John F. Gibbs

Gastrointestinal Stromal Tumors: Current Diagnosis, Biologic Behavior, and Management

Gastrointestinal stromal tumors (GIST) are rare tumors of the gastrointestinal (GI) tract that arise from primitive mesenchymal cells. GISTs occur throughout the GI tract but are usually located in the stomach and small intestine. The majority of GISTs are immunohistochemically positive for c-kit protein (CD117) and CD34. GISTs express a heterogeneous clinical course not easily predicted by standard pathological means. The most important prognostic factors are size >5 cm, tumor necrosis, infiltration and metastasis to other sites, mitotic count >1–5 per 10 high-powered fields, and most recently, mutation in the c-kit gene. Surgical resection remains the mainstay of treatment, as chemotherapy and radiation are ineffective. Long-term follow-up is imperative, as recurrence rates are high.

Sentinel node biopsy in breast cancer

AbstractBackground: Sentinel lymph node biopsy (SNB) in breast cancer may be used in place of axillary lymph node dissection (ALND) if SNB accurately stages the axilla. This study assessed the success and accuracy of axillary SNB with isosulfan blue (ISB) and technetium-99 sulfur colloid (TSC) compared to ALND. Methods: Forty-two women with T1 or T2 breast cancer underwent SNB and ALND. Sixty to 90 minutes before anesthetic induction, a mixture of 3 mL ISB and 1 mCi TSC was injected around the primary cancer or prior biopsy site. Intraoperatively, the SLN was identified using a gamma detector (Neoprobe 1000) or by visualization of the blue-stained lymph node and afferent lymphatics. The SLN was excised separately, and a level I/II ALND was completed. The histologic findings of the axillary contents and SLN were compared. Results: An axillary SLN was found in 38 of 42 (90%) cases. SLN localization rate and predictive value were the same for women who had and those who had not undergone excisional biopsy before the date of SNB. Fifteen of 42 (36%) patients had lymph node metastases. The SLN was positive in all women with axillary metastases (negative predictive value, 100%). Conclusions: If confirmed by larger series, a negative SNB may eliminate the need for ALND for select women with breast cancer.

Nodal basin recurrence following lymph node dissection for melanoma: implications for adjuvant radiotherapy

PURPOSE To analyze patterns of failure in malignant melanoma patients with lymph node involvement who underwent complete lymph node dissection (LND) of the nodal basin. To determine prognostic factors predictive of local recurrence in the lymph node basin in order to select patients who may benefit from adjuvant radiotherapy. METHODS AND MATERIALS A retrospective analysis of 338 patients undergoing complete LND for melanoma between 1970 and 1996 who had pathologically involved lymph nodes was performed. Mean follow-up from the time of LND was 54 months (range: 12-306 months). Lymph node basins dissected included the neck (56 patients), axilla (160 patients), and groin (122 patients). Two hundred fifty-three patients (75%) underwent therapeutic LND for clinically involved nodes, while 85 patients (25%) had elective dissections. Forty-four percent of patients received adjuvant systemic therapy. No patients received adjuvant radiotherapy to the lymph node basin. RESULTS Overall and disease-specific survival for all patients at 10 years was 30% and 36%, respectively. Overall nodal basin recurrence was 30% at 10 years. Mean time to nodal basin recurrence was 12 months (range: 2-78 months). Site of nodal involvement was prognostic with 43%, 28%, and 23% nodal basin recurrence at 10 years with cervical, axillary, and inguinal involvement, respectively (p = 0.008). Extracapsular extension (ECE) led to a 10-year nodal basin failure rate of 63% vs. 23% without ECE (p < 0.0001). Patients undergoing a therapeutic dissection for clinically involved nodes had a 36% failure rate in the nodal basin at 10 years, compared to 16% for patients found to have involved nodes after elective dissection (p = 0.002). Lymph nodes larger than 6 cm led to a failure rate of 80% compared to 42% for nodes 3-6 cm and 24% for nodes less than 3 cm (p < 0.001). The number of lymph nodes involved also predicted for nodal basin failure with 25%, 46%, and 63% failure rates at 10 years for 1-3, 4-10, and > 10 nodes involved (p = 0.0001). There was no significant difference in nodal basin control in patients with synchronous or metachronous lymph node metastases, nor in patients receiving or not receiving adjuvant systemic therapy. Nodal basin failure was predictive of distant metastasis with 87% of patients with nodal basin recurrence developing distant disease compared to 54% of patients without nodal failure (p < 0.0001). On multivariate analysis, number of positive nodes and type of dissection (elective vs. therapeutic) were significant predictors of overall and disease-specific survival. Size of the largest lymph node was also predictive of disease-specific survival. Site of nodal involvement and ECE were significant predictors of nodal basin failure. CONCLUSIONS Malignant melanoma patients with nodal involvement have a significant risk of nodal basin failure after LND if they have cervical involvement, ECE, >3 positive lymph nodes, clinically involved nodes, or any node larger than 3 cm. Patients with these risk factors should be considered for adjuvant radiotherapy to the lymph node basin to reduce the incidence of nodal basin recurrence. Patients with nodal basin failure are at higher risk of developing distant metastases.

