A Rare Adrenal Incidentaloma That Mimics Adrenocortical Carcinoma

OBJECTIVE

We present a case of an adrenal hemangioma, an uncommon cause of an adrenal mass, and review the clinical presentation, work-up, and management of adrenal incidentalomas.

BACKGROUND

A 64-year-old male was found to have a right adrenal incidentaloma during work-up for elevated liver transaminase levels, later found to be from hepatitis C. The mass was suspicious for adrenocortical carcinoma on CT imaging. Biochemical evaluation revealed no evidence of function. He underwent an open right adrenalectomy. The mass was found to be an adrenal hemangioma on histopathologic analysis.

METHODS

This is a case report with pertinent review of the diagnosis and management of adrenal incidentalomas.

RESULTS

Adrenal hemangiomas are rare, benign, nonfunctional tumors typically found during imaging for other reasons. As illustrated by this case, they appear similar to adrenocortical carcinoma on CT imaging. The diagnosis is usually not made prior to surgical resection.

CONCLUSION

Adrenal hemangioma is a rare nonfunctional adrenal incidentaloma that displays atypical features on CT imaging. The suspicion for adrenocortical carcinoma usually prompts adrenalectomy.

RAS pathway biomarkers for breast cancer prognosis

Metastatic breast cancer is a highly heterogeneous, rapidly evolving and devastating disease that challenges our ability to find curative therapies. RAS pathway activation is an understudied research area in breast cancer. EGFR/RAS pathway activation is prevalent in breast cancer with poor prognosis. The prognostic RAS pathway biomarkers can be used to identify resistant tumour clones, stratify patients and guide therapies.

SIAH and EGFR, Two RAS Pathway Biomarkers, are Highly Prognostic in Locally Advanced and Metastatic Breast Cancer

BACKGROUND

Metastatic breast cancer exhibits diverse and rapidly evolving intra- and inter-tumor heterogeneity. Patients with similar clinical presentations often display distinct tumor responses to standard of care (SOC) therapies. Genome landscape studies indicate that EGFR/HER2/RAS "pathway" activation is highly prevalent in malignant breast cancers. The identification of therapy-responsive and prognostic biomarkers is paramount important to stratify patients and guide therapies in clinical oncology and personalized medicine.

METHODS

In this study, we analyzed matched pairs of tumor specimens collected from 182 patients who received neoadjuvant systemic therapies (NST). Statistical analyses were conducted to determine whether EGFR/HER2/RAS pathway biomarkers and clinicopathological predictors, alone and in combination, are prognostic in breast cancer.

FINDINGS

SIAH and EGFR outperform ER, PR, HER2 and Ki67 as two logical, sensitive and prognostic biomarkers in metastatic breast cancer. We found that increased SIAH and EGFR expression correlated with advanced pathological stage and aggressive molecular subtypes. Both SIAH expression post-NST and NST-induced changes in EGFR expression in invasive mammary tumors are associated with tumor regression and increased survival, whereas ER, PR, and HER2 were not. These results suggest that SIAH and EGFR are two prognostic biomarkers in breast cancer with lymph node metastases.

INTERPRETATION

The discovery of incorporating tumor heterogeneity-independent and growth-sensitive RAS pathway biomarkers, SIAH and EGFR, whose altered expression can be used to estimate therapeutic efficacy, detect emergence of resistant clones, forecast tumor regression, differentiate among partial responders, and predict patient survival in the neoadjuvant setting, has a clear clinical implication in personalizing breast cancer therapy.

FUNDING

This work was supported by the Dorothy G. Hoefer Foundation for Breast Cancer Research (A.H. Tang); Center for Innovative Technology (CIT)-Commonwealth Research Commercialization Fund (CRCF) (MF14S-009-LS to A.H. Tang), and National Cancer Institute (CA140550 to A.H. Tang).

Abstract B70: Developing a new and potent anti-K-RAS strategy by inhibiting SIAH E3 ligase, the most downstream “gatekeeper” in the oncogenic K-RAS signal pathway, to block well-established pancreatic tumor growth

Hyperactive K-RAS signaling is a major menace that drives aggressive cancer cell dissemination, tumor progression and metastasis in human pancreatic cancer. Currently, there are no effective therapies to control human pancreatic cancers that have oncogenic K-RAS mutations that confer drug resistance, aggressive tumor growth, systemic metastasis and poor clinical outcome. Therefore, finding novel approaches and new drug targets to inhibit oncogenic K-RAS activation is an urgent goal and major challenge in targeted therapy development in pancreatic cancer. Instead of targeting an upstream signaling module such as EGFR/K-RAS/B-RAF/MEK/MAPK/ERK/AKT/mTOR, we targeted the most downstream signaling module in the K-RAS signaling pathway called the SIAH-dependent proteolytic machinery. SIAHs are the human homologs of Seven-In-Absentia (SINA), an evolutionarily conserved RING E3 ligase, an essential downstream signaling module and a critical “gatekeeper” required for proper K-RAS signal transduction. Guided by the insights and principles learned from Drosophila RAS signaling pathway, we have conducted preclinical studies to dissect SIAH function in the context of K-RAS-mediated tumorigenesis and metastasis in human pancreatic cancer cells and tumor specimens. We found that inhibiting SIAH function is highly effective to abolish well-established and late-stage pancreatic tumor growth and metastasis in our pre-clinical studies. These findings demonstrate that SIAH is indeed an attractive, logical and potent anti-K-RAS therapeutic target for us to develop new and effective anticancer strategy against human pancreatic cancer. Through our work, SIAH has emerged as a new and effective drug target against oncogenic K-RAS hyperactivation in human pancreatic cancer. As one of the most evolutionarily conserved E3 ligases, SIAH is ideally and logically positioned to become a next-generation anti-K-RAS drug target in human cancer. Our preclinical studies have demonstrated that “SIAH-dependent proteolysis” is indeed an Achilles’ heel for human pancreatic cancer cells. Hence, anti-SIAH-based small molecule inhibitors may aid in expanding our arsenal of novel anticancer therapies in pancreatic cancer. By attacking the most downstream “gatekeeper” critical for the proper oncogenic ERBB/K-RAS signaling transmission, we may be in a position to halt the genesis, progression and metastasis of the most aggressive and the deadliest forms of human pancreatic cancer in the future.

Citation Format: Vasilena Zheleva, Minglei Bian, Xiaofei Gao, Justin J. Odanga, Monicah M. Njogu, Zena M. Urban, Bruce E. Knudsen, Richard A. Hoefer, Roger R. Perry, Amy H. Tang. Developing a new and potent anti-K-RAS strategy by inhibiting SIAH E3 ligase, the most downstream “gatekeeper” in the oncogenic K-RAS signal pathway, to block well-established pancreatic tumor growth. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B70.

