Lymph node count and prognosis in colorectal cancer: the influence of examination quality

Measurement that matters: A systematic review and modified Delphi of multidisciplinary colorectal cancer quality indicators

AIM

To develop a priority set of quality indicators (QIs) for use by colorectal cancer (CRC) multidisciplinary teams (MDTs).

METHODS

The review search strategy was executed in four databases from 2009-August 2019. Two reviewers screened abstracts/manuscripts. Candidate QIs and characteristics were extracted using a tailored abstraction tool and assessed for scientific soundness. To prioritize candidate indicators, a modified Delphi consensus process was conducted. Consensus was sought over two rounds; (1) multidisciplinary expert workshops to identify relevance to Australian CRC MDTs, and (2) an online survey to prioritize QIs by clinical importance.

RESULTS

A total of 93 unique QIs were extracted from 118 studies and categorized into domains of care within the CRC patient pathway. Approximately half the QIs involved more than one discipline (52.7%). One-third of QIs related to surgery of primary CRC (31.2%). QIs on supportive care (6%) and neoadjuvant therapy (6%) were limited. In the Delphi Round 1, workshop participants (n = 12) assessed 93 QIs and produced consensus on retaining 49 QIs including six new QIs. In Round 2, survey participants (n = 44) rated QIs and prioritized a final 26 QIs across all domains of care and disciplines with a concordance level > 80%. Participants represented all MDT disciplines, predominantly surgical (32%), radiation (23%) and medical (20%) oncology, and nursing (18%), across six Australian states, with an even spread of experience level.

CONCLUSION

This study identified a large number of existing CRC QIs and prioritized the most clinically relevant QIs for use by Australian MDTs to measure and monitor their performance.

Optimal examined lymph node number for accurate staging and long-term survival in rectal cancer: a population-based study

BACKGROUND

Although the recommended minimal examined lymph node (ELN) number in rectal cancer (RC) is 12, this standard remains controversial because of insufficient evidence. We aimed to refine this definition by quantifying the relationship between ELN number, stage migration and long-term survival in RC.

METHODS

Data from a Chinese multi-institutional registry (2009-2018) and the Surveillance, Epidemiology, and End Results (SEER) database (2008-2017) on stages I-III resected RC were analysed to determine the relationship between ELN count, stage migration, and overall survival (OS) using multivariable models. The series of odds ratios (ORs) for negative-to-positive node stage migration and hazard ratios (HRs) for survival with more ELNs were fitted using a Locally Weighted Scatterplot Smoothing (LOWESS) smoother, and structural breakpoints were determined using the Chow test. The relationship between ELN and survival was evaluated on a continuous scale using restricted cubic splines (RCS).

RESULTS

The distribution of ELN count between the Chinese registry ( n =7694) and SEER database ( n =21 332) was similar. With increasing ELN count, both cohorts exhibited significant proportional increases from node-negative to node-positive disease (SEER, OR, 1.012, P <0.001; Chinese registry, OR, 1.016, P =0.014) and serial improvements in OS (SEER: HR, 0.982; Chinese registry: HR, 0.975; both P <0.001) after controlling for confounders. Cut-point analysis showed an optimal threshold ELN count of 15, which was validated in the two cohorts, with the ability to properly discriminate probabilities of survival.

CONCLUSIONS

A higher ELN count is associated with more precise nodal staging and better survival. Our results robustly conclude that 15 ELNs are the optimal cut-off point for evaluating the quality of lymph node examination and stratification of prognosis.

Advantages of ligating the rectum with gauze pad band in laparoscopic anterior resection of rectal cancer: a propensity score matched analysis

Purpose

It is difficult to maintain sufficient tension throughout laparoscopic anterior resection with total mesorectal excision, which causes a decline in surgical quality. We used a soft, inexpensive gauze pad band pulling the rectal tube to analyze the effect of surgery.

Methods

A gauze pad band was positioned at the proximal of the tumor, followed by fastening the rectal tube and ligating the rectum. 233 patients undergoing laparoscopic anterior resection for mid to low rectal cancer were enrolled between January 2018 and December 2020. After propensity score matching, 63 cases were selected in gauze pad band group and 126 cases were selected in traditional group. The two groups were compared in preoperative, intraoperative, and pathological characteristics.

