Ethnicity influences lymph node resection in colon cancer

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.

Racial Disparities in the Management of Locoregional Colorectal Cancer

Racial disparities pervade nearly all aspects of management of locoregional colorectal cancer, including time to treatment, receipt of resection, adequacy of resection, postoperative complications, and receipt of neoadjuvant and adjuvant multimodality therapies. Disparate gaps in treatment translate into enduring effects on survivorship, recurrence, and mortality. Efforts to reduce these gaps in care must be undertaken on a multilevel basis and focus on modifiable factors that underlie racial disparity.

A reappraisal of lymph node dissection in colorectal cancer during primary surgical resection

Purpose

Controversy exists regarding the extent to which lymph node dissection (LND) should be performed for operable colorectal cancers (CRCs) during primary surgical resection. We reappraised the role of LND in CRCs.

Methods

Seventy-three CRC patients (mean age, 65.3 years; 43 males) undergoing primary surgical resection at Taipei Hospital, Ministry of Health and Welfare, Taiwan, within a 3-year period were retrospectively analyzed. Their pathological T/N/M statuses and cancer stages were defined according to the American Joint Committee on Cancer (AJCC) 8th edition staging system. The numbers of total dissected lymph nodes (TDLNs), positive dissected lymph nodes (PDLNs), and negative dissected lymph nodes (NDLNs) for each CRC patient were recorded in detail (TDLNs = PDLNs + NDLNs). Possible prognostic variables were evaluated.

Results

An advanced N status (N1/N2 vs. N0; HR, 5.749/17.677 vs. 1.000; p = 0.056/0.009) and M1 status (M1 vs. M0; HR, 7.517 vs. 1.000; p = 0.010) were independent variables for a poor prognosis. For all 73 CRC patients (p = 0.030), as well as T2 CRC patients (p = 0.061), those with > 15 TDLNs tended to have more PDLNs than those with ≤ 15 TDLNs. For 42 N(+) CRC patients (p = 0.007), as well as N2 CRC patients (p = 0.011), those with > 21 TDLNs tended to have more PDLNs than those with ≤ 21 TDLNs.

Conclusion

For CRC patients undergoing primary surgical resection, the number of TDLNs influences the accuracy of nodal staging. A minimum of 15 TDLNs is necessary for positive lymph nodes to be identified in CRC patients, and 21 TDLNs is sufficient for the severity of the N(+) status to be distinguished in N(+) CRC patients.

Alterations of lymph nodes evaluation after colon cancer resection: patient and tumor heterogeneity should be taken into consideration

Despite the adequacy of nodal evaluation was gradually improved for colon cancer (CC), rare attention has been paid for the effect of patient and tumor heterogeneity on nodal evaluation. We identified 109902 CC patients in stage I-III from Surveillance, Epidemiology, and End-Results (SEER) database during 2004-2013. The lymph nodes evaluations were separately assessed in different patient- and tumor-related features, including gender, age, T stage, histology, tumor differentiation, tumor size and tumor location. The 5-year cancer specific survival (CSS) was calculated with Kaplan-Meier method, log-rank tests were used to compare the differences of CSS in patients with ≥12 and <12 lymph nodes examined. Here, we identified features including gender, age, T stage, tumor differentiation, tumor size and location were independently associated with the median number of lymph node, the rate of ≥12 lymph nodes and the rate of node positivity of CC patients. We then divided CC patients into 29 subgroups according to different patient- and tumor-related features. The median number of lymph node presented a large variance from 12 to 24, the rate of ≥12 lymph nodes increased from 53.2% to 91.2% under the combined effect of patient and tumor heterogeneity. Furthermore, the positive association between increased lymph nodes count and improved survival couldn't be observed in 8261 CC patients with the effect of this heterogeneity. In conclusion, the tumor and patient heterogeneity lead to large alterations of nodal evaluation; we should pay more attention to this effect in clinical practice.

Non-surgical factors influencing lymph node yield in colon cancer

There are numerous factors which can affect the lymph node (LN) yield in colon cancer specimens. The aim of this paper was to identify both modifiable and non-modifiable factors that have been demonstrated to affect colonic resection specimen LN yield and to summarise the pertinent literature on these topics. A literature review of PubMed was performed to identify the potential factors which may influence the LN yield in colon cancer resection specimens. The terms used for the search were: LN, lymphadenectomy, LN yield, LN harvest, LN number, colon cancer and colorectal cancer. Both non-modifiable and modifiable factors were identified. The review identified fifteen non-surgical factors: (13 non-modifiable, 2 modifiable) which may influence LN yield. LN yield is frequently reduced in older, obese patients and those with male sex and increased in patients with right sided, large, and poorly differentiated tumours. Patient ethnicity and lower socioeconomic class may negatively influence LN yield. Pre-operative tumour tattooing appears to increase LN yield. There are many factors that potentially influence the LN yield, although the strength of the association between the two varies greatly. Perfecting oncological resection and pathological analysis remain the cornerstones to achieving good quality and quantity LN yields in patients with colon cancer.

