Patterns of care and outcomes of radiotherapy or hormone therapy in patients with medically inoperable endometrial adenocarcinoma.

OBJECTIVE: The optimal treatment for medically inoperable endometrioid endometrial adenocarcinoma is unknown. The goal of this study was to evaluate the patterns of care and efficacy of radiotherapy (RT) or hormone therapy (HT) in the treatment of these patients. METHODS: We performed a query of the National Cancer Database (NCDB) of patients with medically inoperable endometrioid adenocarcinoma of the endometrium diagnosed between 2004 and 2016 and treated with either RT or HT. A multivariate Cox regression model and propensity weighted analyses were used to evaluate overall survival after controlling for confounding variables. A multinomial logistic regression model was used to assess predictors of RT or HT use. RESULTS: A total of 1036 patients were included in this cohort, and 73% (n = 759) were treated with RT alone. Patients who received definitive HT compared to RT were more likely to be older, diagnosed in the earlier years of this analysis, treated at lower-case volume centers, diagnosed with high-grade disease, or located outside of metropolitan areas. On multivariate analysis, treatment with HT alone versus RT alone was associated with significantly worse overall survival in the multivariate Cox model but not on propensity score weighted analysis. Interaction effect testing revealed that older patients and those treated at lower-volume centers had improved survival with RT compared to HT. CONCLUSIONS: We identified factors associated with the receipt of RT or HT in medically inoperable endometrial cancer patients. Treatment with RT correlated with improved survival compared to HT in older patients and those treated at lower-volume centers.

Role of adjuvant chemotherapy in patients with FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma treated with surgery and post-operative radiotherapy.

BACKGROUND: The optimal treatment of patients with FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma remains unknown. OBJECTIVE: To compare overall survival following treatment with a hysterectomy and adjuvant radiotherapy with or without chemotherapy in this group of patients. METHODS: Patients diagnosed between January 2004 and January 2016 with FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma treated with hysterectomy and postoperative radiotherapy with or without adjuvant concurrent chemotherapy were identified in the National Cancer Database. Overall survival was assessed with Kaplan-Meier curves. A Cox model was constructed to evaluate survival after controlling for confounding variables. A logistic regression model was used to reveal predictors of chemotherapy use. RESULTS: A total of 2173 patients were included. The receipt of chemotherapy was associated with an increased 5-year overall survival from 67.6% to 75.6% (p=0.0313). This association trended toward statistical significance on multivariate analysis (adjusted HR (aHR) 0.80; 95% CI 0.63 to 1.01; p=0.0653). Other factors associated with improved survival were undergoing a lymphadenectomy, absence of lymphovascular space invasion, younger age, smaller tumor size, non-black race, and absence of comorbidities. Patients who underwent brachytherapy, had lymphovascular space invasion, were younger, were diagnosed in the more recent years, and were treated in higher volume centers were more likely to receive adjuvant chemotherapy. CONCLUSION: Adjuvant chemotherapy and radiation therapy were associated with an increase in survival in patients with FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma compared with those treated with adjuvant radiotherapy alone.

Trends in Incidence and Mortality Rates of Uterine Cancer in Kentucky.

OBJECTIVES: The objective of this analysis was to gauge how the incidence and mortality of uterine cancer in Kentucky have changed from 1995 through 2017. An assessment of the trends in incidence and mortality across different geographic areas and between different races was also performed. METHODS: Age-adjusted annual incidence and mortality rates for uterine cancer were obtained from the Kentucky Cancer Registry. A meta-regression framework was used to assess changes in incidence and mortality rates during the time frame and to determine differences in these rates between rural versus urban counties, Appalachian versus non-Appalachian counties, and Black versus White women. RESULTS: The incidence of uterine cancer has significantly increased throughout the state of Kentucky since 1995. Uterine cancer incidence was 10% and 22% higher in rural and Appalachian counties, respectively, compared with urban and non-Appalachian counties (P < 0.0001) from 1995 through 2017. In contrast, urban and non-Appalachian women had higher or equivalent age-adjusted mortality from uterine cancer, compared with rural and Appalachian women, respectively. The incidence of uterine cancer was significantly higher in White women compared with Black women from 1995 through 2006, but since 2007, there has been no significant difference in uterine cancer incidence based on race. Black women had higher age-adjusted mortality than White women throughout the entire time period examined. CONCLUSIONS: The incidence of uterine cancer is higher in rural and Appalachian Kentucky, without a corresponding geographic trend in mortality. Uterine cancer mortality is significantly higher in Black women.

