Extent Of Tumor Necrosis Research Articles

Multimodal Integrative Genomics and Pathology Analyses in Neoadjuvant Nivolumab Treatment for Intermediate and Locally Advanced Hepatocellular Carcinoma

Introduction: Immunotherapy has resulted in pathologic responses in hepatocellular carcinoma (HCC), but the benefits and molecular mechanisms of neoadjuvant immune checkpoint blockade are largely unknown. Methods: In this study, we evaluated the efficacy and safety of preoperative nivolumab (anti-PD-1) in patients with intermediate and locally advanced HCC and determined the molecular markers for predicting treatment response. Results: Between July 2020 and November 2021, 20 treatment-naive HCC patients with intermediate and locally advanced tumors received preoperative nivolumab at 3 mg/kg for 3 cycles prior to surgical resection. Nineteen patients underwent surgical resection on trial. Seven (36.8%) of the 19 patients had major pathologic tumor necrosis (≥60%) in the post-nivolumab resection specimens, with 3 having almost complete (>90%) tumor necrosis. The tumor necrosis was hemorrhagic and often accompanied by increased or dense immune cell infiltrate at the border of the tumors. None of the patients developed major adverse reactions contradicting hepatectomy. RNA-sequencing analysis on both pre-nivolumab tumor biopsies and post-nivolumab resected specimens showed that, in cases with major pathologic necrosis, the proportion of CD8 T cells in the HCC tissues predominantly increased after treatment. Moreover, to investigate noninvasive biomarker for nivolumab response, we evaluated the copy number variation (CNV) using target-panel sequencing on plasma cell-free DNA of the patients and derived a CNV-based anti-PD-1 score. The score correlated with the extent of tumor necrosis and was validated in a Korean patient cohort with anti-PD-1 treatment. Conclusion: Neoadjuvant nivolumab demonstrated promising clinical activity in intermediate and locally advanced HCC patients. We also identified useful noninvasive biomarker predicting responsiveness.

Impact of immediate cryopreservation on the establishment of patient derived xenografts from head and neck cancer patients

BackgroundPatient-derived xenografts established from human cancers are important tools for investigating novel anti-cancer therapies. Establishing PDXs requires a significant investment and many PDXs may be used infrequently due to their similarity to existing models, their growth rate, or the lack of relevant mutations. We performed this study to determine whether we could efficiently establish PDXs after cryopreservation to allow molecular profiling to be completed prior to implanting the human cancer.MethodsFresh tumor was split with half used to establish a PDX immediately and half cryopreserved for later implantation. Resulting tumors were assessed histologically and tumors established from fresh or cryopreserved tissues compared as to the growth rate, extent of tumor necrosis, mitotic activity, keratinization, and grade. All PDXs were subjected to short tandem repeat testing to confirm identity and assess similarity between methods.ResultsTumor growth was seen in 70% of implanted cases. No growth in either condition was seen in 30% of tumors. One developed a SCC from the immediate implant but a lymphoproliferative mass without SCC from the cryopreserved specimen. No difference in growth rate was seen. No difference between histologic parameters was seen between the two approaches.ConclusionsFresh human cancer tissue can be immediately cryopreserved and later thawed and implanted to establish PDXs. This resource saving approach allows for tumor profiling prior to implantation into animals thus maximizing the probability that the tumor will be utilized for future research.

Exploring Correlation between Extent of Tumour Necrosis on MRI And Histological Grade of Soft Tissue Sarcoma. An Initial Experience

Exploring Correlation between Extent of Tumour Necrosis on MRI And Histological Grade of Soft Tissue Sarcoma. An Initial Experience

Tumor Necrosis Impacts Prognosis of Patients Undergoing Curative-Intent Hepatocellular Carcinoma.

