Perioperative and oncological outcomes following robotic en bloc multivisceral resection for colorectal cancer.

AIM: As multidisciplinary treatment strategies for colorectal cancer have improved, aggressive surgical resection has become commonplace. Multivisceral and extended resections offer curative-intent resection with significant survival benefit. However, limited data exist regarding the feasibility and oncological efficacy of performing extended resection via a minimally invasive approach. The aim of this study was to determine the perioperative and long-term outcomes following robotic extended resection for colorectal cancer. METHOD: We describe the population of patients undergoing robotic multivisceral resection for colorectal cancer at our single institution. We evaluated perioperative details and investigated short- and long-term outcomes, using the Kaplan-Meier method to analyse overall and recurrence-free survival. RESULTS: Among the 86 patients most tumours were T3 (47%) or T4 (47%) lesions in the rectum (78%). Most resections involved the anterior compartment (72%): bladder (n = 13), seminal vesicle/vas deferens (n = 27), ureter (n = 6), prostate (n = 15) and uterus/vagina/adnexa (n = 27). Three cases required conversion to open surgery; 10 patients had grade 3 complications. The median hospital stay was 4 days. Resections were R0 (>1 mm) in 78 and R1 (0 to ≤1 mm) in 8, with none being R2. The average nodal yield was 26 and 48 (55.8%) were pN0. Three-year overall survival was 88% and median progression-free survival was 19.4 months. Local recurrence was 6.1% and distant recurrence was 26.1% at 3 years. CONCLUSION: Performance of multivisceral and extended resection on the robotic platform allows patients the benefit of minimally invasive surgery while achieving oncologically sound resection of colorectal cancer.

Modifier 22 Use in Fee-for-Service Medicare.

Importance: Modifier 22 is a mechanism designed for surgeons to identify cases that are more complex than their Current Procedural Terminology code accounts for. However, empirical studies of the use and efficacy of modifier 22 are lacking. Objective: To assess the use of modifier 22 in common surgical procedures and the association of use with compensation. Design, Setting, and Participants: This was a cross-sectional analysis of the 2021 Physician/Supplier Procedure Summary Limited Data Set including all Part B carrier and durable medical equipment fee-for-service claims. Claims for 10 common surgical procedures were evaluated, including mastectomy, total hip arthroplasty, total knee arthroplasty, coronary artery bypass grafting, laparoscopic right colectomy, laparoscopic appendectomy, laparoscopic cholecystectomy, kidney transplant, laparoscopic total abdominal hysterectomy and bilateral salpingo-oophorectomy, and lumbar laminectomy. Data were analyzed from August to November 2023. Main Outcomes and Measures: Rate of modifier 22 use, rate of claim denial, mean charges, mean payment for accepted claims, and mean payment for all claims. Results: The sample included 625 316 surgical procedures performed in calendar year 2021. The proportion of modifier 22 coding for a procedure ranged from 5725 of 251 521 (2.3%) in total knee arthroplasty to 1566 of 18 459 (8.5%) in laparoscopic total abdominal hysterectomy and bilateral salpingo-oophorectomy. Submitted charges were 11.1% (95% CI, 9.1-13.2) to 22.8% (95% CI, 21.3-24.3) higher for claims with modifier 22, depending on the procedure. Among accepted claims, those with modifier 22 had increased payments ranging from 0.8% (95% CI, 0.7-1.0) to 4.8% (95% CI, 4.5-5.1). However, claims with modifier 22 were more likely to be denied (7.4% vs 4.0%; P < .001). As a result, overall mean payments were mixed, with 4 procedures having lower payments when modifier 22 was appended, 4 procedures having higher payments with modifier 22, and 2 procedures with no difference. The largest increase in mean payment for modifier 22 claims was for kidney transplant with an increased payment of $71.46 (95% CI, 55.32-87.60), which translates to a relative increase of 3.4% (95% CI, 2.9-4.6). Conclusions and Relevance: The findings in this study suggest that modifier 22 had little to no financial benefit when appended to claims for a diverse panel of surgical procedures. In the current system, surgeons have little reason to request modifier 22, and no mechanisms currently exist for surgeons to recoup payment for difficult operations.

Reporting of Circumferential Resection Margin in Rectal Cancer Surgery.

