Malignant tumors in tuberous sclerosis complex: a case report and review of the literature.

BACKGROUND: Tuberous sclerosis complex (TSC) is a rare, autosomal dominant genetic disease that arises from TSC1 or TSC2 genetic mutations. These genetic mutations can induce the development of benign tumors in any organ system with significant clinical implications in morbidity and mortality. In rare instances, patients with TSC can have malignant tumors, including renal cell carcinoma (RCC) and pancreatic neuroendocrine tumor (PNET). It is considered a hereditary renal cancer syndrome despite the low incidence of RCC in TSC patients. TSC is typically diagnosed in prenatal and pediatric patients and frequently associated with neurocognitive disorders and seizures, which are often experienced early in life. However, penetrance and expressivity of TSC mutations are highly variable. Herein, we present a case report, with associated literature, to highlight that there exist undiagnosed adult patients with less penetrant features, whose clinical presentation may contain non-classical signs and symptoms, who have pathogenic TSC mutations. CASE PRESENTATION: A 31-year-old female with past medical history of leiomyomas status post myomectomy presented to the emergency department for a hemorrhagic adnexal cyst. Imaging incidentally identified a renal mass suspicious for RCC. Out of concern for hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome, the mass was surgically removed and confirmed as RCC. Discussion with medical genetics ascertained a family history of kidney cancer and nephrectomy procedures and a patient history of ungual fibromas on the toes. Genetic testing for hereditary kidney cancer revealed a 5'UTR deletion in the TSC1 gene, leading to a diagnosis of TSC. Following the diagnosis, dermatology found benign skin findings consistent with TSC. About six months after the incidental finding of RCC, a PNET in the pancreatic body/tail was incidentally found on chest CT imaging, which was removed and determined to be a well-differentiated PNET. Later, a brain MRI revealed two small cortical tubers, one in each frontal lobe, that were asymptomatic; the patient's history and family history did not contain seizures or learning delays. The patient presently shows no evidence of recurrence or metastatic disease, and no additional malignant tumors have been identified. CONCLUSIONS: To our knowledge, this is the first report in the literature of a TSC patient without a history of neurocognitive disorders with RCC and PNET, both independently rare occurrences in TSC. The patient had a strong family history of renal disease, including RCC, and had several other clinical manifestations of TSC, including skin and brain findings. The incidental finding and surgical removal of RCC prompted the genetic evaluation and diagnosis of TSC, leading to a comparably late diagnosis for this patient. Reporting the broad spectrum of disease for TSC, including more malignant phenotypes such as the one seen in our patient, can help healthcare providers better identify patients who need genetic evaluation and additional medical care.

Geographic variation in attitudes regarding management of locally advanced pancreatic cancer.

Background: Recent literature suggests wide variations exist in the international management of locally advanced pancreatic cancer. This study sought to evaluate how geography contributes to variations in management of locally advanced pancreatic cancer. Methods: An electronic survey investigating preferences for the evaluation and management of locally advanced pancreatic cancer was distributed to an international cohort of pancreatic surgeons. Surgeons were classified according to geographic location of practice, and survey responses were compared across locations. Results: A total of 153 eligible responses were received from 4 continents: North and South America (n = 94, 61.4%), Europe (n = 25, 16.3%), and Asia (n = 34, 22.2%). Preferences for the use and duration of neoadjuvant chemotherapy and radiotherapy varied widely. For example, participants in Asia commonly preferred 2 months of neoadjuvant chemotherapy (61.8%), whereas North and South American participants preferred 4 months (52.1%), and responses in Europe were mixed (P = .006). Participants in Asia were less likely to consider isolated liver or lung metastases contraindications to exploration and consequently had a greater propensity to consider exploration in a vignette of oligometastatic disease (56.7% vs North and South America: 25.6%, Europe: 43.5%; P = .007). Conclusion: In an international survey of pancreatic surgeons, attitudes regarding locally advanced pancreatic cancer and metastatic disease management varied widely across geographic locations. Better evidence is needed to define optimal management of locally advanced pancreatic cancer.