The impact of tumor necrosis relative to prognosis among patients undergoing curative-intent resection for hepatocellular carcinoma (HCC) remains ill-defined. Patients who underwent curative-intent resection for HCC without any prior treatment between 2000 and 2017 were identified from an international multi-institutional database. Tumor necrosis was graded as absent, moderate (< 50% area), or extensive (≥ 50% area) on histological examination. The relationship between tumor necrosis, clinicopathologic characteristics, and long-term survival were analyzed. Among 919 patients who underwent curative-intent resection for HCC, the median tumor size was 5.0cm (IQR, 3.0-8.5). Tumor necrosis was present in 367 (39.9%) patients (no necrosis: n = 552, 60.1% vs < 50% necrosis: n = 256, 27.9% vs ≥ 50% necrosis: n = 111, 12.1%). Extent of tumor necrosis was also associated with more advanced tumor characteristics. HCC necrosis was associated with OS (median OS: no necrosis, 84.0months vs < 50% necrosis, 73.6months vs ≥ 50% necrosis: 59.3months; p < 0.001) and RFS (median RFS: no necrosis, 49.6months vs < 50% necrosis, 38.3months vs ≥ 50% necrosis: 26.5months; p < 0.05). Patients with T1 tumors with extensive ≥ 50% necrosis had an OS comparable to patients with T2 tumors (median OS, 62.9 vs 61.8months; p = 0.645). In addition, patients with T2 disease with necrosis had long-term outcomes comparable to patients with T3 disease (median OS, 61.8 vs 62.4months; p = 0.713). Tumor necrosis was associated with worse OS and RFS, as well as T-category upstaging of patients. A modified AJCC T classification that incorporates tumor necrosis should be considered in prognostic stratification of HCC patients.

Pediatric Application of Dynamic Contrast-Enhanced MR Imaging (DCE-MR) in the Management of Extra-Cranial Tumor: Experience in Routine Clinical Practice

Background: Dynamic contrast-enhanced MR imaging (DCE-MR) is becoming a widely accepted complementary method for diagnosing breast cancer and other cancers in adults. It is useful to predict tumor response to anticancer therapy and monitor the tumor response to the therapy. This form of imaging techniques has not been adequately explored in pediatric oncology patients. Objective: To determine the potential role of dynamic contrast-enhanced MR imaging (DCE-MR) in the diagnosis and treatment response monitoring of childhood and young adult extra-cranial tumors in routine clinical setting. Methods: Children with suspected extra-cranial solid tumors, including newly diagnosed or follow-up cases of confirmed tumors, were recruited. DCE-MR was performed with intravenous injection of 0.1 mmol/kg contrast. The enhancement time curves were plotted and the enhancement patterns were categorized into type 1, 2 and 3 curves. Enhancement curve patterns and maximal enhancement intensity were compared with types of tumor in newly diagnosed cases. The preoperative percentiles of inactive area on the colour map were compared with the necrotic areas on histologic sections of the resected specimens in follow-up cases. Pearson Chi-square test and Unpaired two-sample t-test were used for statistical analysis. Results: There were 36 patients, involving 28 malignant and 8 benign cases. There were 14 type 3 curves, (all of them were malignant tumors), 6 type 2 curves and 16 type 1 curves. All the benign cases (n = 8) demonstrated type 1 curve (accuracy & negative predictive value = 100%). All the malignant cases after treatment showed type 2 or 1 curve. For those cases with operation done afterwards, the extent of tumor necrosis was correlated closely with pathology findings (accuracy = 93.3%). Conclusion: Type 1 curve was a good predictor of benign lesion. DEC-MR may have a role to play in the monitoring of the progress of treatment and extent of tumor necrosis.

Histologic Response to Neoadjuvant Therapy Is Not Predictive of Favorable Outcomes in High-grade Pleomorphic Soft Tissue Sarcoma

The College of American Pathologists recommends reporting the histologic response of soft tissue sarcomas (STS) to neoadjuvant therapy, presumably as an assessment of chemosensitivity and a prognostic indicator, despite lack of evidence of clinical utility as such. This study examines whether extent of neoadjuvant therapy effect in STS is a favorable prognostic factor for disease-free survival. Extent of tumor necrosis and stromal hyalinization/fibrosis were determined in 143 high-grade, nonmetastatic, pleomorphic STS of the extremity or trunk. Multivariable nonlinear Cox proportional hazard regression was used to evaluate the prognostic impact of tumor necrosis and fibrosis. Cross-model comparisons of regression coefficients from nested parametric survival models were used to investigate possible effects of multicollinearity (inverse correlation) between tumor necrosis and fibrosis. Increasing tumor necrosis after neoadjuvant therapy (with or without adjusting for fibrosis) was associated with increased hazard ratios. In contrast, hazard ratios for increasing tumor fibrosis did not significantly change when unadjusted for necrosis, but were similar to necrosis after adjusting for tumor necrosis. This suggests that tumor fibrosis evolves as a reparative response to regional tumor necrosis, a conclusion supported by evidence that extent of tumor fibrosis was positively correlated with interval between initiation of neoadjuvant therapy and surgical resection. Increasing amounts of tumor necrosis observed in STS after neoadjuvant therapy are not indicative of a good therapeutic response or better prognosis. Instead, tumor necrosis simply reflects higher histologic grade and biological aggressiveness. Stromal hyalinization/fibrosis is not an independent prognostic factor either, and likely represents organization of prior tumor necrosis.