Results

Compared to traditional group, the median operation duration (203 min vs. 233 min, p < 0.001) and the median intraoperative bleeding (48 ml vs. 67 ml, p < 0.001) were lesser in gauze pad band group. A higher percentage of one cartridge transection of rectum (36/63 vs. 51/126, p = 0.030), shorter length of cartridges used (6.88 ± 1.27 cm vs. 7.28 ± 1.25 cm, p = 0.040), and longer distal resection margin (2.74 ± 0.76 cm vs. 2.16 + 0.68 cm, p < 0.001) were found in the gauze pad band group. The completeness of total mesorectal excision (61/63 vs. 109/126, p = 0.022), harvested lymph nodes (19 vs. 17, p < 0.001) and positive lymph nodes (1 vs. 0, p = 0.046) were higher in gauze pad band group.

Conclusion

Ligation of the rectum with a gauze pad band allows for a reduction in operative time and intraoperative bleeding while increasing the rate of one cartridge transection. It also protected the quality of total mesorectal excision and membrane anatomy.

Trial registration: Not applicable.

Incidence and Mortality of Proximal and Distal Colorectal Cancer in Germany

BACKGROUND

The use of colonoscopy has increased and colorectal cancer (CRC) incidence has decreased after the introduction of screening colonoscopy in Germany. However, it remains unknown to what extent progress has been achieved in the prevention of cancer in the proximal colon, distal colon, and rectum.

METHODS

We analyzed trends in CRC incidence (2000-2016) and mortality (2000-2018) in Germany by sex, age, and tumor location.

RESULTS

The age-standardized incidence of CRC declined by 22.4% (from 65.3 to 50.7 per 100 000) in men and by 25.5% (from 42.7 to 31.8 per 100 000) in women. CRC mortality declined by 35.8% (from 29.6 to 19.0 per 100 000) in men and by 40.5% (19.0 to 11.3 per 100 000) in women. Despite demographic changes, the annual numbers of CRC cases and deaths still decreased from about 60 400 to 58 300 and from around 28 700 to 24 200, respectively. The decline in incidence was greatest in groups aged ≥ 55 years. While the incidence of cancer in the distal colon and rectum decreased by 34.5% and 26.2%, respectively, in men and by 41.0% and 27.9% in women, the incidence of proximal colon cancer remained stable in men and decreased by only 7.0% in women. However, a major shift towards earlier stages was observed for the proximal cancers.

CONCLUSION

The results support the assumption that the increased use of colo - noscopy has contributed to substantial reductions in the incidence of distal CRC incidence and the mortality from cancers in the entire colon and rectum.

Colorectal cancer incidence, mortality, and stage distribution in European countries in the colorectal cancer screening era: an international population-based study

BACKGROUND

Colorectal cancer screening programmes and uptake vary substantially across Europe. We aimed to compare changes over time in colorectal cancer incidence, mortality, and stage distribution in relation to colorectal cancer screening implementation in European countries.

METHODS

Data from nearly 3·1 million patients with colorectal cancer diagnosed from 2000 onwards (up to 2016 for most countries) were obtained from 21 European countries, and were used to analyse changes over time in age-standardised colorectal cancer incidence and stage distribution. The WHO mortality database was used to analyse changes over time in age-standardised colorectal cancer mortality over the same period for the 16 countries with nationwide data. Incidence rates were calculated for all sites of the colon and rectum combined, as well as the subsites proximal colon, distal colon, and rectum. Average annual percentage changes (AAPCs) in incidence and mortality were estimated and relevant patterns were descriptively analysed.

FINDINGS

In countries with long-standing programmes of screening colonoscopy and faecal tests (ie, Austria, the Czech Republic, and Germany), colorectal cancer incidence decreased substantially over time, with AAPCs ranging from -2·5% (95% CI -2·8 to -2·2) to -1·6% (-2·0 to -1·2) in men and from -2·4% (-2·7 to -2·1) to -1·3% (-1·7 to -0·9) in women. In countries where screening programmes were implemented during the study period, age-standardised colorectal cancer incidence either remained stable or increased up to the year screening was implemented. AAPCs for these countries ranged from -0·2% (95% CI -1·4 to 1·0) to 1·5% (1·1 to 1·8) in men and from -0·5% (-1·7 to 0·6) to 1·2% (0·8 to 1·5) in women. Where high screening coverage and uptake were rapidly achieved (ie, Denmark, the Netherlands, and Slovenia), age-standardised incidence rates initially increased but then subsequently decreased. Conversely, colorectal cancer incidence increased in most countries where no large-scale screening programmes were available (eg, Bulgaria, Estonia, Norway, and Ukraine), with AAPCs ranging from 0·3% (95% CI 0·1 to 0·5) to 1·9% (1·2 to 2·6) in men and from 0·6% (0·4 to 0·8) to 1·1% (0·8 to 1·4) in women. The largest decreases in colorectal cancer mortality were seen in countries with long-standing screening programmes.