Abstract A26: Attacking the most downstream “gatekeeper,” the SIAH-dependent proteolytic machinery, in the oncogenic ERBB/K-RAS signaling pathway to block tumorigenesis and control metastasis in human cancer

Oncogenic K-RAS activation is a major menace that drives aggressive tumor progression and metastasis in 30% of all human cancer. Currently, there are no effective therapies to treat stage III and IV metastatic human cancers with oncogenic K-RAS hyperactivation that often confer drug resistance, aggressive tumor growth, systemic metastasis, and poor clinical outcome. Therefore, finding novel approaches and new drug targets to inhibit oncogenic K-RAS pathway activation is an urgent goal and the major challenge in cancer therapy and anti-K-RAS-based drug development. Instead of targeting an upstream signaling module such as EGFR/HER2/K-RAS/B-RAF, we targeted the most downstream signaling module in the oncogenic K-RAS signaling pathway called the SIAH-dependent proteolytic machinery. SIAHs are the human homologs of Seven-In-Absentia (SINA), an evolutionarily conserved RING E3 ligase - the most downstream signaling module and a critical “gatekeeper” required for proper RAS signal transduction. Guided by the insights and fundamental principles learned from the Drosophila RAS signal transduction, we conducted preclinical studies to dissect SIAH function in promoting the oncogenic K-RAS-driven tumorigenesis and metastasis in human cancer. We found that (1) SIAH is a new biomarker reflective of oncogenic K-RAS activation in human cancer, and (2) SIAH loss-of-function is highly effective to block tumorigenesis and metastasis against the well-established, end-stage and metastatic pancreatic cancer and triple negative breast cancer (TNBC). These findings demonstrate that SIAH is an attractive and logical new therapeutic target for developing novel and effective anti-K-RAS and anticancer therapy against metastatic human cancer. Through our work, SIAH has emerged as a promising new drug target against oncogenic K-RAS hyperactivation in metastatic human cancer cells. Using anti-SIAH molecules to block oncogenic K-RAS signaling in human cancer is an excellent example of science going “from the bench (basic research in fruit flies) to the bedside (preclinical studies and ultimately clinical trials)”. As a highly evolutionarily conserved E3 ligase that is the most downstream and the most conserved “signaling gatekeeper” in the oncogenic K-RAS signaling network, SIAH is uniquely and strategically positioned to become a great and logical anti-K-RAS drug target. Our preclinical studies have demonstrated that “SIAH-dependent proteolysis” is indeed an Achilles' heel in metastatic human cancer cells. Knowledge gained from our preclinical study has promising translational values. Anti-SIAH-based small molecule inhibitors are likely to aid in expanding our limited arsenal of novel anti-K-RAS-based anticancer therapies. By attacking the oncogenic K-RAS pathway using multi-pronged synergistic inhibitions at upstream (EGFR/HER2 membrane receptors), midstream (K-RAS/B-RAF/MEK/mTOR) and downstream (SIAH E3 ligase) signaling modules in parallel, we will be in a position to control the late-stage, relapsed and metastatic human cancers by shutting down the hyperactivated K-RAS signaling transduction cascades in cancer cells in the future.

Citation Format: Minglei Bian, Yang Liao, Vasilena Zheleva, Zena Urban, Monicah Njogu, Justin J. Odanga, Andrew J. Isbell, Roger R. Perry, Richard A. Hoefer, Thomas C. Smyrk, Gloria M. Petersen, Amy H. Tang. Attacking the most downstream “gatekeeper,” the SIAH-dependent proteolytic machinery, in the oncogenic ERBB/K-RAS signaling pathway to block tumorigenesis and control metastasis in human cancer. [abstract]. In: Proceedings of the AACR Special Conference on RAS Oncogenes: From Biology to Therapy; Feb 24-27, 2014; Lake Buena Vista, FL. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(12 Suppl):Abstract nr A26. doi: 10.1158/1557-3125.RASONC14-A26

Abstract C62: Attacking the most downstream “gatekeeper” signaling module in the oncogenic ERBB/K-RAS signaling pathway to block tumorigenesis and metastasis in human cancer

Hyperactive ERBB/K-RAS signaling is a major menace that drives aggressive tumor growth and metastasis in human cancer. Currently, there are no effective ways to treat late-stage and relapsed human cancers that have oncogenic ERBB/K-RAS mutations that often confer drug resistance, aggressive tumor growth, systemic metastasis, and poor clinical outcome. Therefore, finding novel approaches and new drug targets to inhibit oncogenic ERBB/K-RAS activation is an urgent goal and the major challenge in cancer therapy and treatment. Instead of targeting an upstream signaling module such as EGFR/HER2/KRAS/B-RAF, we targeted the most downstream signaling module in the EGFR/HER2/K-RAS pathway called the SIAH-dependent proteolytic machinery. SIAHs are the human homologs of Seven-In-Absentia (SINA), an evolutionarily conserved RING E3 ligase, an essential downstream signaling module and a critical “gatekeeper” required for proper EGFR/HER2/K-RAS/B-RAF signal transduction. Guided by the insights and fundamental principles learned from the Drosophila RAS signaling pathway, we conducted preclinical studies to dissect SIAH function in the context of ERBB/K-RAS-mediated tumorigenesis and metastasis in human cancer cells and human cancer biospecimens. We found that (1) SIAH is a great prognostic and predictive biomarker for human cancer, and (2) inhibiting SIAH function is highly effective to block tumorigenesis and metastasis against the well-established, late-stage and metastatic pancreatic cancer and triple negative breast cancer (TNBC). These findings demonstrate that SIAH is an attractive and logical new therapeutic target for novel anti-ERBB/oncogenic K-RAS and anticancer therapy in human cancer. Through our work, SIAH has emerged as a new and effective drug target against oncogenic ERBB/K-RAS activation in human cancer cells. Using anti-SIAH molecules to block K-RAS signaling in human cancer is an excellent example of science going “from the bench (basic research in fruit flies) to the bedside (preclinical studies and ultimately clinical trials)”. As a highly evolutionarily conserved E3 ligase and the most downstream “gatekeeper” of EGFR/HER2/K-RAS/B-RAF signaling pathway, SIAH is uniquely and logically positioned to become a next-generation anti-ERBB/anti-K-RAS drug target. Our preclinical studies have demonstrated that “SIAH-dependent proteolysis” is indeed an Achilles' heel in human cancer. Knowledge gained from our study has great promise and immediate translational values. Anti-SIAH-based small molecule inhibitors may aid in expanding our arsenal of novel anticancer therapies. By attacking the oncogenic ERBB/K-RAS/B-RAF pathway using multi-pronged synergistic inhibitions at upstream (EGFR/HER2 membrane receptors), midstream (K-RAS/B-RAF/MEK/mTOR) and downstream (SIAH E3 ligase) signaling modules in parallel, we will be in a position to control the late-stage, relapsed and metastatic human cancers. If successful, we hope to develop anti-SIAH-based therapy and translate our findings to the cancer clinics to treat cancer patients with metastatic diseases in the near future.