18F-fluorodeoxyglucose positron emission tomography is correlated with the pathological necrosis and decreased microvessel density in lung adenocarcinomas.

We explored the relationship between preoperative 18F-FDG-PET parameters, tumor necrosis, and microvessel density (MVD) in patients with pulmonary adenocarcinomas. A total of 164 patients, who underwent surgical resection for lung adenocarcinoma, were reviewed retrospectively. The maximum standardized uptake value (SUVmax), peak SUV corrected for lean body mass (SULpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) values were measured by preoperative 18F-FDG-PET. The extent of tumor necrosis was examined and CD31 expression was evaluated to count the MVD. The SUVmax, SULpeak, MTV, and TLG levels were significantly lower in patients exhibiting no necrosis compared to those with necrosis. When we divided the patients into two groups based on high vs. low PET parameter values, elevated SUVmax, SULpeak, MTV, and TLG values were significantly more associated with partial or diffuse necrosis than were lower values (p < 0.001). A negative correlation was evident between the MVD and SUVmax, MVD and SULpeak, MVD and MTV, and MVD and TLG. Tumor necrosis was correlated with a shorter overall survival (OS) (p = 0.007) and recur-free survival (RFS) (p < 0.001). However, multivariate analysis revealed that necrosis was not of prognostic significance. The SUVmax, MTV and TLG were associated with inferior OS or RFS rates in univariate analysis, however, not in multivariate analysis. High-level FDG accumulation is correlated with tumor necrosis in lung adenocarcinoma.

Risk factors of early recurrence after curative hepatectomy in hepatocellular carcinoma.

Early recurrence is common after curative hepatectomy for hepatocellular carcinoma and is associated with poor prognosis. This study aimed to identify risk factors of early recurrence after curative hepatectomy in hepatocellular carcinoma. Overall, 63 patients who underwent curative hepatectomy for hepatocellular carcinoma were enrolled. Patients were divided into the early recurrence group, who developed recurrence within 12 months after hepatectomy (n = 10), and the non-early recurrence group (n = 53). Clinicopathological factors of early recurrence were retrospectively analyzed. Among the 63 patients, 10 (15.9%) patients experienced early recurrence. Univariate analysis showed tumor necrosis (p = 0.012), level of PIVKA-II (prothrombin induced by vitamin K absence or antagonist-II; p = 0.002), and microvascular invasion (p = 0.029) to be associated with early recurrence. By multivariate analysis, there were significant differences in high PIVKA-II (p < 0.001) and tumor necrosis (p = 0.012) in patients with early recurrence. The optimal cutoff values of PIVKA-II and tumor necrosis were 46 mAU/mL and 3% of total tumor volume, respectively. Patients with a high preoperative PIVKA-II level and extent of tumor necrosis, which are independent risk factors for early recurrence, should be actively treated and monitored closely after hepatectomy.

Long-term effectiveness of irreversible electroporation in a murine model of colorectal liver metastasis

Irreversible electroporation (IRE) has recently gained in popularity as an ablative technique, however little is known about its oncological long-term outcomes. To determine the long-time survival of animals treated with a high dose of IRE and which histological changes it induces in tumoral tissue, IRE ablation was performed in forty-six athymic-nude mice with KM12C tumors implanted in the liver by applying electric current with different voltages (2000 V/cm, 1000 V/cm). The tumors were allowed to continue to grow until the animals reached the end-point criteria. Histology was harvested and the extent of tumor necrosis was semi-quantitatively assessed. IRE treatment with the 2000 V/cm protocol significantly prolonged median mouse survival from 74.3 ± 6.9 days in the sham group to 112.5 ± 15.2 days in the 2000 V/cm group. No differences were observed between the mean survival of the 1000 V/cm and the sham group (83.2 ± 16.4 days, p = 0.62). Histology revealed 63.05% ± 23.12 of tumor necrosis in animals of the 2000 V/cm group as compared to 17.50% ± 2.50 in the 1000 V/cm group and 25.6% ± 22.1 in the Sham group (p = 0.001). IRE prolonged the survival of animals treated with the highest electric field (2000 V/cm). The animals in this group showed significantly higher rate of tumoral necrosis.