Cervical cancer incidence and mortality rates in Kentucky.

OBJECTIVES: The goal of this study was to assess how the incidence and mortality of cervical cancer in Kentucky has changed from 1995 through 2017. Additionally, trends in incidence and mortality across different geographic areas and between different races were evaluated. METHODS: Age-adjusted annual incidence and mortality rates for cervical cancer were collected from the Kentucky Cancer Registry (KCR). A quadratic fit model was used to evaluate changes in the incidence and mortality over time and to compare differences in cervical cancer incidence and mortality by: 1) rural versus urban counties, 2) Appalachian versus non-Appalachian counties, and 3) black versus white women. RESULTS: Overall, the incidence of cervical cancer has significantly decreased throughout Kentucky since 1995. When comparing different geographic regions, the incidence was 14% and 23% higher in rural and Appalachian counties, respectively, compared to urban and non-Appalachian counties (p < 0.0001) throughout the study period. The incidence of cervical cancer was significantly higher in black women compared to white women from 1995 through 2007, but since 2008 there has been no significant difference in cervical cancer incidence based on race. Similar to incidence rates, mortality from cervical cancer was 29% higher in Appalachia (p = 0.0004) throughout the studied time period. Black women had higher age-adjusted mortality than white women until 2012, but since that time there has not been a significant difference in cervical cancer mortality based on race. CONCLUSIONS: Women residing in rural and Appalachian Kentucky have higher cervical cancer incidence and mortality rates.

Dosimetric and toxicity comparison between Syed-Neblett and Fletcher-Suit-Delclos Tandem and Ovoid applicators in high dose rate cervix cancer brachytherapy.

PURPOSE: To compare patient and tumor characteristics, dosimetry, and toxicities between interstitial Syed-Neblett and intracavitary Fletcher-Suit-Delclos Tandem and Ovoid (T&O) applicators in high dose rate (HDR) cervical cancer brachytherapy. METHODS: A retrospective analysis was performed for cervical cancer patients treated with 3D-based HDR brachytherapy from 2011 to 2023 at a single institution. Dosimetric parameters for high-risk clinical target volume and organs at risk were obtained. Toxicities were evaluated using the Common Terminology Criteria for Adverse Events version 5.0. RESULTS: A total of 115 and 58 patients underwent Syed and T&O brachytherapy, respectively. Patients treated with Syed brachytherapy were more likely to have larger tumors and FIGO stage III or IV disease. The median D2cc values to the bladder, small bowel, and sigmoid colon were significantly lower for Syed brachytherapy. Patients treated with Syed brachytherapy were significantly more likely to be free of acute gastrointestinal (44% vs. 21%, p = 0.003), genitourinary (58% vs. 36%, p = 0.01), and vaginal toxicities (60% vs. 33%, p = 0.001) within 6 months following treatment compared to patients treated with T&O applicators. In contrast, Syed brachytherapy patients were more likely to experience late gastrointestinal (68% vs. 49%, p = 0.082), genitourinary (51% vs. 35%, p = 0.196), and vaginal toxicities (70% vs. 57%, p = 0.264). CONCLUSIONS: Syed-Neblett and T&O applicators are suitable for HDR brachytherapy for cervical cancer in distinct patient populations. Acute toxicities are more prevalent with T&O applicators, while patients treated with Syed-Neblett applicators are more likely to develop late toxicities.

Verrucous carcinoma of the vulva: Patterns of care and treatment outcomes.

