Cardiac Surgery Exposure in General Surgery Residency-A Survey of General Surgery Residency Program Directors

BACKGROUND

Little is known regarding how much exposure general surgery residents have to cardiac surgery, despite cardiothoracic (CT) surgery being an offered postresidency fellowship and career. Exposure to a subspecialty is important in shaping residents' interests and career decisions.

METHODS

A survey was sent to all general surgery program directors via the Association of Program Directors in Surgery examining cardiac surgery exposure during training. The survey examined the presence of operative rotations in cardiac surgery and cardiac critical care, portions of cases residents were permitted to perform, cardiac surgery mentorship and education, and perceived biases in applying to cardiac surgery. Differences between programs with and without cardiothoracic training programs were analyzed.

RESULTS

In total, 44% (102/230) of program directors responded to the survey. Residents were involved in operative cardiac and cardiac ICU rotations in 61 programs (69.8%) and 39 programs (38.2%), respectively. Twenty programs (19.6%) had a dedicated cardiothoracic surgery training program and these programs had significantly more graduates who aspired to be cardiac surgeons (M = 2.75, SD = 2.47) compared to hospitals with no CT programs (M = 1.43, SD = 1.41; p = 0.031). 35.3% of program directors reported resident concern over family life.

CONCLUSIONS

There is a notable heterogeneity in general surgery resident exposure to cardiac surgery, cardiac ICU, and cardiac surgery mentorship. Increased exposure, mentorship and mitigating resident concern over the impact of social factors on cardiac surgical careers should be key areas of focus to ensure continued encouragement of future trainees and surgeons.

Conditional Survival Following Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Surface Malignancies: An Analysis from the US HIPEC Collaborative

INTRODUCTION

The long-term prognosis of patients who undergo cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal surface malignancies (PSM) varies considerably on the basis of histological and operative factors. While overall survival (OS) estimates are used to inform adjuvant therapy and surveillance strategies, conditional survival may provide more clinically relevant estimates of prognosis by accounting for disease-free time elapsed.

PATIENTS AND METHODS

All patients from 12 academic institutions who underwent CRS ± HIPEC for PSM from 2000 to 2017 were retrospectively analyzed. OS and disease-free survival (DFS) rates were calculated using the Kaplan-Meier method while conditional overall (COS) and conditional disease-free survival (CDFS) rates were calculated at 1, 2, or 3 years from surgery for different tumor histologies.

RESULTS

Overall, 1610 patients underwent CRS ± HIPEC. Among patients with benign appendiceal mucinous tumors (N = 460), 5-year OS and COS at 3 years were 92.1% and 96.3% (Δ4.2%), respectively. For patients with well-differentiated appendiceal cancers (N = 400), 5-year OS and COS at 3 years were 76.3% and 88.3% (Δ12.0%), respectively. For patients with high-grade appendiceal cancers (N = 258), 5-year OS and COS at 3 years were 43.8% and 75.4% (Δ31.6%), respectively. For patients with colorectal cancers (N = 362), 5-year OS and COS at 3 years were 31.8% and 67.3% (Δ35.5%), respectively. For patients with peritoneal mesothelioma (N = 130), 5-year OS and COS at 3 years were 67.6% and 89.7% (Δ22.1%), respectively. Similar trends were observed for DFS/CDFS.

CONCLUSION

The conditional survival of patients undergoing CRS ± HIPEC for PSM is associated with tumor histology. COS and CDFS provide a more accurate, dynamic estimate of survival than OS and DFS, especially for patients with more aggressive histologies.

Development and Validation of an Explainable Machine Learning Model for Major Complications After Cytoreductive Surgery

Importance

Cytoreductive surgery (CRS) is one of the most complex operations in surgical oncology with significant morbidity, and improved risk prediction tools are critically needed. Machine learning models can potentially overcome the limitations of traditional multiple logistic regression (MLR) models and provide accurate risk estimates.

Objective

To develop and validate an explainable machine learning model for predicting major postoperative complications in patients undergoing CRS.

Design, Setting, and Participants

This prognostic study used patient data from tertiary care hospitals with expertise in CRS included in the US Hyperthermic Intraperitoneal Chemotherapy Collaborative Database between 1998 and 2018. Information from 147 variables was extracted to predict the risk of a major complication. An ensemble-based machine learning (gradient-boosting) model was optimized on 80% of the sample with subsequent validation on a 20% holdout data set. The machine learning model was compared with traditional MLR models. The artificial intelligence SHAP (Shapley additive explanations) method was used for interpretation of patient- and cohort-level risk estimates and interactions to define novel surgical risk phenotypes. Data were analyzed between November 2019 and August 2021.

Exposures

Cytoreductive surgery.

Main Outcomes and Measures

Area under the receiver operating characteristics (AUROC); area under the precision recall curve (AUPRC).

Results

Data from a total 2372 patients were included in model development (mean age, 55 years [range, 11-95 years]; 1366 [57.6%] women). The optimized machine learning model achieved high discrimination (AUROC: mean cross-validation, 0.75 [range, 0.73-0.81]; test, 0.74) and precision (AUPRC: mean cross-validation, 0.50 [range, 0.46-0.58]; test, 0.42). Compared with the optimized machine learning model, the published MLR model performed worse (test AUROC and AUPRC: 0.54 and 0.18, respectively). Higher volume of estimated blood loss, having pelvic peritonectomy, and longer operative time were the top 3 contributors to the high likelihood of major complications. SHAP dependence plots demonstrated insightful nonlinear interactive associations between predictors and major complications. For instance, high estimated blood loss (ie, above 500 mL) was only detrimental when operative time exceeded 9 hours. Unsupervised clustering of patients based on similarity of sources of risk allowed identification of 6 distinct surgical risk phenotypes.

Conclusions and Relevance

In this prognostic study using data from patients undergoing CRS, an optimized machine learning model demonstrated a superior ability to predict individual- and cohort-level risk of major complications vs traditional methods. Using the SHAP method, 6 distinct surgical phenotypes were identified based on sources of risk of major complications.

Radiological assessment of persistent retroperitoneal and lateral pelvic lymph nodes after neoadjuvant therapy for rectal cancer: An analysis of the United States Rectal Cancer Consortium

INTRODUCTION

Management of retroperitoneal and lateral pelvic lymph nodes (RLPN) in rectal cancer remains unclear. With total neoadjuvant therapy (TNT), more patients have radiologic complete clinical response (rCR). We sought to evaluate the impact of radiographic persistent RLPN after neoadjuvant therapy on survival.

