Impact Of Margin Status Research Articles

ASO Visual Abstract: Impact of Margin Status on Local Recurrence in Patients with Breast Cancer Undergoing Breast-Conserving Surgery After Neoadjuvant Chemotherapy: A Retrospective Multi-Institutional Cohort Study.

ASO Visual Abstract: Impact of Margin Status on Local Recurrence in Patients with Breast Cancer Undergoing Breast-Conserving Surgery After Neoadjuvant Chemotherapy: A Retrospective Multi-Institutional Cohort Study.

Impact of Margin Status on Local Recurrence in Patients with Breast Cancer Undergoing Breast-Conserving Surgery After Neoadjuvant Chemotherapy: A Retrospective Multi-Institutional Cohort Study.

Questions have been raised as to an increased risk of local recurrence with breast-conserving surgery (BCS) post NAC highlighting the uncertainty around optimal margin width in this patient population. We examined the association between margin status and local recurrence-free survival (LRFS) in patients who underwent BCS following NAC. We performed a retrospective cohort study of adult female patients with stage I-III breast cancer who underwent NAC followed by BCS between 2012 and 2021 at two cancer centers. Margins were categorized as "close" if they were < 1 mm. The full cohort included 544 patients with a median age of 53 years (interquartile range [IQR] 44-64). Pathologic complete response (pCR) was achieved in 41.2% of the overall cohort (n = 224). Of the 320 with residual disease, 29.4% (n = 94) had at least one close margin, and 10.9% (n = 35) had ≥2 close margins. Median follow-up was 55 months (IQR 32-83); 4.8% had an ipsilateral breast recurrence (n = 26). Patients with pCR had a higher 5-year LRFS than those with residual disease (98.0% vs. 91.6%, p = 0.02). There was no difference in 5-year LRFS between the margin categories (clear vs. 1 close margin vs. ≥2 close margins) in those with residual disease (92.2% vs. 88.9% vs. 92.9%) (p = 0.78). In patients undergoing BCS post-NAC, those who achieved pCR had a significantly higher LRFS compared with those with residual disease at the time of surgery, but LRFS was not associated with margin width nor the number of close margins.

Resection status and margin control in intraoperative frozen sectioning analysis of oral squamous cell carcinoma

PurposeIntraoperative frozen section analysis (IFSA) is a well-established procedure for determining the intraoperative soft tissue resection status in patients with oral squamous cell carcinoma (OSCC). Margin status is a major predictor of the patient´s outcome, histologically free margins of ≥ 5 mm are demanded. This study evaluates the accuracy of IFSA, the impact of margin status and the impact of intraoperative margin revision on disease-free survival (DFS) and overall survival (OS).MethodsThis retrospective study included 213 patients with OSCC. IFSA results were compared with definitive histopathological reports, Kaplan–Meier analysis was performed. Cut-off values were calculated for resection margins considering known risk factors.ResultsIFSA showed positive margins in 8 cases (3.8%). Kaplan–Meier analysis revealed no significant differences for OS or DFS if R0-status was achieved by initial resection or immediate re-resection.Final histopathological evaluation revealed false-positive IFSA in 3/8 cases (37.5%) and false-negative IFSA in 1/205 cases (0.5%). Sensitivity was 83.3% and specificity was 98.6%.Analysis of optimal cut-off values showed no general need for larger resection margins in patients with risk factors. Cut-off values were slightly higher for patients with the risk factor alcohol consumption (7 mm for OS and DFS) or pN + ECS- disease (7 mm for DFS). Optimal cut-off values for tumour-margin-distance were around 6 mm.ConclusionIFSA provides a valuable assessment method for intraoperative soft tissue resection margins. Risk factors seemingly do not significantly influence the extent of tumour resection.

Multidisciplinary management in the treatment of intrahepatic cholangiocarcinoma.

Multidisciplinary management in the treatment of intrahepatic cholangiocarcinoma.

Higher Tumor Burden Status Dictates the Impact of Surgical Margin Status on Overall Survival in Patients Undergoing Resection of Intrahepatic Cholangiocarcinoma.