BACKGROUND: Verrucous vulvar carcinoma (VC) is an uncommon and distinct histologic subtype of squamous cell carcinoma (SCC). The available literature on VC is currently limited to case reports and small single institution studies. AIMS: The goals of this study were to analyze data from the National Cancer Database (NCDB) to quantitate the incidence of VC and to investigate the effects of patient demographics, tumor characteristics, and treatment regimens on overall survival (OS) in women with verrucous vulvar carcinoma. METHODS AND RESULTS: Patients diagnosed with vulvar SCC or VC between the years of 2004 and 2016 were identified in the NCDB. OS was assessed with Kaplan-Meier curves and the log-rank test. Construction of a Cox model compared survival after controlling for confounding variables. The reported incidence of SCC of the vulva has significantly increased since 2004 (p < .0001). In contrast, the incidence of VC has remained stable (p = .344) since 2004. Compared to SCC, VC was significantly more likely to be diagnosed in older women (p < .0001) and treated with surgery alone (p < .0001). However, on propensity score weighted analysis there was a trend toward improved 5-year OS in women with VC compared to those with SCC (63.4% vs. 57.7%, p = .0794). Multivariable Cox survival analysis showed an improvement in OS in VC patients treated with both primary site and regional lymph node surgery compared to primary site surgery alone (adjusted hazard ratio [aHR] 0.67, 95% confidence interval [CI] 0.46-0.97, p = .0357). CONCLUSION: Verrucous carcinoma is more likely to present in older women. Regional lymph node surgery in addition to primary site surgery significantly improves OS in VC patients.

VEGFR-2 expression in carcinoid cancer cells and its role in tumor growth and metastasis.

Carcinoid tumors are slow growing and highly vascular neuroendocrine neoplasms that are increasing in incidence. Previously, we showed that carcinoid tumors express vascular endothelial growth factor receptor 2 (VEGFR-2) in the epithelial compartment of carcinoid tumor sections; yet, its role is not completely understood. The purpose of our study was to: (i) assess the expression of VEGFR-2 in the novel human carcinoid cell line BON, (ii) to determine the role of PI3K/Akt signaling on VEGFR-2 expression and (iii) to assess the effect of VEGFR-2 on BON cell invasion, migration and proliferation. We found that, although VEGFR-2 is expressed in BON cells, reduction in VEGFR-2 expression actually enhanced proliferation, invasion, and migration of the BON cell line. Also, expression of VEGFR-2 was inversely related to PI3K signaling. Carcinoid liver metastases in mice demonstrated decreased VEGFR-2 expression. Furthermore, the expression of a truncated, soluble form of VEGFR-2 (sVEGFR-2), a protein demonstrated to inhibit cell growth, was detected in BON cells. The presence of VEGFR-2 in the epithelial component of carcinoid tumors and in the BON cell line suggests an alternate role for VEGFR-2, in addition to its well-defined role in angiogenesis. The expression of sVEGFR-2 may explain the inverse relationship between VEGFR-2 expression and PI3K/Akt signaling and the inhibitory effect VEGFR-2 has on BON cell proliferation, migration and invasion.

The impact of brachytherapy boost and radiotherapy treatment duration on survival in patients with vaginal cancer treated with definitive chemoradiation.

PURPOSE: Vaginal cancer is a rare tumor that is optimally treated with a combination of chemotherapy (CHT) and radiation therapy. Because of the rarity of this cancer, the benefit of a brachytherapy boost (BT) and the relevance of radiotherapy time to treatment completion (TTC) are unclear. METHODS: Patients diagnosed between 2004 and 2015 with non-metastatic vaginal cancer treated with definitive CHT and external beam radiotherapy with or without BT but with no surgery were identified in the National Cancer Database. Overall survival (OS) was assessed with Kaplan-Meier curves, and differences between groups were compared with the log-rank test. A Cox model was constructed to evaluate survival after controlling for confounders. A Cox model using a penalized spline function was constructed to evaluate how the length of radiation therapy correlated with OS among patients receiving BT. RESULTS: A total of 1094 patients who met the inclusion criteria were identified. The utilization of BT was associated with improved 5-year OS (62.9% vs. 49.3%, p = 0.0126) on propensity score-weighted analyses. TTC of 63 days or less was associated with improved 5-year OS (67.8% vs. 54.5%, p = 0.0031) in patients who underwent BT. Other factors associated with improved OS in patients who received CHT, external beam radiotherapy, and BT were younger age, absent comorbidity score, and negative lymph nodes. CONCLUSIONS: A brachytherapy boost and shorter TTC were associated with a survival benefit in a cohort of patients with non-metastatic vaginal cancer treated with definitive chemoradiotherapy.

