Dissection For Stage Research Articles

Unilateral post-chemotherapy robot-assisted retroperitoneal lymph node dissection in Stage II non-seminomatous germ cell tumor: A tertiary care experience

ObjectivePost-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) represents an integral component of the management of patients with non-seminomatous germ cell tumor (NSGCT). Modified templates have been proposed to minimize the surgical morbidity of the procedure. Moreover, the implementation of robotic surgery in this setting has been explored. We report our experience with unilateral post-chemotherapy robot-assisted retroperitoneal lymph node dissection (PC-rRPLND) for clinical Stages IIA and IIB NSGCTs. MethodsA retrospective single institution review was performed including 33 patients undergoing PC-rRPLND for Stages IIA and IIB NSGCTs between January 2015 and February 2019. Following orchiectomy, patients were scheduled for chemotherapy with three cycles of bleomycin-etoposide-cisplatin. Patients with a residual tumor of <5 cm and an ipsilateral metastatic disease on pre- and post-chemotherapy CT scans were eligible for a unilateral template in absence of rising tumor markers. Descriptive statistics were provided for demographics, clinical characteristics, intraoperative and postoperative parameters. Perioperative, oncological, and functional outcomes were recorded. ResultsOverall, 7 (21.2%) patients exhibited necrosis or fibrosis; 14 (42.4%) had mature teratoma; and 12 (36.4%) had viable tumor at final histology. The median lymph node size at surgery was 25 (interquartile range [IQR] 21–36) mm. Median operative time was 180 (IQR 165–215) min and no major postoperative complications were observed. Anterograde ejaculation was preserved in 75.8% of patients. Median follow-up was 26 (IQR 19–30) months and a total of three recurrences were recorded. ConclusionPC-rRPLND is a reliable and technically reproducible procedure with safe oncological outcomes and acceptable postoperative ejaculatory function in well selected patients with NSGCTs.

A0562 - Surgical and oncological outcomes of post chemotherapy laparoscopic retroperitoneal lymph node dissection in stage IIA-III non seminomatous germ-cell tumors

A0562 - Surgical and oncological outcomes of post chemotherapy laparoscopic retroperitoneal lymph node dissection in stage IIA-III non seminomatous germ-cell tumors

SC235 - Perioperative outcomes of post chemotherapy laparoscopic retroperitoneal lymph node dissection in stage IIA-III non seminomatous germ-cell tumors

SC235 - Perioperative outcomes of post chemotherapy laparoscopic retroperitoneal lymph node dissection in stage IIA-III non seminomatous germ-cell tumors

Extent of mediastinal nodal dissection in stage I non-small cell lung cancer with a radiological pure-solid appearance

BackgroundRadiological pure-solid lung cancer denotes a high invasive nature compared to one that is part-solid. Mediastinal lymph nodal dissection (mLND) is a standard surgical procedure for nodal management in lung cancer surgery, however, the prognostic impact of the extent of mLND in pure-solid lung cancer is still unknown. MethodsWe reviewed 459 patients with c-stage I radiological pure-solid lung cancer that underwent pulmonary lobectomy with mLND. Pure-solid was defined as a tumor showing only a consolidation without any ground glass opacity. The extent of mLND was classified into lobe-specific (L-mLND) and systematic (S-mLND). Prognostic significance of mLND was assessed by a multivariable analysis using propensity-score matching. Survivals were calculated by Kaplan-Meier methods using log-rank test. ResultsPathological nodal metastasis was found in 127 (27.6%) patients (hilar: 52 (11.3%), mediastinal: 75 (16.3%)). L-mLND was performed in 278 (61%) patients. A multivariable analysis did not show the survival difference for the extent of mLND (p = 0.266). The 5-year overall survival (OS) was not significantly different between S-mLND and L-mLND (74.3% vs. 72.7%, p = 0.712), which was similar even in 114 propensity-score matched pairs (78.8% vs. 79.9%, p = 0.665). While S-mLND showed a trend for survival benefit compared to L-mLND provided that the tumor showed higher standardized uptake value (SUVmax) (5y-OS: 70.0% vs. 59.2%, p = 0.093). ConclusionsPrognostic impact of L-mLND was similar to S-mLND in c-stage I radiological pure-solid lung cancers in the propensity-score matched comparison. Among them, higher SUVmax value might be a promising indicator to decide the extent of mediastinal lymphadenectomy.