Importance: Circumferential resection margin (CRM) in rectal cancer surgery is a major prognostic indicator associated with local recurrence and overall survival. Facility rates of CRM positivity have recently been established as a new quality measure by the Commission on Cancer (CoC); however, the completeness of CRM status reporting is not well characterized. Objective: To describe the changes in CRM reporting and factors associated with low rates of reporting. Design, Setting, and Participants: A retrospective cohort study was conducted using data from the National Cancer Database between January 2010 and December 2019. Data were analyzed between October 1, 2021, and February 1, 2022. Data from the National Cancer Database included patients diagnosed with nonmetastatic rectal adenocarcinoma receiving surgical treatment at CoC-accredited facilities throughout the US. Exposures: Patient, tumor, and facility-level factors. Facilities were divided by surgical volume, safety-net status, and CoC facility type. Main Outcomes and Measures: Circumferential resection margin missingness rates. Results: A total of 110 571 patients (59.3% men) with rectal adenocarcinoma who underwent curative-intent surgery at 1307 CoC-accredited hospitals were included for analysis. Reporting of CRM improved over the study period, with a mean (SE) missing 12.0% (0.32%) decreased from 16.3% (0.36%). Academic facilities had a higher missingness than other facility types (14.3% vs 10.5%-12.7%; P < .001). Mean (SE) rates of missingness were similar between hospitals of varying volume (lowest quartile: 12.2% [0.93%] vs highest quartile: 12.4% [0.53%]; P = .96). Cases in which fewer than 12 lymph nodes were removed had higher rates of missingness (18.1% vs 11.4%; P < .001). Increased odds of CRM missingness were noted with T category (odds ratio [OR], 1.50; 95% CI, 1.35-1.65) and N category (OR, 2.00; 95% CI, 1.82-2.20). Black race was associated with missingness (OR, 1.13; 95% CI, 1.06-1.14). Conclusion and Relevance: Although CRM positivity reporting has improved over the last decade, the findings of this study suggest there is substantial room for improvement as it becomes a quality standard. Missingness appears to be associated with poor performance on other quality metrics and facility type. This measure appears to be ideal for targeted institution-level feedback to improve quality of care nationally.

Peritoneal recurrence after resection for Stage I-III colorectal cancer: A population analysis.

BACKGROUND: Colorectal cancer (CRC) often recurs in the peritoneum, although the pattern of peritoneal recurrence (PR) has received less attention. We sought to describe the presentation and risk factors for PR following CRC resection. METHODS: We performed a cohort study of patients undergoing resection of Stage I-III CRC from 2006 to 2007 using merged data from a Commission on Cancer Special Study and the National Cancer Database. We estimated the timing, method of detection, and risk factors for isolated PR. RESULTS: Here, 8991 patients were included and isolate PR occurred in 77 (0.9%) patients. The median time to PR was 16.2 months (intrquartile range = 9.3-28.0 months) and most patients were identified via new symptoms (36.4%). Pathologic factors associated with increased odds of PR included higher T stage (T3 vs. T2, odds ratio [OR] = 4.8, 95% confidence interval [CI] = 1.5-15.7), N stage (N1 vs. N0, OR = 2.00, CI = 1.1-3.7), and signet ring (OR = 8.2, CI = 3.0-22.3) or mucinous histology (OR = 2.6, CI = 1.5-4.7). CONCLUSIONS: The majority of PR was detected within 18 months and few were identified by surveillance. Advanced T/N stage and signet ring/mucinous histology were associated with increased odds of PR.

Association of Medicaid expansion with racial disparities in cancer stage at presentation.

BACKGROUND: This study evaluates the independent association of Medicaid expansion on stage of presentation among patients of Black and White race with colorectal (CRC), breast, or non-small cell lung cancer (NSCLC). METHODS: A cohort study of patients with CRC, breast cancer, or NSCLC (2009-2017) in the National Cancer Database was performed. Difference-in-differences (DID) analysis was used to compare changes in tumor stage at diagnosis between Medicaid expansion (MES) and non-expansion states (non-MES) before and after expansion. Predictive margins were calculated by race, year, and insurance status to account for effect heterogeneity. Stage migration was determined by measuring the combined proportional increase in stage I and decrease in stage IV disease at diagnosis. RESULTS: Black patients gained less Medicaid coverage than White patients (6.0% vs 13.1%, p < 0.001) after expansion. Among Black and White patients, there was a shift towards increased early-stage diagnosis (DID 3.5% and 3.5%, respectively; p < 0.001) and decreased late-stage diagnosis (DID White: -3.5%; Black -2.5%; p < 0.001) in MES compared to non-MES following expansion. Overall stage migration was greater for White compared to Black patients with CRC (10.3% vs. 5.1%) and NSCLC (8.1% vs. 6.7%) after expansion. Stage migration effects in patients with breast cancer were similar by race (White 4.8% vs. Black 4.5%). CONCLUSION: An increased proportion of Black and White patients residing in Medicaid expansion states presented with earlier stage cancer following Medicaid expansion. However, because the proportion of Black patients is higher in non-expansion states, national racial disparities in cancer stage at presentation appear worse following Medicaid expansion.