Citation Format: Minglei Bian, Yang Liao, Vasilena Zheleva, Xiaofei Gao, Zena M. Urban, Monicah M. Njogu, Justin J. Odanga, Andrew J. Isbell, Rebecca L. Schmidt, Rie Takahashi, Roger R. Perry, Richard A. Hoefer, Thomas C. Smyrk, Gloria M. Petersen, Amy H. Tang. Attacking the most downstream “gatekeeper” signaling module in the oncogenic ERBB/K-RAS signaling pathway to block tumorigenesis and metastasis in human cancer. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr C62.

Abstract A88: Make a difference and save lives in human metastatic cancer by attacking the Achilles heel in the oncogenic ERBB/K-RAS signaling pathway

The dismal prognosis of patients diagnosed with metastatic cancer points to our limited arsenal of effective anticancer and anti-metastasis therapies. Chemotherapy, radiation and targeted therapies are largely ineffective against metastatic cancer, resulting in the deaths of more than half million cancer patients each year. Oncogenic EGFR/HER2/K-RAS/B-RAF pathway activation is a major menace that drives aggressive cancer cell dissemination, tumor invasion and systemic metastasis. Therefore, finding novel approaches and new drug targets to inhibit hyperactive EGFR/HER2/K-RAS/B-RAF signaling is an urgent goal and major challenge in the struggle against metastatic diseases. Guided by the insights and principles learned from the evolutionarily conserved RAS signal transduction cascade in Drosophila, we targeted the most downstream signaling module in the EGFR/HER2/K-RAS/B-RAF signaling pathway, the SIAH-dependent proteolytic machinery. SIAHs are the human homologs of Seven-In-Absentia (SINA), a highly conserved RING E3 ligase, an essential downstream signaling module and a critical “gatekeeper” required for proper EGFR/HER2/K-RAS/B-RAF signal transduction. We found that inhibiting SIAH function is highly effective in halting cancer cell dissemination, altering cell adhesion and motility, inhibiting tumor invasion and cancer metastasis of human cancer cells. Importantly, our anti-SIAH-based anticancer strategy is effective in reducing tumor burdens in the late-stage and aggressive tumor growth and metastasis in the preclinical models. These exciting results and new findings demonstrate that SIAH is a highly attractive, mechanistically logical and great therapeutic target for developing novel anti-ERBB/K-RAS/B-RAF and anticancer therapies against invasive and metastatic cancer. Through our work, SIAH has emerged as a new, potent and promising drug target against metastatic diseases. As a highly evolutionarily conserved E3 ligase and the most downstream “gatekeeper” of EGFR/HER2/K-RAS/B-RAF signaling pathway, SIAH is ideally and logically positioned to become a next-generation anticancer and anti-metastasis drug target in the clinic. By simultaneously attacking the tumor-driving and metastasis-promoting ERBB/K-RAS signaling pathway using multi-pronged synergistic inhibitions at upstream (EGFR/HER2 membrane receptors), midstream (K-RAS/B-RAF/MEK/mTOR) and downstream (SIAH E3 ligase) signaling modules, we aim to make a difference and save lives from the deadliest forms of human metastatic cancers in the future.

Citation Format: Amy H. Tang, Yang Liao, Minglei Bian, Vasilena Zheleva, Zena M. Urban, Monicah M. Njogu, Xiaofei Gao, Oscar A. Gonzalez, Justin J. Odanga, Bruce E. Knudsen, Roger R. Perry, Richard A. Hoefer, Thomas C. Smyrk, Gloria M. Petersen. Make a difference and save lives in human metastatic cancer by attacking the Achilles heel in the oncogenic ERBB/K-RAS signaling pathway. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr A88.

Cutaneous melanoma in Asian-Americans

BACKGROUND

There is little information available on melanoma in non-white populations. Our objective was to characterize melanoma in Asian-Americans (AsA) and compare patient demographics and tumor characteristics with the non-Hispanic White (NHW) population.

METHODS

483,050 cutaneous melanoma patients diagnosed between 1986 and 2005 were identified using the National Cancer Data Base (NCDB); 1,237 were AsA, and 409,564 were NHW. Age, gender, site, histologic type, tumor thickness, AJCC stage, and survival were compared.

RESULTS

AsA were more likely to be diagnosed with acral lentiginous tumors (6.7%) than NHW (0.8%, P < 0.001). A greater proportion of AsA were diagnosed with T4 tumors (15.6%) than NHW (8.5%, P < 0.001). AsA presented with fewer early stage I-II tumors and more late stage III-IV tumors than NHW (P < 0.001). Survival was similar for AsA and NHW.

CONCLUSIONS

This is the largest study to date on melanoma in AsA. Compared to NHW, AsA are more likely to have acral lentinginous tumors, thick tumors, and higher stage. Despite this, their survival is similar to the NHW population.

Serum biomarkers to differentiate benign and malignant mammographic lesions

BACKGROUND

Mammographic screening has increased detection of earlier-stage breast cancers and has decreased mortality from breast cancer. A Breast Imaging-Reporting and Data System (BIRADS) 4 classification prompts a biopsy that most often reveals benign disease. Our objective was to determine if serum protein-expression profiles could be used to differentiate between benign and malignant mammographic lesions.

STUDY DESIGN

After IRB approval, women undergoing an image-guided biopsy for a BIRADS category 4 lesion were recruited. Serum was collected prebiopsy and labeled retrospectively after final pathology was reviewed. Serum was incubated with weak cation exchange magnetic beads and assayed in duplicate for analysis on matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) instrumentation (Bruker Daltonics). Spectra were analyzed using ClinProTools 2.0 software (Bruker Daltonics), and classifications determined using a genetic-clustering algorithm.

RESULTS

In a 14-month period, 260 subjects were recruited into this study. Sera from 92 subjects were randomly selected to form benign (n = 46) and cancer (n = 46) cohorts. The MALDI-TOF spectra analysis yielded 273 peaks, with 14 peaks expressed differentially (p < 0.05) between the cancer and benign cohorts. A genetic algorithm model was generated, yielding a sensitivity of 88.3% and specificity of 85.8%.

CONCLUSIONS

MALDI-TOF protein-expression profiles generated from BIRADS 4 sera could be used to distinguish between benign and malignant mammographic lesions.

