Dhruvil R. Shah

Current oncologic applications of radiofrequency ablation therapies

Radiofrequency ablation (RFA) uses high frequency alternating current to heat a volume of tissue around a needle electrode to induce focal coagulative necrosis with minimal injury to surrounding tissues. RFA can be performed via an open, laparoscopic, or image guided percutaneous approach and be performed under general or local anesthesia. Advances in delivery mechanisms, electrode designs, and higher power generators have increased the maximum volume that can be ablated, while maximizing oncological outcomes. In general, RFA is used to control local tumor growth, prevent recurrence, palliate symptoms, and improve survival in a subset of patients that are not candidates for surgical resection. Its equivalence to surgical resection has yet to be proven in large randomized control trials. Currently, the use of RFA has been well described as a primary or adjuvant treatment modality of limited but unresectable hepatocellular carcinoma, liver metastasis, especially colorectal cancer metastases, primary lung tumors, renal cell carcinoma, boney metastasis and osteoid osteomas. The role of RFA in the primary treatment of early stage breast cancer is still evolving. This review will discuss the general features of RFA and outline its role in commonly encountered solid tumors.

Text Messaging Among Residents and Faculty in a University General Surgery Residency Program: Prevalence, Purpose, and Patient Care

BACKGROUND There is little information about the use of text messaging (texting) devices among resident and faculty physicians for patient-related care (PRC). OBJECTIVE To determine the prevalence, frequency, purpose, and concerns regarding texting among resident and attending surgeons and to identify factors associated with PRC texting. DESIGN E-mail survey. SETTING University medical center and its affiliated hospitals. PARTICIPANTS Surgery resident and attending staff. OUTCOME MEASURES Prevalence, frequency, purpose, and concerns regarding patient-related care text messaging. RESULTS Overall, 73 (65%) surveyed physicians responded, including 45 resident (66%) and 28 attending surgeons (62%). All respondents owned a texting device. Majority of surgery residents (88%) and attendings (71%) texted residents, whereas only 59% of residents and 65% of attendings texted other faculty. Most resident to resident text occurred at a frequency of 3-5 times/d (43%) compared with most attending to resident texts, which occurred 1-2 times/d (33%). Most resident to attending (25%) and attending to attending (30%) texts occurred 1-2 times/d. Among those that texted, PRC was the most frequently reported purpose for resident to resident (46%), resident to attending (64%), attending to resident (82%), and attending to other attending staff (60%) texting. Texting was the most preferred method to communicate about routine PRC (47% of residents vs 44% of attendings). Age (OR: 0.86, 95% CI: 0.79-0.95; p = 0.003), but not sex, specialty/clinical rotation, academic rank, or postgraduate year (PGY) level predicted PRC texting. CONCLUSIONS Most resident and attending staff surveyed utilize texting, mostly for PRC. Texting was preferred for communicating routine PRC information. Our data may facilitate the development of guidelines for the appropriate use of PRC texting.

Treatment Options for Metaplastic Breast Cancer

Metaplastic breast cancer (MBC) is a malignancy characterized by the histologic presence of two or more cellular types, commonly a mixture of epithelial and mesenchymal components. MBC is rare relative to invasive ductal carcinoma (IDC), representing less than 1% of all breast cancers. Other than a lower rate of lymph node metastases, MBC tumors display poorer prognostic features relative to IDC. Due to its low incidence and pathological variability, the ideal treatment paradigm for MBC is unknown. Because of its rarity, MBC has been treated as a variant of IDC. Despite similar treatment regimens, however, patients with MBC have worse outcomes. Recent research is focused on biological differences between MBC and IDC and potential novel targets for chemotherapeutic agents. This paper serves as a summation of current literature on approaches to the multidisciplinary treatment of patients with MBC.