First clinical experience with a dedicated MRI-guided high-intensity focused ultrasound system for breast cancer ablation.

ObjectivesTo assess the safety and feasibility of MRI-guided high-intensity focused ultrasound (MR-HIFU) ablation in breast cancer patients using a dedicated breast platform.MethodsPatients with early-stage invasive breast cancer underwent partial tumour ablation prior to surgical resection. MR-HIFU ablation was performed using proton resonance frequency shift MR thermometry and an MR-HIFU system specifically designed for breast tumour ablation. The presence and extent of tumour necrosis was assessed by histopathological analysis of the surgical specimen. Pearson correlation coefficients were calculated to assess the relationship between sonication parameters, temperature increase and size of tumour necrosis at histopathology.ResultsTen female patients underwent MR-HIFU treatment. No skin redness or burns were observed in any of the patients. No correlation was found between the applied energy and the temperature increase. In six patients, tumour necrosis was observed with a maximum diameter of 3–11 mm. In these patients, the number of targeted locations was equal to the number of areas with tumour necrosis. A good correlation was found between the applied energy and the size of tumour necrosis at histopathology (Pearson = 0.76, p = 0.002).ConclusionsOur results show that MR-HIFU ablation with the dedicated breast system is safe and results in histopathologically proven tumour necrosis.Key Points• MR-HIFU ablation with the dedicated breast system is safe and feasible • In none of the patients was skin redness or burns observed • No correlation was found between the applied energy and the temperature increase • The correlation between applied energy and size of tumour necrosis was good

Abstract IA25: Mechanisms of protective tumor immunity

Abstract Efficacious cancer immunotherapies will likely require combinations of strategies that enhance tumor antigen presentation and antagonize negative immune regulatory circuits. We demonstrated that vaccination with irradiated, autologous melanoma cells engineered to secrete GM-CSF followed by antibody blockade of CTLA-4 accomplishes clinically significant tumor destruction with minimal toxicity in a majority of stage IV metastatic melanoma and some advanced ovarian carcinoma patients. The extent of tumor necrosis in post-treatment biopsies was linearly related to the natural logarithm of the ratio of infiltrating CD8+ effector T cells to FoxP3+ Tregs, suggesting that further Treg inhibition might increase the frequency of clinical responses. Through an analysis of cytokine deficient mice, we delineated a critical role for GM-CSF in Treg homeostasis. GM-CSF is required for the expression of the phosphatidylserine binding protein MFG-E8 in antigen presenting cells, whereas the uptake of apoptotic cells by phagocyte-derived MFG-E8 maintains peripheral Treg activity. The pharmacologic inhibition of MFG-E8 function through genetic or engineering-based approaches blocks Treg induction, which intensifies vaccine-induced responses, leading to the regression of established tumors in mice. The clinical translation of these therapeutic strategies to Phase I testing in humans is underway. The detailed analysis of patients achieving sustained clinical benefits from irradiated, autologous GM-CSF secreting tumor cell vaccines and CTLA-4 antibody blockade also affords a rich opportunity to identify antigens associated with immune-mediated tumor destruction and to delineate mechanisms of therapeutic immunity. In this regard, we have identified antibodies against a panel of secreted and cell surface proteins that play important roles in tumor development and immune evasion. Isolation of the rare, antigen-specific memory B cells directed towards these important targets provides new opportunities for developing human monoclonal antibodies for cancer immunotherapy. Citation Format: Glenn Dranoff. Mechanisms of protective tumor immunity. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr IA25.