Lymph nodes' evaluation in relation to colorectal cancer staging among African Americans

Background

Lymph nodes’ examination in colorectal cancer (CRC) resection specimens is an important determinant that aids in the accuracy of CRC staging and treatment outcomes. Current guidelines call for the examination of at least 12 lymph nodes (LN) in resected specimens in order to establish accurate staging.

Aim

To investigate lymph nodes’ examination protocol as it relates to accurate CRC staging.

Methods

We reviewed 216 African American CRC patients from 1996–2013 who underwent CRC resection and met inclusion criteria for this study. The number of retrieved LNs, length of resected specimens, tumor grade, stage, location, size and histology were examined.

Results

The cohort study was made of 49 % males, median age was 63 years and 45 % of patients were at stage III and IV. The median (IQR) number of examined LNs was 15 (10–22) and the rate of patients with more than 12 examined LNs was 64 %. There was a gradual increase in the percentage of patients with adequate number (>12) of examined LNs during the study period (from 60 % in 1996–2000 to 84 % in 2010–2013 period, P = 0.014). Adequate LNs resection was neither associated with shift of stage from II to III (P = 0.3) nor with the changes from stage IIIa to IIIc (P = 0.9). Metastatic LNs were observed in 8 % of samples with LNs (>12) vs. 13 % of samples with <12 examined LNs (P = 0.1). Patients that had pre-surgical treatment (chemotherapy and radiotherapy) before surgery had <12 LNs examined. There was also a trend of having more examined lymph nodes in large tumors.

Conclusions

Our study shows that there has been an increase in the number of lymph nodes examined in CRC resections since the advent of the current quality initiative. However this increase does not seem to affect the stage or percentage of metastatic lymph nodes’ detection in CRC patients.

Characterization of the Hispanic or latino population in health research: a systematic review

The size and diversity of the Hispanic population in the United States has dramatically increased, with vast implications for health research. We conducted a systematic review of the characterization of the Hispanic population in health research and described its implications. Relevant studies were identified by searches of PubMed, Embase Scopus, and Science/Social Sciences Citation Index from 2000 to 2011. 131 articles met criteria. 56% of the articles reported only "Hispanic" or "Latino" as the characteristic of the Hispanic research population while no other characteristics were reported. 29% of the articles reported language, 27% detailed country of origin and 2% provided the breakdown of race. There is great inconsistency in reported characteristics of Hispanics in health research. The lack of detailed characterization of this population ultimately creates roadblocks in translating evidence into practice when providing care to the large and increasingly diverse Hispanic population in the US.

Clinico-pathological factors influencing lymph node yield in colorectal cancer and impact on survival: analysis of New Zealand Cancer Registry data

BACKGROUND

Lymph node yield (LNY) and lymph node ratio (LNR) are recognized as independent prognostic factors in colorectal cancer (CRC).

OBJECTIVES

To examine the relationship between LNY and other clinico-pathological variables, and the prognostic value of LNY and LNR on patient survival in CRC.

METHODS

The clinico-pathological and survival data for patients diagnosed from January 2000 to July 2012 were retrieved from the New Zealand Cancer Registry. Multiple linear regression was used to identify clinico-pathological factors influencing LNY, and Cox regression was used to determine the association between LNY and LNR and patient survival.

RESULTS

14,646 patients were included in the study (mean age 70.3 years, 50.1% male). Mean LNY was 17.4. Younger age, right-sided disease, higher T stage, female sex and no neoadjuvant radiotherapy (rectal cancer) were all associated with higher LNY (P ≤ 0.001). Overall survival in Stage I-III disease increased with higher LNY (for LNY ≥ 12, HR = 0.67, 95% CI 0.64-0.72; P < 0.001). Survival in Stage III-IV disease was inversely related to LNR (HR = 0.56, 95% CI 0.51-0.62; P < 0.001).

CONCLUSION

LNY is influenced by patient age, site of disease and T stage. LNY (Stage I-II) and LNR (Stage III-IV) have independent prognostic value in CRC.

Colon cancer lymph node evaluation among military health system beneficiaries: an analysis by race/ethnicity

BACKGROUND

The number of lymph nodes examined during colon cancer surgery falls below nationally recommended guidelines in the general population, with Blacks and Hispanics less likely to have adequate nodal evaluation in comparison to Whites. The Department of Defense's (DoD) Military Health System (MHS) provides equal access to medical care for its beneficiaries, regardless of racial/ethnic background. This study aimed to investigate whether racial/ethnic treatment differences exist in the MHS, an equal-access medical care system.

METHODS

Linked data from the DoD cancer registry and administrative claims databases were used and included 2,155 colon cancer cases. Multivariate logistic regression assessed the association between race/ethnicity and the number of lymph nodes examined (<12 and ≥12) overall and for stratified analyses.

RESULTS

No overall racial/ethnic differences in the number of lymph nodes examined was identified. Further stratified analyses yielded similar results, except potential racial/ethnic differences were found among persons with poorly differentiated tumors, where non-Hispanic Blacks tended to be less likely to have ≥12 lymph nodes dissected (odds ratio 0.34; 95 % confidence interval 0.14-0.80; p = 0.01) compared with non-Hispanic Whites.

