Faculty Bibliography

Colorectal cancer is the third most common cancer in the United States and the second most common cause of cancer-related death. Approximately 20-30% of patients will develop hepatic metastasis in the form of synchronous or metachronous disease. The treatment of colorectal liver metastasis (CRLM) has evolved into a multidisciplinary approach, with chemotherapy and a variety of locoregional treatments, such as ablation and portal vein embolization, playing a crucial role. However, resection remains a core tenet of management, serving as the gold standard for a curative-intent therapy. As such, the input of a dedicated hepatobiliary surgeon is paramount for appropriate patient selection and choice of surgical approach, as significant advances in the field have made management decisions extremely nuanced and complex. We herein aim to review the contemporary surgical management of colorectal liver metastasis with respect to both perioperative and operative considerations.

OBJECTIVES:We aimed to determine whether surgeon variation in management of intraductal papillary mucinous neoplasm (IPMN) is driven by differences in risk perception and quantify surgeons' risk threshold for changing their recommendations. BACKGROUND:Surgeons vary widely in management of IPMN. METHODS:We conducted a survey of members of the Americas HepatoPancreatoBiliary Association, presented participants with 2 detailed clinical vignettes and asked them to choose between surgical resection and surveillance. We also asked them to judge the likelihood that the IPMN harbors cancer and that the patient would have a serious complication if surgery was performed. Finally, we asked surgeons to rate the level of cancer risk at which they would change their treatment recommendation. We examined the association between surgeons' treatment recommendations and their risk perception and risk threshold. RESULTS:One hundred fifty surgeons participated in the study. Surgeons varied in their recommendations for surgery [19% for vignette 1 (V1) and 12% for V2] and in their perception of the cancer risk (interquartile range: 2%-10% for V1 and V2) and risk of surgical complications (V1 interquartile range: 10%-20%, V2 20-30%). After adjusting for surgeon characteristics, surgeons who were above the median in cancer risk perception were 22 percentage points (27% vs 5%) more likely to recommend resection than those who were below the median (95% CI: 11%-4%; P <0.001). The median risk threshold at which surgeons would change their recommendation was 15% (V1 and V2). Surgeons who recommended surgery had a lower risk threshold for changing their recommendation than those who recommended surveillance (V1: 10.0 vs 15.0, P =0.06; V2: 7.0 vs 15.0, P =0.05). CONCLUSIONS:The treatment that patients receive for IPMNs depends greatly on how their surgeons perceive the risk of cancer in the lesion. Efforts to improve cancer risk prediction for IPMNs may lead to decreased variations in care.

OBJECTIVES/OBJECTIVE:We aimed to determine whether surgeon variation in management of IPMN is driven by differences in risk perception and quantify surgeons' risk threshold for changing their recommendations. SUMMARY BACKGROUND DATA/BACKGROUND:Surgeons vary widely in management of intraductal papillary mucinous neoplasms (IPMN). METHODS:We conducted a survey of members of the Americas HepatoPancreatoBiliary Association (AHPBA), presented participants with 2 detailed clinical vignettes and asked them to choose between surgical resection and surveillance. We also asked them to judge the likelihood that the IPMN harbors cancer and that the patient would have a serious complication if surgery was performed. Finally, we asked surgeons to rate the level of cancer risk at which they would change their treatment recommendation. We examined the association between surgeons' treatment recommendations and their risk perception and risk threshold. RESULTS:150 surgeons participated in the study. Surgeons varied in their recommendations for surgery (19% for vignette 1 (V1) and 12% for V2) and in their perception of the cancer risk (interquartile range [IQR] 2-10% for V1 and V2) and risk of surgical complications (V1 IQR 10-20%, V2 20-30%). After adjusting for surgeon characteristics, surgeons who were above the median in cancer risk perception were 22 percentage points (27% vs. 5%) more likely to recommend resection than those who were below the median (95% CI 11,34%; P<0.001). The median risk threshold at which surgeons would change their recommendation was 15% (V1 and V2). Surgeons who recommended surgery had a lower risk threshold for changing their recommendation than those who recommended surveillance (V1: 10.0 vs. 15.0, P=0.06; V2: 7.0 vs. 15.0, P=0.05). CONCLUSIONS:The treatment that patients receive for IPMNs depends greatly on how their surgeons perceive the risk of cancer in the lesion. Efforts to improve cancer risk prediction for IPMNs may lead to decreased variations in care.

OBJECTIVE:To evaluate long-term oncologic outcomes of patients with stage IV pancreatic ductal adenocarcinoma (PDAC) and identify survival benchmarks for comparison when considering resection in these patients. SUMMARY BACKGROUND DATA/BACKGROUND:Highly selected cohorts of patients with liver-oligometastatic pancreas cancer have reported prolonged survival following resection. The long-term impact of surgery in this setting remains undefined due to a lack of appropriate control groups. METHODS:We identified patients with clinical stage IV PDAC with synchronous liver metastases within our cancer registry. We estimated overall survival (OS) among various patient subgroups using the Kaplan-Meier method. To mitigate immortal time bias, we analyzed long-term outcomes of patients who survived beyond 12 months (landmark time) from diagnosis. RESULTS:We identified 241 patients. Median OS was 7 months (95%CI 5-9), both overall and for patients with liver-only metastasis (n=144). Ninety patients (38% of liver-only; 40% of whole cohort) survived at least 12 months; those who received chemotherapy in this subgroup had a median OS of 26 months (95%CI 17-39). Of these patients, those with resectable or borderline resectable primary tumors and resectable liver-only metastasis (n=9, 4%) had a median OS of 39 months (95%CI 13-NR). CONCLUSIONS:The 4% of our cohort that were potentially eligible for surgery experienced a prolonged survival compared to all-comers with stage IV disease. Oncologic outcomes of patients undergoing resection of metastatic pancreas cancer should be assessed in the context of the expected survival of patients potentially eligible for surgery and not relative to all patients with stage IV disease.

INTRODUCTION/BACKGROUND:There is no consensus regarding the role of primary tumor resection for patients with metastatic pancreatic neuroendocrine tumors (panNET). We assessed surgical treatment patterns and evaluated the survival impact of primary tumor resection in patients with metastatic panNET. METHODS:Patients with synchronous metastatic nonfunctional panNET in the National Cancer Database (2004-2016) were categorized based on whether they underwent primary tumor resection. We used logistic regressions to assess associations with primary tumor resection. We performed survival analyses with Kaplan-Meier survival functions, log-rank test, and Cox proportional hazard regression within a propensity score matched cohort. RESULTS:In the overall cohort of 2613 patients, 68% (n = 839) underwent primary tumor resection. The proportion of patients who underwent primary tumor resection decreased over time from 36% (2004) to 16% (2016, p < 0.001). After propensity score matching on age at diagnosis, median income quartile, tumor grade, size, liver metastasis, and hospital type, primary tumor resection was associated with longer median overall survival (OS) (65 vs. 24 months; p < 0.001) and was associated with lower hazard of mortality (HR: 0.39, p < 0.001). CONCLUSION/CONCLUSIONS:Primary tumor resection was significantly associated with improved OS, suggesting that, if feasible, surgical resection can be considered for well-selected patients with panNET and synchronous metastasis.

BACKGROUND:Time to treatment (TTT) varies widely for patients with gastric cancer. We aimed to evaluate relationships between time to treatment, overall survival (OS), and other surgical outcomes in patients with stage I-III gastric cancer. METHODS:We identified patients with clinical stage I-III gastric cancer who underwent curative-intent gastrectomy within the National Cancer Database (2006-2015) and grouped them by treatment sequence: neoadjuvant chemotherapy or surgery upfront. We defined TTT as weeks from diagnosis to treatment initiation (neoadjuvant chemotherapy or definitive surgical procedure, respectively). Survival differences were assessed by Kaplan-Meier estimate, Cox proportional hazard regression, and log rank test. RESULTS:Among the 22,846 patients with stage I-III gastric cancer, most (56%) received surgery upfront. Median TTT was 5 weeks (IQR 4-7) and 6 weeks (IQR 3-9) for patients in the neoadjuvant and surgery upfront groups, respectively. In the neoadjuvant group, increasing TTT was significantly associated with increasing median OS up to TTT of 5 weeks, with no change in median OS when TTT was > 5 weeks. In the surgery group, increasing TTT was significantly associated with increasing median OS up to 6 weeks; however, increasing TTT between 14 and 21 weeks was associated with decreasing median OS. CONCLUSIONS:The relationship between time to treatment and survival outcomes is non-linear. Among patients who underwent surgery upfront, the relationship between time to treatment and OS was bimodal, suggesting that deferring definitive surgery, up to 14 weeks, is not associated with worse OS or oncologic outcomes. The relationship between time to treatment and overall survival among patients was bimodal, suggesting that deferring definitive surgery up to 14 weeks is not associated with worse OS.

BACKGROUND:Adherence to evidence-based guidelines for gastric cancer is low, particularly at the hospital level, despite a strong association with improved overall survival (OS). We aimed to evaluate patterns of hospital and regional adherence to National Comprehensive Cancer Network guidelines for gastric cancer. METHODS:Using the National Cancer Database (2004-2015), we identified patients with stage I-III gastric cancer. Hospital-level guideline adherence was calculated by dividing the patients who received guideline adherent care by the total patients treated at that hospital. OS was estimated for each hospital. Associations between adherence, region, and survival were compared using mixed-effects, hierarchical regression. RESULTS:Among 576 hospitals, the median hospital guideline adherence rate was 25% (range 0-76%) and varied significantly by region (p = 0.001). Adherence was highest in the Middle Atlantic (29%) and lowest in the East South Central region (19%); hospitals in the New England, Middle Atlantic, and East North Central regions were more likely to be guideline adherent than those in the East South Central region (all p < 0.05), after adjusting for patient and hospital mix. Most (35%) of the adherence variation was attributable to the hospital. Median 2-year OS varied significantly by region. After adjusting for hospital and patient mix, hazard of mortality was 17% lower in the Middle Atlantic (hazard ratio 0.82, 95% confidence interval 0.74-0.90) relative to the East South Central region, with most of the variation (54%) attributable to patient-level factors. CONCLUSIONS:Hospital-level guideline adherence for gastric cancer demonstrated significant regional variation and was associated with longer OS, suggesting that efforts to improve guideline adherence should be directed toward lower-performing hospitals.

BACKGROUND AND OBJECTIVES/OBJECTIVE:The recent de-escalation of care for differentiated thyroid cancer (DTC) has broadened the range of initial treatment options. We examined the association between physicians' perception of risk and their management of DTC. METHODS:Thyroid specialists were surveyed with four clinical vignettes: (1) indeterminate nodule (2) tall cell variant papillary thyroid cancer (PTC), (3) papillary thyroid microcarcinoma (mPTC), and (4) classic PTC. Participants judged the operative risks and likelihood of structural cancer recurrence associated with more versus less aggressive treatments. A logistic mixed effect model was used to predict treatment choice. RESULTS:Among 183 respondents (13.4% response rate), 44% were surgical and 56% medical thyroid specialists. Risk estimates and treatment recommendation varied markedly in each case. Respondents' estimated risk of 10-year cancer recurrence after lobectomy for a 2.0-cm PTC ranged from 1% to 53% (interquartile range [IQR]: 3%-12%), with 66% recommending lobectomy and 34% total thyroidectomy. Respondents' estimated 5-year risk of metastastic disease during active surveillance of an 0.8-cm mPTC ranged from 0% to 95% (IQR: 4%-15%), with 36% choosing active surveillance. Overall, differences in perceived risk reduction explained 10.3% of the observed variance in decision-making. CONCLUSIONS:Most of the variation in thyroid cancer treatment aggressiveness is unrelated to perceived risk of cancer recurrence.