Four cases of completion lobectomy for locally relapsed lung cancer after segmentectomy

BackgroundAlthough completion lobectomy is the treatment of choice for local recurrence of non-small cell lung cancer after segmentectomy, few cases have been reported. We report four patients who underwent completion lobectomies for staple line recurrence after segmentectomy for stage I non-small cell lung cancer.Case presentationThree women aged 65, 82, and 81 years underwent completion lower lobectomy after superior segmentectomy of the same lobe for local recurrence of stage I non-small cell lung cancer. A 67-year-old man, who had a tumor recurrence on the staple line after apical segmentectomy with superior mediastinal nodal dissection for stage I non-small cell lung cancer, underwent completion right upper lobectomy. These four patients underwent segmentectomy because of comorbidities or advanced age. Local recurrence was confirmed by computed tomography-guided needle biopsy. The interval between the two operations was 37, 39, 41, and 16 months, respectively. Although minimal hilar adhesion was seen for the three completion lower lobectomies, tight adhesions after apical segmentectomy made completion right upper lobectomy quite difficult to dissect, which led to injury of the superior pulmonary vein. No recurrence was recorded after completion lobectomies for 62, 70, 67, and 72 months, respectively.ConclusionsAlthough completion lobectomy is one of the most difficult modes of resection, among several completion lobectomies, completion lower lobectomy after superior segmentectomy without superior mediastinal nodal dissection was relatively easy to perform because of fewer hilar adhesions.

Study of breast cancer surgeries at a tertiary hospital

Background: Breast cancer is commonly treated by various combinations of surgery, chemotherapy, radiation therapy, hormone therapy and targeted therapy via a multimodality approach. Surgery is the mainstay of treatment of the early stages of breast cancer, and it ranges from lumpectomy to modified radical mastectomy. Surgery typically includes sentinel lymph nodes (LN) dissection for staging the extent of spread into the axilla. In present study we aimed to study surgeries done in patients with breast cancer at our tertiary hospital. Material and Methods: Present study was a prospective, observational study conducted in patients who underwent surgery for breast cancer, followed by histopathological report positive for breast malignancy. Results: Total 86 biopsy proven breast cancer patients underwent surgery during study period. All patients were females, with mean age 47.4 ± 10.7 years, from rural areas (74%), 9% had positive family history, 13% received Hormone Replacement Therapy/Oral Contraceptive Pills (for more than 5 years), 5% were smokers, 64% were premenopausal and 7% had history of breast biopsy. Modified radical mastectomy with axillary node dissection (69%) was most common surgery performed followed by breast conservation surgery (26%). Most patients were from stage II (64%) followed by stage I (15%). Infiltrating ductal carcinoma was most common histopathological variant (81%). Histopathologically most cancers were grade II (52%). Lymph nodal involvement (48%) and positive surgical margins (7%) were noted. Conclusion: Surgery is mainstay in treatment of breast cancer With introduction of BCS cosmetic and other concerns are tackled effectively.

Robotic Extraperitoneal Para-Aortic and Pelvic Lymphadenectomy with the Aid of the Double Bipolar Method

Study Objective To evaluate the efficacy of robotic extraperitoneal paraaortic dissection using the double bipolar method (DBM). Design We will show our double bipolar technique and give retrospective analysis of data. Setting Urban general hospital. Patients or Participants From December 26th 2018 to April 22nd 2019, 13 patients underwent extraperitoneal paraaortic dissection and 3 patients underwent both paraaortic and pelvic extraperitoneal dissection for stage I ovarian cancer (n=5) and endometrial cancer (n=8)- stage I-III. Interventions Informed consent was gained from all patients. Underlaparoscopic observation, we accessed the retroperitoneal space at the lower left flank extraperitoneally using an Endotip cannula. We expanded the peritoneal pocket to establish pneumo-retroperitoneum. Four extraperitoneal trocars along the left flank were placed. The DBM was originated by a robotic gastrointestinal surgeon, Prof Ichiro Uyama. This technique uses Robotic Maryland forceps for both cutting and coagulation. The cutting device is set with a special energy platform at macromode 60W. The lightning strike cutting mechanism is more precise than other instrumentation such as monopolar scissors and causes minimal thermal spread to adjacent organs. Measurements and Main Results The median number of retrieved lymph nodes in the paraaortic dissection was 32, in the pelvic dissection- 27. The estimated blood loss in the paraaortic dissection was almost 0ml, and 75ml in the pelvic. The median operating time was 147mins for the paraaortic dissection and 50mins for the pelvic dissection. No patients who underwent these interventions suffered organ injury or required a blood transfusion. Conclusion Extraperitoneal approach has the advantage of being a no-bowel operative field. The DBM makes it possible to perform accurate, bloodless dissection making it applicable to extended retroperitoneal dissection. The combination of this approach and technique can potentially be applied to total retroperitoneal dissection including para-aortic and pelvic lymphadenectomy cases.