The present study aimed to examine the prognostic significance of margin status following hepatectomy of intrahepatic cholangiocarcinoma (ICC) relative to overall tumor burden and nodal status. Patients who underwent curative-intent surgery for ICC between 1990 and 2017 were included from a multi-institutional database. The impact of margin status and width on overall survival (OS) was examined relative to TBS and preoperative nodal status. Among 1105 patients with ICC who underwent resection, median tumor burden score (TBS) was 6.1 (IQR 4.2-8.8) and 218 (19.7%) patients had N1 disease. More than one in eight patients had an R1 surgical margin (n = 154, 13.9%). Among patients with low or medium TBS, an increasing margin width was associated with an incrementally improved 5-year OS (R1 31.9% vs. 1-3 mm 38.5% vs. 3-10 mm 48.0% vs. ≥ 10 mm 52.3%). In contrast, among patients with a high TBS, margin width was not associated with better survival (R1 28.9% vs. 1-3 mm 22.8% vs. 3-10 mm 29.6% vs. ≥ 10 mm 13.7%). In addition, surgical margin status did not impact survival with cutoffs of TBS 7 or greater. Furthermore, patients with low or medium TBS and preoperative negative lymph nodes derived a survival benefit from an R0 resection (R1 resection, HR 2.15, 95% CI 1.35-3.44, p = 0.001). In contrast, margin status was not associated with prognosis among patients with a high TBS and preoperative positive/suspicious lymph nodes (R1 resection, HR 1.34, 95% CI 0.58-3.11, p = 0.50). R0 resection and wider margin resection resulted in improved outcomes in patients with low tumor burden; however, the survival benefit of negative margin status disappeared in patients with underlying poor tumor biology.

Impact of margin status on outcomes after endoscopic resection of well-differentiated duodenal neuroendocrine tumors

Duodenal neuroendocrine tumors (DNETs) are known to have low metastatic potential and follow an indolent course. Although DNETs<1 cm in size are amenable to endoscopic resection, little is known about the long-term outcomes and recurrence rates of this approach. Sixty-three patients with DNETs from 3 centers were retrospectively studied from 2003 to 2018. We analyzed their resection modality (EMR, snare polypectomy, or forceps polypectomy), margin status, risk factors for recurrence, recurrence rate, and endoscopic surveillance patterns. Of the 63 patients who underwent endoscopic resection, 13 (20.6%) had recurrence. The presence of R1 margins was found to be a statistically significant risk factor for recurrence (P= .048). Mean surveillance time for all DNETs was 2.8 ± 2.6 years. Ninety-two percent of recurrences were detected within 3 years of resection. Our data suggest that the main predictor of recurrence in low-grade DNETs<1.0 cm is the presence of positive tumor margins at the initial endoscopic resection. More frequent, earlier surveillance after resection than that currently recommended by European Neuroendocrine Tumor Society guidelines may be warranted to promptly capture DNET recurrences. Additionally, no recurrences occurred in our cohort after 4 years of surveillance.

Impact of margin status on survival after radical nephrectomyfor renal cell carcinoma.

Data about the impact of surgical margin positivity on patient outcomes following radical nephrectomy (RN) for renal cell carcinoma (RCC) is limited. We evaluate the effect of positive surgical margins (PSMs) on relapse-free survival (RFS) and overall survival (OS.) METHODS: Clinicopathologic data of patients who underwent RN for RCC was analyzed based on margin status. χ2 and Student ttest were used to compare groups. Cox regression analysis was used for the analysis. Kaplan-Meier method was used for survival curves. A total of 485 patients who underwent RN for RCC were analyzed. Most patients with T1/T2 stage had NSM. Most patients with T4 had PSM. T3 patients were split between the two groups. Analysis of the T3 group showed shorter RFS in the PSM group at 3 years (hazard ratio[HR]: 4.3, p = .01), and 5 years (HR: 4.3, p = .01.) OS analysis showed worse OS in PSM but not statistically significant. There was a significant association between PSM and laterality (p = .023) and histologic type (p = .025.) CONCLUSIONS: PSM was associated with shorter RFS after RN in T3 RCC patients. There was a trend towards worse OS in the PSM group, but it did not reach statistical significance. Laterality and histologic type were associated with surgical margin status.