CONCLUSION

Racial/ethnic disparities in the number of lymph nodes evaluated among patients with colon cancer were not apparent in an equal-access healthcare system. However, among poorly differentiated tumors there might be racial/ethnic differences in nodal yield, suggesting the possible effects of factors other than access to healthcare.

Predictors of lymph node count in colorectal cancer resections: data from US nationwide prospective cohort studies

OBJECTIVE

To identify factors that influence the total and negative lymph node counts in colorectal cancer resection specimens independent of pathologists and surgeons.

DESIGN

We used multivariate negative binomial regression. Covariates included age, sex, body mass index, family history of colorectal carcinoma, year of diagnosis, hospital setting, tumor location, resected colorectal length (specimen length), tumor size, circumferential growth, TNM stage, lymphocytic reactions and other pathological features, and tumor molecular features (microsatellite instability, CpG island methylator phenotype, long interspersed nucleotide element 1 [LINE-1] methylation, and BRAF, KRAS, and PIK3CA mutations).

SETTING

Two US nationwide prospective cohort studies.

PATIENTS

Patients with rectal and colon cancer (N=918).

MAIN OUTCOME MEASURES

The negative and total node counts (continuous).

RESULTS

Specimen length, tumor size, ascending colon location, T3N0M0 stage, and year of diagnosis were positively associated with the negative node count (all P.002). Mutation of KRAS might also be positively associated with the negative node count (P=.03; borderline significance considering multiple hypothesis testing). Among node-negative (stages I and II) cases, specimen length, tumor size, and ascending colon location remained significantly associated with the node count (all P.002), and PIK3CA and KRAS mutations might also be positively associated (P=.03 and P=.049, respectively, with borderline significance).

CONCLUSIONS

This molecular pathological epidemiology study shows that specimen length, tumor size, tumor location, TNM stage, and year of diagnosis are operator-independent predictors of the lymph node count. These crucial variables should be examined in any future evaluation of the adequacy of lymph node harvest and nodal staging when devising individualized treatment plans for patients with colorectal cancer.

Racial and ethnic differences in lymph node examination after colon cancer resection do not completely explain disparities in mortality

BACKGROUND

In 1999, a multidisciplinary panel of experts in colorectal cancer reviewed the relevant medical literature and issued a consensus recommendation for a 12-lymph node (LN) minimum examination after resection for colon cancer. Some authors have shown racial/ethnic differences in receipt of this evidence-based care. To date, however, none has investigated the correlation between disparities in LN examination and disparities in outcomes after colon cancer treatment.

METHODS

This retrospective analysis used California Cancer Registry linked to California Office of Statewide Health Planning and Development discharge data (1996-2006). Chi-square analysis, logistic regression, and Cox proportional hazard models predicted disparities in receipt of an adequate examination and the effect of an inadequate exam on mortality and disparities. Patients with stage I and II colon cancers undergoing surgery in California were included; patients with stage III and IV disease were excluded.

RESULTS

A total of 37,911 records were analyzed. Adequate staging occurred in fewer than half of cases. An inadequate examination (<12 LNs) was associated with higher mortality rates. Hispanics had the lowest odds of receiving an adequate exam; however, blacks, not Hispanics, had the highest risk of mortality compared with whites. This disparity was not completely explained by inadequate LN examination.

CONCLUSIONS

Inadequate LN exam occurs often and is associated with increased mortality. There are disparities in receipt of the minimum exam, but this only explains a small part of the observed disparity in mortality. Improving the quality of LN examination alone is unlikely to correct colon cancer disparities.

Advanced fellowship training is associated with improved lymph node retrieval in colon cancer resections

BACKGROUND

Examination of at least 12 lymph nodes has been established as the standard of care for adequate staging of colon cancer. The purpose of this study was to determine whether surgeon fellowship training, patient body mass index (BMI), and surgical approach (open versus laparoscopic) are important factors associated with lymph node retrieval at an NCI/NCCN-designated center.

METHODS

We conducted a retrospective review of patients undergoing colectomy for colon cancer from 1994 to 2009. Patients who underwent right, left, and sigmoid colectomy by open or laparoscopic approaches were included. Lymph node retrieval and risk factors for inadequate nodal retrieval (<12 nodes) were analyzed.

RESULTS

A total of 371 patients were included. Lymph node retrieval was found to be significantly increased when surgeons had fellowship training compared with no advanced training (19.9 ± 10.6 versus 14.8 ± 10.6, P = 0.0007). Lymph node retrieval was found to be significantly decreased in obese patients (BMI ≥ 30) compared with non-obese patients (17.3 ± 10.0 versus 19.9 ± 11.5, P = 0.05). There was no significant difference between open and laparoscopic approaches. On multivariate analysis, lack of fellowship training, surgery performed prior to establishment of NCI guidelines for lymph node retrieval, and small tumor size were independent predictors of inadequate lymph node retrieval.

CONCLUSION

Advanced fellowship training of surgeons appears to be associated with higher lymph node retrieval and decreased risk of performing inadequate nodal retrieval. Small tumor size and surgery performed prior to establishment of the 12 lymph node benchmark were also associated with inadequate nodal retrieval.