Role of primary retroperitoneal lymph node dissection in stage I and low-volume metastatic germ cell tumors.

Early-stage testicular cancers are highly curable. Following orchidectomy, management options for stage I disease include active surveillance, nerve-sparing retroperitoneal lymph node dissection (nsRPLND) and primary chemotherapy as recommended by the current guidelines. Primary RPLND has for decades played an integral part of treatment in patients with early-stage testicular germ cell tumors (TGCT), particularly in nonseminomatous germ cell tumors (NSGCT) with focus on reducing the long-term morbidity. We review the role of RPLND in stage I NSCGT as well as stage II A/B NSGCT and as seminoma. Radiation therapy and systemic chemotherapy are established treatments for seminoma; however, long-term data has demonstrated the association of such therapies with late toxicity including secondary malignancies, hearing loss, cardiovascular disease as well as metabolic syndromes. Given the well established role of RPLND in NSGCTs, clinicians have developed an interest in utilization of surgery for low-volume retroperitoneal metastatic disease. Two prospective clinical trials (SEMS and PRIMETEST) are underway to determine the role of RPLND alone in low volume metastatic seminoma. RPLND is a highly effective treatment for early-stage germ cell tumors but represents overtreatment in low-volume stage I disease where active surveillance is recommended. RPLND has shown a promising role in low-volume stage II seminomas. Two phase II clinical trials are underway to further determine the curative potential of this approach.

An examination of the cutoff value of the depth of invasion for prophylactic neck dissection in stage I/II tongue cancer

Background: In stage-I/stage-II oral tongue cancer, the cutoff value of depth of invasion (DOI) for prophylactic neck dissection is controversial.Objectives: To examine the relationship between the DOI and the rate of occult lymph node metastasis. In addition, to examine the relationship between the DOI evaluated by magnetic resonance imaging (MRI) and pathological DOI.Materials and methods: In this retrospective study, 95 patients with clinical T1-2/N0M0 oral tongue cancer were enrolled. The rate of occult lymph node metastasis per DOI between 2 and 11 mm was calculated from the total pathological lymph node metastasis and delayed neck metastasis cases. We measured DOI using MRI and compared DOI obtained from pathology.Results: The total rate of occult lymph node metastasis was 23.9%. In the rate of occult lymph node metastasis per DOI, there were two peaks at point of 5 to 6 mm and 9 to 10 mm. And there was a significant correlation between the DOI evaluated by MRI and the pathological DOI (Pearson’s correlation coefficient was 0.87).Conclusions and significance: There was no consistent increase in the rate of occult lymph node metastasis per DOI. MRI was a useful modality to measure the DOI.

Cutaneous melanoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up†.

Cutaneous melanoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up†.

Functional and supraomohyoid neck dissection in stage cN0/N1 oral squamous cell carcinoma

Objective: To evaluate the clinical effects of functional neck dissection (FND) and supraomohyoid neck dissection (SOND) in patients with cN0/N1 oral squamous cell carcinoma (OSCC). Methods: A total of 210 patients with stage cN0/N1 OSCC underwent FND and SOND between January 2012 and May 2015 were retrospectively reviewed, among which, 147 patients were male and 63 were female, with an age range of 23-82 years and mean age of (62.2±10.2) years. There were 112 and 98 patients in FND and SOND groups, respectively. The follow-up data included cervical lymph node metastasis, movement of shoulder joint, great auricular nerve function, recurrence rate of cervical lymph nodes. Results: There was no significant difference in gender, age, tumor location, T stage, N stage, histological grades between the two groups (all P>0.05). Compared to patients in FND group, the activities of shoulder joint and earlobe numbness improved significantly in SOND group. Of the 210 patients, 17 patients (8.1%) had cervical recurrence, with 9 patients (8.0%) in FND group and 8 patients (8.2%) in SOND group. No significant difference was observed for neck recurrence between the two groups (P=0.973). Conclusion: SOND can be safely performed in cN0 or cN1 OSCC patients, which avoids major complications of FND, and improves postoperative quality of life in those patients.

Risk factors and prognostic significance of lateral pelvic lymph node metastasis in advanced rectal cancer.

