Examined lymph node counts affected the staging and survival in cervical cancer: a retrospective study using the SEER and Chinese cohort

The aim of this study was to clarify the minimum number of examined lymph nodes (MNELNs) required to ensure the quality of lymph node detection and its impact on long-term survival in distal pancreatectomy for pancreatic ductal adenocarcinoma. Clinicopathological characteristics and survival data of patients with resectable pancreatic cancer who underwent distal pancreatectomy between 2004 and 2017 were collected from the Surveillance, Epidemiology, and End Results database. The associations between the number of examined lymph nodes (ELNs) and number of positive lymph nodes (PLNs), stage migration, and overall survival were investigated through adjusted multivariate models with locally weighted scatterplot smoothing smoothing fitting curves and estimation of the structural breakpoints. Kaplan-Meier survival analysis and X-tile software were used to identify the ideal cut-off value for ELNs. In total, 2610 consecutive patients who underwent distal pancreatectomy between 2004 and 2017 were included in this study. The optimal ELN count according to the associations between the number of ELNs and number of PLNs, odds ratio for stage migration, or hazard ratio for overall survival were 19, 17, and 19, respectively. Furthermore, the optimal division of ELN count for maximum overall survival was divided into three populations (ELN≤8, ELN 9-18, ELN≥19) based on X-tile software. A minimal count of 19 lymph nodes was demanded to guarantee the quality of lymph node examination in patients with distal pancreatectomy. Long-term survival could be delimited by MNELNs. A sufficient number of ELNs could improve the accuracy of cancer staging and reflect a better overall survival.

ObjectiveLung cancer is the leading cause of cancer-related mortality. Lymph node involvement remains a crucial prognostic factor in non-small cell lung cancer (NSCLC), and the TNM system is the current standard for staging. However, it mainly considers the anatomical location of lymph nodes, neglecting the significance of node count. Metrics like metastatic lymph node count and lymph node ratio (LNR) have been proposed as more accurate predictors.MethodsWe used data from the SEER 17 Registry Database (2010–2019), including 52,790 NSCLC patients who underwent lobectomy or pneumonectomy, with at least one lymph node examined. Primary outcomes were overall survival (OS) and cancer-specific survival (CSS). Cox regression models assessed the prognostic value of negative lymph node (NLN) count, number of positive lymph node (NPLN), and LNR, with cut-points determined using X-tile software. Model performance was evaluated by the Akaike information criterion (AIC).ResultsThe Cox proportional hazards model analysis revealed that NLN, NPLN, and LNR are independent prognostic factors for OS and LCSS (P < 0.0001). Higher NLN counts were associated with better survival (HR = 0.79, 95% CI = 0.76–0.83, P < 0.0001), while higher NPLN (HR = 2.19, 95% CI = 1.79–2.67, P < 0.0001) and LNR (HR = 1.64, 95% CI = 1.79–2.67, P < 0.0001) values indicated worse outcomes. Kaplan-Meier curves for all three groups (NLN, NPLN, LNR) demonstrated clear stratification (P < 0.0001). The NLN-based model (60,066.5502) exhibited the strongest predictive performance, followed by the NPLN (60,508.8957) and LNR models (60,349.4583), although the differences in AIC were minimal.ConclusionsNLN count, NPLN, and LNR were all identified as independent prognostic indicators in patients with NSCLC. Among these, the predictive model based on NLN demonstrated a marginally superior prognostic value compared to NPLN, with NPLN outperforming the LNR model. Notably, higher NLN counts, along with lower NPLN and LNR values, were consistently associated with improved survival outcomes. The relationship between these prognostic markers and NSCLC survival warrants further validation through prospective studies.