MATERIALS AND METHODS

Patients with rectal adenocarcinoma with isolated RLPN metastasis, who received neoadjuvant therapy before surgery were included from the United States Rectal Cancer Consortium database. Primary outcomes were recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Of 77 patients, all received neoadjuvant therapy, with 35 (46%) receiving TNT. Posttreatment, 33 (43%) had rCR while 44 (57%) had radiographic persistent RLPN. Median number of radiographic positive RLPN was 1 (IQR 1-2). Receipt of TNT was associated with radiographic RLPN rCR (OR 4.77, 95% CI 1.81-12.60, p < .01). However, there was no difference in RFS and OS between patients who achieved rCR or with persistent RLPN (all p > .05).

CONCLUSIONS

Radiographic persistence of RLPN was not associated with worse survival in well-selected patients and may not be a reliable indicator of pathological response. TNT may be the preferred management strategy to select patients given its association with rCR. Radiographic persistence of RLPN after preoperative therapy should not necessarily preclude surgery.

A multi-institutional analysis of Textbook Outcomes among patients undergoing cytoreductive surgery for peritoneal surface malignancies

BACKGROUND

While recent studies have introduced the composite measure of a textbook outcome (TO) for measuring postoperative outcomes, the incidence of a TO has not been characterized among patients undergoing cytoreductive surgery (CRS) for peritoneal surface malignancies (PSM).

STUDY DESIGN

All patients who underwent CRS ± hyperthermic intraperitoneal chemotherapy (HIPEC) between 1999 and 2017 from 12 institutions were included. A TO was defined as the absence of any of the following criteria: completeness of cytoreduction >1, reoperation within 90-days, readmission within 90-days, mortality within 90-days, any grade ≥2 complication, hospital stay >75th percentile, and non-home discharge.

RESULTS

Among 1904 patients who underwent CRS, only 30.9% achieved a TO while 69.1% failed to achieve a TO most commonly because of postoperative complications. On multivariable analysis, factors associated with achieving a TO were age <65 years (OR: 1.5), albumin ≥3.5 g/dl (OR: 5.7), receipt of HIPEC (OR: 4.5), PCI ≤14 (OR: 2.2), intravenous fluid volume ≤10,000 ml (OR: 2.1), blood loss ≤1000 ml (OR: 4.2) and operative time <7 h (OR: 1.9); while receipt of neoadjuvant therapy (OR: 0.7) and liver resection (OR: 0.4) were associated with not achieving a TO (all p < 0.05). TO was associated with improved overall survival (median 159 months vs 56 months, p < 0.01) even after controlling for confounders on Cox regression (hazard ratio: 2.5, p < 0.01).

CONCLUSION

Among patients undergoing CRS ± HIPEC for PSM, failure to achieve a TO is common and independently associated with worse overall survival.

The impact of HIPEC vs. EPIC for the treatment of mucinous appendiceal carcinoma: a study from the US HIPEC collaborative

INTRODUCTION

Mucinous appendiceal carcinoma is a rare malignancy that commonly spreads to the peritoneum leading to peritoneal metastases. Complete cytoreduction with perioperative intraperitoneal chemotherapy (PIC) is the mainstay of treatment, administered as either hyperthermic intra peritoneal chemotherapy (HIPEC) or early post-operative intraperitoneal chemotherapy (EPIC). Our goal was to assess the perioperative and long term survival outcomes associated with these two PIC methods.

MATERIALS AND METHODS

Patients with mucinous appendiceal carcinoma were identified in the US HIPEC Collaborative database from 12 academic institutions. Patient demographics, clinical characteristics, and survival outcomes were compared among patients who underwent HIPEC vs. EPIC with inverse probability weighting (IPW) used for adjustment.

RESULTS

Among 921 patients with mucinous appendiceal carcinoma, 9% underwent EPIC while 91% underwent HIPEC. There was no difference in Grade III-V complications between the two groups (18.5% for HIPEC vs. 15.0% for EPIC, p=.43) though patients who underwent HIPEC had higher rates of readmissions (21.2% vs. 8.8%, p<.01). Additionally, PIC method was not an independent predictor for overall survival (OS) or recurrence-free survival (RFS) after adjustment on multivariable analysis.

CONCLUSIONS

Among patients with mucinous appendiceal carcinoma, both EPIC and HIPEC appear to be associated with similar perioperative and long-term outcomes.

The role of surgeons during the COVID-19 pandemic: impact on training and lessons learned from a surgical resident's perspective

Background

Surgeons are trained as “internists that also operate,” bringing an important skillset to patient management during the current COVID-19 pandemic. A review was performed to illustrate the response of surgical staff during the pandemic with regard to patient care and residency training.

Methods

The evaluation and assessment of the changes enacted at Stony Brook Medicine’s Department of Surgery is illustrated through the unique perspective of surgical residents. No IRB approval or written consent was obtained nor it was necessary for the purposes of this paper.

Results

Hospital policy was enacted to hinder transmission of COVID-19 and included limited gatherings of people, restricted travel, quarantined symptomatic staff, and careful surveillance for disease incidence. Surgical residency transformed as residents were diverted from traditional surgical services to staff new COVID-19 ICUs. Education transitioned to an online-based platform for lectures and reviews. New skills sets were acquired such as PICC line placement and complex ventilator management.

Conclusions

The viral surge impacted surgical training while also providing unique lessons regarding preparedness and strategic planning for future pandemic and disaster management.

Predictors of Non-home Discharge after Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

Using a national database of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) recipients, we sought to determine risk factors for nonhome discharge (NHD) in a cohort of patients.

METHODS

Patients undergoing CRS/HIPEC at any one of 12 participating sites between 2000 and 2017 were identified. Univariate analysis was used to compare the characteristics, operative variables, and postoperative complications of patients discharged home and patients with NHD. Multivariate logistic regression was used to identify independent risk factors of NHD.

RESULTS

The cohort included 1593 patients, of which 70 (4.4%) had an NHD. The median [range] peritoneal cancer index in our cohort was 14 [0-39]. Significant predictors of NHD identified in our regression analysis were advanced age (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.05-1.12; P < 0.001), an American Society of Anesthesiologists (ASA) score of 4 (OR, 2.87; 95% CI, 1.21-6.83; P = 0.017), appendiceal histology (OR, 3.14; 95% CI 1.57-6.28; P = 0.001), smoking history (OR, 3.22; 95% CI, 1.70-6.12; P < 0.001), postoperative total parenteral nutrition (OR, 3.14; 95% CI, 1.70-5.81; P < 0.001), respiratory complications (OR, 7.40; 95% CI, 3.36-16.31; P < 0.001), wound site infections (OR, 3.12; 95% CI, 1.58-6.17; P = 0.001), preoperative hemoglobin (OR, 0.81; 95% CI, 0.70-0.94; P = 0.006), and total number of complications (OR, 1.41; 95% CI, 1.16-1.73; P < 0.001).