The aim of this study was to elucidate the risk factors for and prognostic value of lateral pelvic lymph node (LPLN) metastasis in advanced rectal cancer patients, including those with stage IV disease. The treatment outcomes of 78 patients with advanced rectal cancer, the lower margin of which was located at or below the peritoneal reflection, who underwent curative-intent surgery with bilateral LPLN dissection from 2005 to 2018 were retrospectively analyzed. In total, 78 rectal cancer patients, including 13 patients with stage IV tumors, 9 patients (11.5%) had LPLN metastasis. A multivariate analysis to identify preoperative clinical factors associated with LPLN metastasis showed that tumor location (below the peritoneal reflection: Rb), LPLN metastasis on preoperative imaging and distant metastasis were independent predictors of LPLN metastasis. In addition, metastasis at the regional lymph nodes in the mesorectum was significantly associated with LPLN metastasis. Both the disease-free survival (DFS) and cancer-specific survival (CSS) of patients with LPLN metastasis were significantly worse in comparison to patients without LPLN metastasis, and the CSS of stage IV patients with LPLN metastasis was significantly worse in comparison to stage IV patients without LPLN metastasis. Tumor location (Rb), LPLN metastasis on preoperative imaging and distant metastasis were risk factors for LPLN metastasis. The prognosis of rectal cancer patients with LPLN metastasis is poor. There may not be the indication of LPLN dissection in stage IV lower rectal cancer except cases having complaints due to LPLN metastasis.

Comparison of Right-side and Left-side Colon Cancers Following Laparoscopic Radical Lymphadenectomy

Purpose: The colon originates from the midgut and hindgut, with subsequent differentiation into the right and left colon. The embryology, clinical symptoms, incidence, molecular pathways, and oncologic outcomes differ between right and left colorectal cancers. However, the differences have not been fully accepted.Aim of the Study: This study compared short- and long-term outcomes between right and left colon cancers.Materials and Methods: This study included 966 patients who underwent laparoscopic resection with radical lymph node dissection for stage I, II, and III colon cancers between 2009 and 2014 at a tertiary teaching hospital. We excluded cases with fewer than 12 retrieved lymph nodes, emergency operations, synchronous or multiple cancers, and those located in the transverse colon and rectum.Results: The right colon group included 343 (35.5%) patients and the left colon group 623. Female patients had a high incidence of right colon cancer (p < 0.001). Right colon cancer had longer operative times (p = 0.012), and more bleeding during the operation (p = 0.001). The size of the tumor was larger (p < 0.001) and more lymph nodes were harvested (p < 0.001) on the right side. Vascular (p = 0.006) and lymphatic (p = 0.004) invasion was greater in the right colon, but left colon cancer showed greater neural invasion (p = 0.008). Cancers on the right side also had a tendency to be poorly differentiated (p < 0.001). The groups did not differ in disease-free, overall, and cancer-specific survival rates for stage.Conclusion: Although the oncologic outcomes show no significant differences, colon cancer has characteristic, perioperative, and histopathologic differences according to its embryologic origin.

Impact of visceral pleural invasion on the association of extent of lymphadenectomy and survival in stage I non‐small cell lung cancer

Visceral pleural invasion (VPI) has been identified as an adverse prognostic factor for non‐small cell lung cancer (NSCLC). Accurate nodal staging for NSCLC correlates with improved survival, but it is unclear whether tumors with VPI require a more extensive lymph nodes (LNs) dissection to optimize survival. We aimed to evaluate the impact of VPI status on the optimal extent of LNs dissection in stage I NSCLC, using the Surveillance, Epidemiology, and End Results (SEER) database. We identified 9297 surgically treated T1‐2aN0M0 NSCLC patients with at least one examined LNs. Propensity score matching was conducted to balance the baseline clinicopathologic characteristics between the VPI group and non‐VPI group. Log‐rank tests along with Cox proportional hazards regression methods were performed to evaluate the impact of extent of LNs dissection on survival. VPI was correlated with a significant worse survival, but there was no significant difference in survival rate between PL1 and PL2. Patients who underwent sublobectomy had slightly decreased survival than those who underwent lobectomy. Pathologic LNs examination was significantly correlated with survival. Examination of 7‐8 LNs and 14‐16 LNs conferred the lowest hazard ratio for T1‐sized/non‐VPI tumors (stage IA) and T1‐sized/VPI tumors (stage IB), respectively. The optimal extent of LNs dissection varied by VPI status, with T1‐sized/VPI tumors (stage IB) requiring a more extensive LNs dissection than T1‐sized/non‐VPI tumors (stage IA). These results might provide guidelines for surgical procedure in early stage NSCLC.