Lymph node counts are a measure of quality assurance and are associated with prognosis for numerous malignancies. To date, investigations of lymph node counts in testis cancer are lacking. By using the Memorial Sloan-Kettering Testis Cancer database, the authors identified 255 patients who underwent primary retroperitoneal lymph node dissection (RPLND) for nonseminomatous germ cell tumors (NSGCTs) between 1999 and 2008. Features that were associated with lymph node counts, positive lymph nodes, the number of positive lymph nodes, and the risk of positive contralateral lymph nodes were evaluated with regression models. The median (interquartile range [IQR]) total lymph node count was 38 lymph nodes (IQR, 27-53 total lymph nodes), and it was 48 (IQR, 34-61 total lymph nodes) during the most recent 5 years. Features that were associated with higher lymph node count on multivariate analysis included high-volume surgeon (P = .034), clinical stage (P = .036), and more recent year of surgery (P < .001); whereas pathologist was not associated significantly with lymph node count (P = .3). Clinical stage (P < .001) and total lymph node count (P = .045) were associated significantly with finding positive lymph nodes on multivariate analysis. The probability of finding positive lymph nodes was 23%, 23%, 31%, and 48% if the total lymph node count was <21, 21 to 40, 41 to 60, and >60, respectively. With a median follow-up of 3 years, all patients remained alive, and 16 patients developed recurrent disease, although no patients developed recurrent disease in the paracaval, interaortocaval, para-aortic, or iliac regions. The current results suggested that >40 lymph nodes removed at RPLND improve the diagnostic efficacy of the operation. The authors believe that these results will be useful for future trials comparing RPLNDs, especially when assessing the adequacy of lymph node dissection.