CONCLUSIONS

Early identification of patients at high risk for NHD after CRS/HIPEC is key for preoperative and postoperative counseling and resource allocation, as well as minimizing hospital-acquired conditions and associated health care costs.

Outcomes of neoadjuvant chemotherapy before CRS-HIPEC for patients with appendiceal cancer

BACKGROUND

Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is indicated for patients with peritoneal dissemination of appendiceal cancer. The role of neoadjuvant chemotherapy (NAC) before CRS-HIPEC remains controversial.

METHODS

A retrospective review of adult patients who underwent CRS ± HIPEC for metastatic appendiceal cancer between 2000-2017 was performed. Patients who received NAC followed by surgery were compared with those who underwent surgery first (SF) with and without 1:1 propensity score matching (PSM).

RESULTS

Among 803 patients with appendiceal cancer who underwent CRS ± HIPEC, 225 (28%) received NAC, and 578 (72%) underwent SF. After PSM (n = 186), median overall survival (OS) did not differ (NAC: 40 vs SF: 56 months; P = .210) but recurrence-free survival (RFS) was worse among patients who received NAC (14 vs 22 months; P = .007). NAC was independently associated with worse OS (hazards ratio [HR], 1.81; 95% confidence interval [CI], 1.03-3.18) and RFS (HR, 1.93; 95% CI, 1.25-2.99).

CONCLUSION

In this multi-institutional retrospective analysis of patients with peritoneal dissemination from appendiceal cancer, the use of NAC before CRS-HIPEC was associated with worse OS and RFS even after PSM and multivariable regression. Immediate surgery should be considered for patients with disease amenable to complete cytoreduction.

Phase I Trial of Trametinib with Neoadjuvant Chemoradiation in Patients with Locally Advanced Rectal Cancer

PURPOSE

The RAS/RAF/MEK/ERK signaling pathway is critical to the development of colorectal cancers, and KRAS, NRAS, and BRAF mutations foster resistance to radiation. We performed a phase I trial to determine the safety of trametinib, a potent MEK1/2 inhibitor, with 5-fluorouracil (5-FU) chemoradiation therapy (CRT) in patients with locally advanced rectal cancer (LARC).

PATIENTS AND METHODS

Patients with stage II/III rectal cancer were enrolled on a phase I study with 3+3 study design, with an expansion cohort of 9 patients at the MTD. Following a 5-day trametinib lead-in, with pre- and posttreatment tumor biopsies, patients received trametinib and CRT, surgery, and adjuvant chemotherapy. Trametinib was given orally daily at 3 dose levels: 0.5 mg, 1 mg, and 2 mg. CRT consisted of infusional 5-FU 225 mg/m²/day and radiation dose of 28 daily fractions of 1.8 Gy (total 50.4 Gy). The primary endpoint was to identify the MTD and recommended phase II dose. IHC staining for phosphorylated ERK (pERK) and genomic profiling was performed on the tumor samples.

RESULTS

Patients were enrolled to all dose levels, and 18 patients were evaluable for toxicities and responses. Treatment was well tolerated, and there was one dose-limiting toxicity of diarrhea, which was attributed to CRT rather than trametinib. At the 2 mg dose level, 25% had pathologic complete response. IHC staining confirmed dose-dependent decrease in pERK with increasing trametinib doses.

CONCLUSIONS

The combination of trametinib with 5-FU CRT is safe and well tolerated, and may warrant additional study in a phase II trial, perhaps in a RAS/RAF-mutant selected population.

A United States Rectal Cancer Consortium study of inferior mesenteric artery versus superior rectal artery ligation: How high do we need to go?

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Background: The optimal level of pedicle ligation during proctectomy for rectal cancer, either at the origin of the inferior mesenteric artery (IMA) or the superior rectal artery (SRA), is still debated. Reasons for IMA ligation include facilitating a tension-free anastomosis and improved clearance of regional lymph nodes. Our aim was to determine if SRA ligation portends inferior outcomes. Methods: The US Rectal Cancer Consortium database (2007-2017) was reviewed for pts with primary, non-metastatic rectal adenocarcinoma who underwent treatment with low anterior resection or abdominoperineal resection. Primary outcomes were anastomotic leak rate and lymph node (LN) harvest. Secondary outcomes were locoregional recurrence-free survival (LRFS), recurrence-free survival (RFS), and overall survival (OS). Results: Of 877 pts, median age was 59 years (IQR52-67) and 62% were male (n = 541). 86% received an IMA ligation (n = 755) while 14% SRA (n = 122). 12% were pathologic stage 0 (n = 101), 33% stage I (n = 281), 24% stage II (n = 206), and 31% stage III (n = 269). Median follow-up was 34 mos. SRA ligation was more common in stage III disease (43vs30%, p = 0.005) while IMA ligation was more often performed with a minimally invasive approach (70vs42%, p < 0.001). SRA ligation was associated with a nearly identical anastomotic leak rate compared to IMA (9vs8%, p = 1.0). Similarly, the median number of LNs removed was the same between both ligation groups (15vs15, p = 0.38). On multivariable analysis accounting for an open approach, advanced pathologic stage, and positive resection margin status, SRA ligation was not associated with increased anastomotic leak rate or reduced LRFS, RFS, or OS (all p > 0.1). Conclusions: If a tension-free anastomosis is feasible, SRA ligation is not associated with either a worse technical outcome or inferior lymph node harvest. Furthermore, all cancer survival metrics are similar between SRA and IMA ligation. Given that either approach is safe and feasible from both a technical and oncologic standpoint, this study questions the routine practice of IMA ligation.

Revisiting the value of drains after low anterior resection for rectal cancer: An analysis of 996 patients

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Background: Although potentially associated with increased infections, intraoperative pelvic drains are often placed during low anterior resection (LAR) to evacuate postoperative fluid collections and identify/control potential anastomotic leaks. Our aim was to assess the validity of this practice in a large dataset of patients undergoing LAR for rectal cancer. Methods: Patients from the US Rectal Cancer Consortium (2007-17) who underwent curative-intent LAR for a primary rectal cancer were included. Patients were categorized as receiving a closed suction drain intraoperatively or not. Primary outcomes were superficial surgical site infection(SSI), deep SSI, intraabdominal abscess, anastomotic leak, and need for secondary drain placement. Three subgroup analyses were conducted in patients who received neoadjuvant chemoradiation, had a diverting loop ileostomy (DLI), and had low tumors <6cm from the anal verge. Results: Of 996 pts, average age was 58 yrs, 61% were male, and 67% (n=551) received a drain. Drain patients were more likely to be male (64vs54%), have a smoking history (25vs19%), have received neoadjuvant chemoradiation (73vs61%), have low tumors within 6cm of the anal verge (56vs36%), and have received a DLI (80vs71%) (all p<0.05). Drains were associated with an increased anastomotic leak rate (14vs8%, p=0.041), although there was no difference in the need for a secondary drainage procedure to control the leak (82vs88%, p=0.924). These findings persisted in all subset analyses. Drains were not associated with increased superficial SSI, deep SSI, or intraabdominal abscess in the entire cohort or each subset analysis. Reoperation (12vs10%, p=0.478) and readmission rates (28vs31%, p=0.511) were similar. Conclusions: Although not associated with increased infectious complications, intraoperatively-placed pelvic drains after low anterior resection for rectal cancer are associated with an increase in anastomotic leak rate and no reduction in the need for secondary drain placement or reoperation. Routine drainage should be abandoned.