INTERPRETATION

We observed divergent trends in colorectal cancer incidence, mortality, and stage distribution across European countries, which appear to be largely explained by different levels of colorectal cancer screening implementation.

FUNDING

German Cancer Aid (Deutsche Krebshilfe) and the German Federal Ministry of Education and Research.

Determining the Risk Factors Affecting on Death Due to Colorectal Cancer Progression: Survival Analysis in the Presence of Competing Risks

PURPOSE

In survival analysis, some patients may be at risk of more than one event, for example cancer-related death and cancer-unrelated death. In this case, if the aim of study becomes to assess the impact of risk factors on different causes of death, the competing risk model should be used rather than classical survival model. The aim of the present study is to determine the risk factors for related and unrelated mortality in patients with colorectal cancer using competing risk regression models.

METHODS

The present retrospective cohort study was carried out on 310 CRC patients. Death due to cancer progression was considered as the interest event, and death due to unrelated cancer was considered as a competing event. Two most popular methods, cause-specific and subdistribution hazard regression model, were used to determine the effect of covariates on incidence and cause-specific hazard. Data analysis was performed using R3.6.2 software and cmprsk and survival packages.

RESULTS

The mean (SD) of patients' age was 55.84 ± 13.2 years and 53.9% of them were male. BMI, T and N stage had a significant effect on both incidence and cause specific hazard of cancer-related death.

CONCLUSION

The results of this study showed that cancer-related death is strongly correlated with under-weight (BMI < 18.5) and advanced clinical stage of the disease in patients with colorectal cancer. So, in the presence of competing events, both types of regression hazard models should be applied to permit a full understanding of the impact of covariates on the incidence and the rate of occurrence of each outcome.

Role of lymph node yield and lymph node ratio in predicting outcomes in non-metastatic colorectal cancer

Background

Lymph node yield (LNY) of 12 or more in resection of colorectal cancer is recommended in current international guidelines. Although a low LNY (less than 12) is associated with poorer outcome in some studies, its prognostic value is unclear in patients with early‐stage colorectal or rectal cancer with a complete pathological response following neoadjuvant therapy. Lymph node ratio (LNR), which reflects the proportion of positive to total nodes obtained, may be more accurate in predicting outcome in stage III colorectal cancer. This study aimed to identify factors correlating with LNY and evaluate the prognostic role of LNY and LNR in colorectal cancer.

Methods

An observational study was performed on patients with colorectal cancer treated at three hospitals in Melbourne, Australia, from January 2010 to March 2016. Association of LNY and LNR with clinical variables was analysed using linear regression. Disease‐free (DFS) and overall (OS) survival were investigated with Cox regression and Kaplan–Meier survival analyses.

Results

Some 1585 resections were analysed. Median follow‐up was 27·1 (range 0·1–71) months. Median LNY was 16 (range 0–86), and was lower for rectal cancers, decreased with increasing age, and increased with increasing stage. High LNY (12 or more) was associated with better DFS in colorectal cancer. Subgroup analysis indicated that low LNY was associated with poorer DFS and OS in stage III colonic cancer, but had no effect on DFS and OS in rectal cancer (stages I–III). Higher LNR was predictive of poorer DFS and OS.

Conclusion

Low LNY (less than 12) was predictive of poor DFS in stage III colonic cancer, but was not a factor for stage I or II colonic disease or any rectal cancer. LNR was a predictive factor in DFS and OS in stage III colonic cancer, but influenced DFS only in rectal cancer.

Impact of adjuvant chemotherapy on patients with ypT0-2 ypN0 rectal cancer after neoadjuvant chemoradiation: a cohort study from a tertiary referral hospital

Background

To investigate the importance of adjuvant chemotherapy in locally advanced rectal cancer (≥ cT3 or N+) staged ypT0–2 ypN0 on final histological work-up after neoadjuvant chemoradiation and radical resection.