To the editor, The TNM staging system is currently our best prognostic tool in lung cancer, but poor application of this tool is an increasingly recognized worldwide problem in thoracic oncology (1-3). The main deficiency appears to be suboptimal pathologic lymph node staging, an important problem because lymph node metastasis is the gravest prognostic feature in patients without distant metastasis, who are candidates for curative surgical intervention. The statistics are startling: 17% of lung cancer resections in the US have no lymph nodes examined (pNX) (4), 40-50% of all resections (67% of resections with ‘pN0/pN1’ disease) have no mediastinal lymph nodes examined (5,6), 12% of patients have no hilar/intrapulmonary (N1) lymph nodes examined (7), the median total lymph node count is only 4-5 and less than 15% of patients have more than 10 lymph nodes examined (8-10). Patients with pNX resections are usually managed post-operatively as though known to be pN0, but have a 5-year survival rate closer to patients with pN1 (4). Patients with ‘pN0/pN1 disease’ and no mediastinal lymph nodes examined have an 11% excess lung cancer-specific mortality risk compared to identical stage patients with one or more examined mediastinal lymph node (6). Multiple studies reveal a sequential improvement in survival of patients with ‘pN0’ disease with examination of more lymph nodes. All these studies suggest the minimum required number of lymph nodes is greater than 10 (8-10). Our recent analysis of the pN0 population in the US Surveillance, Epidemiology, and End Results database suggests that the lowest mortality risk occurs in those with 18-20 lymph nodes (Osarogiagbon and Yu, unpublished data). Even in patients with lymph node metastasis, several groups, analyzing different databases from around the world, have consistently reported the direct association between the number of lymph node metastasis and survival (11-15). Indeed, there is an ongoing debate about whether or not the number of lymph nodes with metastasis or the ratio of lymph nodes with and without metastasis may be a more powerful prognostic factor than the anatomic location of lymph node metastasis, which is the sole basis of the current AJCC/UICC lymph node staging system (13,16). What is going on here? We believe the problem is the risk of sampling error and stage mis-attribution (‘the Will Rogers phenomenon’) with incomplete nodal examination. It seems logical that when we do not examine lymph nodes, we will not detect lymph node metastasis. In recognition of this, the Association of Directors of Anatomic and Surgical Pathology made the recommendation to ‘submit every node for microscopic examination’ (17). The problem of poor lymph node examination can be conceptually localized to three sites: events in the operating room, the communication between the operating room and pathology laboratory, and events in the pathology laboratory. Examination of hilar (station 10) and mediastinal (stations 2-9) lymph nodes requires surgical harvest of these nodes, without which pathology examination is impossible; correct identification of lymph node specimens and secure transfer from the operating room to the pathology laboratory are mandatory, loss of specimens in transit or poor identification of the provenance of specimens will impair the pathology examination; finally, proper pathology department processes to ensure thorough examination of submitted specimens is vital to achievement of optimal pathologic staging. A breakdown in any of these links in the chain of events will severely impair proper examination. Successful correction of the problem of poor nodal staging requires understanding of the extent to which problems arise at each of these sites, in order to logically design and implement corrective interventions. For example, it can be argued that no matter what transpires in the operating room and in transit from there to the pathology laboratory, proper pathology examination protocols should assure that pNX resections are rare in patients who undergo lobectomy (or more extensive) resections in the absence of neo-adjuvant therapy, because lymph nodes from stations 11 to 14 are present in the resected lung specimen. Against this background, we evaluated current routine pathology examination processes. We tested our hypothesis that low N1 lymph node counts indicate non-examination of a significant proportion of lymph nodes present within the lung resection specimen by fastidiously re-examining discarded lung resection specimens after completion of the official pathology examination. In calculating our sample size for this project, we estimated that a 20% increase in number of lymph nodes examined, a 10% increase in number of lymph node metastasis detected, and a change in pathologic stage in 5% of patients would all be clinically meaningful. What did we find? Lymph node retrieval increased by 137%, detection of N1 lymph nodes with metastasis increased by 165%, pathologic up-staging in 11% of patients, and missed lymph node metastasis in 12% of patients with ‘pN0’. Clearly, the recommendation that all lymph nodes in the resection specimen should be examined is not being followed. Therefore, we suggested that current pathology examination protocols need to be improved. The editorial by Brzezniak and Giaccone ‘Intrapulmonary lymph node retrieval: unclear benefit for aggressive pathologic dissection’ summarized our results succinctly and accurately, except for a couple of points (18). As shown in Table 1, which is taken from the reference publication (19), majority of the discarded lymph nodes retrieved by our re-dissection protocol, and majority of the retrieved lymph nodes with metastasis, were from the hilar/interlobar zone (mostly station 11). We found relatively few lymph nodes, with or without metastasis, in the peripheral zones (stations 12-14). Therefore, the excursus about the different survival implications of peripheral lymph node metastasis and hilar/interlobar (stations 10-11) metastasis, entirely supports our concern that the missed lymph node metastasis we demonstrated will probably have a significant survival impact. Secondly, although we compared the dissection time of sequential batches of 10 re-dissections in our analysis of the evolution of efficiency of the special dissection protocol, the specimens were not examined in batches of 10, but rather as they became eligible for examination after completion of the routine pathology examination over the study duration from July 2010 to August 2011. Furthermore, the dissections were all performed by a pathology technician working in a community hospital. Therefore, we believe the improvements are feasible in any institution engaged in the business of providing surgical and pathology services to patients with lung cancer. Table 1 Comparison of N1 lymph node examination and metastasis detection rates We agree that our study was not designed to directly examine the impact on survival. Clearly, it will take a prospective comparative effectiveness study, with cost-effectiveness components, to quantify the impact and cost of this corrective intervention. However, the impact of our findings on the quality and outcomes of care for lung cancer patients is potentially great. We are developing a prospective institutional randomization study of a simplified modification of this pathology dissection protocol, in combination with an intra-operative quality improvement intervention in which a specially designed surgical specimen collection kit would be used to help surgeons perform a standardized systematic lymph node dissection (20). This study, titled Strategies to Improve Lymph node Examination in Non-small cell lung Tumors (SILENT) is currently in development through the US clinical research cooperative group SWOG. It will address the pathologic upstaging rate as its primary endpoint and relapse-free survival as one of a number of secondary endpoints. It should provide definitive information on the opportunity to improve patient survival with these two relatively simple corrective interventions. However, until then, it is important to recognize that absence of proof is not proof of absence of a survival benefit from these simple, commonsense interventions.