Impact of Margin Status on Survival in Patients with Pancreatic Ductal Adenocarcinoma Receiving Neoadjuvant Chemotherapy

Historically, a positive margin after pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) was associated with decreased survival. In an era when neoadjuvant chemotherapy (NAC) is being used frequently, the prognostic significance of margin status is unclear. Patients with localized PDAC who received NAC and underwent pancreatectomy from 2011 to 2018 were identified from a single-institution database. Patients with fewer than 2 months of NAC, R2 resection, or fewer than 90 days of follow-up were excluded. A positive margin included tumors within 1 mm of the surgical margin. Four hundred and sixty-eight patients met inclusion criteria. Median age was 65 years and 53% were female. Preoperative clinical staging demonstrated that most had locally advanced (n= 222 [47%]) or borderline resectable (n= 172 [37%]) disease. Median follow-up was 18.5 months (interquartile range 10.6 to 30.0 months). Median duration of NAC was 119 days (interquartile range 87 to 168 days). FOLFIRINOX was first-line therapy for 67%, and 73% received neoadjuvant radiotherapy. Most underwent pancreaticoduodenectomy (69%). Forty percent were node-positive and 80% had an R0 resection. Fifty-six percent received at least 1 cycle of adjuvant therapy. Median overall survival and recurrence-free survival were 22.0 months (95% CI, 19.4 to 25.1 months) and 11.0 months (95% CI, 10.0 to 12.1 months). On multivariate analysis, margin status was not a significant predictor of overall survival or recurrence-free survival. Factors associated with overall survival included clinical stage, duration of NAC, nodal status, histopathologic treatment response score, and receipt of adjuvant chemotherapy. Microscopic margin positivity is not associated with recurrence and survival in localized PDAC patients resected after treatment with NAC. Aggressive surgical extirpation in high-volume centers should be considered in selected patients after extensive NAC.

Prognostic significance of positive surgical margins for scalp angiosarcoma

Scalp angiosarcomas (AS) are aggressive soft tissue sarcomas that present with outcomes different from other AS of the head and neck region. Due to the rarity of the disease, limited data on the clinical outcome of scalp AS are available. In particular, the prognostic significance of surgical margins remains controversial and the impact of margin status on survival has not been documented. We retrospectively reviewed 41 scalp AS patients, including 30 patients with localized disease and 11 patients with initial distant metastasis, treated in our institution between 1997 and 2017. Survival was determined by Kaplan-Meier analysis. In the 30 patients without distant metastasis (localized disease), univariate and multivariate analysis using the Cox proportional hazards model were used to determine clinicopathologic characteristics associated with recurrence free survival (RFS), locoregional control (LRC), and overall survival (OS). Totally 41 patients diagnosed with scalp AS were identified, including 30 patients with localized disease and 11 patients with initial distant metastasis on diagnosis. Overall, the median follow-up period was 19.3 (range 0.3-128.5) months. The median survival time was 16.6 (range 0.3-144.3) months and the 5-year OS (95% Confidence Interval (CI)) rate was 22% (12%-42%). In the 30 patients with localized disease, univariate analysis showed that positive margins, either lateral-side or deep-side, were significant prognostic factors for RFS, LRC, and OS (p<0.05). On multivariate analysis, positive margins emerged as adverse prognostic factors for RFS (Hazard Ratio (HR) 4.29, 95% CI, 1.71-10.75, p=0.002), LRC (HR 6.35, 95% CI, 2.19-18.37, p=0.001), and OS (HR 4.73, 95% CI, 1.71-13.07, p=0.003). Scalp AS is associated with high local recurrence rates and poor survival outcomes. Positive surgical margins are adverse prognostic factors for survival.

Impact of margin status on long-term results of liver resection for hepatocellular carcinoma: single-center time-to-recurrence analysis.

Occult metastasis from the initial tumor and a de novo second primary hepatocellular carcinoma (HCC) were recognized as the main causes for the onset of early and late HCC recurrence, after liver resection (LR). This study aims to compare the time to recurrence after LR for HCC in which a margin ≤ 1mm or > 1mm was achieved. A single-center retrospective study involving 256 patients was conducted from June 2005 to June 2019. HCC patients resected with a radical surgical approach were investigated and stratified into groups A (resection margins ≤ 1mm) and B (> 1mm), as measured on final pathologic assessment. Kaplan-Meier estimators were used to estimate the probability of recurrence, and the log-rank test was used to compare groups. Uni- and multivariable (stepwise) Cox regression models were used to assess the effect of several HCC pathological characteristics. Twenty patients were excluded for the presence of microscopic tumor invasion at pathologic analysis (R1); 236 patients underwent radical (R0) LR, and were included in the study and divided into group A (n = 61, 26%), and group B (n = 175, 74%). No differences between the two groups were detected regarding: epidemiology, tumor characteristics, type of LR, and follow-up. The estimated probability of recurrence for group A and group B at 12 and 24months was 27% and 38%, and, 33% and 46%, respectively. Univariate and multivariable Cox regression model estimates showed that tumor grading (HR 2.1, 95% CI 1.2-3.4, p = 0.006), number of nodules (HR 1.2, 95% CI 1.0-1.4, p = 0.015), and extension of the resection (HR 1.8, 95% CI 1.0-1.1, p = 0.047) were independent risk factors for HCC recurrence, with no significant effect of margin status on time to recurrence. A R0 approach that considers a margin of resection > 1mm does not improve the likelihood of HCC recurrence. Otherwise, our experience confirms that biologic tumor characteristics are the principal factors predictive of local and systemic recurrence.