Magnetic Resonance Imaging Directed Surgical Decision Making for Lateral Pelvic Lymph Node Dissection in Rectal Cancer After Total Neoadjuvant Therapy (TNT).

OBJECTIVE: Lateral pelvic lymph node (LPLN) metastases are an important cause of preventable local failure in rectal cancer. The aim of this study was to evaluate clinical and oncological outcomes following magnetic resonance imaging (MRI)-directed surgical selection for lateral pelvic lymph node dissection (LPLND) after total neoadjuvant therapy (TNT). METHODS: A retrospective consecutive cohort analysis was performed of rectal cancer patients with enlarged LPLN on pretreatment MRI. Patients were categorized as LPLND or non-LPLND. The main outcomes were lateral local recurrence rate, perioperative and oncological outcomes and factors associated with decision making for LPLND. RESULTS: A total of 158 patients with enlarged pretreatment LPLN and treated with TNT were identified. Median follow-up was 20 months (interquartile range 10-32). After multidisciplinary review, 88 patients (56.0%) underwent LPLND. Mean age was 53 (SD±12) years, and 54 (34.2%) were female. Total operative time (509 vs 429 minutes; P =0.003) was greater in the LPLND group, but median blood loss ( P =0.70) or rates of major morbidity (19.3% vs 17.0%) did not differ. LPLNs were pathologically positive in 34.1%. The 3-year lateral local recurrence rates (3.4% vs 4.6%; P =0.85) did not differ between groups. Patients with LPLNs demonstrating pretreatment heterogeneity and irregular margin (odds ratio, 3.82; 95% confidence interval: 1.65-8.82) or with short-axis ≥5 mm post-TNT (odds ratio 2.69; 95% confidence interval: 1.19-6.08) were more likely to undergo LPLND. CONCLUSIONS: For rectal cancer patients with evidence of LPLN metastasis, the appropriate selection of patients for LPLND can be facilitated by a multidisciplinary MRI-directed approach with no significant difference in perioperative or oncologic outcomes.

High Rate of Positive Circumferential Resection Margin in Colon Cancer: A National Appraisal and Call for Action.

OBJECTIVE: To identify rates of positive circumferential resection margin (CRM) for colon cancer surgery in the US. SUMMARY BACKGROUND DATA: CRM is one of the most important determinants of local control in colorectal cancers. The extent to which CRM involvement exists after colon cancer surgery is unknown. METHODS: Colon cancer cases with resection 2010 to 2015 were identified from the National Cancer Data Base. Adjusting for patient and tumor characteristics, comparisons were made between cases with CRM > 1 mm (negative margin) and those with margin involved with tumor or ≤ 1 mm (positive margin, CRM+). Hospital-level analysis was performed, examining observed-to-expected CRM+ rates. RESULTS: In total, 170,022 cases were identified: 150,291 CRM- and 19,731 CRM+ (11.6%). Pathologic T-category was the greatest predictor of CRM+, with higher rates in pT4(25.8%), pT4A(24.7%), and pT4B(31.5%) versus pT1(4.5%), pT2(6.3%) and pT3 (10.9%, P < 0.001). Within pT4 patients, predictors of CRM+ included signet-ring histology (38.1% vs 26.7% nonmucinous, and 26.9% mucinous adenocarcinoma, P < 0.001), removing < 12 lymph nodes (36.5% vs 26.1% >12, P < 0.001), community facilities (32.7%) versus academic/research (23.6%, P < 0.001), year (30.1% 2010 vs 22.6% 2015, P < 0.001), and hospital volume (24.5% highest quartile vs 32.7% lowest, P < 0.001). Across 1288 hospitals, observed-to-expected ratios for CRM+ ranged from 0 to 7.899; 429 facilities had higher than expected rates. CONCLUSIONS: Overall rate of CRM+ in US colon cancer cases is high. Variation exists across hospitals, with higher than expected rates in many facilities. Although biology is a major influencing factor, CRM+ rates represent an area for multidisciplinary improvement in quality of colon cancer care.