Splenic and PB immune recovery in neoadjuvant treated gastrointestinal cancer patients.

In recent years, immune therapy, notably immune checkpoint inhibitors (ICI), in conjunction with chemotherapy and surgery has demonstrated therapeutic activity for some tumor types. However, little is known about the optimal combination of immune therapy with standard of care therapies and approaches. In patients with gastrointestinal (GI) cancers, especially pancreatic ductal adenocarcinoma (PDAC), preoperative (neoadjuvant) chemotherapy has increased the number of patients who can undergo surgery and improved their responses. However, most chemotherapy is immunosuppressive, and few studies have examined the impact of neoadjuvant chemotherapy (NCT) on patient immunity and/or the optimal combination of chemotherapy with immune therapy. Furthermore, the majority of chemo/immunotherapy studies focused on immune regulation in cancer patients have focused on postoperative (adjuvant) chemotherapy and are limited to peripheral blood (PB) and occasionally tumor infiltrating lymphocytes (TILs); representing a minority of immune cells in the host. Our previous studies examined the phenotype and frequencies of myeloid and lymphoid cells in the PB and spleens of GI cancer patients, independent of chemotherapy regimen. These results led us to question the impact of NCT on host immunity. We report herein, unique studies examining the splenic and PB phenotypes, frequencies, and numbers of myeloid and lymphoid cell populations in NCT treated GI cancer patients, as compared to treatment naïve cancer patients and patients with benign GI tumors at surgery. Overall, we noted limited immunological differences in patients 6 weeks following NCT (at surgery), as compared to treatment naive patients, supporting rapid immune normalization. We observed that NCT patients had a lower myeloid derived suppressor cells (MDSCs) frequency in the spleen, but not the PB, as compared to treatment naive cancer patients and patients with benign GI tumors. Further, NCT patients had a higher splenic and PB frequency of CD4+ T-cells, and checkpoint protein expression, as compared to untreated, cancer patients and patients with benign GI tumors. Interestingly, in NCT treated cancer patients the frequency of mature (CD45RO+) CD4+ and CD8+ T-cells in the PB and spleens was higher than in treatment naive patients. These differences may also be associated, in part with patient stage, tumor grade, and/or NCT treatment regimen. In summary, the phenotypic profile of leukocytes at the time of surgery, approximately 6 weeks following NCT treatment in GI cancer patients, are similar to treatment naive GI cancer patients (i.e., patients who receive adjuvant therapy); suggesting that NCT may not limit the response to immune intervention and may improve tumor responses due to the lower splenic frequency of MDSCs and higher frequency of mature T-cells.

Disruption of FDPS/Rac1 axis radiosensitizes pancreatic ductal adenocarcinoma by attenuating DNA damage response and immunosuppressive signalling.

BACKGROUND: Radiation therapy (RT) has a suboptimal effect in patients with pancreatic ductal adenocarcinoma (PDAC) due to intrinsic and acquired radioresistance (RR). Comprehensive bioinformatics and microarray analysis revealed that cholesterol biosynthesis (CBS) is involved in the RR of PDAC. We now tested the inhibition of the CBS pathway enzyme, farnesyl diphosphate synthase (FDPS), by zoledronic acid (Zol) to enhance radiation and activate immune cells. METHODS: We investigated the role of FDPS in PDAC RR using the following methods: in vitro cell-based assay, immunohistochemistry, immunofluorescence, immunoblot, cell-based cholesterol assay, RNA sequencing, tumouroids (KPC-murine and PDAC patient-derived), orthotopic models, and PDAC patient's clinical study. FINDINGS: FDPS overexpression in PDAC tissues and cells (P < 0.01 and P < 0.05) is associated with poor RT response and survival (P = 0.024). CRISPR/Cas9 and pharmacological inhibition (Zol) of FDPS in human and mouse syngeneic PDAC cells in conjunction with RT conferred higher PDAC radiosensitivity in vitro (P < 0.05, P < 0.01, and P < 0.001) and in vivo (P < 0.05). Interestingly, murine (P = 0.01) and human (P = 0.0159) tumouroids treated with Zol+RT showed a significant growth reduction. Mechanistically, RNA-Seq analysis of the PDAC xenografts and patients-PBMCs revealed that Zol exerts radiosensitization by affecting Rac1 and Rho prenylation, thereby modulating DNA damage and radiation response signalling along with improved systemic immune cells activation. An ongoing phase I/II trial (NCT03073785) showed improved failure-free survival (FFS), enhanced immune cell activation, and decreased microenvironment-related genes upon Zol+RT treatment. INTERPRETATION: Our findings suggest that FDPS is a novel radiosensitization target for PDAC therapy. This study also provides a rationale to utilize Zol as a potential radiosensitizer and as an immunomodulator in PDAC and other cancers. FUNDING: National Institutes of Health (P50, P01, and R01).