SELDI-TOF serum profiling for prognostic and diagnostic classification of breast cancers

Surface enhanced laser desorption/ionization (SELDI) time-of-flight mass spectrometry has emerged as a successful tool for serum based detection and differentiation of many cancer types, including breast cancers. In this study, we have applied the SELDI technology to evaluate three potential applications that could extend the effectiveness of established procedures and biomarkers used for prognostication of breast cancers. Paired serum samples obtained from women with breast cancers prior to surgery and post-surgery (6–9 mos.) were examined. In 14/16 post-treatment patients, serum protein profiles could be used to distinguish these samples from the pre-treatment cancer samples. When compared to serum samples from normal healthy women, 11 of these post-treatment samples retained global protein profiles not found in healthy women, including five low-mass proteins that remained elevated in both pre-treatment and post-treatment serum groups. In another pilot study, serum profiles were compared for a group of 30 women who were known BRCA-1 mutation carriers, half of whom subsequently developed breast cancer within three years of the sample procurement. SELDI protein profiling accurately classified 13/15 women with BRCA-1 breast cancers from the 15 non-cancer BRCA-1 carriers. Additionally, the ability of SELDI to distinguish between the serum profiles from sentinel lymph node positive and sentinel lymph node negative patients was evaluated. In sentinel lymph node positive samples, 22/27 samples were correctly classified, in comparison to the correct classification of 55/71 sentinel lymph node negative samples. These initial results indicate the utility of protein profiling approaches for developing new diagnostic and prognostic assays for breast cancers.

Micrometastasis in the sentinel lymph node of breast cancer does not mandate completion axillary dissection

OBJECTIVE

To determine if micrometastatic disease in the sentinel lymph node is a predictor of non-sentinel lymph node (non-SLN) involvement in breast cancer.

SUMMARY BACKGROUND DATA

Sentinel lymph node biopsy (SLN) is an accepted alternative to axillary dissection in staging breast cancer. If the SLN contains metastatic foci, the standard recommendation is completion axillary node dissection (CAD). However, a large subset of patients with metastasis limited to the SLN is unnecessarily subjected to the morbidity of CAD.

METHODS

A retrospective review of prospectively gathered breast cancer patients having SLN was conducted. Patients with metastasis to the SLN were selected for analysis. Various clinicopathologic features were analyzed for association with metastasis to the non-SLN.

RESULTS

A total of 194 women underwent successful SLN dissection. Metastasis to the SLN was found in 48 patients (21 had micrometastases, 27 had macrometastases). Of those with micrometastases, 16 underwent CAD with 1 patient having metastasis to the non-SLN. In patients with macrometastases, 26 had CAD with 14 patients having non-SLN metastasis. Multivariable logistic regression identified only macrometastatic disease in the SLN as significantly associated with involvement of the non-SLN (P = 0.03). None of the patients with micrometastases, including those without CAD, has evidence of local recurrence to date (3-30 months).

CONCLUSION

This study demonstrates that the incidence of non-SLN involvement is low in SLN that contains only micrometastatic foci and is within the accepted range of the false-negative rate of SLN. This suggests that a CAD may be omitted in patients with micrometastatic disease.

Obesity and lymphatic mapping with sentinel lymph node biopsy in breast cancer

BACKGROUND

With increasing sentinel lymph node experience, patient subsets associated with lower success rates are being identified. Obesity may be one such subset.

METHODS

A retrospective review was conducted of breast cancer patients who underwent sentinel lymph node biopsy from March 1997 to September 2002. Factors examined included demographics, body mass index (BMI), breast size, tumor characteristics, lymphoscintigraphy drainage, and success of mapping. Chi-square and exact P values were used for statistical analysis.

RESULTS

One hundred seventy-four breast cancer patients had sentinel lymph node biopsy. Sixty-seven patients were normal weight (BMI <25.1); 56 patients were overweight (BMI 25.1 to 29.9); and 51 patients were obese (BMI >29.9). Failure to identify a sentinel lymph node and the false negative rate were not statistically different (P = 0.7783 and P = 0.9290, respectively) among the three groups.

CONCLUSIONS

Obesity has no significant effect on sentinel node identification rate or false negative rate.

A novel approach toward development of a rapid blood test for breast cancer

Mammography remains the diagnostic test of choice for breast cancer, but 20% of cancers still go undetected. Many serum biomarkers have been reported for breast cancer but none have proven to represent effective diagnostic strategies. ProteinChip mass spectrometry is an innovative technology that searches the proteome for differentially expressed proteins, allowing for the creation of a panel or profile of biomarkers. The objective of this study was to construct unique cancer-associated serum profiles that, combined with a classification algorithm, would enhance the detection of breast cancer Pretreatment serum samples from 134 female patients (45 with cancer, 42 with benign disease, 47 normal) were procured prospectively following institutional review board-approved protocols. Proteins were denatured, applied onto ProteinChip affinity surfaces, and subjected to surface enhanced laser desorption/ionization (SELDI) time-of-flight mass spectrometry. The SELDI output was analyzed using Biomarker Pattern Software to develop a classification tree based on group-specific protein profiles. The cross-validation analysis of cancer versus normal revealed sensitivity and specificity rates of 80% and 79%, and for cancer versus benign disease, 78% and 83%, respectively. When 2 different chip surfaces were combined the sensitivity and specificity increased to 90% and 93%, respectively. The sensitivity and specificity of this technique are comparable to those of mammography and, if confirmed in a larger study, this technique could provide the means toward development of a simple blood test to aid in the early detection of breast cancer. The combination of SELDI ProteinChip mass spectrometry and a classification- and regression-tree algorithm has the potential to use serum protein expression profiles for detection and diagnosis of breast cancer.

A novel approach toward development of a rapid blood test for breast cancer

Mammography remains the diagnostic test of choice for breast cancer, but 20% of cancers still go undetected. Many serum biomarkers have been reported for breast cancer but none have proven to represent effective diagnostic strategies. ProteinChip mass spectrometry is an innovative technology that searches the proteome for differentially expressed proteins, allowing for the creation of a panel or profile of biomarkers. The objective of this study was to construct unique cancer-associated serum profiles that, combined with a classification algorithm, would enhance the detection of breast cancer Pretreatment serum samples from 134 female patients (45 with cancer, 42 with benign disease, 47 normal) were procured prospectively following institutional review board-approved protocols. Proteins were denatured, applied onto ProteinChip affinity surfaces, and subjected to surface enhanced laser desorption/ionization (SELDI) time-of-flight mass spectrometry. The SELDI output was analyzed using Biomarker Pattern Software to develop a classification tree based on group-specific protein profiles. The cross-validation analysis of cancer versus normal revealed sensitivity and specificity rates of 80% and 79%, and for cancer versus benign disease, 78% and 83%, respectively. When 2 different chip surfaces were combined the sensitivity and specificity increased to 90% and 93%, respectively. The sensitivity and specificity of this technique are comparable to those of mammography and, if confirmed in a larger study, this technique could provide the means toward development of a simple blood test to aid in the early detection of breast cancer. The combination of SELDI ProteinChip mass spectrometry and a classification- and regression-tree algorithm has the potential to use serum protein expression profiles for detection and diagnosis of breast cancer.

Multicenter trial of sentinel node biopsy for breast cancer using both technetium sulfur colloid and isosulfan blue dye

OBJECTIVE

To determine the factors associated with false-negative results on sentinel node biopsy and sentinel node localization (identification rate) in patients with breast cancer enrolled in a multicenter trial using a combination technique of isosulfan blue with technetium sulfur colloid (Tc99).

