensive Cancer Network has defined metrics for colorectal cancer; however, the association of metric adherence with patient clinical outcomes remains underexplored. The study aim was to evaluate the association of National Comprehensive Cancer Network metric adherence with recurrence and mortality in Veterans with nonmetastatic colorectal cancer.

METHODS

Veterans with stage I-III colorectal cancer who underwent non-emergent resection from 2001 to 2015 at a single Veterans Affairs Medical Center were included. The primary predictor was completion of eligible National Comprehensive Cancer Network metrics. The primary outcome was a composite of recurrence or all-cause death in three phases of care: surgical (up to 6 months after resection), treatment (6-18 months after resection), and surveillance (18 months-3 years after resection). Hazard ratios were estimated via Cox proportional hazards regression in a propensity score-weighted cohort.

RESULTS

A total of 1107 electronic medical records of patients undergoing colorectal surgery were reviewed, and 379 patients were included (301 colon and 78 rectal cancer). In the surgical phase, the weighted analysis yielded a hazard ratio of 0.37 (95% confidence interval 0.12-1.13) for metric-adherent patients compared with non-adherent patients. In the treatment and surveillance phases, the hazard ratios for metric-adherent care were 0.68 (95% confidence interval 0.25-1.85) and 0.91 (95% confidence interval 0.31-2.68), respectively.

CONCLUSIONS

The National Comprehensive Cancer Network guideline metric adherence was associated with a lower rate of recurrence and death in the surgical phase of care among stage I-III patients with resected colorectal cancer.

ctDNA to Guide Adjuvant Therapy in Localized Colorectal Cancer (CRC)

Currently, the standard treatment for patients with localized colorectal cancer (CRC) includes surgical resection followed by adjuvant chemotherapy based on clinicopathological features. Recurrence risk stratification in those patients is of utmost importance to guide clinicians to avoid both under- and overtreatment. Recently, the concept of minimal residual disease (MRD) has emerged as the detection of circulating tumor DNA (ctDNA) carrying tumor-specific genomic or epigenomic alterations in the bloodstream of patients after surgery. Emerging studies described how the detection of MRD is a powerful prognostic biomarker to identify patients at higher risk of recurrence and who will potentially benefit the most from a systemic adjuvant treatment. Based on that unprecedented finding, several clinical trials involving stage II and III CRC patients are ongoing evaluating the impact of ctDNA guided treatment by escalating or deescalating adjuvant chemotherapy based on ctDNA MRD detection. This review provides a critical overview of current perspectives of liquid biopsy in early-stage CRC including technical, biological, and clinical key points, as well as ongoing ctDNA-based clinical trials that ultimately aim to improve clinical outcomes of patients with CRC.

N1c colon cancer and the use of adjuvant chemotherapy: a current audit of the National Cancer Database

AIM

Colorectal cancer staging has evolved to define N1c as the presence of tumour deposits without concurrent positive lymph nodes. Work to date reports poor prognosis in N1c colon cancer, with Stage III categorization and adjuvant chemotherapy (AC) recommended. No study has yet evaluated the prevalence, treatment compliance or treatment-related outcomes on a national scale. We aimed to evaluate the prevalence of N1c colon cancer, use, outcomes and factors associated with AC in the USA.

METHOD

The National Cancer Database was reviewed for N1cM0 colon adenocarcinomas that underwent resection from 2010 to 2016. Cases were stratified into 'AC' or 'no AC' cohorts. The Kaplan-Meier method was used to estimate overall survival (OS) and compare the AC and no AC cohorts using the log-rank test. Multivariable logistic regression identified factors associated with AC. The main outcome measures were the prevalence and factors associated with AC use and its impact in N1c disease.

RESULTS

Of the 5684 (1.59% of 357 752) colon adenocarcinomas that were N1c, 55% (n = 3071) received AC. AC significantly improved 1-, 3- and 5-year OS compared with no AC (96.2%, 80%, 67.4% and 72.9%, 48.5%, 33.8%, respectively; P < 0.001). Compared with the no AC group, AC patients were younger, had less comorbidity, were of the male gender and received minimally invasive surgery at an academic treatment centre (all P < 0.05). Socioeconomic and procedural factors significantly impacted the use of AC.

CONCLUSION

In the USA, AC is underutilized in N1c colon cancer despite significantly improved OS. Socioeconomic and procedural factors associated with AC were identified, highlighting disparities in AC use and opportunities to improve oncological outcomes and survival.