Racial Disparities in Recurrence and Overall Survival in Patients With Locoregional Colorectal Cancer.

BACKGROUND: The purpose of this study was to determine the association between race and long-term cancer outcomes (recurrence and overall survival) within a population of US patients with locoregional colorectal cancer (CRC). METHODS: A cohort study of primary patient data merged with the National Cancer Database as part of a Commission on Cancer Special Study was performed. The study population was a random sample of patients undergoing surgery for stage I to III CRC between years 2006 and 2007 with 5 years of follow-up. Propensity-weighted multivariable Cox regression was performed with pooled results to yield statistical inferences. Prespecified sensitivity analysis was performed only for patients who received guideline concordant care (GCC) of primary CRC. All statistical tests were 2-sided. RESULTS: The study population included 8176 patients, 9.9% (n = 811) Black and 90.1% (n = 7365) White. Black patients were more likely to be uninsured or underinsured, have lower household income, and lower educational status (all P < .001). Rates of GCC were higher among Black vs White patients with colon cancer (76.9% vs 72.6%, P = .02), and Black and White patients with rectal cancer were treated with radiation at similar rates (69.1% vs 66.6%, P = .64). Black race was independently associated with increased risk of recurrence (hazard ratio [HR] = 1.48, 95% confidence interval [CI] = 1.26 to 1.73) and mortality (HR = 1.37, 95% CI = 1.18 to 1.59). In sensitivity analysis of only patients who received GCC, observed effects for recurrence (HR = 1.51, 95% CI = 1.27 to 1.79) and overall survival (HR = 1.40, 95% CI = 1.18 to 1.66) persisted. CONCLUSIONS: Despite higher rates of GCC for CRC, Black patients experience a higher risk of recurrence and mortality compared with White patients.

Tumor Sidedness, Recurrence, and Survival After Curative Resection of Localized Colon Cancer.

BACKGROUND: Right-sided primary tumor location is associated with worse prognosis in metastatic colon cancer, but the effect of sidedness on recurrence and prognosis for non-metastatic disease is less understood. The purpose of this study was to examine the relationship between sidedness, recurrence, and survival among patients with localized colon cancer. PATIENTS AND METHODS: Consecutive patients who underwent curative resection of colon cancer (2006-2013) were identified from a prospective database and retrospectively analyzed. Risk for recurrence, overall survival, and survival after recurrence (SAR) were compared between left- and right-sided tumors using the log-rank test, and multivariable Cox proportional hazards regression. RESULTS: We evaluated 673 patients (347 right-sided). There was no difference in overall recurrence rates (adjusted hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.54-1.55; P = .75) or overall survival (HR, 1.22; 95% CI, 0.75-1.97; P = .42) between right- and left-sided primary tumors. However, right-sided tumors were more likely to develop multi-focal and poor prognostic site recurrence (P = .04). Among the 71 patients who developed recurrence, those with right-sided tumors had significantly lower SAR (HR, 3.88; 95% CI, 1.42-10.62; P = .008). CONCLUSIONS: Among patients with colon cancer who underwent curative resection, tumor sidedness was not associated with recurrence risk. However, among patients who developed recurrence, right-sidedness was associated with unique recurrence patterns and inferior SAR. For patients presenting with localized disease, treatment stratification should not be based on tumor sidedness alone.

Circumferential Resection Margin as a Hospital Quality Assessment Tool for Rectal Cancer Surgery.