Objective Lymphadenectomy is a fundamental procedure in gynecologic oncology, but there is an ongoing debate concerning its indication in endometrial cancer. Lymph node (LN) count has been used as a surrogate marker for quality of staging in endometrial cancer. Because of variability in reported LN counts in the literature and within our practice, we aimed to better understand the factors that influence the final LN count in endometrial cancer staging. Methods We conducted a retrospective case study of patients with endometrial cancer who underwent surgical staging at our institution between April 1, 2005, and February 3, 2007. Linear regression was used to determine the association between LN count and a series of predictor variables. Results Of 131 patients, 100 patients (76%) had stage I disease and 9 patients (7%) had LN metastasis. The mean (SD) LN count was 9.5 (7.8). We found no significant difference in LN count according to age, tumor histology, stage, or surgeon. Lymph node count decreased by 1 for each 5-unit (kg/m2) increase in body mass index (coefficient, −0.2; P = 0.038). The strongest predictor associated with LN count was the pathologist, with 2 groups of pathologists counting an average 7.7 (P Conclusions Our study confirms that LN count varies markedly. Although not the only contributor, the pathologist, we found, was the most significant determining factor in LN count variation. This highlights the need to exercise caution when drawing conclusions from published LN counts in endometrial cancer research.

Objectives: The optimal number of the examined lymph nodes (ELNs) in pancreaticoduodenectomy for pancreatic ductal adenocarcinoma has been widely studied. However, the accuracy of nodal positivity for the patients with inadequate lymphadenectomy is still unclear. The purpose of our study was to determine the accuracy of the number of positive nodes reported for patients with 1–3 positive nodes and the probability that 4 or more nodes could be positive along with tumor size and number of nodes examined.Methods: We obtained data on patients who underwent pancreaticoduodenectomy for resectable pancreatic ductal adenocarcinoma diagnosed during 2004–2013 from the US Surveillance, Epidemiology, and End Results registry. An mathematical model based on Hypergeometric Distribution and Bayes' Theorem was used to estimate the accuracy.Results: Among the 9,945 patients, 55.6% underwent inadequate lymphadenectomy. Of them, 1,842, 6,049, and 2,054 had T1, T2, and T3 stage disease, respectively. The accuracy of the number of observed positive nodes increased as the number of ELNs increased and the tumor size decreased. To rule out the possibility of N2 stage (4 and more positive nodes), there should be at least 13 ELNs for the patients with 1 observed positive lymph node and 14 for the patients with 2.Conclusion: Inadequate lymphadenectomy could result in underestimation of the N stage, and this would have adverse impact on recurrence, efficacy of postoperative treatment, and even overall survival. This model combined with the observed positive lymph nodes, the number of ELNs, and tumor size could provide a more accurate determination of nodal positivity of these patients.