Postoperative chemotherapy improves survival in patients with resected high-risk Stage II colorectal cancer: results of a systematic review and meta-analysis

AIM

The aim was to assess the benefit of adjuvant chemotherapy in high-risk Stage II colorectal cancer.

METHOD

A systematic literature review and meta-analysis was performed comparing survival in patients with resected Stage II colorectal cancer and high-risk features having postoperative chemotherapy vs no chemotherapy.

RESULTS

Of 1031 articles screened, 29 were included, reporting on 183 749 participants. Adjuvant chemotherapy significantly improved overall survival [hazard ratio (HR) 0.61, P < 0.0001], disease-specific survival (HR = 0.73, P = 0.05) and disease-free survival (HR = 0.59, P < 0.0001) compared to no chemotherapy. Adjuvant chemotherapy significantly increased 5-year overall survival (OR = 0.53, P = 0.0008) and 5-year disease-free survival (OR = 0.50, P = 0.001). Overall survival and disease-free survival remained significantly prolonged during subgroup analysis of studies published from 2015 onwards (HR = 0.60, P < 0.0001; HR = 0.65, P = 0.0001; respectively), in patients with two or more high-risk features (HR = 0.59, P = 0.0001; HR = 0.70, P = 0.03; respectively) and in colon cancer (HR = 0.61, P < 0.0001; HR = 0.51, P = 0.0001; respectively). Overall survival, disease-specific survival and disease-free survival during subgroup analysis of individual high-risk features were T4 tumour (HR = 0.58, P < 0.0001; HR = 0.50, P = 0.003; HR = 0.75, P = 0.05), < 12 lymph nodes harvested (HR = 0.67, P = 0.0002; HR = 0.80, P = 0.17; HR = 0.72, P = 0.02), poor differentiation (HR = 0.84, P = 0.35; HR = 0.85, P = 0.23; HR = 0.61, P = 0.41), lymphovascular or perineural invasion (HR = 0.55, P = 0.05; HR = 0.59, P = 0.11; HR = 0.76, P = 0.05) and emergency surgery (HR = 0.60, P = 0.02; HR = 0.68, P = 0.19).

CONCLUSION

Adjuvant chemotherapy in high-risk Stage II colorectal cancer results in a modest survival improvement and should be considered on an individual patient basis. Due to potential heterogeneity and selection bias of the included studies, and lack of separate rectal cancer data, further large randomized trials with predefined inclusion criteria and standardized chemotherapy regimens are required.

Patient Selection for Adjuvant Chemotherapy in High-Risk Stage II Colon Cancer: A Systematic Review and Meta-Analysis

OBJECTIVES

Patients with high-risk stage II colon cancer (CC) are recommended to undergo adjuvant chemotherapy (ACT). However, whether such patients can benefit from ACT remains unclear. This meta-analysis aimed to investigate the clinicopathologic parameters that are important for selecting patients for ACT in high-risk stage II CC.

METHODS

We systematically retrieved articles from PubMed, the Cochrane Library, and Embase that were published up to September 13, 2018. We analyzed overall survival (OS) and disease-free survival (DFS) based on hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A total of 23 cohort studies and 1 randomized controlled trial were included in our study. Overall analyses showed that ACT improved OS (HR=0.64, 95% CI=0.51-0.80, P<0.001) and DFS (HR=0.46, 95% CI=0.28-0.76, P=0.002) in patients with high-risk stage II CC. Subgroup analyses showed that ACT improved OS in patients with localized intestinal perforation and obstruction and pT4 lesions and improved OS and DFS in patients with <12 sampled lymph nodes. However, ACT had no significant effect on OS in patients with lymphovascular invasion, perineural invasion, or poorly differentiated histology.

CONCLUSIONS

Our study suggests that not all high-risk factors (lymphovascular invasion, perineural invasion, poorly differentiated histology) show a benefit from ACT. Randomized controlled trials selectively targeting high-risk patients will need to be conducted in the future.

Nutritional risk screening score is associated with omission of adjuvant chemotherapy for stage III colon cancer

BACKGROUND

This study aimed to evaluate the association between nutritional risk screening (NRS) score and administration of adjuvant chemotherapy for stage III colon cancer.

METHODS

A total of 404 patients with stage III colon cancer who underwent curative resection between January 2012 and December 2015 were included. Patients with a preoperative high nutritional risk score (NRS ≥4) were compared with those with an NRS <4. Predictive factors for omission of adjuvant chemotherapy, and prognostic factors for overall survival (OS) were analyzed.

