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SN22 and SN38 pharmacokinetics

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Camptothecins are potent topoisomerase I inhibitors used to treat high-risk pediatric solid tumors, but they often show poor efficacy due to intrinsic or acquired chemoresistance. Here, we developed a multivalent, polymer-based prodrug of a structurally optimized camptothecin (SN22) designed to overcome key chemoresistance mechanisms. The ability of SN22 vs. SN38 (the active form of irinotecan/CPT-11) to overcome efflux pump-driven drug resistance was tested. Tumor uptake and biodistribution of SN22 as a polymer-based prodrug (PEG-[SN22]4) compared with SN38 was determined. The therapeutic efficacy of PEG-[SN22]4 to CPT-11 was compared in: (i) spontaneous neuroblastomas (NB) in transgenic TH-MYCN mice; (ii) orthotopic xenografts of a drug-resistant NB line SK-N-BE(2)C (mutated TP53); (iii) flank xenografts of a drug-resistant NB-PDX; and (iv) xenografts of Ewing sarcoma and rhabdomyosarcoma. Unlike SN38, SN22 inhibited NB cell growth regardless of ABCG2 expression levels. SN22 prodrug delivery resulted in sustained intratumoral drug concentrations, dramatically higher than those of SN38 at all time points. CPT-11/SN38 treatment had only marginal effects on tumors in transgenic mice, but PEG-[SN22]4 treatment caused complete tumor regression lasting over 6 months (tumor free at necropsy). PEG-[SN22]4 also markedly extended survival of mice with drug-resistant, orthotopic NB and it caused long-term (6+ months) remissions in 80% to 100% of NB and sarcoma xenografts. SN22 administered as a multivalent polymeric prodrug resulted in increased and protracted tumor drug exposure compared with CPT-11, leading to long-term “cures” in NB models of intrinsic or acquired drug resistance, and models of high-risk sarcomas, warranting its further development for clinical trials.Significance:SN22 is an effective and curative multivalent macromolecular agent in multiple solid tumor mouse models, overcoming common mechanisms of drug resistance with the potential to elicit fewer toxicities than most cancer therapeutics.

BackgroundGroundbreaking studies have linked the gut microbiome with immune homeostasis and antitumor immune responses. Mounting evidence has also demonstrated an intratumoral microbiome, including in soft tissue sarcomas (STS), although detailed characterization of the STS intratumoral microbiome is limited. We sought to characterize the intratumoral microbiome in patients with STS undergoing preoperative radiotherapy and surgery, hypothesizing the presence of a distinct intratumoral microbiome with potentially clinically significant microbial signatures.MethodsWe prospectively obtained tumor and stool samples from adult patients with non-metastatic STS using a strict sterile collection protocol to minimize contamination. Metagenomic classification was used to estimate abundance using genus and species taxonomic levels across all classified organisms, and data were analyzed with respect to clinicopathologic factors.ResultsFifteen patients were enrolled. Most tumors were located at an extremity (67%) and were histologic grade 3 (87%). 40% were well-differentiated/dedifferentiated liposarcoma histology. With a median follow-up of 24 months, 4 (27%) patients developed metastases, and 3 (20%) died. Despite overwhelming human DNA (>99%) intratumorally, we detected a small but consistent proportion of bacterial DNA (0.02–0.03%) in all tumors, includingProteobacteria, Bacteroidetes,andFirmicutes, as well as viral species. In the tumor microenvironment, we observed a strong positive correlation between viral relative abundance and natural killer (NK) infiltration, and higher NK infiltration was associated with superior metastasis-free and overall survival by immunohistochemical, flow cytometry, and multiplex immunofluorescence analyses.ConclusionsWe prospectively demonstrate the presence of a distinct and measurable intratumoral microbiome in patients with STS at multiple time points. Our data suggest that the STS tumor microbiome has prognostic significance with viral relative abundance associated with NK infiltration and oncologic outcome. Additional studies are warranted to further assess the clinical impact of these findings.