Nomograms to predict risk of in-hospital and post-discharge venous thromboembolism after abdominal and thoracic surgery: an American College of Surgeons National Surgical Quality Improvement Program analysis

BACKGROUND Postoperative venous thromboembolism (VTE) is increasingly viewed as a quality of care metric, although risk-adjusted incident rates of postoperative VTE and VTE after hospital discharge (VTEDC) are not available. We sought to characterize the predictors of VTE and VTEDC to develop nomograms to estimate individual risk of VTE and VTEDC. METHODS Using the American College of Surgeons National Surgical Quality Improvement Program database, we identified 471,867 patients who underwent inpatient abdominal or thoracic operations between 2005 and 2010. We excluded primary vascular and spine operations. We built logistic regression models using stepwise model selection and constructed nomograms for VTE and VTEDC with statistically significant covariates. RESULTS The overall, unadjusted, 30-d incidence of VTE and VTEDC was 1.5% and 0.5%, respectively. Annual incidence rates remained unchanged over the study period. On multivariate analysis, age, body mass index, presence of preoperative infection, operation for cancer, procedure type (spleen highest), multivisceral resection, and non-bariatric laparoscopic surgery were significant predictors for VTE and VTEDC. Other significant predictors for VTE, but not VTEDC, included a history of chronic obstructive pulmonary disease, disseminated cancer, and emergent operation. We constructed and validated nomograms by bootstrapping. The concordance indices for VTE and VTEDC were 0.77 and 0.67, respectively. CONCLUSIONS Substantial variation exists in the incidence of VTE and VTEDC, depending on patient and procedural factors. We constructed nomograms to predict individual risk of 30-d VTE and VTEDC. These may allow more targeted quality improvement interventions to reduce VTE and VTEDC in high-risk general and thoracic surgery patients.

Comparative morbidity and mortality from cervical or thoracic esophageal anastomoses.

In the modern era of esophagectomy, we hypothesized that perioperative morbidity and mortality from cervical or thoracic sites of anastomoses would not be different.

Geographic variation in utilization of sentinel lymph node biopsy for intermediate thickness cutaneous melanoma

Sentinel lymph node biopsy (SLNB) is the standard for evaluation of the draining lymphatic basin for intermediate thickness melanoma. Despite this, SLNB has not been uniformly adopted. We hypothesized that there are geographic areas of the United States where patients are less likely to receive SLNB.

Age-related disparities in use of completion lymphadenectomy for melanoma sentinel lymph node metastasis

BACKGROUND Guidelines recommend that patients with melanoma metastatic to the sentinel lymph node (SLN) undergo a completion lymphadenectomy (CLND) of the affected lymph node basin. We have previously reported on decreased use of SLN biopsy among elderly patients. We hypothesized that elderly patients with SLN metastases would have lower rates of CLND relative to their younger counterparts. METHODS The Surveillance, Epidemiology, and End Results database was queried for patients who underwent SLN biopsy for intermediate thickness cutaneous melanoma (Breslow thickness 1.01 mm-4.00 mm) from 2004 to 2008 and were found to have SLN metastasis. Patients were categorized according to age by decade. We then used multivariate logistic regression models to predict receipt of CLND. Additional covariates included sex, race/ethnicity, T stage, tumor histology, tumor location, and ulceration. The likelihood of receiving a CLND was reported as OR with 95% CI; significance was set at P ≤ 0.05. RESULTS Entry criteria were met by 765 patients. Of these, 548 (71.6%) patients underwent CLND. On multivariate analysis, patients in the age groups 70-79 y old (OR 0.39, CI 0.20-0.78; P = 0.007) and ≥ 80 y old (OR 0.27, CI 0.12-0.61; P = 0.001) were less likely to undergo CLND than the youngest age group (1-39 y old). CONCLUSIONS Elderly patients with SLN metastasis are less likely to receive CLND than their younger counterparts. A multi-center randomized clinical trial evaluating the potential survival benefit of CLND is ongoing. Further research to assess reasons why the elderly are less likely to receive CLND are needed.

Utilization of lymph node assessment in patients with ductal carcinoma in situ treated with lumpectomy.