How many lymph nodes are enough?-defining the extent of lymph node dissection in stage I-III gastric cancer using the National Cancer Database.

Surgical resection with lymph node dissection is the primary therapeutic modality for gastric cancer. National Cancer Database (NCDB) was used to determine the extent of lymph nodes (LNs) dissection for gastric cancer. The NCDB was queried from 2004-2013 for patients with margin-negative, invasive resected gastric cancer. The optimal number of LNs dissected was determined using a univariate χ2 cut-point analysis. Multiple sensitivity analyses were utilized to decrease bias. A total of 17,851 patients were included. For all patients, the optimal number of LNs needed to be examined was 20+ nodes. When correcting for stage migration (<7 LNs removed), the optimal cut-off value was 20+ LNs. When stratifying by pathologic nodal stage, the cut-off point was 10+ LNs for pN1 and pN2. The 5-year survival was 30.6%±1.6% for 0-9 removed LNs compared to 48.2%±1.2% for 10+ removed LNs (P<0.001) in pN1 disease and 18.3%±1.7% for 0-9 removed LNs compared to 32.6%±1.2% for 10+ removed LNs (P<0.001) in pN2 disease. For pN3 disease, the optimal cut-off point was 20+ LNs; the 5-year survival was 17.2%±1.3% for 0-19 removed LNs compared to 28.5%±1.7% for 20+ removed LNs (P<0.001). Moreover, the outcome was inferior among patients who had >10% positive dissected LNs (P<0.05). The extent of dissected lymph nodes of 20 or greater lymph nodes was associated with superior survival. Extended LN dissection is to be considered especially in patients with clinical lymphadenopathy.

Risk and survival of patients with medullary thyroid cancer: National perspective

BackgroundMedullary thyroid carcinoma (MTC) is a neuroendocrine tumor account for 1–2% of thyroid cancer. In this study, we aim to examine the characteristics and survival of patients with MTC. MethodsA retrospective cohort study utilizing the National Cancer Data Base, 2004–2014. The study population included adults with either MTC (cases) or with differentiated thyroid cancer (DTC) (controls). ResultsA total of 2,776 MTC and 171,631 DTC patients were included. The median follow-up time for MTC was 55.5 months (interquartile range: 31.2–84.6 months). As compared to DTC, patients with MTC were more likely to be ≥ 45-year old, male, and Black (p < 0.001). Neck dissection improved survival in patients with stage III [HR: 0.26, 95%CI: (0.10, 0.64), p = 0.004]. In patients with stages I and II, neck dissections did not add significant survival benefit to thyroidectomy [stage I, HR: 1.00, 95%CI: (0.54, 1.86), p = 0.99],[stage 2, HR: 0.72, 95%CI: (0.40, 1.29), p = 0.27]. However, neck dissections upgraded staging to N1A and N1B in 17.7% and 14.3% of patients with clinically N0 neck, respectively. In stage IV, thyroidectomy with neck dissection had the highest 5-year survival (84.9%), but this was not significantly different from thyroidectomy alone (84.1%); Patients who had thyroidectomy and EBRT with or without neck dissection had a lower survival than thyroidectomy alone (p < 0.01). ConclusionsNeck dissection performed on patients with clinically N0 neck, is important for accurate staging and associate with improved survival in advanced stages. Thyroidectomy and neck dissection in stage IV not only have palliative role but also add survival advantage.

Percentages of post-mastectomy patients presenting with perinodal extension or inadequate axillary dissection in STAGE I and II carcinoma breast.

e12618Background: Purpose of the study is to assess patients with Stage I and II Carcinoma breast presenting with perinodal extension and inadequate axillary dissection following modified radical m...

Prophylactic lateral pelvic lymph node dissection in stage IV low rectal cancer.