Radiographic characteristics of neuroendocrine liver metastases do not predict clinical outcomes following liver resection

Background

Previous research has demonstrated that specific radiographic criteria, including the presence of calcifications and the enhancement pattern on computed tomography (CT) imaging, correlates with clinicopathologic features and outcomes of patients with gastroenteropancreatic neuroendocrine tumors (NET). We sought to investigate whether these radiographic characteristics were prognostic among patients with neuroendocrine liver metastases (NELM) undergoing surgical resection.

Methods

The preoperative contrast-enhanced CT scans of all patients who underwent resection of NELM at a single institution between 2000-2015 were retrospectively reviewed. The presence of calcifications was determined on non-contrast phase imaging. Enhancement on the arterial phase scan was categorized as hyperenhancing, hypoenhancing, or mixed. Relevant clinicopathologic characteristics as well as recurrence-free survival (RFS) and overall survival (OS) were compared between groups.

Results

Among 82 patients who underwent resection of NELM, 57 had available data on calcifications while 51 had data available on arterial enhancement patterns. Among all patients, median age was 58 (IQR: 47-63) and the majority were female (N=48, 59.5%). The most common primary tumor locations were pancreas (N=25, 30.5%) and small bowel (N=27, 32.9%). The most commonly performed operations were right hepatectomy (N=29, 35.4%), bisegmentectomy (N=15, 18.3%), and segmentectomy (N=14, 17.1%). Median tumor number was 4 (IQR: 2-9), median Ki-67 was 5% (IQR: 2-10%), and median size of the largest liver metastasis was 4.5 (IQR: 2.8-7.7) cm. Twelve (21%) patients had tumor calcifications. Among patients with and without calcifications there were no differences in demographics, clinicopathologic characteristics, RFS (P=0.772) or OS (P=0.095). Arterial enhancement was hypoenhancing in 23 (45.1%), hyperenhancing in 10 (19.6%), and mixed in 18 (35.3%). Similarly, there were no differences between arterial enhancement groups in demographics, clinicopathologic characteristics, RFS (P=0.618) or OS (P=0.268).

Conclusions

Radiographic characteristics on contrast-enhanced CT are not associated with the outcomes of patients undergoing resection of NELM. Future investigations should evaluate the prognostic impact of functional neuroendocrine imaging.

Association of Liver-Directed Local Therapy With Overall Survival in Adults With Metastatic Intrahepatic Cholangiocarcinoma

IMPORTANCE

Intrahepatic cholangiocarcinoma is an aggressive hepatobiliary malignant neoplasm characterized by local progression and frequent metastasis. Definitive local therapy to the liver in the setting of metastatic intrahepatic cholangiocarcinoma may improve overall survival.

OBJECTIVE

To compare the overall survival of patients with metastatic intrahepatic cholangiocarcinoma treated with chemotherapy alone vs chemotherapy with definitive liver-directed local therapy.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used the National Cancer Database to identify 2201 patients with metastatic intrahepatic cholangiocarcinoma diagnosed between January 2004 and December 2014 who received chemotherapy with or without hepatic surgery or external beam radiation to a dose 45 Gy or higher. Multiple imputation, Cox proportional hazards, propensity score matching, and landmark analysis were used to adjust for confounding variables. Analyses were performed between September 2018 and February 2019.

EXPOSURES

Chemotherapy alone and chemotherapy with liver-directed surgery or radiation.

MAIN OUTCOMES AND MEASURES

Overall survival.

RESULTS

A total of 2201 patients (1131 [51.4%] male; median [interquartile range] age, 63 [55-71] years) who received chemotherapy alone (2097 [95.3%]) or chemotherapy with liver-directed local therapy (total, 104 [4.7%]; surgery, 76 [73.1%]; radiation, 28 [26.9%]) were identified. Patients treated with chemotherapy alone had larger median (interquartile range) primary tumor size (7.0 [4.4-10.0] cm vs 5.6 [4.0-8.3] cm; P = .048) and higher frequency of lung metastases (383 [25.9%] vs 7 [6.7%]; P = .004). Patients treated with liver-directed local therapy had higher frequency of distant lymph node metastases (34 [32.7%] vs 528 [25.2%]; P = .045). Liver-directed local therapy was associated with higher overall survival compared with chemotherapy alone on multivariable analysis (hazard ratio [HR], 0.60; 95% CI, 0.48-0.74; P < .001). A total of 208 patients treated with chemotherapy alone were propensity score matched with 104 patients treated with chemotherapy plus liver-directed local therapy. Liver-directed local therapy continued to be associated with higher overall survival (HR, 0.57; 95% CI, 0.44-0.74; P < .001), which persisted on landmark analysis at 3 months (HR, 0.61; 95% CI, 0.47-0.79; log-rank P < .001), 6 months (HR, 0.68; 95% CI, 0.50-0.92; log-rank P = .01), and 12 months (HR, 0.68; 95% CI, 0.47-0.98; log-rank P = .04).

CONCLUSIONS AND RELEVANCE

In this study, the addition of hepatic surgery or irradiation to chemotherapy was associated with higher overall survival when compared with chemotherapy alone in patients with metastatic intrahepatic cholangiocarcinoma. These findings may be valuable given the paucity of available data for this disease and should be validated in an independent cohort or prospective study.

Impact of concomitant ablation on the perioperative outcomes of patients with colorectal liver metastases undergoing hepatectomy: a propensity score matched nationwide analysis

BACKGROUND

Intraoperative ablation (IA) is often performed at the time of liver resection (LR) for colorectal liver metastases (CRLMs) but its impact on postoperative outcomes remains poorly understood.