Predictive factors associated with long-term survival in patients with neuroendocrine tumors of the pancreas

BackgroundNeuroendocrine tumors of the pancreas are rare tumors. We identified predictive factors that are associated with long-term survival (≥5 years).MethodsFifty patients with a diagnosis of neuroendocrine tumors of the pancreas were retrospectively evaluated. The following factors were evaluated for disease-specific mortality: age, sex, primary tumor location, functional status, type of primary tumor treatment, presence or absence of liver metastases, timing of liver metastases occurrence, and type of liver metastases treatment. Aggressive treatment of the liver metastases included surgery, chemoembolization, or intrahepatic arterial infusion chemotherapy.ResultsTwenty-three patients (47%) had tumor located in the head of the pancreas, and 29 patients (58%) had nonfunctioning tumor. Thirty-nine patients (78%) had liver metastases. The median follow-up for the entire group was 35 months (range, 76–206 months). The median survival for the entire group was 40 months, and the overall 1-, 2-, and 5-year survival rates were 84%, 69%, and 36%, respectively. Factors that had a significant favorable effect on survival included curative resection of the primary tumor, metachronous liver metastases, absence of liver metastases, and aggressive treatment of the liver metastases.ConclusionsDefinitive surgical resection of the primary tumor, absence of liver metastases, metachronous liver metastases, and aggressive treatment of the liver metastases were predictors of long-term survival in patients with neuroendocrine tumors of the pancreas.

Epithelial-Mesenchymal Transition (EMT) and Activated Extracellular Signal-regulated Kinase (p-Erk) in Surgically Resected Pancreatic Cancer

BackgroundEMT or transformation to the mesenchymal phenotype plays an important role in tumor invasion and metastasis. In vitro data suggest that mesenchymal transformation may correlate with the activation of PI3 kinase and Ras/Erk pathways. We investigated the expression of EMT markers (low E-cadherin, high fibronectin, and vimentin) and their association with p-Erk in resected pancreatic cancer.MethodsClinical data/surgical specimens from 34 consecutive pancreatic cancer patients (pts) who underwent pancreatectomy were included. Immunohistochemical staining was performed on formalin-fixed paraffin-embedded tissues using monoclonal antibodies against vimentin, fibronectin, E-cadherin, and p-Erk. The results were correlated with clinicopathological parameters and survival. Survival analysis (log-rank test, Cox proportional hazard model), categorical data analysis (Pearson’s chi-square, Fisher’s exact test) and Kendall’s tau were performed at a significance level of 0.05.ResultsThe patient population was formed from 13 males and 21 females, with a median age of 66 years (range 38–84 years); American Joint Committee on Cancer (AJCC) stage 1 (n = 2), 2 (n = 27), 3 (n = 5); histological grade 1 (n = 4), 2 (n = 13), 3 (n = 16), 4 (n = 1). Median survival was 15 months (95% CI: 11–24 months). Fibronectin overexpression correlated with the presence of vimentin (p = 0.0048) and activated Erk (p = 0.0264). There was a borderline association of fibronectin with worsening grade (p = 0.06). A negative association between vimentin and E-cadherin was noted (p = 0.0024). Increased fibronectin or vimentin and decreased E-cadherin correlated with poor survival.ConclusionEMT is associated with poor survival in surgically resected pancreatic adenocarcinoma. A correlation between activated Erk and fibronectin was identified that may open avenues for targeted therapy for this subgroup.