Proclivity to Explore Locally Advanced Pancreas Cancer Is Not Associated with Surgeon Volume.

BACKGROUND AND PURPOSE: There is limited high-level evidence to guide locally advanced pancreas cancer (LAPC) management. Recent work shows that surgeons' preferences in LAPC management vary broadly. We sought to examine whether surgeon volume was associated with attitudes regarding LAPC management. METHODS: An electronic survey was distributed by email to an international cohort of pancreas surgeons to evaluate practice patterns regarding LAPC management. Clinical vignette-based questions evaluated surgeons' attitudes regarding patient eligibility and the proclivity to offer exploration. Surgeons were classified into "low-" or "high-volume" categories according to thresholds of self-reported annual pancreatectomy volume. Surgeon's attitudes regarding LAPC management and inclination to consider exploration were compared across annual volume categories. RESULTS: A total of 153 eligible responses were received from 4 continents, for an estimated response rate of 10.6%. Median duration of practice was 12 years (IQR 6-20). Most respondents reported >25 cases/year (89, 58.2%), of which 34 (22.2%) reported >50. Compared to surgeons with <25 cases/year, surgeons with >25 cases/year practiced longer (median 15 vs. 7.5 years, P<0.001) and were more likely to "always" recommend neoadjuvant chemotherapy (83.2% vs. 56.3%, P=0.001). Surgeons performing >50 cases/year were more likely to offer arterial resection (70.6% vs. 43.7%, P=0.006). The willingness to offer (or defer) exploration did not differ across any categories of surgeons' annual case volume. CONCLUSIONS: In an international survey of pancreas surgeons, the proclivity to consider exploration for LAPC was not associated with multiple categories of surgeon volume. Better evidence is needed to define the optimal management approach to LAPC.

Association of gravity drainage and complications following Whipple: an analysis of the ACS-NSQIP targeted database.

BACKGROUND: The optimal type of operative drainage following pancreaticoduodenectomy (PD) remains unclear. Our objective is to investigate risk associated with closed drainage techniques (passive [gravity] vs. suction) after PD. METHODS: We assessed operative drainage techniques utilized in patients undergoing PD in the ACS-NSQIP pancreas-targeted database from 2016 to 2018. Using multivariable logistic regression to adjust for characteristics of the patient, procedure, and pancreas, we examined the association between use of gravity drainage and postoperative outcomes. RESULTS: We identified 9665 patients with drains following PD from 2016 to 2018, of which 12.7% received gravity drainage. 61.0% had a diagnosis of adenocarcinoma or pancreatitis, 26.5% had a duct <3 mm, and 43.5% had a soft or intermediate gland. After multivariable adjustment, gravity drainage was associated with decreased rates of postoperative pancreatic fistula (odds ratio [OR] 0.779, 95% confidence interval [CI] 0.653-0.930, p=0.006), delayed gastric emptying (OR 0.830, 95% CI 0.693-0.988, p=0.036), superficial SSI (OR 0.741, 95% CI 0.572-0.959, p=0.023), organ space SSI (OR 0.791, 95% CI 0.658-0.951, p=0.012), and readmission (OR 0.807, 95% CI 0.679-0.958, p=0.014) following PD. CONCLUSIONS: Gravity drainage is independently associated with decreased rates of CR-POPF, DGE, SSI, and readmission following PD. Additional prospective research is necessary to better understand the preferred drainage technique following PD.