METHODS

The ACS-NSQIP targeted hepatectomy database was used to identify patients who underwent LR vs LR + IA for CRLMs during 2014-2016. Perioperative outcomes were compared following propensity score match based on age, receipt of neoadjuvant therapy, operative approach, liver resection type, tumor diameter and number of metastases.

RESULTS

Among 1,384 patients, 692 (50%) underwent LR alone and 692 (50%) underwent LR + IA. After propensity score matching, overall morbidity (22% vs 13%, P < 0.0001) was increased among patients undergoing LR alone compared to LR + IA, whereas mortality did not differ (1.1% vs 0.8%, P=0.5911). On multivariable analysis, ASA class ≥3 (OR: 1.5, 95% CI: 1.06-2.3), preoperative biliary stent (OR: 3.5, 95% CI: 0.9-13.01), biliary reconstruction (OR: 5.02, 95% CI: 1.3-18.6), operative time > 245 minutes (OR: 1.8, 95% CI:1.3-2.4) and IA (OR:0.5, 95% CI:0.3-0.7) were associated with overall morbidity.

CONCLUSIONS

In this propensity matched nationwide analysis of patients undergoing LR for CRLM, the use of concomitant IA was associated with decreased postoperative morbidity compared to LR alone. These findings suggest that IA combined with LR is a safe approach that may expand the number of patients who are candidates for curative-intent surgical strategies.

Identification of patients at high risk for post-discharge venous thromboembolism after hepato-pancreato-biliary surgery: which patients benefit from extended thromboprophylaxis?

BACKGROUND

The objective of the current study was to define risk factors associated with the 30-day post-operative risk of VTE after HPB surgery and create a model to identify patients at highest risk of post-discharge VTE.

METHODS

Patients who underwent hepatectomy or pancreatectomy in the ACS-NSQIP Participant Use Files 2011-2015 were identified. Logistic regression modeling was used; a model to predict post-discharge VTE was developed. Model discrimination was tested using area under the curve (AUC).

RESULTS

Among 48,860 patients, the overall 30-day incidence of VTE after hepatectomy and pancreatectomy was 3.2% (n = 1580) with 1.1% (n = 543) of VTE events occurring after discharge. Patients who developed post-discharge VTE were more likely to be white, had a higher median BMI, have undergone pancreatic surgery, had longer median operative times, and to have had a transfusion. A weighted prediction model demonstrated good calibration and fair discrimination (AUC = 0.63). A score of ≥-4.50 had maximum sensitivity and specificity, resulting in 44% of patients being treating with prophylaxis for an overall VTE risk of 1.1%.

CONCLUSIONS

Utilizing independent factors associated with post-discharge VTE, a prediction model was able to stratify patients according to risk of VTE and may help identify patients who are most likely to benefit from pharmacoprophylaxis.

Early experience with a combined surgical and obstetrics/gynecology clerkship: We do get along

BACKGROUND

In 2012, the Ohio State University College of Medicine (OSUCOM) implemented a new undergraduate medical curriculum. We compare outcomes of a third year traditional clerkship format to a combined Surgery and Obstetrics/Gynecology 'ring'.

METHODS

Performance outcomes of 4 consecutive classes were compared between pre- (2014, 2015) and post-curricular revision (2016, 2017).

RESULTS

Three hundred ninety-one students consented use of their educational data for research. We examined medical knowledge (NBME scores, USMLE Step 1 and Step 2 CK scores) and student satisfaction between pre- and post-curricular revision. Results demonstrated no statistically significant difference in the Obstetrics/Gynecology NBME shelf examination. Surgery NBME and USMLE Step 2 scores were increased and statistically significant but satisfaction of both disciplines was higher pre-curricular revision.

CONCLUSION

Medical knowledge outcomes in this combined 'ring' were similar to or higher than performance in previous years'. Future analyses are needed to assess the impact of OSUCOM curricular revision.

Mixed adenoneuroendocrine carcinoma: A review of pathologic characteristics

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare pathologic entity defined as a tumor exhibiting both adenocarcinoma and neuroendocrine carcinoma components. Though uncommon, these tumors show aggressive behavior and generally portend a poor prognosis. This study seeks to further define clinicopathological characteristics of MANEC to aid in accurate diagnosis and properly direct clinical management. Thirty-four confirmed MANECs were identified in our 25-year retrospective review of cases arising in the gastrointestinal tract. Various gross and microscopic variables were compared to overall survival. Tumors diagnosed at advanced stage (pT4), had a prominent mucinous component and lacked goblet cell clusters, which were all significantly associated with worse overall survival. This study supports previous findings and further elucidates clinicopathologic characteristics of MANEC.

Influence of tumor size on outcomes following pelvic exenteration

OBJECTIVE

Pelvic exenteration (PE) is often the only curative option for locally advanced or recurrent pelvic malignancies. Despite radical surgery, recurrence risk and morbidity remain high. In this study, we sought to determine tumor size effect on perioperative outcomes and subsequent survival in patients undergoing PE.

METHODS

Retrospective chart review was performed for female patients who underwent PE at two comprehensive cancer centers from 2000 to 2015. Demographics, complications and outcomes were recorded. Statistical analyses were performed using chi-square, student's t-test, logistic regression, non-parametric tests, log-rank test, and Cox proportional hazards.

RESULTS

Of 151 women who underwent PE, 144 had available pathologic tumor size. Gynecologic oncology, surgical oncology, and urology performed 84, 29, and 31 exenterations, respectively. Tumor dimensions ranged from 0 to 25.5cm. Perioperative complications, 30-day mortality, reoperation, and readmission rates were not associated with tumor size. Obesity and prior radiation increased risk for major perioperative complication while anterior exenterations decreased risk. Larger tumors were more likely to undergo total pelvic exenteration (OR 1.14; 95%CI 1.03-1.27), have positive margins (OR 1.11; 95%CI 1.02-1.22), and recur (65%, 42% and 20% for tumors >4cm, ≤4cm and no residual tumor respectively, p=0.016). Tumor size >4cm and positive margins were associated with worse overall survival amongst gynecologic oncology patients.

CONCLUSION

Tumor size was not associated with perioperative morbidity. Larger tumors were associated with positive margins, more extensive resection, and worse survival in gynecologic oncology patients. Larger studies are needed to further understand tumor size impact on PE outcomes within specific tumor types.