Impact of Positive Margins and Radiation After Tracheal Adenoid Cystic Carcinoma Resection on Survival

Achieving negative margins for adenoid cystic carcinoma (ACC) of the trachea can be technically difficult. This study evaluated the impact of positive margins on prognosis and tested the hypothesis that radiation improves survival in the setting of incomplete resection. The impact of margin status and adjuvant therapy on overall survival of patients with tracheal ACC in the National Cancer Database (1998 to 2014) who underwent resection with known margin status and with no documented nodal or distant disease was evaluated using Kaplan-Meier and Cox proportional hazard analysis. Of 132 patients who met study criteria, 79 (59.8%) had positive margins after resection. Adjuvant radiation was given to 95 patients overall (72.0%) and to 62 of the 79 patients with positive margins (78.5%). The survival of patients with positive margins was not significantly different from that of patients with negative margins (5-year survival, 82.2% [95% confidence interval (CI), 71.3-89.3] compared with 82.0% [95% CI, 67.0-90.6], P= .97), even after multivariable adjustment (hazard ratio, 1.73; 95% CI, 0.62-4.84; P= .30). In the subset of patients with positive margins, there was no significant difference in survival between patients who did or did not receive postoperative radiation therapy (5-year survival, 82.0% [95% CI, 68.8-89.9] compared with 82.4% [95% CI, 54.7-93.9]; P= .80), even after multivariable adjustment (hazard ratio, 1.04; 95% CI, 0.21-5.25; P= .96). The majority of tracheal ACC resections performed in this national cohort had positive margins. Adjuvant radiation was commonly used for positive margins but was not associated with an overall survival benefit.

The Impact of Margin Status on Breast Conservation Rates.

Contemporary data indicate that breast conservation treatment (BCT) results in superior survival outcomes compared with mastectomy. However, positive margins after lumpectomy have implications for local control, and re-excisions are recommended to achieve negative margins. The need for reoperations after an initial attempt at BCT is associated with higher chance of conversion to mastectomy. Achieving negative margins at the first therapeutic surgical procedure is therefore critical to optimise BCT rates and survival outcomes. A compilation of scientific reports on BCT, margin status, rates of reoperation, and the impact on BCT rates was reviewed. Re-excision rates after initial lumpectomy is variable to a staggering degree and reported to be between 0 and 100%. High reoperation rates (ROR) are associated with higher likelihood of conversion to mastectomy, which may not confer favourable treatment outcomes. Although widely agreed that decreasing ROR is a desirable objective, there is controversy regarding the need for its urgent implementation as a quality metric. Critics of this cite challenges related to how this can be achieved and its attendant ramifications. On the other hand, without the appropriate incentive for quality improvement of surgical treatment of breast cancer, patients may be subject to poorer overall outcomes. Techniques and approaches are discussed in this article to enable a reduction in positive margin status, and therefore ROR. The rationale for achieving ROR of 10-20% are explicated, as well as the impact this would have on BCT rates, which translates to better survival outcomes for women with breast cancer.

Impact of margin status on survival after surgery for sinonasal squamous cell carcinoma.