Accuracy of pathologic techniques for the diagnosis of metastatic melanoma in sentinel lymph nodes.

Background: Sentinel lymph node (SLN) biopsy can accurately predict the presence of metastatic melanoma (MM) and has been used to identify patients with occult metastases. We present an analysis of the sensitivity and specificity of standard pathological techniques including intraoperative frozen section, permanent section, and immunohistochemistry in diagnosing MM within the SLN.Methods: Sixty-nine consecutive patients with primary malignant melanoma thickness of .1.0 mm or thinner lesions invading the reticular dermis (Clark level IV) who underwent SLN biopsy were reviewed. Lymph nodes were examined intraoperatively by frozen section (FS), permanent section (H&E), and by immunohistochemistry (IH) for S-100 protein and HMB45.Results: MM was found in 14 of 69 cases (20%). Permanent section H&E was performed in all cases, FS in 64 cases, and IH in 65 cases. FS analysis diagnosed MM in 4 of 14 cases (29%), was suspicious in 2 of 14 (14%), and falsely negative (FN) in 8 of 14 (57%) ultimately found to be positive with further workup. Within the FN group, MM was identified on review of the original FS slides in 3 of 8 cases (38%). Furthermore, within the FN group, the remaining 5 cases were identified as positive for MM by either permanent and/or deeper H&E sections and IH. IH alone with permanent H&E sections would have diagnosed MM in only 8 of 10 cases (80%) that were FS negative or suspicious. In no cases was MM identified by IH alone with the permanent and deeper H&E sections being negative. It is noteworthy that no false-positive cases were identified.Conclusions: Intraoperative FS has low sensitivity in identifying MM within the SLN. IH alone does not increase the diagnostic yield. A combination of permanent H&E sections with deeper levels and S-100 and HMB45 IH dramatically increases the overall diagnostic sensitivity of SLN biopsy. Definitive diagnosis should await permanent H&E sections and IH staining.

Activated Akt and Erk expression and survival after surgery in pancreatic carcinoma

BackgroundLong-term survival of surgically resectable pancreatic cancer patients is uncommon. The epidermal growth factor receptor (EGFR) and the phosphoinositol-3-kinase pathways are often activated in pancreatic cancer, and an understanding of their role in resected cases may help refine adjuvant therapy.MethodsWe investigated the expression of EGFR, Erk, Akt, and their phosphoforms (p-) in pancreatectomy specimens and correlated these with survival. Thirty-nine consecutive surgically resected pancreatic adenocarcinoma cases were included. Immunohistochemical staining of paraffin-embedded blocks was performed by using monoclonal antibodies against EGFR, Erk, p-Erk, Akt, and p-Akt. A standard immunoperoxidase technique was used to detect the avidin-biotin peroxidase complex. Immunostaining was visually scored with the histoscore method by two surgical pathologists.ResultsPatient characteristics were as follows: 17 men and 22 women; median age, 66 years; and American Joint Committee on Cancer stage I, 5 patients; stage II, 4 patients; stage III, 27 patients; and stage IV, 3 patients. The tumor was World Health Organization grade 1 in 4, grade 2 in 17, and grade 3 in 18 cases. Adjuvant therapies were chemotherapy (n = 6), radiotherapy (n = 1), and chemoradiotherapy (n = 17). Immunohistochemistry revealed positive expression of EGFR in 30.8%, Erk in 92.3%, p-Erk in 45.9%, Akt in 71.8%, and p-Akt in 20.5% of cases. On univariate analyses, tumor grade (P = .0098), p-Akt (P = .0003), and p-Erk (P = .0052) expression correlated with survival. On multivariate analyses, age (P = .0002; hazard ratio [HR], 1.8), grade (P = .00318; HR, 3.0), Akt (P = .0433; HR, .4), p-Akt (P = .0002; HR, .2), and p-Erk (P = .0003; HR, 3.5) expression correlated significantly with survival.Conclusionsp-Erk and p-Akt expression may have prognostic and therapeutic implications in pancreatic cancer.