Human splenic myeloid derived suppressor cells: Phenotypic and clustering analysis.

Myeloid derived suppressor cells (MDSCs) can be subset into monocytic (M-), granulocytic (G-) or polymorphonuclear (PMN-), and immature (i-) or early MDSCs and have a role in many disease states. In cancer patients, the frequencies of MDSCs can positively correlate with stage, grade, and survival. Most clinical studies into MDSCs have been undertaken with peripheral blood (PB); however, in the present studies, we uniquely examined MDSCs in the spleens and PB from patients with gastrointestinal cancers. In our studies, MDSCs were rigorously subset using the following markers: Lineage (LIN) (CD3, CD19 and CD56), human leukocyte antigen (HLA)-DR, CD11b, CD14, CD15, CD33, CD34, CD45, and CD16. We observed a significantly higher frequency of PMN- and M-MDSCs in the PB of cancer patients as compared to their spleens. Expression of the T-cell suppressive enzymes arginase (ARG1) and inducible nitric oxide synthase (i-NOS) were higher on all MDSC subsets for both cancer patients PB and spleen cells as compared to MDSCs from the PB of normal donors. Similar findings for the activation markers lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), program death ligand 1 (PD-L1) and program cell death protein 1 (PD-1) were observed. Interestingly, the total MDSC cell number exported to clustering analyses was similar between all sample types; however, clustering analyses of these MDSCs, using these markers, uniquely documented novel subsets of PMN-, M- and i-MDSCs. In summary, we report a comparison of splenic MDSC frequency, subtypes, and functionality in cancer patients to their PB by clustering and cytometric analyses.

Management of Locally Advanced Pancreatic Cancer: Results of an International Survey of Current Practice.

OBJECTIVE: The aim of this study was to investigate surgeon preferences for the management of patients with locally advanced pancreatic cancer (LAPC). BACKGROUND: Select patients with LAPC may become candidates for curative resection following neoadjuvant therapy, and recent reports of survival are encouraging. Yet the optimal management approach remains unclear. METHODS: An extensive electronic survey was systematically distributed by email to an international cohort of pancreas surgeons. Data collected included practice characteristics, management preferences, attitudes regarding contraindications to surgery, and 6 clinical vignettes of patients that ultimately received a margin negative resection (with detailed videos of post-neoadjuvant imaging) to assess propensity for surgical exploration if resection status is not known. RESULTS: A total of 153 eligible responses were received from 4 continents. Median duration of practice is 12 years (interquartile range 6-20) and 77% work in a university setting. Most surgeons (86%) are considered high volume (>10 resections/yr), 33% offer a minimally-invasive approach, and 50% offer arterial resections in select patients. Most (72%) always recommend neoadjuvant chemotherapy, and 65% prefer FOLFIRINOX. Preferences for the duration of chemotherapy varied widely: 39% prefer ≥2 months, 43% prefer ≥4 months, and 11% prefer ≥6 months. Forty-one percent frequently recommend neoadjuvant radiotherapy, and 53% prefer 5 to 6 weeks of chemoradiation. The proportion of surgeons favoring exploration following neoadjuvant varied extensively across 5 vignettes of LAPC, from 14% to 53%. In a vignette of oligometastatic liver metastases, 31% would offer exploration if a favorable therapy response is observed. CONCLUSIONS: In an international cohort of pancreas surgeons, there is substantial variation in management preferences, perceived contraindications to surgery, and the propensity to consider exploration in LAPC. These results emphasize the importance of a robust and nuanced multidisciplinary discussion for each patient, and suggest an evolving concept of "resectability."

Comparative phenotypes of peripheral blood and spleen cells from cancer patients.