Background: Neoadjuvant chemotherapy (NACT) is increasingly used for axillary downstaging in clinically node-positive breast cancer patients, and a considerable proportion achieves axillary pathological complete response (ax-pCR). After NACT, axillary staging can be done by targeted axillary dissection (TAD). In case of metastases at TAD, axillary lymph node dissection (ALND) is offered regardless of metastases size. This contrasts primary surgery, where small sentinel node metastases (ypN0(i) and ypN1mi) and ≤2 positive sentinel nodes do not confer ALND, although a proportion of patients with small metastases have additional metastatic lymph nodes (LNs) in the axilla. So far, the residual metastatic burden in the axilla when TAD LNs are positive after NACT is unknown. If subgroups of patients with low residual metastatic burden in the axilla (non-TAD LNs) could be identified, these subgroups may be offered de-escalated axillary treatment. Therefore, we investigated the risk of residual metastatic burden in the axilla when the TAD LNs harbored metastases. Methods: We retrospectively retrieved DBCG data on patients staged by TAD after NACT in Denmark between 1.1.2016-31.8.2021. We registered: age, breast biopsy date, type of surgery, type of axillary surgery, count of LNs, sentinel nodes, and marked lymph nodes with and without metastases, including metastasis size, breast tumor histology and receptor subtype, breast tumor size at diagnosis and in the surgical specimen, malignancy grade and type of neoadjuvant treatment. We excluded patients with inflammatory breast cancer, &amp;lt; 4/&amp;gt;8 cycles of NACT, or a non-standard NACT regimen. The primary outcome was risk factors for having high ( &amp;gt;3), low (1-3), or no residual metastatic burden in the axilla when the TAD LNs harbored metastases. We modeled risk factors for both high and low residual metastatic burden in the axilla using multivariable logistic regression and constructed risk models based on the regression coefficients. Results: We identified 1626 patients receiving NACT and TAD in the inclusion period. After excluding ineligible patients and patients who achieved ax-pCR with no subsequent ALND (46%), the study included 383 patients with positive LNs at TAD for further analysis: thereof 188, 127, and 68 with 0, 1-3 and &amp;gt;3 positive non-TAD LNs, respectively. In the adjusted logistic regression analysis, we found that breast pCR (OR= 0.06, 95% CI &amp;lt; .01-0.41, p &amp;lt; .001) and a low proportion of positive TAD LNs (0-66% vs &amp;gt;66%) (OR=0.32, 95% CI 0.17-0.58, p = &amp;lt; .001) were associated with low risk of high residual metastatic burden in the axilla. Patients with one or both low-risk factors present had an 8% (14 of 176 patients) risk of high residual metastatic burden in the axilla. The predictive value of the model for having &amp;lt; 3 non-TAD LN metastases was 92%. When analyzing the 315 patients with ≤3 positive non-TAD LNs, the adjusted logistic regression analysis of 1-3 vs 0 positive non-TAD LNs showed that ypN0(i) in the TAD LN (OR=0.14, 95% CI 0.04-0.53, p = 0.002), small tumor size at diagnosis (20-49 mm vs ≥ 50 mm) (OR = 0.29, 95% CI 0.14-0.60, p = 0.002), breast pCR (OR= 0.38, 95% CI 0.15-0.98, p = 0.04) and low proportion of positive TAD LNs (33-66% vs &amp;gt;66%) (OR= 0.46, 95% CI 0.27-0.77, p = 0.01) were associated with no residual metastases in the axilla. Using these risk factors, 19% (11/58) of the patients in the lowest risk quartile had further metastatic spread to the axilla. Conclusion: Based on an extensive breast cancer registry, we find that breast pCR, low proportion of positive TAD LNs, small metastases, and small tumor size are associated with low risk of residual metastatic LNs in the axilla when the TAD LNs are positive after NACT. With these risk factors, we propose two models to identify patients with low non-TAD residual metastatic burden and patients with a high likelihood of no further metastases. The models can guide breast surgeons in de-escalating axillary treatment in these groups. Citation Format: Frederikke Munck, Maj-Britt Jensen, Ilse Vejborg, Maria Gerlach, Maja Maraldo, Niels Kroman, Tove Tvedskov. Predicting Additional Axillary Metastases in Breast Cancer Patients with Positive Targeted Axillary Dissection Lymph Nodes after Neoadjuvant Treatment [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-22-07.

The purpose of this study was to evaluate the impact of the negative lymph node (NLN) count on the prognostic prediction of the ratio between positive and examined lymph nodes (RML) in gastric cancer after curative resection. The positive and negative node counts were determined for 456 patients who underwent curative resection for gastric cancer. Overall survival was examined according to clinicopathologic variables. The correlation between the NLN count and the aforementioned best variable for prediction the disease-specific overall survival was examined. The NLN count cutoffs were designed as 0-9, 10-14, and > or =15, with the 5-year survival rate 4.1, 30.7, and 74.8%, respectively. RML of 98 patients who had an NLN count of nine or fewer was > or =40%. The median survival of these patients was 12 months. Of 88 patients who had 10 to 14 NLN count, 7 had 74-month median survival with 0.1-10% RML, 52 had 47-month median survival with 10.1-40% RML, and 29 had 22-month median survival with >40% RML. Of 270 patients who had > or =15 NLN count, 157 had 114-month median survival without positive nodes, 62 had 98-month median survival with 0.1-10% RML, 45 had 40-month median survival with 10.1-40% RML, and 6 had 14-month median survival with >40% RML. The NLN count is a key factor for improvement of survival prediction of RML in gastric cancer.