Outcomes of metastatic adrenocortical carcinoma (ACC): A 16-year single institutional experience

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Background: ACC is a rare malignancy with limited data to guide management of metastatic disease. Prior research regarding survival has focused on pts with locoregional disease, but has not offered insight into the management and outcomes of pts with metastatic disease. Methods: We retrospectively reviewed patients (pts) with metastatic ACC who were treated with systemic therapy between January 2000 and October 2016 at The Ohio State University Comprehensive Cancer Center. Kaplan-Meier and Cox proportional hazards regression models were used for survival analysis. Results: A total of 18 pts received systemic therapy for distant metastatic disease. Median age at diagnosis was 51 (range 31 – 72). Median overall survival (OS) from time of diagnosis of ACC was 15.5 months (95% CI 4.8 – 28.2), and from time of systemic treatment (ST) was 7.1 months (95% CI 3.3 – 26). A germline variant of uncertain significance in MSH2 (c.138C > G) was identified in one patient. Baseline FDG-PET scans were obtained in 11/18 pts, and demonstrated avidity in all patients. Maximum SUV ranged from 4.1 to 47.6, with a median of 15. First line therapy was etoposide, doxorubicin, cisplatin, and mitotane (EDPM) in 13/18 pts and clinical trial with IMC-A12 (IGF-1 receptor antibody) in four pts. Median duration of first line therapy was 1.8 months (95% CI 0.9 – 2.8). Survival was not statistically different for patients receiving EDPM as first or second line therapy (median OS 23.3 vs 12.0 months, p = 0.96). Additional lines of therapy included EDPM, IMC-A12, AT-101, mifepristone, OSI-906 (IGF-1R inhibitor), and nivolumab. Median lines of therapy given were 2. The presence of bone metastases (p = 0.69) or lung metastases (p = 0.21) at the time of initiation of ST was not associated with OS from ST. Conclusions: In our experience, the prognosis of pts with metastatic ACC receiving systemic therapy is poor with most pts receiving ≤ 2 lines of therapy. Patients receiving first or second line EDPM seemed to have worse outcomes than noted in previously published trials, possibly due to our patients being sicker at baseline. Metastasis to the lung or bone at initiation of ST did not impact OS.

Appendiceal Mixed Adeno-Neuroendocrine Carcinoma: A Population-Based Study of the Surveillance, Epidemiology, and End Results Registry

INTRODUCTION

Mixed adeno-neuroendocrine carcinoma (MANEC) is a rare pathological diagnosis recently defined by the World Health Organization (WHO) in 2010. Prior to the definition by the WHO, tumors with both adenocarcinoma and neuroendocrine components were given multiple pathological designations making it difficult to characterize the disease. The aim of our study is to better characterize MANEC to better understand its natural history to influence patient care and positively impact outcomes.

MATERIALS AND METHODS

The surveillance, epidemiology, and end results program database was queried for all patients aged 18 years or older between 1973 and 2012 who had the diagnosis composite carcinoid (n = 249) of the appendix. Composite carcinoid tumors refer to tumors that have both adenocarcinoma and carcinoid tumor components present, consistent with that pathological diagnosis MANEC. For comparison, the database was also queried for carcinoid tumor of the appendix (n = 950), signet ring cell carcinoma of the appendix (n = 579), and goblet cell carcinoid (GCC) tumors of the appendix (n = 944). The data were retrospectively reviewed, and clinicopathological characteristics, treatment regimens, and survival data were obtained.

RESULTS

The median age of diagnosis of MANEC tumors was 58 years of age. Eighty percent of patients were White, and 49% were female. Fifty-four percent of patients underwent hemicolectomy and 31% had partial/subtotal colectomy as their surgical management. Median overall survival for MANEC was 6.5 years (95% CI 4.5-9.7), which was statistically significantly shorter (p < 0.0001) in comparison to 13.8 years (95% CI 12.1-16.5) for GCC, 2.1 years (95% CI 1.8-2.3) for signet ring cell carcinoma, and 39.4 years (95% CI 37.1-NA) for carcinoid tumors.

DISCUSSION

MANEC is a more aggressive clinical entity than both GCC of the appendix and carcinoid tumors of the appendix. Based on these findings, patients with MANEC tumors should undergo aggressive multidisciplinary cancer management.

Mixed Adeno-neuroendocrine Carcinoma: An Aggressive Clinical Entity

BACKGROUND

Mixed adeno-neuroendocrine carcinoma (MANEC) is a rare pathologic diagnosis recently defined by the World Health Organization in 2010. Due to poor understanding of MANEC as a clinical entity, there is significant variation in the management of these patients. The purpose of our study was to characterize MANEC to develop evidence-based treatment strategies.

METHODS

The Ohio State University patient database was queried for the diagnosis of MANEC and 46 patients were identified. For comparison, the database also was queried for goblet cell carcinoid (GCC) of the appendix, signet ring cell carcinoma, and carcinoid/neuroendocrine tumor of the appendix. Charts were then retrospectively reviewed for clinicopathologic characteristics, patient treatment, and survival data.

RESULTS

The mean age of diagnosis of MANEC was 54 years. Eighty-seven percent of MANEC arose from the appendix, with 28 % of patients undergoing appendectomy and 35 % undergoing right hemicolectomy as their index operation. Immunohistochemical staining was positive for chromogranin (82 %), synaptophysin (97 %), and CD56 (67 %). Sixty-seven percent of patients presented with stage IV disease and 41 % had nodal metastases. Overall survival was 4.1 years, which was statistically significantly different (p ≤ 0.05) compared with carcinoid tumors (13.4 years), GCC (15.4 years), and signet ring carcinoma (2.2 years).

CONCLUSIONS

MANEC is a more aggressive clinical entity than both GCC of the appendix and carcinoid/neuroendocrine tumors of the appendix. Based on these findings, we recommend patients with MANEC tumors undergo aggressive multidisciplinary cancer management and close surveillance.

Hyperthermic Intraperitoneal Chemotherapy Following Cytoreductive Surgery Improves Outcome in Patients With Primary Appendiceal Mucinous Adenocarcinoma: A Pooled Analysis From Three Tertiary Care Centers

PURPOSE

Appendiceal mucinous neoplasms (AMN) are a rare heterogeneous group of diseases. In the absence of randomized trials, AMN management is controversial. The goal of this study was to evaluate the impact of hyperthermic intraperitoneal chemotherapy (HIPEC) after cytoreductive surgery on survival in AMN patients.

PATIENTS AND METHODS

Patient data including demographics, pathology, type of therapy, and outcomes were collected from Emory University, the Ohio State University, and Wayne State University databases. One of the three centers did not use HIPEC. Statistical analysis evaluating overall survival (OS) of AMN patients was performed.