BACKGROUND: Circumferential resection margin (CRM) status is an important predictor of outcomes after rectal cancer operation, and is influenced not only by operative technique, but also by incorporation of a multidisciplinary treatment strategy. This study sought to develop a risk-adjusted quality metric based on CRM status to assess hospital-level performance for rectal cancer operation. STUDY DESIGN: We conducted a retrospective observational cohort study of 58,374 patients with resected stage I to III rectal cancer within 1,303 hospitals who were identified from the National Cancer Database (2010 to 2015). The number of observed cases with a positive CRM (≤ 1 mm) was divided by the risk-adjusted expected number of cases with positive CRM to form the observed-to-expected (O/E) ratio. Secondary endpoint was overall survival. RESULTS: The overall rate of CRM positivity was 15.9%. Based on the O/E ratio for 1,139 hospitals, 147 (12.9%) and 103 (9.0%) were significantly worse and better performers, respectively. The majority of hospitals (n = 570) performed as expected. Positive CRMs using criteria of 0 mm and 0.1 to 1 mm were associated with a significantly shorter 5-year overall survival of 49% and 63.5% (hazard ratio 1.67; 95% CI, 1.57 to 1.76 and hazard ratio 1.19; 95% CI, 1.12 to 1.26) than negative CRM > 1 mm of 74.1% (all p < 0.001). CONCLUSIONS: CRM-based O/E ratio is a robust hospital-based quality measure for rectal cancer operation. It allows facilities to compare their performance with that of centers of similar characteristics and helps identify underperforming, at-risk, and high-performing centers. National quality-improvement initiatives for rectal cancer should focus on ensuring high-quality data collection and providing ready access to risk-adjusted comparative metrics.

Predicting Risk of Recurrence After Colorectal Cancer Surgery in the United States: An Analysis of a Special Commission on Cancer National Study.

BACKGROUND: Several factors can affect the risk of recurrence after curative resection of colorectal cancer (CRC). We aimed to develop a risk model for recurrence after definitive treatment of Stage I-III CRC using data from a nationally representative database and to develop an individualized web-based risk calculator. METHODS: A random sample of patients who underwent resection for Stage I-III CRC between 2006 and 2007 at Commission on Cancer (CoC) accredited centers were included. Primary data regarding first recurrence was abstracted from medical records and merged with the National Cancer Database. Multivariable cox regression analysis was used to test for factors associated with cancer recurrence, stratified by stage. Model performance was tested by c statistic and calibration plots. Hazard Ratios were utilized to develop an individualized web-based recurrence prediction tool. RESULTS: A total of 8249 patients from 1175 CoC centers were included. Of these, 1656 (20.1%) patients had a recurrence during 5 years of follow-up. Median time to recurrence was 16 months. The final predictive models displayed excellent discrimination and calibration with concordance indexes of 0.7. The online calculator included 12 variables, including tumor site, stage, time since surgery, and surveillance intensity. Output is displayed numerically and graphically with an icon array. CONCLUSIONS: Using primarily abstracted recurrence data from a random sample of patients treated for CRC at CoC accredited centers across the United States, we successfully created an individualized CRC recurrence risk assessment tool. This web-based calculator can be used by physicians and patients in shared decision making to guide management discussions. TRIAL REGISTRATION: ClinicalTrials.gov Registration Number: NCT02217865.

Small cell carcinoma of the kidney: a case report and analysis of data from the Surveillance, Epidemiology, and End Results registry.

BACKGROUND: Primary small cell carcinoma of the kidney is an extremely rare neoplasm. The clinical features of small cell carcinoma of the kidney are not well established due to its rarity and scarcity of case reports. We present an unusual case of small cell carcinoma of the kidney complicated by syndrome of inappropriate antidiuretic hormone secretion. We identify cases using a population-based dataset from the Surveillance, Epidemiology, and End Results registry and compare small cell carcinoma of the kidney with small cell carcinoma of the lung. CASE PRESENTATION: A 69-year-old Filipino man presented with hematuria for 1 month. A computed tomography scan demonstrated a large left kidney mass with biopsy demonstrating small cell carcinoma. Within 2 months he developed dizziness and was found to have a metastatic lesion to his brain. He was hyponatremic due to syndrome of inappropriate antidiuretic hormone secretion. He did not receive chemotherapy due to his poor functional status. He died within 8 months of presentation. RESULTS: From 1973 to 2013, 60 cases with small cell carcinoma of the kidney were identified in the Surveillance, Epidemiology, and End Results registry. Most (62%) presented with extensive stage, which occurred predominantly in white men in their seventh decade. The median overall survival with extensive stage small cell carcinoma of the kidney was 3 months versus 11 months with limited stage of small cell carcinoma of the kidney; this was worse than small cell carcinoma of the lung with a median survival of 5 and 13 months, respectively. CONCLUSION: We present a rare case of small cell carcinoma of the kidney complicated by syndrome of inappropriate antidiuretic hormone secretion. This adds to our understanding of the clinical features of small cell carcinoma of the kidney. Furthermore, this is the first population-based study of small cell carcinoma of the kidney using the Surveillance, Epidemiology, and End Results database. Analysis shows that overall survival is worse in small cell carcinoma of the kidney relative to that of small cell carcinoma of the lung. Small cell carcinoma of the kidney presents very aggressively, and further studies are needed to develop a standard of care.