Sinonasal squamous cell carcinoma (SNSCC) is the most common malignancy of the paranasal sinuses. Surgery is the mainstay of treatment, yet positive surgical margins (PSM) are common and the prognostic impact on overall survival (OS) is mixed. Given the heterogeneity of impact of PSM on OS within the literature, we hypothesized that extent of tumor extirpation (microscopic PSM vs macroscopic PSM) may play a role in OS. Patients with SNSCC were identified in the National Cancer Database (NCDB, n = 7808). Of these, 4543 patients underwent surgery, 3265 patients underwent nonsurgical therapy. Kaplan-Meier curves were used to compare OS between negative surgical margin (NSM), micro-PSM, and macro-PSM cohorts vs patients undergoing primary nonsurgical therapy in a propensity-score-matched analysis. Multivariable analysis of factors associated with macro-PSM was also performed. One thousand thirty-three (22.0%) of the surgery patients had PSM, and approximately half (n = 521, 50.6%) of these had macro-PSM. When compared with nonsurgical treatment, propensity-score-matched results demonstrated improved OS in patients with NSM and micro-PSM (p < 0.001), but macro-PSM patients did not demonstrate improvement (p = 0.20). Tumor within the paranasal sinuses and advanced nodal classification (N2/N3) (odds ratio [OR], 1.18; p = 0.02; and OR, 15.09; p = 005, respectively) was associated with increased odds of macro-PSM on multivariable analysis. We demonstrate that the degree of tumor extirpation correlates with OS. Macro-PSM did not confer a benefit to OS when compared with nonsurgical therapy, and factors including tumor location and advanced nodal status affect whether surgery will result in macro-PSM. Given these findings, informed, shared decisionmaking between patient and surgeon regarding nonsurgical alternatives should occur before electing to proceed with surgery in SNSCC.

Impact of margin status on survival after liver resection for colorectal liver metastasis

Background: Nowadays, the optimal surgical margin of the resected metastasis and the parenchyma sparing surgical technic have become an issue among hepatic surgeons. Some authors suggest performing parenchyma sparing surgery as the best surgical strategy for colorectal liver metastases (CLRM) to keep as much liver tissue as possible. Furthermore, the microscopically positive surgical margin (R1 resection) is presumed not have worse survival outcomes compared to patients with microscopically negative surgical margin (R0 resection).

Nature and role of surgical margins in transoral laser microsurgery for early and intermediate glottic cancer.

Summarize recent findings regarding the impact of margin status on oncologic outcomes and organ preservation, as well as evaluate possible management policies of close and positive margins after transoral laser microsurgery (TLM) for Tis-T2 glottic carcinomas. Impact of margin status on survival rates remains controversial, whereas some authors found close and positive margins to be independent risk factors for recurrence and poorer survival rates, others did not find any significant variations compared with negative ones. A common trend can be observed in performing a watchful waiting policy or second look TLM in patients with close-superficial and positive single-superficial margins. Further treatment seems preferable in case of deep and positive multiple superficial margins. Positive margins are present in up to 50% of patients treated by TLM, even though a high rate of false positivity, reaching 80%, has been described. Close and positive single superficial margins seem to be linked to higher recurrence rates compared with negative margins, even though watchful wait and see policy, especially when performed by adjunctive visual aids like Narrow Band Imaging, maintains good final oncological and organ preservation outcomes. Further treatments are required in case of deep margin positivity.

Multicolour versus monocolour inking specimens after pancreaticoduodenectomy for periampullary cancer: A single centre prospective randomised clinical trial

BackgroundR status represents an important prognostic factors in periampullary cancers. Thus, it is useful to verify if it can be influenced by different techniques of margination. MethodsSingle-centre, randomised clinical trial of patients affected by periampullary cancer who underwent pancreaticoduodenectomies which included two different types of margination: arm A (multicolour inking) and arm B (monocolour inking). The primary endpoint was the overall R1 resection rate and its difference between the two arms. The secondary endpoints were the R1 resection rate in each margin and its difference between the two arms, and the impact of margin status on survival. ResultsFifty patients were randomised, 41 analysed: 22 in arm A, 19 arm B. The overall R1 status was 61%, without significant differences between the two arms. The margin most commonly involved was the superior mesenteric artery (SMA) (36.6%). A trend in favour of arm B was shown for the superior mesenteric artery margin (arm A = 22.7% versus arm B = 52.6%; P = 0.060). The anterior surface (P = 0.015), SMA (P = 0.047) and pancreatic remnant (P = 0.018) margins significantly influenced disease-free survival. ConclusionsThe R status was not influenced by different techniques of margination using a standardised pathological protocol. The SMA margin seemed to be the most important margin for evaluating both R status and disease-free survival.

Impact of positive margins on outcomes of oropharyngeal squamous cell carcinoma according to p16 status.

Currently, positive surgical margins in head and neck cancer are considered to be an indicator for postoperative chemoradiotherapy (CRT) over radiotherapy (RT) alone. However, there are less data regarding the impact of margin status on human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (SCC). We performed a retrospective review of 55 patients with oropharyngeal SCC undergoing primary surgical treatment. The impact of margin status on disease-specific survival (DSS) was studied according to p16 status. Twenty-one patients had positive margins. Adjuvant treatment in these cases was CRT (n = 6), RT alone (n = 14), and none (n = 1). Among p16-negative patients, positive margins and dysplasia at margins predicted significantly worse DSS. Among patients with p16-positive disease, margin status had no impact on DSS. Patients with p16-positive oropharyngeal SCC and positive margins after excision maintain a low risk of recurrence despite most receiving RT alone as adjuvant treatment. These findings raise questions regarding the additional benefit of postoperative CRT in this group.