RESULTS

Between 1990 and 2010, 163 AMN patients were identified. Histology showed 60 patients had diffuse peritoneal adenomucinosis, 88 had peritoneal mucinous carcinomatosis (PMCA), and 15 had PMCA with indeterminate or discordant features. Complete surgical resection was achieved in 76 patients. HIPEC was used in 79 patients. The median OS was 77 months for patients who received HIPEC compared with 25 months for patients who did not (p < .001). In multivariable analysis, histopathologic subtype (p < .001), complete surgical resection (p < .001), and HIPEC (p < .001) were independent predictors for improved OS. A survival advantage for AMN patients treated at HIPEC-treating centers was observed (p = .0026). After adjusting for HIPEC therapy, no significant survival difference was observed between the non-HIPEC-treating center and the HIPEC-treating centers (p = .094).

CONCLUSION

The addition of HIPEC to cytoreductive surgery likely provides a survival advantage and should be considered in the treatment strategy for AMN.

Outcomes in patients with obstructive jaundice from metastatic colorectal cancer and implications for management

INTRODUCTION

Patients with metastatic colorectal cancer can develop jaundice from intrahepatic or extrahepatic causes. Currently, there is little data on the underlying causes and overall survival after onset of jaundice. The purpose of this study was to characterize the causes of jaundice and determine outcomes.

METHODS

Six hundred twenty-nine patients treated for metastatic colorectal cancer between 2004 and 2010 were retrospectively reviewed. Those developing jaundice were grouped as having intrahepatic or extrahepatic obstruction. Demographics, clinicopathologic, and outcome data were analyzed.

RESULTS

Sixty-two patients with metastatic colorectal cancer developed jaundice. Intrahepatic biliary obstruction was most common, occurring in younger patients. Time from metastatic diagnosis to presentation of jaundice was similar between groups, as was the mean number of prior lines of chemotherapy. Biliary decompression was successful 41.7 % of the time and was attempted more commonly for extrahepatic causes. Median overall survival after onset of jaundice was 1.5 months and it was similar between groups, but improved to 9.6 months in patients who were able to receive further chemotherapy.

CONCLUSIONS

Jaundice due to metastatic colorectal cancer is an ominous finding, representing aggressive tumor biology or exhaustion of therapies. Biliary decompression is often difficult and should only be pursued when additional treatment options are available.

A randomized prospective multicenter trial of pancreaticoduodenectomy with and without routine intraperitoneal drainage

OBJECTIVE

To test by randomized prospective multicenter trial the hypothesis that pancreaticoduodenectomy (PD) without the use of intraperitoneal drainage does not increase the frequency or severity of complications.

BACKGROUND

Some surgeons have abandoned the use of drains placed during pancreas resection.

METHODS

We randomized 137 patients to PD with (n = 68, drain group) and without (n = 69, no-drain group) the use of intraperitoneal drainage and compared the safety of this approach and spectrum of complications between the 2 groups.

RESULTS

There were no differences between drain and no-drain cohorts in demographics, comorbidities, pathology, pancreatic duct size, pancreas texture, baseline quality of life, or operative technique. PD without intraperitoneal drainage was associated with an increase in the number of complications per patient [1 (0-2) vs 2 (1-4), P = 0.029]; an increase in the number of patients who had at least 1 ≥grade 2 complication [35 (52%) vs 47 (68%), P = 0.047]; and a higher average complication severity [2 (0-2) vs 2 (1-3), P = 0.027]. PD without intraperitoneal drainage was associated with a higher incidence of gastroparesis, intra-abdominal fluid collection, intra-abdominal abscess (10% vs 25%, P = 0.027), severe (≥grade 2) diarrhea, need for a postoperative percutaneous drain, and a prolonged length of stay. The Data Safety Monitoring Board stopped the study early because of an increase in mortality from 3% to 12% in the patients undergoing PD without intraperitoneal drainage.

CONCLUSIONS

This study provides level 1 data, suggesting that elimination of intraperitoneal drainage in all cases of PD increases the frequency and severity of complications.

Effect of postoperative chemotherapy (CT) on survival in patients (pts) with resected rectal cancer who received neoadjuvant therapy

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Background: Pts with stage II/III rectal cancers are treated with neoadjuvant chemoradiation and surgical resection followed by adjuvant CT per practice guidelines. It is unclear whether adjuvant CT provides survival benefit, and the purpose of this study was to measure outcome in pts who did and did not receive adjuvant CT. Methods: We used a prospectively collected database for pts treated at The Ohio State University and analyzed overall survival (OS), time to recurrence (TTR), pt characteristics, tumor features, and treatments. Survival curves were estimated using Kaplan-Meier method and compared by the log-rank test. Age was compared using the Wilcoxon test, and other categorical variables were compared using Chi-square test or Fisher’s exact test. Results: Between August, 2005 to July, 2011, 110 pts were identified and 71 pts had received adjuvant CT. There was no significant difference in sex, race, pathologic tumor (T) stage, and pathologic complete response between the two groups. Pts receiving adjuvant CT were significantly younger (median age 54.3 vs. 62 years, p=0.01) and had more advanced pathologic nodal (N) stage (43 vs. 19% N1 or N2, p=0.02). Median OS was 72.6 months with CT vs. 36.4 months without CT (p=0.0003). Median TTR has not yet been reached. Conclusions: In this retrospective analysis, adjuvant CT was associated with a longer OS despite more advanced pathologic nodal staging. Prospective randomized studies are warranted to determine whether adjuvant CT provides a survival benefit for pts across the spectrum of stage II and III rectal cancer. [Table: see text]

Survival differences in patients (pts) with resected rectal cancer who received neoadjuvant therapy with or without postoperative chemotherapy (CT)

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Background: Pts with stage II/III rectal cancers are treated with neoadjuvant chemoradiation and surgical resection followed by adjuvant CT per practice guidelines. It is unclear whether adjuvant CT provides survival benefit, and the purpose of this study was to measure outcome in pts who did and did not receive adjuvant CT. Methods: We used a prospectively collected database for pts treated at The Ohio State University, and analyzed overall survival (OS), time to recurrence (TTR), pt characteristics, tumor features, and treatments. Survival curves were estimated using Kaplan-Meier method and compared by the log-rank test. Age was compared using the Wilcoxon test, and other categorical variables were compared using Chi-square test or Fisher’s exact test. Results: Between August 2005 to July 2011, 110 pts were identified and 71 pts had received adjuvant CT. There was no significant difference in sex, race, pathologic tumor (T) stage, and pathologic complete response between the two pt groups. Pts receiving adjuvant CT were significantly younger (median age 54.3 vs. 62 years, p=0.01) and had more advanced pathologic nodal (N) stage (43 vs. 19%, p=0.02). Median OS was 72.6 months with CT vs. 36.4 months without CT (p=0.0003). Median TTR has not yet been reached. Conclusions: In this retrospective analysis, adjuvant CT was associated with a longer OS despite more advanced pathologic nodal staging. Prospective randomized studies are warranted to determine whether adjuvant CT provides a survival benefit for pts across the spectrum of stage II and III rectal cancer. [Table: see text]

Influence of KRAS mutation status in metachronous and synchronous metastatic colorectal adenocarcinoma

BACKGROUND

Mutations in the v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) are present in approximately 30% to 40% of colorectal adenocarcinomas. Wild-type (WT) KRAS mutation status is predictive of tumor response with epidermal growth factor receptor-directed therapies, but the results from studies evaluating the prognostic value of KRAS status in localized disease have been contradictory. The prognostic value of KRAS in metastatic disease, specifically according to whether patients have synchronous or metachronous disease at presentation, is less understood.