PurposeWe investigated the correlation between the number of examined lymph nodes (ELNs) and correct staging and long-term survival in non–small-cell lung cancer (NSCLC) by using large databases and determined the minimal threshold for the ELN count.MethodsData from a Chinese multi-institutional registry and the US SEER database on stage I to IIIA resected NSCLC (2001 to 2008) were analyzed for the relationship between the ELN count and stage migration and overall survival (OS) by using multivariable models. The series of the mean positive LNs, odds ratios (ORs), and hazard ratios (HRs) were fitted with a LOWESS smoother, and the structural break points were determined by Chow test. The selected cut point was validated with the SEER 2009 cohort.ResultsAlthough the distribution of ELN count differed between the Chinese registry (n = 5,706) and the SEER database (n = 38,806; median, 15 versus seven, respectively), both cohorts exhibited significantly proportional increases from N0 to N1 and N2 disease (SEER OR, 1.038; China OR, 1.012; both P < .001) and serial improvements in OS (N0 disease: SEER HR, 0.986; China HR, 0.981; both P < .001; N1 and N2 disease: SEER HR, 0.989; China HR, 0.984; both P < .001) as the ELN count increased after controlling for confounders. Cut point analysis showed a threshold ELN count of 16 in patients with declared node-negative disease, which were examined in the derivation cohorts (SEER 2001 to 2008 HR, 0.830; China HR, 0.738) and validated in the SEER 2009 cohort (HR, 0.837).ConclusionA greater number of ELNs is associated with more-accurate node staging and better long-term survival of resected NSCLC. We recommend 16 ELNs as the cut point for evaluating the quality of LN examination or prognostic stratification postoperatively for patients with declared node-negative disease.

Introduction and objectives: The lymph node (LN) count and node positivity are important prognostic indicators in primary colorectal adenocarcinomas. The LN count shows significant variations with adjuvant therapy (AT). This study compares the LN status of AT-given (AT-G) and AT-not-given (AT-NG) left colectomy specimens.Methodology: This retrospective study included all left colectomy specimens reported at the Department of Pathology, University of Peradeniya, for one year from October 2021. Clinicopathological data were extracted from the archives. The data were analyzed with demographic factors and neoadjuvant status.Results: There were twenty-five (25) left colectomy specimens; 48% (n=12) were AT-G and 52% (n=13) were AT-NG. The male-to-female ratio was 2.3:1 (n=9:4) and 1:1 (n=5:5) in the AT-G and AT-NG groups, respectively. Patients’ age range was 42-83 years, and the majority were between 60-69 years in both groups. The AT-G group had &gt;12 LNs in 46% (n=6) of cases and a mean LN count of 12. The AT-NG group had &gt;12 LNs in 83% (n=10) of specimens, and a mean LN count of 19. LN positivity was 0% in 84% of the AT-G category and 53% in the AT-NG category.Discussion and conclusion: The total cases were relatively similar in both groups, but more men received AT than women. The mean LN count and the LN positivity in the AT-G group were lower than that of the AT-NG group. The majority of the cases in the AT-G group were classified under the ypN0 category.