SUMMARY BACKGROUND DATA

Sentinel node biopsy is a diagnostic test used to detect breast cancer metastases. To test the reliability of this method, a complete lymph node dissection must be performed to determine the false-negative rate. Single-institution series have reported excellent results, although one multicenter trial reported a false-negative rate as high as 29% using radioisotope alone. A multicenter trial was initiated to test combined use of Tc99 and isosulfan blue.

METHODS

Investigators (both private-practice and academic surgeons) were recruited after attending a course on the technique of sentinel node biopsy. No investigator participated in a learning trial before entering patients. Tc99 and isosulfan blue were injected into the peritumoral region.

RESULTS

Five hundred twenty-nine patients underwent 535 sentinel node biopsy procedures for an overall identification rate in finding a sentinel node of 87% and a false-negative rate of 13%. The identification rate increased and the false-negative rate decreased to 90% and 4.3%, respectively, after investigators had performed more than 30 cases. Univariate analysis of tumor showed the poorest success rate with older patients and inexperienced surgeons. Multivariate analysis identified both age and experience as independent predictors of failure. However, with older patients, inexperienced surgeons, and patients with five or more metastatic axillary nodes, the false-negative rate was consistently greater.

CONCLUSIONS

This multicenter trial, from both private practice and academic institutions, is an excellent indicator of the general utility of sentinel node biopsy. It establishes the factors that play an important role (patient age, surgical experience, tumor location) and those that are irrelevant (prior surgery, tumor size, Tc99 timing). This widens the applicability of the technique and identifies factors that require further investigation.

Multiple ectopic parathyroid glands

Parathyroid surgery to correct primary hyperparathyroidism is successful in 80 to 97 per cent of initial explorations. Failures are often linked to inability to locate ectopic parathyroid glands. Although ectopic parathyroid glands are relatively common (15%) multiple ectopic glands are rarely reported. We describe a case of multiple ectopic parathyroid glands and the intraoperative approach to their localization and review the anatomy and embryology of ectopic parathyroid glands. A 39-year-old woman presented with fatigue, lethargy, and depression. On biochemical evaluation she was noted to be hypercalcemic and hyperparathyroid. Preoperative parathyroid localization failed to identify abnormal parathyroid glands. At exploration three of four parathyroid glands, including an adenoma, were located in ectopic positions by a meticulous and systematic dissection. A careful exploration coupled with a thorough knowledge of parathyroid anatomy and embryology will produce successful surgical correction of primary hyperparathyroidism in greater than 95 per cent of patients even in the few patients with multiple ectopic parathyroid glands.

Multiple Ectopic Parathyroid Glands

Parathyroid surgery to correct primary hyperparathyroidism is successful in 80 to 97 per cent of initial explorations. Failures are often linked to inability to locate ectopic parathyroid glands. Although ectopic parathyroid glands are relatively common (15%) multiple ectopic glands are rarely reported. We describe a case of multiple ectopic parathyroid glands and the intraoperative approach to their localization and review the anatomy and embryology of ectopic parathyroid glands. A 39-year-old woman presented with fatigue, lethargy, and depression. On biochemical evaluation she was noted to be hypercalcemic and hyperparathyroid. Preoperative parathyroid localization failed to identify abnormal parathyroid glands. At exploration three of four parathyroid glands, including an adenoma, were located in ectopic positions by a meticulous and systematic dissection. A careful exploration coupled with a thorough knowledge of parathyroid anatomy and embryology will produce successful surgical correction of primary hyperparathyroidism in greater than 95 per cent of patients even in the few patients with multiple ectopic parathyroid glands.

Parameters that predict nipple involvement in breast cancer

BACKGROUND

Breast conservation therapy has been shown to produce survival rates equivalent to those seen with modified radical mastectomy. Synchronous occult neoplastic involvement of the nipple may lead to incomplete excision of the tumor in patients undergoing breast conservation therapy, possibly leading to recurrence.

STUDY DESIGN

The charts of 803 breast cancer patients treated between 1990 and 1995 at two teaching hospitals were retrospectively reviewed. The patients were divided into three groups: nipple-positive for malignancy (n = 54), nipple-negative for malignancy (n = 404), and nipple-not-removed (n = 345). Ten different clinical and tumor parameters including age, race, primary tumor location, histologic grade, primary tumor size, nodal involvement, TNM stage, estrogen receptor status, DNA ploidy, and S-phase were examined for the ability to predict cancerous nipple involvement.

RESULTS

Overall, the rate of nipple positivity was 12%. In univariate analysis pathologic stage, tumor size, lymph node status, histologic grade, and tumor location were significant predictors of positive nipple involvement. Patients with tumors that were stage III or higher were nearly ten times (odds ratio [OR] = 9.8, 95% confidence interval [CI] = 5.5 to 17.7) more likely to have nipple involvement than patients with early-stage tumors. Patients with a tumor size of 4 cm or greater were nearly eight times (OR = 7.8, 95% CI = 4.2 to 14.5) more likely to have nipple involvement than patients with tumor size less than 4 cm. Patients with positive lymph nodes were five times (OR = 5.0, 95% CI = 2.7 to 9.1) more likely to have nipple involvement than patients with negative lymph nodes. Patients with tumors in a central location or that overlapped quadrants were nearly four times (OR = 3.8, 95% CI = 2.2 to 6.8) more likely to have nipple involvement than patients with tumors in other locations. Patients with grade 3 or undifferentiated tumors were three times (OR = 3.0, 95% CI = 1.4 to 6.4) more likely to have nipple involvement than patients with lower grade tumors. In multivariable analysis, stage > or = 3 (OR = 9.2, 95% CI = 4.2 to 20.3) central/ overlap location (OR = 4.1, 95% CI = 2.0 to 8.7) and grade 3 or undifferentiated (OR = 3.1, 95% CI = 1.3 to 7.5) were the only variables that remained significant predictors of nipple involvement.

CONCLUSIONS

The decision to perform breast conservation surgical procedures with nipple preservation can be difficult, particularly in patients with larger, more centrally located tumors. The multivariable model developed in this study may be useful in predicting the risk of cancerous nipple involvement and selecting appropriate breast conservation patients for nipple preservation.

Relationship between colorectal cancer glutathione levels and patient survival: early results

PURPOSE

Elevated glutathione is a cause of resistance to anticancer agents and x-rays. The purpose of this study was to determine the frequency and clinical significance of glutathione elevation in human colorectal cancer.

METHODS

Glutathione levels were measured in 41 colon cancers, 24 rectal cancers, and corresponding normal tissues. The patients were then followed up prospectively for tumor recurrence and survival. Survival was analyzed by the Kaplan-Meir method and Cox proportional hazards regression.