Background Volume of operative cases may be an important factor associated with improved survival for early-stage pancreatic cancer. Most high-volume pancreatic centers are also academic institutions, which have been associated with additional healthcare costs. We hypothesized that at high-volume centers, the value of the extra survival outweighs the extra cost. Study Design This retrospective cohort study used data from the California Cancer Registry linked to the Office of Statewide Health Planning and Development database from January 1, 2004 through December 31, 2012. Stage I-II pancreatic cancer patients who underwent resection were included. Multivariable analyses estimated overall survival and 30-day costs at low- vs high-volume pancreatic surgery centers. The incremental cost-effectiveness ratio (ICER) and incremental net benefit (INB) were estimated, and statistical uncertainty was characterized using net benefit regression. Results Of 2,786 patients, 46.5% were treated at high-volume centers and 53.5% at low-volume centers. There was a 0.45-year (5.4 months) survival benefit (95% CI 0.21–0.69) and a $7,884 extra cost associated with receiving surgery at high-volume centers (95% CI $4,074–$11,694). The ICER was $17,529 for an additional year of survival (95% CI $7,997–$40,616). For decision-makers willing to pay more than $20,000 for an additional year of life, high-volume centers appear cost-effective. Conclusions Although healthcare costs were greater at high-volume centers, patients undergoing pancreatic surgery at high-volume centers experienced a survival benefit (5.4 months). The extra cost of $17,529 per additional year is quite modest for improved survival and is economically attractive by many oncology standards.

Camptothecins are potent topoisomerase I inhibitors used to treat high-risk pediatric solid tumors, but they often show poor efficacy due to intrinsic or acquired chemoresistance. Here, we developed a multivalent, polymer-based prodrug of a structurally optimized camptothecin (SN22) designed to overcome key chemoresistance mechanisms. The ability of SN22 vs. SN38 (the active form of irinotecan/CPT-11) to overcome efflux pump-driven drug resistance was tested. Tumor uptake and biodistribution of SN22 as a polymer-based prodrug (PEG-[SN22]4) compared with SN38 was determined. The therapeutic efficacy of PEG-[SN22]4 to CPT-11 was compared in: (i) spontaneous neuroblastomas (NB) in transgenic TH-MYCN mice; (ii) orthotopic xenografts of a drug-resistant NB line SK-N-BE(2)C (mutated TP53); (iii) flank xenografts of a drug-resistant NB-PDX; and (iv) xenografts of Ewing sarcoma and rhabdomyosarcoma. Unlike SN38, SN22 inhibited NB cell growth regardless of ABCG2 expression levels. SN22 prodrug delivery resulted in sustained intratumoral drug concentrations, dramatically higher than those of SN38 at all time points. CPT-11/SN38 treatment had only marginal effects on tumors in transgenic mice, but PEG-[SN22]4 treatment caused complete tumor regression lasting over 6 months (tumor free at necropsy). PEG-[SN22]4 also markedly extended survival of mice with drug-resistant, orthotopic NB and it caused long-term (6+ months) remissions in 80% to 100% of NB and sarcoma xenografts. SN22 administered as a multivalent polymeric prodrug resulted in increased and protracted tumor drug exposure compared with CPT-11, leading to long-term “cures” in NB models of intrinsic or acquired drug resistance, and models of high-risk sarcomas, warranting its further development for clinical trials. Significance: SN22 is an effective and curative multivalent macromolecular agent in multiple solid tumor mouse models, overcoming common mechanisms of drug resistance with the potential to elicit fewer toxicities than most cancer therapeutics.

OBJECTIVES: Comorbid psychiatric illness has been associated with worse outcomes following some major surgical procedures. We hypothesized that patients with pre-existing mood disorders would have worse postoperative and oncologic outcomes after pancreatic cancer resection. METHODS: This retrospective cohort study analyzed Surveillance, Epidemiology, & End Results patients with resectable pancreatic adenocarcinoma. A pre-existing mood disorder was classified if a patient was diagnosed and/or treated with medication approved for depression/anxiety within 6 months before surgery. RESULTS: Of 1305 patients, 16% had a pre-existing mood disorder. Mood disorders had no impact on hospital length of stay (12.9 vs 13.2 days, P = 0.75), 30-day complications (26% vs 22%, P = 0.31), 30-day readmissions (26% vs 21%, P = 0.1), or mortality (30 days: 3% vs 4%, P = 0.35); only an increased 90-day readmissions rate (42% vs 31%, P = 0.001) was observed. No effect on adjuvant chemotherapy receipt (62.5% vs 69.2%, P = 0.06) or survival (24-months, 43% vs 39%, P = 0.44) was observed. CONCLUSIONS: Pre-existing mood disorders influenced 90-day readmissions after pancreatic resection, but not other postoperative or oncologic outcomes. These findings suggest that affected patients should be expected to have outcomes similar to patients without mood disorders.