THE CENTRAL TENETS OF CANCER STAGING ARE accuracy, prognostic significance, and therapeutic implications. For solid tumors, accurate cancer staging is highly dependent on the evaluation of sufficient numbers of regional lymph nodes to ensure that positive nodes, if present, will be detected. Positive nodes are markers for disease spread and therefore for patients with a higher risk of recurrence and metastatic disease. Staging influences treatment decisions because adjuvant chemotherapy for patients with positive lymph node findings has been shown to be efficacious in improving disease-free and overall survival. Observational studies have suggested that very thorough lymph node searches are warranted because of this relationship between lymph node positivity, the subsequent decision to administer chemotherapy, and improved survival. Consequently, retrieval and examination of at least 12 lymph nodes during colon cancer resection has been established as a quality indicator for colon cancer care. With increasing demand for higher-quality cancer ca re , qua l i t y ind i ca to r s se rve a s benchmarks by which physicians, payers, and policy makers can measure and improve processes of care and patient outcomes. However, several recent reports could not link high-profile surgical performance measures with intended improvements in outcomes. For instance, improved adherence to the Surgical Care Improvement Project infection prevention measures at US Department of Veterans Affairs (VA) hospitals was not associated with lower surgical site infection rates at the patient and hospital levels. In another VA hospital–based study, investigators found deleterious effects from implementation of evidence-based processes of care. Adherence to a “bundle” of best practices for prevention paradoxically led to a 2.5-fold higher risk of superficial skin infection compared with standard practices. Adherence to quality indicators may not improve patient outcomes and, in fact, may result in unintended harm. In this issue of JAMA, Parsons and colleagues report on the association between lymph node counts for colon cancer, node positivity, and cancer survival. Using data from the Surveillance, Epidemiology, and End Results (SEER) program, the authors examined the relationship between the increasing number of lymph nodes evaluated and findings of node positivity following resection for colon cancer. Over a 20-year period, there has been a significant increase in the proportion of patients with at least 12 lymph nodes evaluated. During 1988-1990, 35% of patients had 12 or more nodes examined per specimen, with an increase to 74% by 2006-2008. The total lymph node count also increased with time, with 20 or more nodes evaluated in 12% of patients in 1988-1990 and in 34% of patients at the end of the study period. Despite searching for and finding many more lymph nodes in resected colon specimens, the proportion of patients with node-positive cancers during this time was unchanged, ranging from 40% to 42%. Although there was no significant association between higher numbers of nodes examined and detection of more node-positive cancers, higher lymph node counts were significantly associated with improved survival. A previous SEER study of a cohort of patients with colon and rectal cancer demonstrated a trend of increasing lymph node counts, with the overall rate of more than 12 lymph nodes counted increasing from 32% among patients in 1988 to 44% in 2001. The current study by Parsons et al extends this analysis and demonstrates a continued increase in lymph node retrieval with time. The secular increase in number of lymph nodes examined likely resulted from the perception that exami-

Determinants of lymph node count in endometrial cancer surgical staging.

Background: Lymph node (LN) positivity is a prognostic indicator in patients with colon cancer regardless of age, and age is an important parameter that impacts therapeutic recommendations. But little is known about the impact of age on LN positivity in patients with colon cancer.Methods: We analyzed 257,334 patients with colon cancer diagnosed from SEER database. Logistic regression was used to examine the association of age and LN positivity. Poisson regression was used to evaluate whether age was associated with the number of positive LNs.Results: LN positivity was inversely associated with age (P < .001 for each T stage). Age was predictive of LN positivity after adjustment for number of LNs examined and other covariates (P < .001 for each T stage). Adjusted odds ratios (ORs) for LN positivity for age 20 to 39 vs 80+ were 3.06 for stage T1 (95 % CI, 2.09 to 4.48), 2.46 for stage T2 (95 % CI, 2.00 to 3.02), 1.77 for stage T3 (95 % CI, 1.62 to 1.93), and 1.68 for stage T4 (1.51 to 1.86). Young age was a significant predictor of an increased number of positive LNs (P < .005 for each T stage).Conclusion: Young age at diagnosis is associated with an increased risk of LN positivity. LN examination and resection could aid younger patients more with detection and removal of metastasis. Guidelines that define postdetection interventions may be needed to limit the overtreatment of older patients, who may be vulnerable to unnecessary tests and treatments.

Are RTOG Para-aortic Contouring Guidelines for Pancreatic Neoplasm Applicable to Other Malignancies?: Assessment of Nodal Distribution in Gynecological Malignancies

Mapping Location of PET Positive Lymph Nodes in Cervical Cancer