AIMTo assess the clinical significance of prophylactic lateral pelvic lymph node dissection (LPLND) in stage IV low rectal cancer.METHODSWe selected 71 consecutive stage IV low rectal cancer patients who underwent primary tumor resection, and enrolled 50 of these 71 patients without clinical LPLN metastasis. The patients had distant metastasis such as liver, lung, peritoneum, and paraaortic LN. Clinical LPLN metastasis was defined as LN with a maximum diameter of 10 mm or more on preoperative pelvic computed tomography scan. All patients underwent primary tumor resection, 27 patients underwent total mesorectal excision (TME) with LPLND (LPLND group), and 23 patients underwent only TME (TME group). Bilateral LPLND was performed simultaneously with primary tumor resection in LPLND group. R0 resection of both primary and metastatic sites was achieved in 20 of 50 patients. We evaluated possible prognostic factors for 5-year overall survival (OS), and compared 5-year cumulative local recurrence between the LPLND and TME groups.RESULTSFor OS, univariate analyses revealed no significant benefit in the LPLND compared with the TME group (28.7% vs 17.0%, P = 0.523); multivariate analysis revealed that R0 resection was an independent prognostic factor. Regarding cumulative local recurrence, the LPLND group showed no significant benefit compared with TME group (21.4% vs 14.8%, P = 0.833).CONCLUSIONProphylactic LPLND shows no oncological benefits in patients with Stage IV low rectal cancer without clinical LPLN metastasis.

A prediction tool incorporating the biomarker S-100B for patient selection for completion lymph node dissection in stage III melanoma

IntroductionCompletion lymph node dissection (CLND) in sentinel node (SN)-positive melanoma patients is accompanied with morbidity, while about 80% yield no additional metastases in non-sentinel nodes (NSNs). A prediction tool for NSN involvement could be of assistance in patient selection for CLND. This study investigated which parameters predict NSN-positivity, and whether the biomarker S-100B improves the accuracy of a prediction model. MethodsRecorded clinicopathologic factors were tested for their association with NSN-positivity in 110 SN-positive patients who underwent CLND. A prediction model was developed with multivariable logistic regression, incorporating all predictive factors. Five models were compared for their predictive power by calculating the Area Under the Curve (AUC). A weighted risk score, ‘S-100B Non-Sentinel Node Risk Score’ (SN-SNORS), was derived for the model with the highest AUC. Besides, a nomogram was developed as visual representation. ResultsNSN-positivity was present in 24 (21.8%) patients. Sex, ulceration, number of harvested SNs, number of positive SNs, and S-100B value were independently associated with NSN-positivity. The AUC for the model including all these factors was 0.78 (95%CI 0.69–0.88). SN-SNORS was the sum of scores for the five parameters. Scores of ≤9.5, 10–11.5, and ≥12 were associated with low (0%), intermediate (21.0%) and high (43.2%) risk of NSN involvement. ConclusionsA prediction tool based on five parameters, including the biomarker S-100B, showed accurate risk stratification for NSN-involvement in SN-positive melanoma patients. If validated in future studies, this tool could help to identify patients with low risk for NSN-involvement.

How many lymph nodes is enough? Defining the optimal lymph node dissection in stage I-III gastric cancer using the National Cancer Database.

4034 Background: Gastric cancer is one of the most causes of cancer-related death worldwide. Surgical resection with lymph node dissection is the primary therapeutic modality. However, the appropriate extent of lymph node dissection remains controversial. Herein, the National Cancer Database (NCDB) was used to determine the optimal number of lymph nodes (LNs) to be dissected for resectable gastric cancer. Methods: The NCDB was queried from 2004-2013 for patients with invasive gastric cancer who underwent surgical resection with negative margins. The optimal number of LNs dissected was determined using a univariate χ2 cut-point analysis. Actuarial survival was determined using the Kaplan Meier method, and comparisons of survival estimates were completed with log-rank tests. Multiple sensitivity analyses were utilized to decrease bias. Results: 17,851 patients were included. The mean (±SD) number of LNs examined was 16 ± 11. For all patients, the optimal number of LNs needed to be examined was 20+ nodes. When correcting for stage migration ( &lt; 7 LNs removed), the optimal cut-off value was 20+ LNs. When stratifying by pathologic nodal stage, the cutpoint was 10+ LNs for pN1 and pN2. The 5-year survival was 30.6 ± 1.6% for 0-9 removed LNs compared to 48.2 ± 1.2% for 10+ removed LNs (p &lt; 0.001) in pN1 disease and 18.3 ± 1.7% for 0-9 removed LNs compared to 32.6 ± 1.2% for 10+ removed LNs (p &lt; 0.001) in pN2 disease. For pN3 disease, the optimal cut-off point was 20+ LNs; the 5-year survival was 17.2 ± 1.3% for 0-19 removed LNs compared to 28.5 ± 1.7% for 20+ removed LNs (p &lt; 0.001). Moreover, the outcome was inferior among patients who had &gt; 10% positive dissected LNs (p &lt; 0.05). Conclusions: The optimal number of dissected LNs of 20+ LNs was associated with superior survival. Extended LN dissection is to be considered especially in patients with &gt; 10% positive dissected LNs.