The Impact of Tumor Diameter and Tumor Necrosis on Oncologic Outcomes in Patients With Urothelial Carcinoma of the Bladder Treated With Radical Cystectomy

To evaluate the influence of tumor diameter and tumor necrosis on oncologic outcomes in patients with urothelial carcinoma of the bladder treated with radical cystectomy (RC). We treated 517 consecutive patients with urothelial carcinoma of the bladder treated with RC without neoadjuvant chemotherapy at our institution between 1996 and 2011. All RC specimens were meticulously re-reviewed for the largest residual tumor diameter and for the presence and extent of tumor necrosis. Cox regression models evaluated the association with disease recurrence and cancer-specific survival. At RC, 155 patients (30.0%) had a residual tumor diameter ≥3 cm and tumor necrosis was present in 156 patients (30.2%). Tumor diameter and necrosis were significantly correlated (P <.001). Both a tumor diameter ≥3 cm and the presence of tumor necrosis were associated with an older age, advanced tumor stage, higher tumor grade, lymph node metastasis, positive surgical margin status, lymphovascular invasion, and administration of adjuvant chemotherapy (P values ≤.009). A tumor diameter ≥3 cm and the presence of tumor necrosis were associated with disease recurrence and cancer-specific mortality in Kaplan-Meier analyses, respectively (pairwise P values <.001). In addition, a tumor diameter ≥3 cm was an independent predictor of cancer-specific mortality in multivariate analysis that adjusted for standard clinicopathologic features. Tumor diameter and necrosis are closely correlated and associated with aggressive tumor features and inferior oncologic outcomes. A residual tumor diameter ≥3 cm is an independent predictor of cancer-specific mortality. This additional information should be considered to be reported in every pathology report for consideration in patient counseling and treatment decision making. In addition, these results underscore the importance of a thorough transurethral resection of the bladder tumor before RC.

Prognostic significance of treatment-induced pathologic necrosis in extremity and truncal soft tissue sarcoma after neoadjuvant chemoradiotherapy.

Histologic response to chemotherapy has been shown to be an independent prognostic factor in patients with osteosarcoma and Ewing sarcoma. However, in patients with soft tissue sarcoma (STS), the prognostic impact of histologic response to chemotherapy is less clear. In the current study, the authors sought to determine the prognostic significance of treatment-induced pathologic necrosis in patients receiving neoadjuvant chemoradiotherapy for STS. Between 1989 and 2011, a total of 113 patients with grade 2 or 3 (graded according to the National Cancer Institute grading system using 3 tiers) extremity or truncal STS were identified who received neoadjuvant interdigitated chemoradiotherapy according to protocol followed by surgery. The extent of tumor necrosis in the resected specimens was quantified and correlated with outcome. The median tumor necrosis rate was 90%, and 103 patients (91%) received all 3 cycles of planned neoadjuvant chemotherapy. The likelihood of achieving ≥95% necrosis was not related to the number of preoperative cycles of chemotherapy received but was found to be related to tumor histology (62% for malignant fibrous histiocytoma vs 0% for synovial sarcoma [P<.001]; 56% for myxoid liposarcoma vs 0% for synovial sarcoma [P = .002]). At a median follow-up of 6 years, there were no statistically significant differences noted in the 5-year local control, disease-specific survival, and overall survival rates for patients with ≥95% necrosis (50 patients; 44%) and <95% necrosis (63 patients; 56%), even when stratifying by histology. In a homogeneous population of patients with high-grade extremity and truncal STS who were treated with neoadjuvant chemoradiotherapy, the extent of pathologic tumor necrosis did not correlate with outcome.

Utility of diffusion-weighted imaging to assess hepatocellular carcinoma viability following transarterial chemoembolization.

The purpose of the present study was to evaluate whether diffusion-weighted imaging (DWI) can be used to assess hepatocellular carcinoma (HCC) viability following transarterial chemoembolization (TACE). A total of 41 consecutive patients were treated according to chemoembolization protocols. The follow-up was performed between six and eight weeks post-chemoembolization by multidetector computed tomography [or enhanced magnetic resonance imaging (MRI)] and DW-MRI on the same day. The presence of any residual tumor and the extent of tumor necrosis were evaluated according to the European Association for the Study of the Liver. The apparent diffusion coefficient (ADC) values of the entire area of the treated mass and the vital and necrotic tumor tissues were recorded. Correlation coefficients were also calculated to compare the percentage of necrosis with ADC values. The mean ADC values of the necrotic and vital tumor tissues were 2.22±0.31×10−3 mm2/sec and 1.42±0.25×10−3 mm2/sec, respectively (Mann-Whitney U test, P<0.001). The results from the receiver operating characteristic analysis showed that the threshold ADC value was 1.84×10−3 mm2/sec with 92.3% sensitivity and 100% specificity for identifying the necrotic tumor tissues. A significant linear regression correlation was identified between the ADC value of the entire area of the treated mass and the extent of tumor necrosis (r=0.58; P<0.001). In conclusion, DWI can be used to assess HCC viability following TACE.