Comorbidity Assessment in the National Cancer Database for Patients With Surgically Resected Breast, Colorectal, or Lung Cancer (AFT-01, -02, -03).

PURPOSE: Accurate comorbidity measurement is critical for cancer research. We evaluated comorbidity assessment in the National Cancer Database (NCDB), which uses a code-based Charlson-Deyo Comorbidity Index (CCI), and compared its prognostic performance with a chart-based CCI and individual comorbidities in a national sample of patients with breast, colorectal, or lung cancer. PATIENTS AND METHODS: Through an NCDB Special Study, cancer registrars re-abstracted perioperative comorbidities for 11,243 patients with stage II to III breast cancer, 10,880 with stage I to III colorectal cancer, and 9,640 with stage I to III lung cancer treated with definitive surgical resection in 2006-2007. For each cancer type, we compared the prognostic performance of the NCDB code-based CCI (categorical: 0 or missing data, 1, 2+), Special Study chart-based CCI (continuous), and 18 individual comorbidities in three separate Cox proportional hazards models for postoperative 5-year overall survival. RESULTS: Comorbidity was highest among patients with lung cancer (13.2% NCDB CCI 2+) and lowest among patients with breast cancer (2.8% NCDB CCI 2+). Agreement between the NCDB and Special Study CCI was highest for breast cancer (rank correlation, 0.50) and lowest for lung cancer (rank correlation, 0.40). The NCDB CCI underestimated comorbidity for 19.1%, 29.3%, and 36.2% of patients with breast, colorectal, and lung cancer, respectively. Within each cancer type, the prognostic performance of the NCDB CCI, Special Study CCI, and individual comorbidities to predict postoperative 5-year overall survival was similar. CONCLUSION: The NCDB underestimated comorbidity in patients with surgically resected breast, colorectal, or lung cancer, partly because the NCDB codes missing data as CCI 0. However, despite underestimation of comorbidity, the NCDB CCI was similar to the more complete measures of comorbidity in the Special Study in predicting overall survival.

Association Between Intensity of Posttreatment Surveillance Testing and Detection of Recurrence in Patients With Colorectal Cancer.

Importance: Surveillance testing is performed after primary treatment for colorectal cancer (CRC), but it is unclear if the intensity of testing decreases time to detection of recurrence or affects patient survival. Objective: To determine if intensity of posttreatment surveillance is associated with time to detection of CRC recurrence, rate of recurrence, resection for recurrence, or overall survival. Design, Setting, and Participants: A retrospective cohort study of patient data abstracted from the medical record as part of a Commission on Cancer Special Study merged with records from the National Cancer Database. A random sample of patients (n=8529) diagnosed with stage I, II, or III CRC treated at a Commission on Cancer-accredited facilities (2006-2007) with follow-up through December 31, 2014. Exposures: Intensity of imaging and carcinoembryonic antigen (CEA) surveillance testing derived empirically at the facility level using the observed to expected ratio for surveillance testing during a 3-year observation period. Main Outcomes and Measures: The primary outcome was time to detection of CRC recurrence; secondary outcomes included rates of resection for recurrent disease and overall survival. Results: A total of 8529 patients (49% men; median age, 67 years) at 1175 facilities underwent surveillance imaging and CEA testing within 3 years after their initial CRC treatment. The cohort was distributed by stage as follows: stage I, 25.0%; stage II, 35.2%; and stage III, 39.8%. Patients treated at high-intensity facilities-4188 patients (49.1%) for imaging and 4136 (48.5%) for CEA testing-underwent a mean of 2.9 (95% CI, 2.8-2.9) imaging scans and a mean of 4.3 (95% CI, 4.2-4.4) CEA tests. Patients treated at low-intensity facilities-4341 patients (50.8%) for imaging and 4393 (51.5%) for CEA testing-underwent a mean of 1.6 (95% CI, 1.6-1.7) imaging scans and a mean of 1.6 (95% CI, 1.6-1.7) CEA tests. Imaging and CEA surveillance intensity were not associated with a significant difference in time to detection of cancer recurrence. The median time to detection of recurrence was 15.1 months (IQR, 8.2-26.3) for patients treated at facilities with high-intensity imaging surveillance and 16.0 months (IQR, 7.9-27.2) with low-intensity imaging surveillance (difference, -0.95 months; 95% CI, -2.59 to 0.68; HR, 0.99; 95% CI, 0.90-1.09) and was 15.9 months (IQR, 8.5-27.5) for patients treated at facilities with high-intensity CEA testing and 15.3 months (IQR, 7.9-25.7) with low-intensity CEA testing (difference, 0.59 months; 95% CI, -1.33 to 2.51; HR, 1.00; 95% CI, 0.90-1.11). No significant difference existed in rates of resection for cancer recurrence (HR for imaging, 1.22; 95% CI, 0.99-1.51 and HR for CEA testing, 1.12; 95% CI, 0.91-1.39) or overall survival (HR for imaging, 1.01; 95% CI, 0.94-1.08 and HR for CEA testing, 0.96; 95% CI, 0.89-1.03) among patients treated at facilities with high- vs low-intensity imaging or CEA testing surveillance. Conclusions and Relevance: Among patients treated for stage I, II, or III CRC, there was no significant association between surveillance intensity and detection of recurrence. Trial Registration: clinicaltrials.gov Identifier: NCT02217865.