Vaginal cuff brachytherapy: do we need to treat to more than a two-centimeter active length?

PURPOSE: American Brachytherapy Society (ABS) guidelines recommend using a 3-5 cm active length (AL) when treating vaginal cuff (VC) in adjuvant setting of endometrial cancer (EC). The purpose of this study was to evaluate local control and toxicity, using an AL of 1 or 2 cm and immobilization with a traditional table-mounted (stand) or patient-mounted (suspenders) device. MATERIAL AND METHODS: Between 2005 and 2019, 247 patients with EC were treated with adjuvant high-dose-rate vaginal cuff (HDR-VC) brachytherapy with or without external beam radiation (EBRT). Treatment was prescribed to a 0.5 cm depth, with an AL of 1 or 2 cm, using stand or suspenders. VC boost after EBRT was typically administered with 2 fractions of 5.5 Gy, while VC brachytherapy alone was typically applied with 3 fractions of 7 Gy or 5 fractions of 5.5 Gy. RESULTS: The combination of suspender immobilization and an AL of 2 cm (n = 126, 51%) resulted in 5-year local control of 100%. An AL of 2 cm compared to 1 cm correlated with better local control (99.1% vs. 88.5%, p = 0.0479). Regarding immobilization, suspenders correlated with improved local control compared to stand (100% vs. 86.7%, p = 0.0038). Immobilization technique was significantly correlated with AL (p < 0.0001). Only 5 (2.0%) patients experienced grade ≥ 3 toxicity, all of whom received EBRT. CONCLUSIONS: In the present series, an AL of 2 cm provided excellent local control, while 1 cm was inadequate. Suspender immobilization was a practical alternative to stand immobilization in HDR brachytherapy of the vaginal cuff.

Development and characterization of a novel in vivo model of carcinoid syndrome.

PURPOSE: Carcinoid syndrome, characterized by flushing, diarrhea, and valvular heart disease, can occur following carcinoid tumor metastasis to the liver and systemic release of bioactive hormones into the systemic circulation. Treatment of this devastating disease is hampered by the lack of an in vivo model that recapitulates the clinical syndrome. EXPERIMENTAL DESIGN: Here, we have injected BON cells, a novel human carcinoid cell line established in our laboratory, into the spleens of athymic nude mice to establish liver metastases. RESULTS: The majority of mice injected intrasplenically with BON cells developed significant increases in plasma serotonin and urine 5-hydroxyindoleacetic acid, and several mice exhibited mesenteric fibrosis, diarrhea, and fibrotic cardiac valvular disease reminiscent of carcinoid syndrome by both echocardiographic and histopathologic evaluation. Mice pretreated with octreotide, a long-acting somatostatin analogue, or bevacizumab, a vascular endothelial growth factor inhibitor, developed fewer liver metastases and manifestations of carcinoid syndrome, including valvular heart disease. CONCLUSION: We have provided an important in vivo model to further delineate novel treatment modalities for carcinoid syndrome that will also be useful to elucidate the factors contributing to the sequelae of carcinoid disease (e.g., mesenteric fibrosis and valvular heart disease).

National Cancer Database Analysis of the effect of brachytherapy on overall survival in patients with base of tongue cancer.