BACKGROUND Lymph node assessment (LNA), including sentinel lymph node biopsy (SLNB), is controversial in patients undergoing lumpectomy for ductal carcinoma in situ (DCIS). Our goal was to identify factors influencing LNA in these patients. METHODS We used the Surveillance Epidemiology and End Results database to identify all female patients treated with lumpectomy for DCIS from 2000 to 2008. We excluded patients without histologic confirmation, including those diagnosed at autopsy, and those for whom LNA status was unknown. Multivariate logistic regression models predicted use of LNA. Likelihood of undergoing LNA was reported as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS A total of 62,935 patients met inclusion criteria. Approximately 15% (N = 9726) had regional LNA at the time of lumpectomy, with 12% (N = 7294) undergoing SLNB. Factors associated with an increased likelihood of undergoing LNA included treatment in the Southeast (OR 1.25, CI 1.04-1.22); treatment after the year 2000; grade II (OR 2.71, CI 2.48-2.96), III (OR 2.38, CI 2.18-2.59), or IV (OR 2.61, CI 2.37-2.88) tumors; DCIS size 2-5 cm (OR 1.49, CI 1.37-1.62) or >5 cm (OR 2.16, CI 1.78-2.61), and estrogen receptor-negative (OR 1.29, CI 1.16-1.43) or progesterone receptor-negative (OR 1.22, CI 1.11-1.33) tumors. Factors associated with a decreased likelihood of undergoing regional LNA were age >60 (OR 0.83, CI 0.79-0.87), and Asian race (OR 0.88, CI 0.81-0.96). Factors predictive of LNA in general were also predictive of SLNB. CONCLUSIONS Although LNA is controversial for patients undergoing lumpectomy for DCIS, it is used in 15% of cases. Further research establishing for the benefit of LNA in DCIS patients treated with lumpectomy is needed.

Sentinel Lymph Node Biopsy in Patients with Thick Primary Cutaneous Melanoma: Patterns of Use and Underuse Utilizing a Population-Based Model

Background. Sentinel lymph node biopsy (SLNB) for thick cutaneous melanoma is supported by national guidelines. We report on factors associated with the use and underuse of SLNB for thick primary cutaneous melanoma. Methods. The Surveillance, Epidemiology, and End Results database was queried for patients who underwent surgery for thick primary cutaneous melanoma from 2004 to 2008. We used multivariate logistic regression models to predict use of SLNB. Results. Among 1,981 patients, 833 (41.8%) did not undergo SLNB. Patients with primary melanomas of the arm (OR 2.07, CI 1.56–2.75; P < 0.001), leg (OR 2.40, CI 1.70–3.40; P < 0.001), and trunk (OR 1.82, CI 1.38–2.40; P < 0.001) had an increased likelihood of receiving a SLNB, as did those with desmoplastic histology (OR 1.47, CI 1.11–1.96; P = 0.008). A decreased likelihood of receiving SLNB was noted for advancing age ≥ 60 years (age 60 to 69: OR 0.58, CI 0.33–0.99, P = 0.047; age 70 to 79: OR 0.32, CI 0.19–0.54, P < 0.001; age 80 or more: OR 0.10, CI 0.06–0.16, P < 0.001) and unknown race/ethnicity (OR 0.21, CI 0.07–0.62; P = 0.005). Conclusions. In particular, elderly patients are less likely to receive SLNB. Further research is needed to assess whether use of SLNB in this population is detrimental or beneficial.

Pancreatic Neuroendocrine Tumors (PNETs)

Pancreatic neuroendocrine tumors (PNETs) are tumors that arise from hormone-secreting cells of the islets of Langerhans; however, not all tumors will be associated with a clinical syndrome of hormonal hypersecretion. Surgical intervention is guided by overarching principles of functioning/nonfunctioning tumors, extent of disease, and location of the tumor. Even in the setting of advanced disease including hepatic metastasis, surgical intervention may be appropriate and can provide durable periods of disease-free survival. In addition, recent molecular characterization of PNETs has allowed the identification of newer systemic therapies with improving efficacy.