Correlation of vascular endothelial growth factor and hypoxia-inducible factor-1α expression with pathological renal artery changes in patients with renal cell carcinoma

Objective. The aim of this study was to correlate the expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) with pathological renal artery changes in patients with renal cell carcinoma (RCC). A further aim was to correlate intratumoral microvessel density (MVD) with VEGF and HIF-1α expression and prognostic factors for RCC, including tumour necrosis. Material and methods.Formalin-fixed and paraffin-embedded tissue blocks from 150 patients with RCC and 50 patients with non-tumorous kidney diseases were analysed. The control group consisted of specimens from both renal arteries obtained from 25 decedents at routine autopsy (50 cases in total). Immunohistochemistry was performed using primary antibodies to VEGF, HIF-1α and CD31. Results.Pathological renal artery changes were more common in patients with RCC and non-tumorous kidney diseases than in the control group. MVD was higher in the RCCs of patients with pathological renal artery changes. Tumours with higher HIF-1α expression had higher MVD; however, VEGF expression was not associated with MVD. A significant association was also found between MVD and the extent of tumour necrosis, in that less necrotic tumours had higher MVD. No association between renal artery changes and VEGF and HIF-1α expression was established. Conclusion.Considering the results of this study, the evaluation of renal artery changes in forthcoming research on RCC would be helpful for several reasons: to estimate their incidence in a larger number of patients, to clarify their connection with RCC and to reveal their relationship with MVD in RCC.

EComment. Soft-tissue sarcomas in a ‘nutshell’

We read this interesting retrospective study by Luo et al. [1] and we would like to add a comment on soft-tissue sarcomas. Soft-tissue sarcomas are a group of malignant neoplasms originating from mesenchymal tissue and deriving etymologically from the Greek word 'σάρξ' (flesh) and the suffix 'ώμα' (tumour). They make up less than 2% and 10–15% of all adult and paediatric malignant neoplasms respectively and their overall incidence is approximately 6 per 100 000 persons/year [2]. Histological typing (according to WHO) is based on the tissue giving origin to the tumour, and histological grading, which is a good predictor of distant metastasis and overall survival, is based on a three-grade system (1–3) and depends on the mitotic index and the extent of tumour necrosis [3]. Staging of these tumours is clinically important and imparts additional prognostic information. The TNM system is employed, which combines histological grade, tumour size and depth, regional lymph node involvement and distant metastases [3]. Histological diagnosis should be based on the WHO classification for the grade and stage to be determined. Five-year survival has been reported to be 95%, 75%, and 45% in patients with grade 1, 2, and 3 sarcomas respectively [2]. Thoracic sarcomas account for 10% of all sarcomas and the rest are found on upper (15%) and lower (35%) limbs, visceral organs (15%), abdomen and retroperitoneum (15%), followed by head and neck (10%) [2]. Metastasis may either occur locally to nearby tissues or distally through the circulatory system predominantly to the lung and less frequently to the liver and bones [2]. Good prognosis is associated with young age, female gender, low histological grade, stage 1 tumours and complete surgical resection, while poor prognosis is related to high-grade tumours, stage 2 sarcomas, incomplete surgical removal, metastatic disease and relapses as well as aggressive histological subtypes [2]. For non-metastatic disease, the treatment of choice is surgical removal, which, depending on its outcomes, may be combined with radiotherapy. Each case should be approached on an individual basis and assessed by a multi-disciplinary team considering the need for neoadjuvant or adjuvant chemotherapy and its medications [2]. Even though there is inadequate evidence to dictate specific policies for follow-up, risk assessment should be conducted based on tumour grade, size and site with primary focus on the lungs (for metastatic disease) for routine follow-up. Standard follow-up should consist of clinical history, clinical examination for local recurrence (followed by ultrasound scan or MRI if needed), and chest X-ray with subsequent CT scan for suspicious lesions. The European Society of Medical Oncology (ESMO) recommends follow-up every 3–4 months in surgically treated intermediate/high-risk patients in the first 2 years, later on twice a year until the fifth year and then yearly afterwards. Those with low-grade sarcomas may be investigated for local relapse every 4–6 months, with chest X-rays or CT scan at larger intervals in the first 3–5 years, and then once a year [4,5]. In summary, the role of a multidisciplinary team is essential in the management of these challenging tumours and further well-conducted research is necessary for evidence-based guidelines to be devised [5]. Conflict of interest: none declared.