Patients with resectable tumor, either in the body or the tail of the pancreas, and cancer patients with a primary tumor adjacent to the splenic vasculature frequently undergo a splenectomy as standard of care during resection. The spleen provides an unutilized source of lymphocytes with potential utility for adoptive cellular therapy (ACT). In this report, spleen and peripheral blood (PB) cells from cancer patients were compared to one another and normal PB by flow cytometry with a focus on CD8+ T-cells, memory phenotype, and their relative expression of checkpoint proteins including program death ligand-1 (PD1). PD1 is both an activation marker for T-cells including antigen (Ag) specific responses, as well as a marker of T-cell exhaustion associated with co-expression of other checkpoint molecules such as lymphocyte activating gene-3 (LAG-3) and T-cell immunoglobulin and mucin domain containing-3 (TIM-3). In summary, the spleen is a rich source of CD8+PD1+ T-cells, with an 8-fold higher frequency compared to the PB. These CD8+ T-cells are predominantly central and transitional memory T-cells with associated effector phenotypes and low expression of TIM-3 and LAG-3 with potential utility for ACT".

Robotic assisted placement of hepatic artery infusion pump is a safe and feasible approach.

BACKGROUND: Hepatic artery infusion (HAI) chemotherapy can be combined with systemic chemotherapy for the treatment of isolated unresectable colorectal liver metastases (IU-CRLM) and intrahepatic cholangiocarcinoma (U-ICC). However, HAI pump placement requires a major laparotomy that may be associated with morbidity. We hypothesized that the computer-assisted robotic platform would be well suited for this procedure and report the first single institutional case series of robotic assisted HAI pump placement for primary and secondary malignancies of the liver. METHODS: A retrospective review of patients who underwent robotic assisted HAI pump placement from January 2008 to January 2016. Peri-operative outcomes were evaluated. RESULTS: A total of 24 consecutive patients underwent robotic assisted HAI pump placement. Median age was 61 years and 50% were females. Main indications were colorectal cancer = 17 (71%) and intrahepatic cholangiocarcinoma = 4 (17%). The majority (87.5%) of patients had bilobar disease with a median of 6 liver lesions. Concurrent procedures including ablation +/- resection and colectomies were performed in 58% of the patients. Median operative time was 282 min, with median blood loss of 100 ml and length of stay 6 days. Conversion to open was required in one (4%) case. Grade 3 or higher complications were seen in 13% of cases and pump related complications were seen in 21% of patients. All except one HAI pumps could be used for pump chemotherapy. CUSUM analysis of operative time indicated a learning curve of eight cases. CONCLUSION: Robotic assisted placement of HAI pump placement is safe, feasible, and obviates the need for major laparotomy. J. Surg. Oncol. 2016;114:342-347. © 2016 Wiley Periodicals, Inc.

Targeting N-cadherin increases vascular permeability and differentially activates AKT in melanoma.

OBJECTIVE: We investigate the mechanism through which N-cadherin disruption alters the effectiveness of regional chemotherapy for locally advanced melanoma. BACKGROUND: N-cadherin antagonism during regional chemotherapy has demonstrated variable treatment effects. METHODS: Isolated limb infusion (ILI) with melphalan (LPAM) or temozolomide (TMZ) was performed on rats bearing melanoma xenografts after systemic administration of the N-cadherin antagonist, ADH-1, or saline. Permeability studies were performed using Evans blue dye as the infusate, and interstitial fluid pressure was measured. Immunohistochemistry of LPAM-DNA adducts and damage was performed as surrogates for LPAM and TMZ delivery. Tumor signaling was studied by Western blotting and reverse-phase protein array analysis. RESULTS: Systemic ADH-1 was associated with increased growth and activation of the PI3K (phosphatidylinositol-3 kinase)-AKT pathway in A375 but not DM443 xenografts. ADH-1 in combination with LPAM ILI improved antitumor responses compared with LPAM alone in both cell lines. Combination of ADH-1 with TMZ ILI did not improve tumor response in A375 tumors. ADH-1 increased vascular permeability without effecting tumor interstitial fluid pressure, leading to increased delivery of LPAM but not TMZ. CONCLUSIONS: ADH-1 improved responses to regional LPAM but had variable effects on tumors regionally treated with TMZ. N-cadherin-targeting agents may lead to differential effects on the AKT signaling axis that can augment growth of some tumors. The vascular targeting actions of N-cadherin antagonism may not augment some regionally delivered alkylating agents, leading to a net increase in tumor size with this type of combination treatment strategy.