Esophageal resection for carcinoma in patients older than 70 years.

BackgroundA larger number of older patients are presenting as candidates for esophageal resection. An aggressive surgical approach in this population is controversial.MethodsFour hundred thirteen patients with esophageal cancer who presented to Roswell Park Cancer Institute from 1991 to 1998 were retrospectively reviewed. Clinical data, perioperative details, and postoperative courses were compared for patients older and younger than 70 years.ResultsOne hundred forty-seven patients (36%) were older than 70 years. Risk factors, clinical symptoms, histology, and stage at presentation were equivalent for both age groups. A higher percentage of patients <70 years were candidates for curative resection. There were no significant differences between groups for estimated blood loss, intraoperative transfusions, length of stay, overall morbidity, or mortality. Only postoperative myocardial infarction and atrial fibrillation were increased in the older group. Excluding stage IV disease, there was a significant and similar improvement in median survival after resection for patients both <70 years and >70 years.ConclusionsIn conclusion, esophageal cancer in older patients warrants surgical resection because the benefit to the patient is the same as it is for younger patients, without a significant increase in operative morbidity or mortality.

Complications and outcome of external hemipelvectomy in the management of pelvic tumors.

AbstractBackground: Although the technique of external hemipelvectomy has been adequately described, little is known about its complications and late results. Design: Retrospective review of 68 external hemipelvectomies performed at our Institute between 1973 and 1994. Materials and methods: Eleven patients had bone tumor; 39 patients, soft-tissue sarcoma; seven patients, melanoma; 10 patients, squamous cell carcinoma; and one patient, giant neurofibroma. In 48 (71%) patients, the intent was curative. In 17 cases, the hemipelvectomy was extended. Results: Postoperative complications occurred in 36 (53%) patients, including flap necrosis in 11 (16%), wound infection in 24 (35%), and other complications in 12 (18%). Four (6%) patients died postoperatively. The average hospital stay after curative versus palliative resection was 39 versus 24 days. Only three (5%) patients were able to use a prosthesis, whereas 55 (81%) used crutches, six (9%) remained wheelchair bound, and four patients (6%) spent most of the time in bed. Local recurrence occurred in 35% of the patients. The estimated 5-year survival for curatively resected patients was 21%. Conclusions: External hemipelvectomy is a procedure with considerable morbidity and is indicated for only a minority of far-advanced tumors. It offers a chance of palliation and possibly cure when lesser surgical options have been exhausted.

Malignant fibrous histiocytoma: an institutional review.

Background: A thorough understanding of malignant fibrous histiocytoma (MFH), the most common subtype of soft tissue sarcoma, will lead to improved histologic-specific protocols. Methods: 126 patients with histologically confirmed MFH were analyzed. The median follow-up was 42 months (range 1–233 months). Results: Overall survival was 58% at 5 years and 38% at 10 years. Grade significantly influenced prognosis, with 10-year survival of 90%, 60%, and 20% for low, intermediate, and high grade tumors, respectively (p = 0.0007). Distant metastases at initial presentation (p = 0.0002) and size of the primary tumor (p = 0.0007) influenced outcome. Neither anatomic site nor depth of the primary tumor were significant prognostic factors. Positive microscopic margins were associated with a decreased disease-free survival (p = 0.006). Conclusions: Tumor grade, size, and distant metastases at initial presentation remain the most important prognostic factors for MFH. Resection with negative microscopic margins decreased the incidence of local recurrence.