RESULTS

Glutathione levels in primary colorectal cancers were significantly higher than in the corresponding normal tissues. Elevated glutathione levels had a significant negative effect on survival in patients with colorectal cancer, whether based on the mean (P = 0.02) or median (P = 0.04) normal tissue levels. A negative effect of glutathione levels on survival was apparent in patients with colorectal cancer, whether or not they were treated with postoperative therapy. The larger the ratio of tumor glutathione to normal tissue glutathione, the poorer the prognosis. When adjusted for other covariates, glutathione was still a significant predictor of survival.

CONCLUSIONS

An elevated tumor glutathione level at the time of diagnosis appears to confer a poor prognosis in patients with colorectal cancer. Longer-term study using a larger number of patients will be required to confirm these findings. Knowledge of tumor glutathione content may help identify patients requiring more intensive therapy.

The importance of DT-diaphorase in mitomycin C resistance in human colon cancer cell lines

BACKGROUND

Prior studies have suggested the multifactorial nature of mitomycin C (MMC) resistance. However, the relative importance of the different resistance mechanisms is unknown.

MATERIALS AND METHODS

A panel of colon cancer cell lines with levels of MMC resistance from 2- to 15-fold compared to the parent line HT-29 was produced by repeated MMC exposure. Cell survival was measured using clonogenic assay. Glutathione and related enzymes and DT-diaphorase were measured using biochemical assays. P-glycoprotein expression was measured using flow cytometry. Topoisomerase II activity was measured using the pBR322 DNA relaxation assay.

RESULTS

Multiple drug resistance mechanisms were altered in the resistant cell lines (glutathione reductase, glutathione peroxidase, topoisomerase II). However, the level of DT-diaphorase correlated best with the degree of MMC resistance. The importance of DT-diaphorase was confirmed by using BMY 25282, an MMC analogue which is less dependent on DT-diaphorase for activation. Resistance in the HT-29R54 cell line was 15-fold with MMC compared to 5-fold with BMY 25282. P-glycoprotein-mediated resistance does not appear important in this model.

CONCLUSIONS

Although MMC resistance appears to be multifactorial, the results of this study strongly suggest that DT-diaphorase is the major contributor to MMC resistance under aerobic conditions. Strategies to enhance drug activation may therefore be useful for reversing MMC resistance.

Antiproliferative and antiinvasive effects of carboxyamido-triazole on breast cancer cell lines

BACKGROUND

Basement membrane invasion is one of the critical components of the metastatic cascade. The antiproliferative and antiinvasive activity of carboxyamido-triazole (CAI), a calcium influx inhibitor, was studied in five human breast cancer cell lines (MCF-7, MCF-7/ADRR, MDA-231, MDA-231R44, and BT-474).

METHODS

Sensitivity of the cell lines to CAI was measured with a microculture tetrazolium assay. The Boyden chamber Matrigel chemoinvasion assay was used to measure the antiinvasive activity of CAI. Matrix metalloproteinase activity was analyzed by gelatin zymography.

RESULTS

The 50% inhibitory concentrations of CAI were cell line dependent and ranged from 7.49 +/- 4.05 mumol/L to 46.1 +/- 8.6 mumol/L. CAI at a low, minimally toxic concentration (5 mumol/L) inhibited invasion by greater than 75% in the four invasive cell lines (MCF-7/ADRR, MDA-231, MDA-231R44, and BT-474) regardless of estrogen receptor or p-glycoprotein status (p < 0.01). CAI treatment also reduced matrix metalloproteinase activity in conditioned media from three of the four invasive lines (p < 0.05).

CONCLUSIONS

CAI at clinically achievable concentrations is an effective antiproliferative and antiinvasive agent against human breast cancer cell lines regardless of estrogen receptor or p-glycoprotein status. Reduction in matrix metalloproteinase activity may be partially responsible for CAI inhibition of invasion.

Managed health care: a concept not understood by rural Oklahomans

OBJECTIVE

The purpose of the study was to find out what people in rural Oklahoma know and understand about managed care.

METHODS

A fourteen-statement survey instrument was developed. A panel of managed care professionals were asked to participate to provide a "standard" to compare the responses of the general public. The survey was administered to the general public in five rural communities and to recipients of the Oklahoma AHEC Newsletter.

RESULTS

Overall, the panel tended to agree and created an industry profile useful in comparison to the responses of the general public: (1) 55-65% of the respondents answered I Don't Know or Neither Agree nor Disagree to statements using the term "managed care" and only 15-20% of the public respondents answered I Don't Know to statements not including the term, "managed care." (2) 25-30% of the general public answered in accordance with the managed care panel. (3) Over 50% of the public respondents Agreed that changes are necessary in the health sector.

CONCLUSIONS

The results of this survey suggest that rural Oklahomans are uninformed about the concept of managed care and need to become better informed.

Treatment and prognosis of primary malignant small bowel tumors

Primary malignant tumors of the small bowel are a heterogeneous group of tumors and are uncommon compared to tumors in other locations of the gastrointestinal tract. These tumors have been traditionally associated with a poor prognosis. The charts of 53 patients with primary malignant small bowel tumors at major Eastern Virginia Medical School teaching hospitals were retrospectively reviewed. Patient characteristics and presenting symptoms and signs were nonspecific. No single radiographic or endoscopic procedure was performed on every patient, and the diagnosis was suspected preoperatively in only 50 per cent of the patients. Tumors were most common in the ileum, and the most common histologic types were adenocarcinoma (53 per cent) and carcinoid (32 per cent). In univariate analysis, factors determining survival included histologic type, location of tumor, and stage. There was also a trend toward worse survival in patients receiving chemotherapy or radiation therapy, possibly due to patient selection factors. In multivariate analysis, only histology and stage significantly influenced survival. The overall 10-year survival of the entire group was 44 per cent. Small bowel tumors have a variable prognosis. A high index of suspicion and more frequent use of enteroclysis may lead to earlier detection and improved survival.

Effect of acute and chronic intermittent hypoxia on DNA topoisomerase II alpha expression and mitomycin C-induced DNA damage and cytotoxicity in human colon cancer cells

Recently, we reported that alterations in topoisomerase II (topo II) activity appear to contribute to mitomycin C (MMC) resistance in HT-29R13 human colon cancer cells under aerobic conditions. In this study, the expression of topo II alpha and topo II beta in parent HT-29 and MMC resistant variant HT-29R13 cells was investigated under aerobic, acute hypoxic (after 4 hr in 95% N2, 5% CO2 < 0.01% O2), and chronic intermittent hypoxic (after 4 hr hypoxia/day x 7 days) conditions. Acute hypoxia induced topo II alpha mRNA and protein, effects that were more pronounced in HT-29 cells. Chronic intermittent hypoxia caused a decrease in topo alpha mRNA and protein, changes that were again more pronounced in HT-29 cells. The observed changes in topo II alpha protein were associated with parallel changes in topo II activity under all conditions tested. Topo II beta mRNA was expressed at a very low level in both cell lines under aerobic and hypoxic conditions. Compared with cells under aerobic conditions, HT-29 cells were more sensitive to MMC under acute hypoxia but more resistant under chronic intermittent hypoxia. In contrast, the senstivity of HT-29R13 cells was unchanged under acute hypoxia, but the cells were more resistant under chronic intermittent hypoxia. Under all conditions tested, the degree of cytotoxicity corresponded to the frequency of MMC-induced DNA cross-links and topo II alpha protein levels and activity. Our results demonstrated that MMC cytotoxicity in hypoxic cells is highly dependent upon the type of hypoxia and the cell type. Hypoxia has significant effects on topo II alpha expression in HT-29 and HT-29R13 cells which correlate with MMC cytotoxicity.