Feeding jejunostomy during Whipple is associated with increased morbidity.

BACKGROUND: Placement of a feeding jejunostomy tube (FJ) is often performed during pancreaticoduodenectomy (PD). Few studies, however, have sought to determine whether such placement affects postoperative outcomes after PD. MATERIALS AND METHODS: This is a retrospective analysis of the National Surgical Quality Improvement Program (NSQIP) database to determine the 30-d-postoperative mortality rate, major complication rate, and overall complication rate of jejunostomy tube placement at the time of PD. Univariate and multivariate comparison of postoperative outcomes between patients with and without FJ placement during PD was performed on a total of 4930 patients. RESULTS: Thirty-day-postoperative mortality did not differ between the two groups (4.0% for patients with FJ versus 2.7% without, P = 0.13), whereas overall morbidity (43.3% with FJ versus 34.6% without, P < 0.0001) and serious morbidity (29.5% with FJ versus 22.8% without, P < 0.0001) were significantly higher in patients undergoing FJ placement during PD. The specific complications that occurred more frequently in FJ patients than patients without FJ included deep space surgical site infection, pneumonia, unplanned reintubation, acute renal failure, and sepsis. CONCLUSION: Although FJ placement during PD is considered to be routine at many institutions, our analysis of data from NSQIP suggest that FJ placement may be associated with increased postoperative morbidity.

Bevacizumab-induced alterations in vascular permeability and drug delivery: a novel approach to augment regional chemotherapy for in-transit melanoma.

PURPOSE: To investigate whether the systemically administered anti-VEGF monoclonal antibody bevacizumab could improve regional chemotherapy treatment of advanced extremity melanoma by enhancing delivery and tumor uptake of regionally infused melphalan (LPAM). EXPERIMENTAL DESIGN: After treatment with systemic bevacizumab or saline, changes in vascular permeability were determined by spectrophotometric analysis of tumors infused with Evan's blue dye. Changes in vascular structure and tumor hemoglobin-oxygen saturation HbO(2) were determined by intravital microscopy and diffuse reflectance spectroscopy, respectively. Rats bearing the low-VEGF secreting DM738 and the high-VEGF secreting DM443 melanoma xenografts underwent isolated limb infusion (ILI) with melphalan (LPAM) or saline via the femoral vessels. The effect of bevacizumab on terminal drug delivery was determined by immunohistochemical analysis of LPAM-DNA adducts in tumor tissues. RESULTS: Single-dose bevacizumab given three days before ILI with LPAM significantly decreased vascular permeability (50.3% in DM443, P < 0.01 and 35% in DM738, P < 0.01) and interstitial fluid pressure (57% in DM443, P < 0.01 and 50% in DM738, P = 0.01). HbO(2) decreased from baseline in mice following treatment with bevacizumab. Systemic bevacizumab significantly enhanced tumor response to ILI with LPAM in two melanoma xenografts, DM443 and DM738, increasing quadrupling time 37% and 113%, respectively (P = 0.03). Immunohistochemical analyses of tumor specimens showed that pretreatment with systemic bevacizumab markedly increased LPAM-DNA adduct formation. CONCLUSIONS: Systemic treatment with bevacizumab before regional chemotherapy increases delivery of LPAM to tumor cells and represents a novel way to augment response to regional therapy for advanced extremity melanoma.

Current trends in regional therapy for melanoma: lessons learned from 225 regional chemotherapy treatments between 1995 and 2010 at a single institution.