Oncologic and Functional Hazards of Obesity Among Patients With Locally Advanced Rectal Cancer Following Neoadjuvant Chemoradiation Therapy.

OBJECTIVE: Obesity is a major health concern and risk factor for colorectal cancer that may also impact cancer treatment and outcomes. Rectal cancer response to chemoradiotherapy (CXRT) is associated with long-term survival and sphincter preservation. The purpose of this study was to evaluate the impact of obesity on treatment outcomes after neoadjuvant CXRT for rectal cancer. METHODS: A retrospective cohort study of patients diagnosed (1993 to 2010) with cT3-4 or cN+ (by endorectal ultrasound, computed tomography, or magnetic resonance imaging) rectal carcinoma and treated with CXRT and total mesorectal excision was performed. Patients were classified as obese (body mass index ≥30 kg/m) or nonobese (body mass index <30 kg/m), and by response to CXRT: complete (pCR) or incomplete (pIR). Associations between obesity, tumor response, and sphincter preservation were evaluated using multivariate logistic regression analysis and survival outcomes by Cox regression. RESULTS: A total of 753 patients met criteria and 28.7% (n=216) patients were obese. Obese and nonobese groups did not differ in age, sex, tumor location, grade, or number of examined lymph nodes. However, obesity was associated with a lower rate of pCR (ORmulti=0.60; 95% confidence interval, 0.38-0.94; P=0.04) and among mid to low rectal cancer patients, a lower rate of sphincter preservation (ORmulti=0.67; 95% confidence interval, 0.45-0.99). Among both obese and nonobese patients, CR was associated with more favorable recurrence-free survival than pIR. CONCLUSIONS: Considering the increasing obesity prevalence and its association with CXRT response, oncologic outcomes, and sphincter preservation, further study is needed regarding the impact of obesity on neoadjuvant treatment response. Moreover, obesity should be targeted as a modifiable risk factor for adverse outcomes following multimodality treatment for rectal cancer.

Comparative effectiveness of primary tumor resection in patients with stage IV colon cancer.