BACKGROUND: We performed an analysis of the National Cancer Database (NCDB) to evaluate overall survival (OS) in patients with base of tongue (BOT) cancer treated with external beam radiation therapy (EBRT) combined with brachytherapy (BT). METHODS: The tongue NCDB Participant User File was used to obtain demographic and clinical patient data. The Kaplan-Meier method was used to determine OS. Significance was determined using univariable and multivariable Cox proportional hazards models. RESULTS: At 3 years, OS was 69.6%, 77.1%, and 63.7% for patients treated with EBRT (n = 27 954), EBRT + BT (n = 209), or BT alone (n = 154), respectively (P = .01). On multivariable analysis, the instantaneous hazard of death for patients receiving EBRT + BT was 25% (Hazard ratio [HR] = 0.75, 95% CI: 0.58-0.98) lower than patients receiving only EBRT (P = .03). CONCLUSIONS: The addition of BT to EBRT in BOT cancer has an OS benefit.

Integrating a 92-Gene Expression Analysis for the Management of Neuroendocrine Tumors of Unknown Primary

Background: Neuroendocrine tumors (NETs) are rare tumors that can originate from any part of the body. Often, imaging or exploratory surgery can assist in the identification of the tumor primary site, which is critical to the management of the disease. Neuroendocrine tumors (NETs) of unknown primary constitute approximately 10-15% of all NETs. Determining the original site of the tumor is critical to providing appropriate and effective treatment. Methods: We performed a retrospective review of neuroendocrine tumors at our institution between 2012 and 2016 using a 92-gene cancer ID analysis. Results: 56 patients with NETs of unknown primary were identified. Samples for 38 of the 56 underwent the 92-gene cancer ID analysis. The primary site of the tumor was identified with >95% certainty in 35 of the 38 patients. Conclusion: The 92-gene cancer ID analysis identified a primary site in 92% of our NETs study cohort that previously had been unknown. The results have direct implications on management of patients with regard to FDA-approved treatment options.

Oligometastatic Disease State Is Associated with Improved Local Control in Patients Undergoing Three or Five Fraction Spine Stereotactic Body Radiotherapy.

BACKGROUND: The objective of our study was to describe the local control (LC) outcomes with 3- or 5-fraction stereotactic body radiotherapy (SBRT) to the spine in patients with oligometastatic (≤5 systemic metastases) versus polymetastatic disease (>5 metastases). METHODS: We retrospectively reviewed the outcomes of patients who had undergone SBRT for spinal metastases. No patients had undergone previous surgical intervention or had spinal cord compression. All patients were treated with 3-fraction (median dose, 27 Gy; range, 24-30 Gy) or 5-fraction (median dose, 35 Gy; range, 25-40 Gy) SBRT. The Kaplan-Meier method and Spine Response Assessment in Neuro-Oncology criteria were used to determine LC. RESULTS: We included 61 patients with a total of 72 distinct SBRT targets who had been treated from August 2007 to June 2017. The median follow-up period was 13.58 months. We treated 20 targets and 52 targets with 3 and 5 fractions, respectively. Thirteen patients (18.1%) had undergone previous RT to the SBRT area. Twenty patients (35% of the distinct SBRT targets) had an oligometastatic disease state. The 1-year LC rate was 83% for the entire cohort. On univariable analysis, polymetastases (1-year LC, 73.8% vs. 100%; P = 0.07) showed a trend toward worse LC. On multivariable analysis, patients with an oligometastatic state (hazard ratio, 0.21; P = 0.04) had improved LC. CONCLUSIONS: Our study was hypothesis-generating in that patients with an oligometastatic disease state appear to have improved LC after SBRT, suggesting a biological advantage exists with local therapy for this group of patients not seen for patients with polymetastatic disease.

Does adjuvant concurrent or sequential chemotherapy increase the radiation-related toxicity of vaginal brachytherapy for endometrial cancer patients?