Role of c-myc in tamoxifen-induced apoptosis estrogen-independent breast cancer cells

BACKGROUND

The antiestrogen tamoxifen (TAM) is effective in the treatment of estrogen receptor (ER)-positive as well as some ER-negative breast cancers. However, the precise mechanism of action of TAM, especially in estrogen-independent cells, remains unclear. Previous work by our laboratory has demonstrated that TAM induces the morphologic and biochemical changes that are characteristic of apoptosis in both ER-positive and ER-negative cells.

PURPOSE

We compared the effect of TAM at a clinically achievable concentration on cell growth and apoptosis with the effect of TAM on c-myc (also known as C-MYC) messenger RNA (mRNA) and protein expression in ER-negative MDA-231 cells.

METHODS

MDA-231 cells were treated for up to 72 hours with 1.0 microM TAM alone or in the presence of 50 microM c-myc antisense or nonsense oligonucleotides. c-myc mRNA expression was determined by northern blot analysis, protein expression by western blot analysis, cell growth inhibition counts, and DNA cleavage by agarose gel electrophoretic analysis. Differences between the mean values from different treatment groups were compared with the use of the two-sided Wilcoxon Ranksum test.

RESULTS

TAM treatment for 72 hours increased c-myc mRNA five-fold (from a relative radiolabeled hybridization signal intensity of 17 +/- 4 up to 93 +/- 10; P<.05) and c-MYC protein threefold (from a relative immunofluorescence signal intensity of 28 +/- 7 up to 83+/-21; P< .05). The induction of c-myc by TAM was accompanied by internucleosomal DNA cleavage characteristic of apoptotic cell death. Addition of c-myc antisense oligonucleotide (5'CACGTTGAGGGGCAT-3') to MDA-231 cells resulted in a nearly twofold decrease of basal c-myc mRNA (P< .05) and a sevenfold decrease of basal c-Myc protein (P< .05) expression. Addition of c-myc antisense oligomer also antagonized the TAM-induced increase in c-myc mRNA (P< .05) and protein expression (P< .05) and inhibited TAM-induced cytostasis (P< .01) and apoptosis. In parallel experiments, addition of the nonsense oligomer had no effect on any of the measured parameters.

CONCLUSIONS

These results indicate that the effects of TAM on ER-negative MDA-231 cells may be mediated through c-myc overexpression. c-myc may play a critical role in the growth and progression of MDA-231 breast cancer cells.

Pathologic fracture secondary to subungual melanoma

Subungual melanoma is uncommon, and delays in diagnosis and misdiagnosis occur frequently. We describe a 61-year-old black male who presented with a non-healing area in his left thumb nailbed with many of the features of subungual melanoma. However, the patient also had a pathologic fracture of the distal phalanx, leading to some initial confusion about the diagnosis. Despite aggressive multimodality therapy, the disease rapidly progressed, resulting in the patient's death. Pathologic fracture due to subungual melanoma may indicate a particularly poor prognosis.

Endocrine tumors of the gastrointestinal tract

Endocrine tumors of the gastrointestinal tract produce a variety of secretory products that cause unique clinical syndromes. Diagnosis, which is often delayed, requires a strong index of suspicion and must be confirmed by biochemical tests. Precisely where these tumors originate remains a topic of controversy. However, several growth factors that may be involved in tumor development have been identified, and genetic abnormalities in patients with multiple endocrine neoplasia have been described. New pre- and intraoperative localization techniques have greatly increased the ability to identify and resect these tumors. The long-acting somatostatin analogue octreotide is frequently useful as a tracer to localize tumors and as symptomatic therapy for limiting release of secretory products produced by the tumors. In some instances it may also have direct anti-tumor activity.

p-Glycoprotein expression as a predictor of breast cancer recurrence

BACKGROUND

Many new prognostic factors for breast cancer have been described, and yet the ability to predict patient outcomes remains poor. Overexpression of p-glycoprotein (p-gp), the multidrug resistance efflux pump, confers a worse prognosis to patients with certain leukemias and other tumors. The purpose of this study was to analyze the potential usefulness of p-gp expression as a prognostic factor in patients with breast cancer.

METHODS

Paraffin blocks were obtained from 55 previously untreated patients who underwent surgery between 1987 and 1988. To determine p-gp expression, tumor cell suspensions were incubated with the p-gp-specific C219 monoclonal antibody and analyzed using an indirect immunofluorescent flow cytometric assay.

RESULTS

Twenty-four (44%) of the tumors were p-gp positive and 31 (56%) were p-gp negative. Among the p-gp positive patients, 65% had recurrence of their disease, whereas only 13% of the p-gp negative patients experienced recurrence (p = 0.0001). The 5-year disease-free rate for p-gp positive patients was 39% compared with 83% for p-gp negative patients (p = 0.0001). In univariate analysis examining 10 different variables, significant predictors of recurrence were p-gp, stage, and tumor size. Multivariate analysis using Cox Proportional Hazards regression showed that only p-gp and stage were significant independent predictors of recurrence (p = 0.0002).

CONCLUSIONS

p-gp is frequently expressed in patients with untreated breast cancer, with p-gp-positive patients being at significantly greater risk for disease recurrence. p-gp appears to be a useful prognostic factor in breast cancer and could potentially help guide management.

Relationship between tamoxifen-induced transforming growth factor beta 1 expression, cytostasis and apoptosis in human breast cancer cells

Previously we have shown that tamoxifen (TAM) induces morphological and biochemical changes typical of apoptosis in oestrogen receptor (ER)-positive MCF-7 or ER-negative MDA-231 human breast cancer cells. In this study the effects of TAM on expression of transforming growth factor beta 1 (TGF-beta 1) were correlated with the effects on cell cycle kinetics and apoptosis. TAM had similar biphasic effects on both cell lines. Short-term (< 6 h) TAM incubation resulted in a slight decrease in TGF-beta 1 protein despite an increase in TGF-beta 1 mRNA and was associated with an increase in cells in S-phase. No apoptotic effects were noted. Longer (> or = 12 h) TAM incubation induced TGF-beta 1 protein (about 3-fold) and mRNA expression (about 2-fold) in both cell lines, and was associated with G1/G0 blockade and induction of apoptosis. The accumulation of TAM-induced TGF-beta 1 mRNA was increased by cycloheximide, but was not affected by 17 beta-oestradiol. Long-term incubation with TAM had no significant effect on TGF-beta 1 gene copy number. TAM-induced internucleosomal DNA cleavage was inhibited in both cell lines by the addition of an anti-TGF-beta 1 antibody. TAM has dose- and time-dependent effects on TGF-beta 1 expression associated with changes in cell cycle kinetics. These effects are independent of ER status and may be the result of a direct regulatory effect of TAM on TGF-beta 1 transcription. It also appears that induction of TGF-beta 1 plays an important role in TAM-induced apoptosis in breast cancer cells.