BACKGROUND: Although the safety of combination chemotherapy without primary tumor resection (PTR) in patients with stage IV colon cancer has been established, questions remain regarding a potential survival benefit with PTR. The objective of this study was to compare mortality rates in patients who had colon cancer with unresectable metastases who did and did not undergo PTR. METHODS: An observational cohort study was conducted among patients with unresectable metastatic colon cancer identified from the National Cancer Data Base (2003-2005). Multivariate Cox regression analyses with and without propensity score weighting (PSW) were performed to compare survival outcomes. Instrumental variable analysis, using the annual hospital-level PTR rate as the instrument, was used to account for treatment selection bias. To account for survivor treatment bias, in situations in which patients might die soon after diagnosis from different reasons, a landmark method was used. RESULTS: In the total cohort, 8641 of 15,154 patients (57%) underwent PTR, and 73.8% of those procedures (4972 of 6735) were at landmark. PTR was associated with a significant reduction in mortality using Cox regression (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.44-0.47) or PSW (HR, 0.46; 95% CI, 0. 44-0.49). However, instrumental variable analysis revealed a much smaller effect (relative mortality rate, 0.91; 95% CI, 0.87-0.96). Although a smaller benefit was observed with the landmark method using Cox regression (HR, 0.6; 95% CI, 0.55-0.64) and PSW (HR, 0.59; 95% CI, 0.54-0.64), instrumental variable analysis revealed no survival benefit (relative mortality rate, 0.97; 95% CI, 0.87-1.06). CONCLUSIONS: Among patients with unresectable metastatic colon cancer, after adjustment for confounder effects, PTR was not associated with improved survival compared with systemic chemotherapy; therefore, routine noncurative PTR is not recommended. Cancer 2017;123:1124-1133. © 2016 American Cancer Society.

Oncologic Outcomes of Extended Robotic Resection for Rectal Cancer.

BACKGROUND: Surgery for locally advanced rectal cancers beyond the plane of total mesorectal excision (TME) or extramesorectal nodal involvement should include complete resection. This study evaluated the oncologic feasibility and safety of robot-assisted surgery for rectal cancer beyond the TME plane. METHODS: The study analyzed the operative, perioperative, and oncologic outcomes for all patients who underwent robot-assisted extended rectal cancer surgery from April 2009 to February 2015. RESULTS: Of 36 patients, 22 underwent multivisceral en bloc resection, and 18 underwent extramesorectal lymph node (EMRLN) dissection. The median tumor location was 5 cm [interquartile range (IQR), 2.2-9.0 cm] from the anal verge. A total of 32 patients underwent neoadjuvant chemoradiation therapy. The median body mass index of the patients was 26.8 kg/m(2) (IQR, 24.0-31.9 kg/m(2)). Conversion was required for one patient because of inability to tolerate the Trendelenburg position. All the resections were R0, and there were no incomplete TMEs. The vagina and prostate or periprostatic structures were the most commonly resected (n = 13/22), and the lateral pelvic nodes were the most common EMRLNs (n = 16/18). The median numbers of examined mesorectal lymph nodes and EMRLNs were respectively 20 (IQR, 18.0-28.0) and 2.5 (IQR, 1.0-6.0). The median hospital stay was 4 days (IQR, 3.0-5.5 days). Six patients experienced Clavien-Dindo grade 3 complications, the most common of which was deep abscess (n = 5, 13.8 %). The 5-year actuarial local recurrence rate was 3.6 %. CONCLUSIONS: Minimally invasive resection for rectal cancer can be performed with extended lymph node dissection or en bloc multivisceral resection using the surgical robot in selected patients. This technique is feasible and has acceptable morbidity.

Variation in positron emission tomography use after colon cancer resection.

PURPOSE: Colon cancer surveillance guidelines do not routinely include positron emission tomography (PET) imaging; however, its use after surgical resection has been increasing. We evaluated the secular patterns of PET use after surgical resection of colon cancer among elderly patients and identified factors associated with its increasing use. PATIENTS AND METHODS: We used the SEER-linked Medicare database (July 2001 through December 2009) to establish a retrospective cohort of patients age ≥ 66 years who had undergone surgical resection for colon cancer. Postoperative PET use was assessed with the test for trends. Patient, tumor, and treatment characteristics were analyzed using univariable and multivariable logistic regression analyses. RESULTS: Of the 39,221 patients with colon cancer, 6,326 (16.1%) had undergone a PET scan within 2 years after surgery. The use rate steadily increased over time. The majority of PET scans had been performed within 2 months after surgery. Among patients who had undergone a PET scan, 3,644 (57.6%) had also undergone preoperative imaging, and 1,977 (54.3%) of these patients had undergone reimaging with PET within 2 months after surgery. Marriage, year of diagnosis, tumor stage, preoperative imaging, postoperative visit to a medical oncologist, and adjuvant chemotherapy were significantly associated with increased PET use. CONCLUSION: PET use after colon cancer resection is steadily increasing, and further study is needed to understand the clinical value and effectiveness of PET scans and the reasons for this departure from guideline-concordant care.