PURPOSE: To compare radiation toxicity in endometrial cancer patients treated with adjuvant vaginal brachytherapy (VBT) vs. VBT with concurrent chemotherapy (CCT) or sequential chemotherapy (SCT) METHODS: We retrospectively analyzed 131 patients with endometrial cancer treated with VBT without external beam radiation therapy. Toxicities were graded according to the Common Terminology Criteria for Adverse Events v4.03. CCT was defined as VBT delivered between the first and last cycle of chemotherapy (CT); SCT was defined as VBT delivered before or after CT. RESULTS: Median followup was 36 months, with a 3-year survival rate of 88%. Of the 131 patients, 92 were treated with VBT alone, 34 with VBT and CCT, and 5 with VBT and SCT. The most common toxicity was vaginal stricture, with 30 (22.9%) patients affected. The distribution of toxicities was vaginal 28%, urinary 12%, rectal 11%, and fatigue 5%; none greater than Grade 2. Compared with patients treated with VBT alone, the addition of CT did not increase the chance of vaginal stricture formation (p = 0.84). The difference in system-specific toxicities between treatment modalities was not statistically significant. CONCLUSION: The most common pelvic toxicity from VBT is vaginal stenosis with other toxicities being infrequent and generally Grade 1. The addition of CT in a sequential or concurrent fashion did not increase the rate of pelvic toxicity from VBT alone.

Clinical Application of a Hybrid RapidArc Radiotherapy Technique for Locally Advanced Lung Cancer.

OBJECTIVE: Radiation treatment planning for locally advanced lung cancer can be technically challenging, as delivery of ≥60 Gy to large volumes with concurrent chemotherapy is often associated with significant risk of normal tissue toxicity. We clinically implemented a novel hybrid RapidArc technique in patients with lung cancer and compared these plans with 3-dimensional conformal radiotherapy and RapidArc-only plans. MATERIALS/METHODS: Hybrid RapidArc was used to treat 11 patients with locally advanced lung cancer having bulky mediastinal adenopathy. All 11 patients received concurrent chemotherapy. All underwent a 4-dimensional computed tomography planning scan. Hybrid RapidArc plans concurrently combined static (60%) and RapidArc (40%) beams. All cases were replanned using 3- to 5-field 3-dimensional conformal radiotherapy and RapidArc technique as controls. RESULTS: Significant reductions in dose were observed in hybrid RapidArc plans compared to 3-dimensional conformal radiotherapy plans for total lung V20 and mean (-2% and -0.6 Gy); contralateral lung mean (-2.92 Gy); and esophagus V60 and mean (-16.0% and -2.2 Gy; all P < .05). Contralateral lung doses were significantly lower for hybrid RapidArc plans compared to RapidArc-only plans (all P < .05). Compared to 3-dimensional conformal radiotherapy, heart V60 and mean dose were significantly improved with hybrid RapidArc (3% vs 5%, P = .04 and 16.32 Gy vs 16.65 Gy, P = .03). However, heart V40 and V45 and maximum spinal cord dose were significantly lower with RapidArc plans compared to hybrid RapidArc plans. Conformity and homogeneity were significantly better with hybrid RapidArc plans compared to 3-dimensional conformal radiotherapy plans ( P < .05). Treatment was well tolerated, with no grade 3+ toxicities. CONCLUSION: To our knowledge, this is the first report on the clinical application of hybrid RapidArc in patients with locally advanced lung cancer. Hybrid RapidArc permitted safe delivery of 60 to 66 Gy to large lung tumors with concurrent chemotherapy and demonstrated advantages for reduction in low-dose lung volumes, esophageal dose, and mean heart dose.

Image-Based Brachytherapy for the Treatment of Cervical Cancer.

Cervical cancer is a disease that requires considerable multidisciplinary coordination of care and labor in order to maximize tumor control and survival while minimizing treatment-related toxicity. As with external beam radiation therapy, the use of advanced imaging and 3-dimensional treatment planning has generated a paradigm shift in the delivery of brachytherapy for the treatment of cervical cancer. The use of image-based brachytherapy, most commonly with magnetic resonance imaging (MRI), requires additional attention and effort by the treating physician to prescribe dose to the proper volume and account for adjacent organs at risk. This represents a dramatic change from the classic Manchester approach of orthogonal radiographic images and prescribing dose to point A. We reviewed the history and currently evolving data and recommendations for the clinical use of image-based brachytherapy with an emphasis on MRI-based brachytherapy.

The effect of PTEN on serotonin synthesis and secretion from the carcinoid cell line BON.