Abstract PL07-03: Mechanisms of protective tumor immunity.

Abstract Efficacious cancer immunotherapies will likely require combinations of strategies that enhance tumor antigen presentation and antagonize negative immune regulatory circuits. We demonstrated that vaccination with irradiated, autologous melanoma cells engineered to secrete GM-CSF followed by antibody blockade of CTLA-4 accomplishes clinically significant tumor destruction with minimal toxicity in a majority of stage IV metastatic melanoma and some advanced ovarian carcinoma patients. The extent of tumor necrosis in post-treatment biopsies was linearly related to the natural logarithm of the ratio of infiltrating CD8+ effector T cells to FoxP3+ Tregs, suggesting that further Treg inhibition might increase the frequency of clinical responses. Through an analysis of cytokine deficient mice, we delineated a critical role for GM-CSF in Treg homeostasis. GM-CSF is required for the expression of the phosphatidylserine binding protein MFG-E8 in antigen presenting cells, whereas the uptake of apoptotic cells by phagocyte-derived MFG-E8 maintains peripheral Treg activity. The pharmacologic inhibition of MFG-E8 function through genetic or engineering-based approaches blocks Treg induction, which intensifies vaccine-induced responses, leading to the regression of established tumors in mice. The clinical translation of these therapeutic strategies to Phase I testing in humans is underway. The detailed analysis of patients achieving sustained clinical benefits from irradiated, autologous GM-CSF secreting tumor cell vaccines and CTLA-4 antibody blockade also affords a rich opportunity to identify antigens associated with immune-mediated tumor destruction and to delineate mechanisms of therapeutic immunity. We elucidated several of the molecular pathways that underlie these antitumor effects, including the NKG2D system and multiple secreted/or cell surface proteins that contribute to tumor promoting inflammation. The therapy-induced antibodies manifest functional activity in vitro, antagonizing tumor cell survival, invasive potential, and angiogenesis. These findings support a key role for humoral immunity in tumor destruction, and highlight interest in more detailed characterization of the antitumor B cell repertoire in vaccinated patients. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):PL07-03. Citation Format: Glenn Dranoff. Mechanisms of protective tumor immunity. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr PL07-03.

Sarcoma Chemotherapy

Sarcomas are a rare, heterogeneous group of malignant tumors of the bone or soft tissue. Although historically intended for the pharmaceutical treatment of microbes, today chemotherapy is used in orthopaedic oncology and is arguably the primary reason for improved survivorship. Agents such as anthracyclines (eg, doxorubicin), alkylating agents (eg, cyclophosphamide, ifosfamide), antimetabolites (eg, methotrexate), topoisomerase inhibitors (eg, etoposide [VP-16]), vinca alkaloids (eg, vincristine), and cytotoxic antibiotics (eg, actinomycin D) are used in various combinations to manage different types of tumors. Side effects are common and range from mild to severe. The effectiveness of the chemotherapy regimen correlates with the extent of tumor necrosis.

Abstract SY27-04: Engineering improved cancer vaccines.