Methods

The clinical course of patients with rectal cancer and ypT0–2 ypN0 stages after neoadjuvant chemoradiation and radical resection was analyzed from 1999 to 2012. Patients were divided into two groups depending on whether adjuvant chemotherapy was administered or not. Overall survival, distant metastases, and local recurrence were compared between both groups.

Results

Fifty-four patients with adjuvant (ACT) and 50 patients without adjuvant chemotherapy (NACT) after neoadjuvant chemoradiation followed by radical resection for rectal cancer were included in the analysis. Mean follow-up was 68 ± 33.7 months. One patient without adjuvant chemotherapy and none in the ACT group developed a local recurrence. Five patients in the NACT group and three patients in the ACT group had distant recurrences. Median disease-free survival for all patients was 65.5 ± 34.5 months. Multivariate analysis showed adjuvant chemotherapy to be the most relevant factor for disease-free and overall survival. Patients staged ypT2 ypN0 showed a significantly better disease-free survival after application of adjuvant chemotherapy. Disease-free survival in ypT0–1 ypN0 patients showed no correlation to the administration of adjuvant chemotherapy.

Conclusion

Administration of adjuvant chemotherapy after neoadjuvant chemoradiation and radical resection in rectal cancer improved disease-free and overall survival of patients with ypT0–2 ypN0 tumor stages in our study. In particular, ypT2 ypN0 patients seem to profit from adjuvant treatment.

A nomogram improves AJCC stages for colorectal cancers by introducing CEA, modified lymph node ratio and negative lymph node count

Lymph node stages (pN stages) are primary contributors to survival heterogeneity of the 7^th AJCC staging system for colorectal cancer (CRC), indicating spaces for modifications. To implement the modifications, we selected eligible CRC patients from the Surveillance Epidemiology and End Results (SEER) database as participants in a training (n = 6675) and a test cohort (n = 6760), and verified tumor deposits to be metastatic lymph nodes to derive modified lymph node count (mLNC), lymph node ratio (mLNR), and positive lymph node count (mPLNC). After multivariate Cox regression analyses with forward stepwise elimination of the mLNC and mPLNC for the training cohort, a nomogram was constructed to predict overall survival (OS) via incorporating preoperative carcinoembryonic antigen, pT stages, negative lymph node count, mLNR and metastasis. Internal validations of the nomogram showed concordance indexes (c-index) of 0.750 (95% CI, 0.736-0.764) and 0.749 before and after corrections for overfitting. Serial performance evaluations indicated that the nomogram outperformed the AJCC stages (c-index = 0.725) with increased accuracy, net benefits, risk assessment ability, but comparable complexity and clinical validity. All the results were reproducible in the test cohort. In summary, the proposed nomogram may serve as an alternative to the AJCC stages. However, validations with longer follow-up periods are required.

Complete mesocolic excision and extended (D3) lymphadenectomy for colonic cancer: is it worth that extra effort? A review of the literature

PURPOSE

Recent interest in complete mesocolic excision (CME) with central vascular ligation (CVL) or extended (D3) lymphadenectomy (EL) for curative resection of colon cancer has been driven by published series from experienced practitioners showing excellent survival outcomes and low recurrence rates. In this article, we attempt to clarify the role of CME or EL in modern colorectal surgery.

METHODS

A narrative review of the evidence for CME and EL in the curative treatment of colon cancer.

RESULTS

The principal of CME surgery, similar to total mesorectal excision (TME) for rectal cancer, is the removal of all lymphatic, vascular, and neural tissue in the drainage area of the tumour in a complete mesocolic envelope with intact mesentery, peritoneum and encasing fascia. Extended (D3) lymphadenectomy (EL) is based on similar principles. Sound anatomical and oncological arguments are made to support the principles of removing the tumor contained within an intact mesocolic facial envelope together with an extended lymph node harvest. Excellent oncological outcomes with minimal morbidity and mortality have been reported. This has led to calls for the standardisation of surgery for colon cancer using CME. However, there is conflicting evidence regarding the prognostic benefit of greater lymph node harvests and the evidence for an oncological benefit of CME is limited by methodology flaws and several potential confounding factors.

CONCLUSIONS

Although there is a reasonable anatomical and oncological basis for these techniques, there are no randomised controlled trials from which to draw confident conclusions and there is insufficient consistent high quality evidence to recommend widespread adoption of CME.