Management and prognosis of adenocarcinoma of the appendix

PURPOSE

Adenocarcinoma of the appendix is a rare neoplasm, and controversies persist regarding management. The purpose of this study was to identify prognostic factors and define management strategies for patients with adenocarcinoma of the appendix.

METHODS

A retrospective case series was conducted at three medical school teaching hospitals over a 20-year period from 1972 to 1992. Overall survival was determined by the actuarial life table method. Comparisons of prognostic factors were made using exact nonparametric log-rank tests.

RESULTS

Thirteen patients were diagnosed during the study period. Median age was 62 years. There were five males and eight females. The disease was not suspected in any patient preoperatively. Seventy-seven percent of patients had metastatic disease at presentation. Second primary malignancies were found in 15 percent of patients. Thirty-eight percent of female patients had synchronous ovarian lesions. Median survival was 22 months, with an estimated five-year survival of 43 percent (95 percent confidence interval, 22-84 percent). Patients with colonic histology had significantly worse survival than patients with mucinous histology (P = 0.0093). Patients with carcinomatosis had a significantly worse survival than noncarcinomatosis patients (P = 0.0078). Patients who underwent right hemicolectomy had a better prognosis for survival than appendectomy patients, but the difference was not statistically significant.

CONCLUSIONS

Carcinoma of the appendix is very difficult to diagnose preoperatively, and most patients are not identified until disease is advanced. Good prognostic factors include mucinous histology and the absence of carcinomatosis. Right hemicolectomy appears to be a reasonable option, although its superiority to appendectomy alone has not been definitively proven. High frequency of ovarian metastases in women suggests a role for bilateral oophorectomy. In addition, a complete work-up of the patient for a synchronous malignancy, especially in the gastrointestinal tract, should be considered.

Clinical review 72: diagnosis and management of functioning islet cell tumors

Functional islet cell tumors cause recognizable clinical syndromes based on the peptide products they secrete (Table 1). Frequently, the diagnosis of these tumors is delayed. A high index of suspicion coupled with the use of appropriate biochemical and provocative tests should lead to earlier diagnosis. A suggested management plan for patients suspected of having an islet cell tumor is shown in Fig. 1. Earlier diagnosis coupled with advances in preoperative and intraoperative localization techniques have resulted in an increased number of patients being cured.

Effects of tamoxifen on growth and apoptosis of estrogen-dependent and -independent human breast cancer cells

BACKGROUND

Apoptosis ("programmed cell death") is an active process characterized by prominent nuclear changes and DNA cleavage, which distinguishes it from cellular necrosis. In this study we investigated whether tamoxifen (TAM) treatment of estrogen receptor ER(+) MCF-7 and ER(-) MDA-231 human breast cancer cells resulted in cytotoxicity and cellular changes typical of apoptosis.

METHODS

Cytotoxicity was measured using a tetrazolium assay. Cellular morphologic changes were observed using transmission electron microscopy. DNA cleavage was assessed using 1.6% agarose gel electrophoresis and was also quantitated biochemically.

RESULTS

Exposure of cells to TAM for 24 h resulted in dose-dependent cytotoxicity, and MCF-7 cells were somewhat more sensitive to TAM. TAM induced chromatin condensation around the nuclear periphery in both cell lines, changes typical of apoptosis. TAM-induced cytotoxicity correlated with dose-dependent DNA cleavage, which showed the characteristic "internucleosomal ladder." DNA cleavage occurred at a slightly lower TAM dose and occurred somewhat sooner in MCF-7 cells. TAM-induced DNA cleavage in MCF-7 cells was inhibited by the protein synthesis inhibitor cycloheximide, the RNA synthesis inhibitor actinomycin D, and by 17 beta-estradiol. However, in MDA-231 cells, DNA cleavage was inhibited by cycloheximide, partially but not significantly inhibited by actinomycin D, and not inhibited by 17 beta-estradiol.

CONCLUSIONS

TAM induces typical apoptosis in ER(+) or ER(-) human breast cancer cells. TAM induction of apoptosis in MCF-7 cells involves the estrogen receptor, and requires the synthesis of new protein and mRNA. TAM induction of apoptosis in MDA-231 cells depends primarily on protein synthesis. TAM-induced cytotoxicity and DNA damage appear to be explained in part by the induction of apoptosis.

Cancer of the male breast

A retrospective review of 28 male breast cancer patients at Eastern Virginia Medical School and affiliated hospitals was performed to learn about patient characteristics, treatment, and outcome. The mean age of the patients was 64 years, and 60 per cent of patients were obese. The most common presenting symptoms were mass in 79 per cent and nipple discharge in 29 per cent. The median duration of symptoms was 3.3 months. All patients except two underwent mastectomy, and most tumors were early stage (0, I, or II). Many patients, particularly those with advanced disease, were also treated with chemotherapy, radiation therapy, and/or endocrine therapy. At a median follow-up of 29 months, the actuarial 5-year survival was 43 per cent, somewhat worse than the survival of female breast cancer patients in the literature. Male breast cancer patients are treated in a similar fashion to female patients. Aggressive systemic treatment should be considered for patients with poor prognosis disease. The high frequency of estrogen receptor positivity suggests tamoxifen may prove to be particularly useful in these patients.

Intratumor variability in prognostic indicators may be the cause of conflicting estimates of patient survival and response to therapy

The DNA index, percentage of S-phase cells, proliferation fraction, and glutathione (GSH) content were determined at more than 1100 separate sites in 140 human tumors and 140 normal tissues. The study showed that the variability was so great from site to site within a tumor that there was only a 61% chance of identifying an aneuploid tumor clone (when present) if only a single site sample was analyzed for DNA content. Similar broad variability was observed in the percentage of S-phase cells, proliferation fraction, and glutathione content. Since these tumor characteristics are often used to predict the outcome of therapy and patient survival, the inaccuracy and underestimation of the test results may cause conflicting or erroneous predictions. The probability of finding an aneuploid clone or elevated percentage of S-phase cells proliferation fraction and GSH content increased dramatically as the number of sample sites studied per tumor was increased. Statistical analyses indicated that in order to achieve a 90% probability that the test results for these parameters were representative of the whole tumor: (a) all single site testing should be abandoned; (b) assays should be performed on samples taken from 3-7 different sites within each tumor; or (c) samples from each tumor should be pooled and the analyses run on a thoroughly mixed or homogenized aliquot of the multisite sample.