PurposeCurrent treatment guidelines for male breast cancer are guided by female-only trials despite data suggesting distinct clinicopathologic differences between sexes. We sought to evaluate whether radiation therapy (RT) after lumpectomy was associated with equivalent survival among men > 70 years of age with stage I, estrogen receptor (ER) positive tumors, as seen in women from the Cancer and Leukemia Group B (CALGB) 9343 trial.MethodsWe performed a retrospective analysis of 752 stage I, ER-positive male breast cancer patients ≥70 years who were treated with hormone therapy and surgery, with or without RT, from the National Cancer Database between 2004 and 2014. Patients were categorized based on surgery and RT (lumpectomy alone, lumpectomy with RT, and mastectomy alone). Multivariable Cox proportional hazards regression analysis was used to compare overall survival between treatment groups.ResultsMost patients underwent total mastectomy, with only 32.6% treated with lumpectomy. Of those who underwent lumpectomy, 72.7% received adjuvant RT. In multivariate analysis, there was no statistical difference in overall survival when comparing lumpectomy alone and lumpectomy with RT (aHR 0.72 [95% CI 0.38-1.37], p=0.31) or when comparing lumpectomy (alone or with RT) and mastectomy (aHR 1.28 [95% CI 0.88-1.87], p=0.20).ConclusionsIn this national sample of elderly men with ER-positive early-stage disease treated with endocrine therapy, there were no significant differences in overall survival when comparing lumpectomy alone and lumpectomy with RT, or lumpectomy (alone or with RT) and mastectomy. These results suggest that less aggressive treatment may be appropriate for a subset of male breast cancer patients.

Background There are many potential treatment options for patients with early stage hepatocellular carcinoma (HCC) and practice patterns vary widely. This project aimed to use a Delphi conference to generate consensus regarding the management of small resectable HCC. Methods A base case was established with review by members of AHPBA Research Committee. The Delphi panel of experts reviewed the literature and scored clinical case statements to identify areas of agreement and disagreement. Following initial scoring, discussion was undertaken, questions were amended, and scoring was repeated. This cycle was repeated until no further likelihood of reaching consensus existed. Results The panel achieved agreement or disagreement consensus regarding 27 statements. The overarching themes included that resection, ablation, transplantation, or any locoregional therapy as a bridge to transplant were all appropriate modalities for early or recurrent HCC. For larger lesions, consensus was reached that radiofrequency ablation and microwave ablation were not appropriate treatments. Conclusion Using a validated system for identifying consensus, an expert panel agreed that multiple treatment modalities are appropriate for early stage HCC. These consensus guidelines are intended to help guide physicians through treatment modalities for early HCC; however, clinical decisions should continue to be made on a patient-specific basis.

Tumor infiltrating lymphocytes (TILs) have been shown to predict survival in soft tissue sarcomas (STS), but the specific contribution of natural killer (NK) and CD8+ T cells to outcomes is undefined. Therefore, we sought to characterize the extent of NK and CD8+ T cell infiltration in STS. Prospectively, we evaluated 15 patients using fresh tumor from surgery for flow cytometric analysis. Retrospectively, we evaluated archived tumor tissue from 90 STS patients by immunohistochemistry (IHC) for CD3, CD8, CD45RO, NKp46, TIGIT, MHC-I, and p53. We analyzed metastasis-free survival (MFS) and overall survival (OS) by Kaplan-Meier method and log-rank test. By flow cytometry, we observed significant variability in CD45+ leukocytes in the STS TME (mean 29±24% of total live cells) with low percentages of tumor-infiltrating CD3-CD56+ NK cells (1.7±1.9% of total live cells and 5.3±3.0% of live CD45+ cells) and CD8+ T cells (1.6±1.6% of total live cells and 29.6±30.5% of live CD45+ cells). By IHC, NK and T cell infiltrates were low (median H score 0, range 0–66.5 and 2.7, range 0–110, respectively). We confirmed a positive correlation between CD8+ T cell infiltration and significantly improved OS (P Infiltration of NK and CD8+ T cells is overall low in STS patients undergoing surgery but associated with superior OS. Further characterization of the immune infiltrate in STS may yield better biomarkers of prognosis and immune targeting. Supported by the following grants: NIH/NCI 1R03CA252793 NIH/NCI T32 CA251007-01