Abstract Efficacious cancer immunotherapies will likely require combinations of strategies that enhance tumor antigen presentation and antagonize negative immune regulatory circuits. We demonstrated that vaccination with irradiated, autologous melanoma cells engineered to secrete GM-CSF followed by antibody blockade of CTLA-4 accomplishes clinically significant tumor destruction with minimal toxicity in a majority of stage IV metastatic melanoma and some advanced ovarian carcinoma patients. The extent of tumor necrosis in post-treatment biopsies was linearly related to the natural logarithm of the ratio of infiltrating CD8+ effector T cells to FoxP3+ Tregs, suggesting that further Treg inhibition might increase the frequency of clinical responses. Through an analysis of cytokine deficient mice, we delineated a critical role for GM-CSF in Treg homeostasis. GM-CSF is required for the expression of the phosphatidylserine binding protein MFG-E8 in antigen presenting cells, whereas the uptake of apoptotic cells by phagocyte-derived MFG-E8 maintains peripheral Treg activity. The pharmacologic inhibition of MFG-E8 function through genetic or engineering-based approaches blocks Treg induction, which intensifies vaccine-induced responses, leading to the regression of established tumors in mice. The clinical translation of these therapeutic strategies to Phase I testing in humans is underway. The detailed analysis of patients achieving sustained clinical benefits from irradiated, autologous GM-CSF secreting tumor cell vaccines and CTLA-4 antibody blockade also affords a rich opportunity to identify antigens associated with immune-mediated tumor destruction and to delineate mechanisms of therapeutic immunity. We elucidated several of the molecular pathways that underlie these anti-tumor effects, including the NKG2D system and multiple secreted/or cell surface proteins that contribute to tumor promoting inflammation. The therapy-induced antibodies manifest functional activity in vitro, antagonizing tumor cell survival, invasive potential, and angiogenesis. These findings support a key role for humoral immunity in tumor destruction, and highlight interest in more detailed characterization of the anti-tumor B cell repertoire in vaccinated patients. Citation Format: Glenn Dranoff. Engineering improved cancer vaccines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr SY27-04. doi:10.1158/1538-7445.AM2013-SY27-04

Abstract 1729: Mitochondrial necrosis pathway drives tumor progression.

Abstract Necrosis is a prominent feature of aggressive and invasive cancers. Previous clinical/epidemiological studies have suggested an association between the extent of tumor necrosis and poor prognosis and survivorship for some cancers. Evasion of apoptosis is widely accepted as a hallmark of cancer. However, whether necrotic cell death plays no role, limits, or drives carcinogenesis has not been studied in any cancer. Recent work suggests that necrosis may be an actively regulated form of cell death. In contrast to apoptosis where permeabilization of the outer mitochondrial membrane is the defining event, the central event in necrosis is the opening of a pore in the inner mitochondrial membrane termed the mitochondrial permeability transition pore (mPTP). Cyclophilin D, a peptidyl prolyl cis-trans isomerase in the mitochondrial matrix, encoded by the gene ppif, is critical for opening of the mPTP. Stable expression of ppif shRNA was used to deplete cyclophilin D in Met-1 cells, a metastatic breast cancer cell line. We first confirmed that knockdown of ppif in Met-1 cells abrogated necrosis, but not apoptosis. When these cells were transplanted into the mammary glands of wildtype FVB mice, tumors resulting from cells that express ppif shRNA were markedly smaller, with decreased volume and mass, than those derived from cells expressing control shRNA. Reconstitution of ppif knockdown cells with wild type cyclophilin D, but not an enzymatically inactive mutant, rescued tumor volume and mass. As expected, tumors arising from ppif knockdown cells exhibited less necrosis, while rates of apoptosis were unchanged. Moreover, rates of BrdU incorporation were significantly decreased in these tumors. Necrotic cell death is characterized by loss of plasma membrane integrity resulting in a marked inflammatory response. Neutrophils and macrophages recruited to tumors often secrete growth/survival/angiogenic factors that promote tumor growth and metastasis. Consistent with this model, both macrophage and neutrophil recruitment were reduced in tumors derived from ppif knockdown cells. In addition, rates of spontaneous pulmonary metastasis were markedly decreased in mice harboring tumors derived from ppif knockdown cells compared with controls. Our data suggest that, in contrast to apoptotic cell death which limits carcinogenesis, necrotic cell death actually drives disease progression by altering the tumor microenvironment. These findings may have therapeutic implications in that they suggest that inhibition - rather than promotion - of necrotic cell death may provide a novel treatment paradigm for some cancers. Citation Format: Melissa K. James, Richard N. Kitsis. Mitochondrial necrosis pathway drives tumor progression. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1729. doi:10.1158/1538-7445.AM2013-1729