BACKGROUND: Carcinoid tumors are associated with the carcinoid syndrome, a set of symptoms resulting from the peptide and amine products, including serotonin, secreted from the cancer cells. The purpose of this study was to investigate the relationship between the phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) inhibitor PTEN (phosphatase and tensin homolog deleted on chromosome ten) and serotonin synthesis and secretion in the carcinoid cancer cell line BON. MATERIALS AND METHODS: PTEN was inhibited by pharmacological and molecular approaches, and the resultant secretion of serotonin and expression of tryptophan hydroxylase 1 (TPH1), the rate-limiting enzyme in serotonin synthesis, was assessed. RESULTS: Inhibition of PTEN in vitro, with concomitant increased Akt signaling, resulted in decreased secretion of serotonin, as well as decreased serotonin synthesis, as confirmed by reduced expression of TPH1. Inhibition of PTEN in BON cells in an animal model resulted in decreased serum serotonin. CONCLUSION: By inhibiting signaling through Akt, PTEN indirectly promotes serotonin synthesis and secretion.

PKD3 is the predominant protein kinase D isoform in mouse exocrine pancreas and promotes hormone-induced amylase secretion.

The protein kinase D (PKD) family of serine/threonine kinases, which can be activated by gastrointestinal hormones, consists of three distinct isoforms that modulate a variety of cellular processes including intracellular protein transport as well as constitutive and regulated secretion. Although isoform-specific functions have been identified in a variety of cell lines, the expression and function of PKD isoforms in normal, differentiated secretory tissues is unknown. Here, we demonstrate that PKD isoforms are differentially expressed in the exocrine and endocrine cells of the pancreas. Specifically, PKD3 is the predominant isoform expressed in exocrine cells of the mouse and human pancreas, whereas PKD1 and PKD2 are more abundantly expressed in the pancreatic islets. Within isolated mouse pancreatic acinar cells, PKD3 undergoes rapid membrane translocation, trans-activating phosphorylation, and kinase activation after gastrointestinal hormone or cholinergic stimulation. PKD phosphorylation in pancreatic acinar cells occurs viaaCa2+-independent, diacylglycerol- and protein kinase C-dependent mechanism. PKD phosphorylation can also be induced by physiologic concentrations of secretagogues and by in vivo stimulation of the pancreas. Furthermore, activation of PKD3 potentiates MEK/ERK/RSK (RSK, ribosomal S6 kinase) signaling and significantly enhances cholecystokinin-mediated pancreatic amylase secretion. These findings reveal a novel distinction between the exocrine and endocrine cells of the pancreas and further identify PKD3 as a signaling molecule that promotes hormone-stimulated amylase secretion.

An analysis of trends and growth factor receptor expression of GI carcinoid tumors.

INTRODUCTION: The purpose of our study was twofold: (1) to determine the incidence, patient and tumor characteristics, and outcome of patients with gastrointestinal carcinoid tumors using the Surveillance, Epidemiology and End Results (SEER) database, and (2) to delineate the expression pattern of growth factor receptors (GFRs) in carcinoid tumors. MATERIALS AND METHODS: The SEER database search provided information on patients diagnosed with carcinoid tumors from 1990 to 2002. Carcinoid tumor sections (n = 46) were stained for the GFRs: epidermal growth factor receptor, insulin-like growth factor receptor (IGFR), vascular endothelial growth factor receptor (VEGFR), and HER-2/neu. RESULTS: Over the 12-year analysis period, 18,180 patients were identified with carcinoid tumors of the foregut, midgut, and hindgut; the incidence of carcinoid tumors increased approximately 2-fold during this time period. Of the patients with carcinoid tumors, there was a trend of increased expression of VEGFR and IGFR, particularly in the foregut and midgut carcinoids. Analysis of the SEER database confirms that the incidence of carcinoid tumors is increasing with an approximate doubling in the number of carcinoid cases from 1990 to 2002. Furthermore, an increase in VEGFR and IGFR expression suggests that GFR inhibitors may be effective adjuvant therapy for carcinoid cancer.