RESULTS

Eighty (19.8%) patients had a high nutritional risk (NRS ≥4). An NRS score ≥4 was associated with higher risk of omission of adjuvant chemotherapy (26.3% vs. 13.6%, p = 0.006), which was significant after adjusting for covariables (odds ratio = 1.862, p = 0.047). Multivariable survival analysis showed that omission of adjuvant chemotherapy was an independent poor prognostic factor for OS (hazard ratio = 4.060, p < 0.001).

CONCLUSIONS

An NRS score ≥4 was associated with omission of adjuvant chemotherapy in stage III colon cancer, which resulted in poor OS.

Overuse and Limited Benefit of Chemotherapy for Stage II Colon Cancer in Young Patients

BACKGROUND

Few studies have confirmed a benefit for adjuvant chemotherapy (aCTX) in stage II colon cancer. We used the National Cancer Database to explore the use and efficacy of aCTX in patients with both normal-risk (NR) and high-risk (HR) young stage II colon cancer.

PATIENTS AND METHODS

We identified patients with stage II colon cancer who underwent colectomy between 2010 and 2015. HR patients included at least: lymphovascular or perineural invasion, < 12 lymph nodes, poor/un-differentiation, T4, or positive margins. Rates of aCTX by age and risk were calculated, and adjusted factors associated with aCTX were identified. Overall survival was estimated using the Kaplan-Meier method and Cox multivariable analyses for patients < 50 years.

RESULTS

Among the 81,066 stage II patients who underwent colectomy, 6093 (7.5%) were < 50 years old. Of these, 2669 patients were HR. Thirty percent of NR and almost 60% of HR patients < 50 years received aCTX, compared with 8% and 23% of patients > 50 years (P < .001). In NR patients < 50 years, 35.3% with microsatellite-stable tumors and 18% with microsatellite unstable tumors received aCTX (P < .001), whereas 63.6% and 43.2%, respectively, of HR patients did (P < .001). The most significant multivariable predictors of aCTX were risk status and age. On univariate analysis, there was no survival benefit associated with aCTX in patients < 50 years. Multivariate analysis failed to demonstrate a survival benefit for aCTX for either group (HR, 0.97; P = .84; NR, 0.1.03; P = .90).

CONCLUSION

Young patients with HR and NR colon cancer received aCXT more frequently than older patients with no demonstrable survival benefit. This bears further evaluation to avoid the real risks of over-treatment in this increasing population.

Robotic Complete Mesocolic Excision Versus Conventional Laparoscopic Hemicolectomy for Right-Sided Colon Cancer

Background: Robotic technique has been proposed to overcome the limitations of laparoscopic surgery. In this study, we aimed at determining whether robotic complete mesocolic excision (CME) for right-sided colon cancer can be safe and effective as conventional laparoscopic right hemicolectomy (CLRH). Materials and Methods: Between February 2015 and September 2017, patients undergoing robotic right CME and CLRH with curative intent for right-sided colon cancer were included. Patient characteristics, short-term and histopathological outcomes were compared between the groups. Results: Ninety-six patients (robotic, n = 35) were included in this study. The operative time (286 ± 77 versus 132 ± 40 minutes, P = .0001) was significantly longer in the robotic group. There were no conversions in either group. No significant differences existed between the groups regarding the mean estimated blood loss, time to first flatus, length of hospital stay (6 ± 3 versus 6 ± 3 days, P = .64), and follow-up times (robotic 15 ± 8 versus laparoscopic 16 ± 10 months P = .11). Overall complication rates (n = 10 [29%] versus n = 15 [25%], P = .67) were similar. In the robotic group, vascular injury occurred in 2 patients, and both were repaired robotically. The mean number of harvested lymph nodes was significantly higher (41 ± 12 versus 33 ± 10, P = .04) and length between the vascular tie and colonic wall was longer (13 ± 3.5 versus 11 ± 3, P = .02) in the robotic group. Conclusion: Although robotic right CME seems equally safe to CLRH in terms of short-term morbidity, future prospective randomized trials are needed to define its role for treatment of right colectomy.

The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Treatment of Colon Cancer

The American Society of Colon and Rectal Surgeons is dedicated to ensuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Clinical Practice Guidelines Committee is composed of society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than to dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient.