Explainable Machine Learning Model to Preoperatively Predict Postoperative Complications in Inpatients With Cancer Undergoing Major Operations.

PURPOSE: Preoperative prediction of postoperative complications (PCs) in inpatients with cancer is challenging. We developed an explainable machine learning (ML) model to predict PCs in a heterogenous population of inpatients with cancer undergoing same-hospitalization major operations. METHODS: Consecutive inpatients who underwent same-hospitalization operations from December 2017 to June 2021 at a single institution were retrospectively reviewed. The ML model was developed and tested using electronic health record (EHR) data to predict 30-day PCs for patients with Clavien-Dindo grade 3 or higher (CD 3+) per the CD classification system. Model performance was assessed using area under the receiver operating characteristic curve (AUROC), area under the precision recall curve (AUPRC), and calibration plots. Model explanation was performed using the Shapley additive explanations (SHAP) method at cohort and individual operation levels. RESULTS: A total of 988 operations in 827 inpatients were included. The ML model was trained using 788 operations and tested using a holdout set of 200 operations. The CD 3+ complication rates were 28.6% and 27.5% in the training and holdout test sets, respectively. Training and holdout test sets' model performance in predicting CD 3+ complications yielded an AUROC of 0.77 and 0.73 and an AUPRC of 0.56 and 0.52, respectively. Calibration plots demonstrated good reliability. The SHAP method identified features and the contributions of the features to the risk of PCs. CONCLUSION: We trained and tested an explainable ML model to predict the risk of developing PCs in patients with cancer. Using patient-specific EHR data, the ML model accurately discriminated the risk of developing CD 3+ complications and displayed top features at the individual operation and cohort level.

Combined Liver and Colon Resection of Synchronous Colorectal Liver Metastases at a Quaternary Center.

INTRODUCTION: Existing literature on the safety of combined liver and colorectal resections for synchronous colorectal liver metastases is mixed. Using a retrospective review of our institutional data, we aimed to show that combined colorectal and liver resections for synchronous metastases is both feasible and safe in a quaternary center. METHODS: A retrospective review of combined resections for synchronous colorectal liver metastases at a quaternary referral center from 2015 to 2020 was completed. Clinicopathologic and perioperative data was collected. Univariate and multivariable analyses were performed to identify risk factors for major postoperative complications. RESULTS: One hundred one patients were identified, with 35 undergoing major liver resections ( ≥ 3 segments) and 66 undergoing minor liver resections. The vast majority of patients (94%) received neoadjuvant therapy. There was no difference in postoperative major complications (Clavien-Dindo grade 3+) between major and minor liver resections (23.9% versus 12.1%, P = 0.16). On univariate analysis, Albumin-Bilirubin (ALBI) score >1 (P < 0.05) was predictive of major complication. However, on multivariable regression analysis, no factor was associated with significantly increased odds of major complication. CONCLUSIONS: This work demonstrates that with thoughtful patient selection, combined resection for synchronous colorectal liver metastases can be safely performed at a quaternary referral center.

Unconscious Bias in Speaker Introductions at a Surgical Oncology Meeting: Hierarchy Reigns Over Gender.

BACKGROUND: Recent reviews of medical conferences have shown that women were less likely to receive a formal introduction compared with men. We examined speaker introductions at the Society of Surgical Oncology (SSO) annual meeting to determine whether similar biases exist within our organization. METHODS: An observational study of video-archived speaker introductions at the 2018 and 2019 SSO annual meetings was conducted. Professional address was defined as professional title followed by full name or last name. Multivariable logistic regression was used to identify factors associated with form of address. RESULTS: There were 499 speaker introductions reviewed. Speakers included 290 (58%) men and 238 (49%) post-graduate trainees (residents and fellows). A non-professional form of address was used to introduce 148 (30%) speakers and was most often used for post-graduate trainees (33%). Full professors were more likely than junior faculty to introduce speakers with a non-professional form of address (37% of full professors vs 18% of assistant professors, p < 0.001). In multivariable regression analysis these findings persisted. Trainees were 2.8 times more likely to receive a non-professional form of address (p = 0.003). Use of a non-professional introduction did not significantly vary by the speaker's nor the introducer's gender. CONCLUSIONS: Residents and fellows were more likely to receive a non-professional form of address, and the likelihood of this increased with rising seniority of the introducer. The manner of speaker introduction did not vary by gender in our organization. More research is needed to explore the influence of these disparities on academic advancement for the next generation of surgical oncologists.

Management Considerations for the Surgical Treatment of Colorectal Cancer During the Global Covid-19 Pandemic.

OBJECTIVE: The COVID-19 pandemic requires to conscientiously weigh "timely surgical intervention" for colorectal cancer against efforts to conserve hospital resources and protect patients and health care providers. SUMMARY BACKGROUND DATA: Professional societies provided ad-hoc guidance at the outset of the COVID-19 pandemic on deferral of surgical and perioperative interventions, but these lack specific parameters to determine the optimal timing of surgery. METHODS: Using the GRADE system, published evidence was analyzed to generate weighted statements for stage, site, acuity of presentation, and hospital setting to specify when surgery should be pursued, the time and duration of oncologically acceptable delays, and when to utilize nonsurgical modalities to bridge the waiting period. RESULTS: Colorectal cancer surgeries-prioritized as emergency, urgent with imminent emergency or oncologically urgent, or elective-were matched against the phases of the pandemic. Surgery in COVID-19-positive patients must be avoided. Emergent and imminent emergent cases should mostly proceed unless resources are exhausted. Standard practices allow for postponement of elective cases and deferral to nonsurgical modalities of stage II/III rectal and metastatic colorectal cancer. Oncologically urgent cases may be delayed for 6(-12) weeks without jeopardizing oncological outcomes. Outside established principles, administration of nonsurgical modalities is not justified and increases the vulnerability of patients. CONCLUSIONS: The COVID-19 pandemic has stressed already limited health care resources and forced rationing, triage, and prioritization of care in general, specifically of surgical interventions. Established guidelines allow for modifications of optimal timing and type of surgery for colorectal cancer during an unrelated pandemic.

Fine-needle aspiration biopsy of thyroid nodules: Is routine ultrasound-guidance necessary?

BACKGROUND: Current guidelines recommend either ultrasound-guided or palpation-guided fine-needle aspiration biopsy for evaluation of a thyroid nodule. However, it has been suggested that ultrasound-guided fine-needle aspiration biopsy should be used routinely in all patients to reduce the rate of nondiagnostic and false negative results. The purpose of this study was to determine whether any difference exists in nondiagnostic and false negative rates between the two methods of fine-needle aspiration biopsy at our institution. METHODS: A retrospective review of a prospectively maintained thyroid database was completed to determine the rates of nondiagnostic and false negative fine-needle aspiration biopsy in patients with nodular thyroid disease evaluated during the period 1990-2017. RESULTS: From 1990 to 2017, a total of 2,322 patients underwent fine-needle aspiration biopsy for evaluation of nodular thyroid disease, 1,123 (48%) underwent ultrasound-guided fine-needle aspiration biopsy and 1,199 (52%) underwent palpation-guided fine-needle aspiration biopsy. Ultrasound-guided fine-needle aspiration biopsy was nondiagnostic in 4.5% and had a 5.2% false negative rate, compared with palpation-guided fine-needle aspiration biopsy, which was nondiagnostic in 5.0% and had a 2.6% false negative rate (P = .53 and .14, respectively). CONCLUSION: The rate of nondiagnostic and false negative fine-needle aspiration biopsy results is similar whether US guidance is used or not. To minimize resource utilization, ultrasound-guided fine-needle aspiration biopsy can be used selectively for nonpalpable, predominantly cystic, or previously nondiagnostic nodules.

Systemic administration of ß-glucan of 200 kDa modulates melanoma microenvironment and suppresses metastatic cancer.

Converting an immunosuppressive melanoma microenvironment into one that favors the induction of antitumor immunity is indispensable for effective cancer immunotherapy. In the current study we demonstrate that oat-derived ß-(1-3)-(1-4)-glucan of 200 kDa molecular size (BG34-200) previously shown to mediate direct interaction with macrophages could alter the immune signature within melanoma microenvironment. Systemic administration of BG34-200 resulted in reversion of tolerant melanoma microenvironment to an immunogenic one that allows M1-type activation of macrophages, the induction of pro-inflammatory cytokines/chemokines including IFN-γ, TNF-α, CXCL9, and CXCL10, and enhanced IRF1 and PD-L1 expression. In turn, BG34-200 induced a superior antitumor response against primary and lung metastatic B16F10 melanoma compared to untreated controls. The enhanced tumor destruction was accompanied with significantly increased tumor infiltration of CD4+ and CD8+ T cells as well as elevated IFN-γ in the tumor sites. Systemic administration of BG34-200 also provoked systemic activation of tumor draining lymph node T cells that recognize antigens naturally expressing in melanoma (gp100/PMEL). Mechanistic studies using CD11b-knockout (KO), CD11 c-DTR transgenic mice and nude mice revealed that macrophages, DCs, T cells and NK cells were all required for the BG34-200-induced therapeutic benefit. Studies using IFN-γ-KO transgenic mice showed that IFN-γ was essential for the BG34-200-elicited antitumor response. Beyond melanoma, the therapeutic efficacy of BG34-200 and its immune stimulating activity were demonstrated in a mouse model of osteosarcoma. Together, BG34-200 is highly effective in modulating antitumor immunity. Our data support the potential therapeutic use of this novel immune modulator in the treatment of metastatic melanoma.

Pancreatoduodenectomy after Roux-en-Y gastric bypass: technical considerations and outcomes.

BACKGROUND: Patients with altered anatomy due to Roux-en-Y gastric bypass (RYGB) present unique diagnostic and therapeutic challenges when they present with periampullary pathology. We describe a series of patients who underwent pancreatoduodenectomy (PD) after gastric surgery with Roux-en-Y reconstruction and review the literature to highlight technical considerations and outcomes. METHODS: Patients from two institutions were identified and data regarding preoperative workup, operative conduct, and pathologic and clinical outcomes were collected. RESULTS: Eleven patients were included in the institutional series. At the time of periampullary pathology, the median age was 64 years and time since RYGB was 10 years. Median operative time was 361 minutes, estimated blood loss was 500 mLs, and length of stay was 6 days. Remnant gastrectomy was performed in nine patients and reconstruction was performed using the biliopancreatic limb (BP) without revision of the jejuno-jejunostomy in ten patients. Pathology revealed pancreatic cancer (8), chronic pancreatitis (2), and duodenal cancer (1). Three patients experienced major complications and there were no 90-day mortalities. CONCLUSION: Pancreatic surgeons will see an increasing number of patients with Roux-en-Y anatomy who will require evaluation and resection for periampullary diseases. For PD after RYGB, we recommend remnant gastrectomy with reconstruction using the BP limb.

Surgical Therapy for Pancreatic and Periampullary Cancer.

Surgery is the key component of treatment for pancreatic and periampullary cancers. Pancreatectomy is complex, and there are numerous perioperative and intraoperative factors that are important for achieving optimal outcomes. This article focuses specifically on key aspects of the surgical management of periampullary and pancreatic cancers.

Thyroid cancer in patients with toxic nodular goiter--is the incidence increasing?

BACKGROUND: There has been a dramatic increase in the incidence of thyroid cancer, but it is unclear if this has occurred in patients with toxic nodular goiter (TNG). METHODS: TNG was defined as one or more thyroid nodules in combination with a low serum TSH level. Patients who underwent thyroidectomy for TNG were identified from a prospectively maintained database. The rates of incidental thyroid cancer were compared over the intervals 1990 to 1999, 2000 to 2009, and 2010 to 2014. RESULTS: There was no significant difference in cancer rate between the 3 time periods. Overall, 7 (4.7%) of the 148 patients had thyroid cancer; similarly, 1 (3.2%) of the 31 patients from 1990 to 1999, 3 (4.2%) of 72 patients from 2000 to 2009, and 3 (6.7%) of the 45 patients from 2010 to 2014 (P > .05) had thyroid cancer. CONCLUSIONS: No significant increase in the rate of carcinoma was observed in patients with TNG. As a result, the risk benefit analysis should not change when considering therapeutic options for TNG.

ortho-Quinone methides from para-quinones: total synthesis of rubioncolin B.

A concise synthesis of rubioncolin B is described, which features an unprecedented intramolecular Diels-Alder reaction involving an ortho-quinone methide and a naphthofuran moiety. The ortho-quinone methide is generated through a surprisingly facile tautomerization of a para-quinone.

Transient left ventricular dilatation in the absence of epicardial disease on angiography.

A 58-year-old woman with a previous anterior myocardial infarction, recurrent chest pain, transient adenosine-induced left ventricular dilatation but no apparent epicardial disease on angiography is presented. Transient ischemic dilatation during myocardial perfusion imaging, and the reported causes of transient left ventricular dilatation in the absence of epicardial disease, are discussed.