BACKGROUND: Hyperthermic isolated limb perfusion (HILP) and isolated limb infusion (ILI) are used to manage advanced extremity melanoma, but no consensus exists as to which treatment is preferable and how to monitor patients post-treatment. STUDY DESIGN: Using a prospectively maintained database, we reviewed our experience with melphalan-based HILP (which included 62 first-time and 10 second-time) and ILI (which included 126 first-time and 18 second-time) procedures performed in 188 patients. PET/CT was obtained 3 months postregional treatment for 1 year and then every 6 months thereafter. RESULTS: Overall response rate (complete response [CR] + partial response) of HILP was 81% (80% CI, 73-87%), and overall response rate from ILI was 43% (80% CI, 37-49%) for first-time procedures only. HILP had a CR rate of 55% with a median duration of 32 months, and ILI had a CR rate of 30% with median duration of 24 months. Patients who experienced a regional recurrence after initial regional treatment were more likely to achieve a CR after repeat HILP (50%, n = 10) compared with repeat ILI (28%, n = 18). Although the spectrum of toxicity was similar for ILI and HILP, the likelihood of rare catastrophic complication of limb loss was greater with HILP (2 of 62) than ILI (0 of 122). PET/CT was effective for surveillance after regional therapy to identify regional nodal and pulmonary disease that was not clinically evident, but often amenable to surgical resection (25 of 49; 51% of cases). In contrast, PET/CT was not effective at predicting complete response to treatment with an accuracy of only 50%. CONCLUSIONS: In the largest single-institution regional therapy series reported to date, we found that although ILI is effective and well-tolerated, HILP is a more definitive way to control advanced disease.

Inhibition of poly(ADP-ribose) polymerase enhances the effect of chemotherapy in an animal model of regional therapy for the treatment of advanced extremity malignant melanoma.

BACKGROUND: Poly(ADP-ribose) polymerase (PARP) is an important regulator of programmed cell death in response to alkylating agents such as temozolomide (TMZ). The goal of this study was to determine if a systemically administered PARP-inhibitor (INO-1001) could augment the efficacy of TMZ in a rat model of extremity malignant melanoma. MATERIALS AND METHODS: PARP activity was measured in vitro across a panel of 5 human malignant melanoma-derived cell lines. To evaluate tumor response to PARP inhibition in combination with regional isolated limb infusion (ILI) therapy with TMZ, two TMZ-resistant malignant melanoma cell lines were grown as xenografts in the hind limb of rats. INO-1001 (400 mg/kg) was injected intraperitoneally 7 times every 8 hours prior to ILI. Tumor volume was measured for up to 40 days. RESULTS: In vitro inhibition of PARP activity by INO-1001 ranged from 25.5% to 65.6%. In a mismatch repair (MMR)-deficient xenograft, treatment with INO-1001 prior to ILI significantly (P < .04) increased the efficacy of TMZ. The increase in tumor volume at day 40 following TMZ-ILI with INO-1001 was only 22.6% compared with 322.8% with TMZ-ILI alone. In a xenograft that was MMR-proficient and had high levels of O(6)-methylguanine-DNA methyltransferase (MGMT) activity, there was little improvement in TMZ efficacy with INO-1001 treatment. CONCLUSION: The PARP-inhibitor, INO-1001, can enhance the response of TMZ-resistant, MMR-deficient, malignant melanoma xenografts to intra-arterially administered TMZ in a regional treatment model of advanced extremity malignant melanoma.

Pharmacokinetics & drug resistance of melphalan in regional chemotherapy: ILP versus ILI.

Two forms of regional chemotherapy for the treatment of advanced melanoma or sarcoma of the extremity are isolated limb perfusion (ILP) and the more recently described isolated limb infusion (ILI). Melphalan is the most commonly employed agent in both ILP and ILI, although it is often used in conjunction with other cytotoxic and/or biologic therapies. While ILP and ILI are far more effective for the treatment of extremity disease than is systemic therapy, there is still significant room for improvement in outcomes, from the standpoint of both response rate and toxicity. An understanding of the pharmacokinetics of regional chemotherapy would allow for the prediction of tumor response and toxicity and therefore patient outcomes. In addition, elucidating the mechanisms of drug resistance would lead to opportunities to develop effective chemo-modulators that enhance the effectiveness of ILP and ILI. This paper reviews progress in these two key areas of active investigation.