METHODS

One-hundred ten consecutive patients with metastatic colorectal adenocarcinoma underwent testing for KRAS exon 2 mutations by polymerase chain reaction amplification and direct nucleotide sequencing. The clinical characteristics, treatments, and outcomes of these patients were then analyzed retrospectively, stratified according to whether patients presented with synchronous or metachronous metastasis and according to KRAS mutation status (WT or mutated).

RESULTS

For the entire cohort, the median overall survival from the date of diagnosis of metastatic disease was 34.3 months (95% confidence interval, 28.3-49.4 months) for patients with WT KRAS (n = 70). The median overall survival for patients with mutated KRAS (n = 40) was 40.3 months (95% confidence interval, 27.9-51.1 months; log-rank P = .91). Kaplan-Meier survival analysis indicated that 3-year overall survival and 5-year overall survival were not statistically different. Within the subgroups of patients with synchronous and metachronous metastatic disease, no significant differences were observed in median overall survival, 3-year overall survival, or 5-year overall survival between the WT KRAS and mutated KRAS groups.

CONCLUSIONS

In this study, KRAS mutation status did not influence overall survival in either synchronous or metachronous metastatic colorectal adenocarcinoma and, as such, had no prognostic role in this disease setting.

Repeat hepatectomy for metastatic colorectal cancer is safe but marginally effective

BACKGROUND

Although hepatectomy for metastatic colorectal cancer (mCRC) offers prolonged survival in up to 40% of people, recurrence rates are high, approaching 70%. Many patients experience recurrent disease in the liver after initial hepatectomy. We examined our experience with repeat hepatectomy for mCRC.

METHODS

After Institutional Review Board approval, we reviewed the records of all patients at a single institution who underwent hepatectomy for mCRC. Repeat hepatectomy was defined as partial liver resection any time after the initial hepatectomy for recurrent mCRC. We estimated time to recurrence and survival by using the Kaplan-Meier method and compared outcomes between groups by using the log-rank test.

RESULTS

From 1998 to 2008, 405 patients underwent hepatectomy for mCRC, and 215 (53%) experienced disease recurrence at a median of 13 months. Of 150 patients with liver-only or liver-predominant recurrence, 52 (35%) underwent repeat hepatectomy. The median time to recurrence after repeat hepatectomy was 10 months, and median overall survival was 19 months. There was one (1.9%) perioperative death, and there were 14 (27%) major complications. The median overall survival in the repeat hepatectomy group from the time of recurrence after initial hepatectomy was 22 months, compared with 15 months in the 98 patients with liver recurrence who were not selected for repeat hepatectomy (P=0.02).

CONCLUSIONS

Repeat hepatectomy for mCRC is feasible in highly selected patients, with acceptable perioperative morbidity and mortality. Although repeat hepatectomy should be considered, recurrence rates are high. Although the initial hepatectomy for mCRC is potentially curative, recurrence of metastatic disease in the liver is unlikely to be cured.

Surgical management of colorectal cancer: A review of the literature

BACKGROUND

Colon cancer management continues to evolve with significant advances in chemotherapy, surgical technique and palliative interventions. As the options of therapy have improved, so have the challenges of management of primary colon cancer.

REVIEW

A review of historical and up to date literature was undertaken utilising Medline/PubMed to examine relevant topics of interest-related to the surgical management. Enhanced knowledge of genetics associated with colon cancer has improved our care of patients with hereditary colon cancer syndromes. Additionally, traditional approaches to surgical intervention for primary colon cancer have been questioned and will be discussed in this review including the role of laparoscopy, use of mechanical bowel preparation, management of the primary tumour in the face of metastatic disease, as well as the role of palliative intervention in select patients.

CONCLUSION

Colon cancer has seen improvement and expansion of therapeutic approaches to primary colon cancer. Laparoscopy and palliative interventions have become widely accepted with level I evidence to demonstrate good patient outcomes. Traditional dogma with mechanical bowel preparation has been challenged and debunked with regards to the efficacious benefits previously accepted. The management of the primary tumour has now become increasingly complex as it appears to be a reasonable approach to manage the primary tumour non-operatively in select cases of extracolonic disease requiring management.

Perioperative (18)F-fluorodeoxyglucose-guided imaging using the becquerel as a quantitative measure for optimizing surgical resection in patients with advanced malignancy

BACKGROUND

(18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) scanning is a widely accepted preoperative tumor imaging modality. Herein, we evaluate the becquerel (Bq) as a potential novel quantitative PET measure for application of surgical specimen imaging.

METHODS

Retrospectively, PET-avid lesions that could be followed from preoperative imaging, confidently identified in the operating room, imaged ex vivo, and correlated with histopathology were included in this study. Bq counts from both in vivo (preoperative) and ex vivo (surgical specimen) PET/CT images were measured and correlated with histopathology.

RESULTS

Fifty-five PET-avid lesions in 37 patients were included. Forty-six of 55 PET-avid lesions identified were found to contain malignancy on histopathology. Mean Bq counts for the PET-avid lesions were significantly higher that the adjacent PET-nonavid areas (background) within both in vivo and ex vivo imaging (P < .001 and P < .001, respectively). When analyzing all 55 lesions, we found significant increases in Bq levels. PET-avid lesions from in vivo to ex vivo images (P < .001) without significant increases in Bq levels in PET-nonavid lesions from in vivo to ex vivo images (P = .06). When comparing Bq levels between the 2 groups (malignant and benign), we found significantly higher Bq counts in the malignant group on in vivo imaging (P = .02) as well as significantly lower Bq counts in FDG-nonavid areas on ex vivo imaging (P = .04) within the malignant group. Significant differences in PET-avid to PET-nonavid Becquerels ratios within both in vivo and ex vivo images (P = .004, P = .002 respectively) were found, with ex vivo ratio being significantly higher (P < .001).

CONCLUSIONS

(18)F-FDG PET/CT imaging using Bqs is the potential to discern malignant lesions from benign tissues within both in vivo and ex vivo scans.