Impact of margin status on survival after radical nephrectomy for renal cell carcinoma (RCC).

e16084 Background: Data is limited regarding outcomes in patients with RCC with positive surgical margins. We sought to evaluate the impact of margin status after radical nephrectomy (RN) on relapse free survival (RFS) and overall survival (OS). Methods: A retrospective study was conducted evaluating patients with RCC having undergone RN at Methodist University Hospital in Memphis, Tennessee, between January 2009 and December 2013. Patients were identified from the tumor registry at this institution, and IRB approval obtained. Patient and tumor characteristics and survival were analyzed by GraphPad Prism, Microsoft Excel and IBM SPSS. Results: 156 patients that underwent RN for RCC were identified; 12 patients (7.7%) had positive margins and 144 had negative margins. Mediation duration of follow-up was 3.4 years. 5 of 12 patients with positive margins relapsed, versus 20 of 144 with negative margins (41.7% v. 13.9%, p = 0.022) with a RR of 3.10 (95% CI 1.417-6.799). Among those who relapsed, there was a statistically significant difference in time to relapse between patients with positive and negative margins (mean number of days to relapse 275 versus 621, respectively, with p = 0.038). On multivariate analysis of age, gender, ethnicity, laterality, tumor histology, margin status, and tumor size, margin status was not a statistically significant determinant of OS at 1, 3, and 5 years (p = 0.051, 0.124 and 0.185 respectively) or RFS at 1, 3, and 5 years (p = 0.372, 0.271 and 0.242 respectively). Pearson correlation analysis showed significant correlation between tumor size and margin status, R = 0.478, p &lt; 0.001. Conclusions: Positive margins were associated with earlier time to relapse among patients following RN. However, in multivariate analysis, margin status was not a statistically significant determinant of OS or RFS. In the current era of multiple available agents in RCC capable of cytoreduction, the risk factors that are predictive of a positive surgical margin at RN should be considered in the design of neoadjuvant systemic therapy trials, with the goal of improving long-term outcomes.

The clinical impact of margin status on recurrence and survival after curative intent surgery for pancreatic ductal adenocarcinoma

The clinical impact of margin status on recurrence and survival after curative intent surgery for pancreatic ductal adenocarcinoma

Impact of margin status and lymphadenectomy on clinical outcomes in resected pancreatic adenocarcinoma: implications for adjuvant radiotherapy.

Adjuvant chemoradiotherapy (CRT) in the treatment of pancreatic ductal adenocarcinoma (PDA) is controversial. Minimal data exists regarding the clinical significance of margin clearance distance and lymph node (LN) parameters, such as extent of dissection and LN ratio. We assessed the impact of these variables on clinical outcomes to more clearly define the subset of patients who may benefit from adjuvant radiotherapy (RT). We identified 106 patients with resected stage 1-3 PDA from 2007-2013. Resection margins were categorized as positive (tumor at ink), ≤1, or >1 mm. LN evaluation included total number examined (NE), number of positive nodes (NP), ratio of NP to NE (NR), extent of dissection, and positive periportal LNs. The impact of these variables was assessed on disease-free survival (DFS) and overall survival (OS) using multivariate cox proportional hazards modeling. In patients receiving adjuvant chemotherapy (CT) alone, greater margin clearance led to improved DFS (P=0.0412, HR =0.51). Range of NE was 4-37, with a mean of 19. NE was not associated with DFS or OS, yet absolute NP of 5 or more was associated with a significantly worse DFS (P=0.005). Whereas periportal lymphadenectomy did not result in improved DFS or OS, patients with positive periportal LN had worse clinical outcomes (DFS, P=0.0052; OS, P=0.023). The use of adjuvant CRT was associated with improved OS (P=0.049; HR=0.29). In patients receiving adjuvant CT alone, there was a clinically significant benefit to clearing the surgical margin beyond tumor at ink. Having ≥5 NP and positive periportal LN led to significantly worse clinical outcomes. The addition of adjuvant RT to CT in resected PDA improved OS. A comprehensive evaluation of resection margin distance and LN parameters may identify more patients at risk for locoregional failure who may benefit from adjuvant CRT.