Phase 1b study of intraperitoneal ipilimumab and nivolumab in patients with recurrent gynecologic malignancies with peritoneal carcinomatosis.

BACKGROUND: Intravenous immune checkpoint blockade (ICB) has shown poor response rates in recurrent gynecologic malignancies. Intraperitoneal (i.p.) ICB may result in enhanced T cell activation and anti-tumor immunity. METHODS: In this phase 1b study, registered at Clinical. TRIALS: gov (NCT03508570), initial cohorts received i.p. nivolumab monotherapy, and subsequent cohorts received combination i.p. nivolumab every 2 weeks and i.p. ipilimumab every 6 weeks, guided by a Bayesian design. The primary objective was determination of the recommended phase 2 dose (RP2D) of the combination. Secondary outcomes included toxicity, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). FINDINGS: The trial enrolled 23 patients: 18 with ovarian cancer, 2 with uterine cancer, and 3 with cervical cancer. Study evaluable patients (n = 16) received a median of 2 prior lines of therapy (range: 1-8). Partial response was observed in 2 patients (12.5%; 1 ovarian, 1 uterine), and complete response was observed in 1 patient (6.3%) with cervical cancer, for an ORR of 18.8% (95% confidence interval: 4.0%-45.6%). The median duration of response was 14.8 months (range: 4.1-20.8), with one complete response ongoing. Median PFS and OS were 2.7 months and not reached, respectively. Grade 3 or higher immune-related adverse events occurred in 2 (8.7%) patients. CONCLUSIONS: i.p. administration of dual ICB is safe and demonstrated durable responses in a subset of patients with advanced gynecologic malignancy. The RP2D is 3 mg/kg i.p. nivolumab every 2 weeks plus 1 mg/kg ipilimumab every 6 weeks. FUNDING: This work was funded by Bristol Myers Squibb (CA209-9C7), an MD Anderson Cancer Center Support Grant (CA016672), the Ovarian Cancer Moon Shots Program, the Emerson Collective Fund, and a T32 training grant (CA101642).

Malignant Mesothelioma and Its Non-Asbestos Causes.

CONTEXT: - Although many mesotheliomas are related to asbestos exposure, not all are, and there is increasing information on other causes of mesothelioma. OBJECTIVE: - To provide a review of non-asbestos causes for malignant mesothelioma. DATA SOURCES: - Review of relevant published literature via PubMed and other search engines. CONCLUSIONS: - Currently, most pleural mesotheliomas (70% to 90%) in men in Europe and North America are attributable to asbestos exposure; for peritoneal mesothelioma the proportion is lower. In North America few mesotheliomas in women at any site are attributable to asbestos exposure, but in Europe the proportion is higher and varies considerably by locale. In certain geographic locations other types of mineral fibers (erionite, fluoro-edenite, and probably balangeroite) can induce mesothelioma. Therapeutic radiation for other malignancies is a well-established cause of mesothelioma, with relative risks as high as 30. Carbon nanotubes can also induce mesotheliomas in animals but there are no human epidemiologic data that shed light on this issue. Chronic pleural inflammation may be a cause of mesothelioma but the data are scanty. Although SV40 can induce mesotheliomas in animals, in humans the epidemiologic data are against a causative role. A small number of mesotheliomas (probably in the order of 1%) are caused by germline mutations/deletions of BRCA1-associated protein-1 ( BAP1) in kindreds that also develop a variety of other cancers. All of these alternative etiologies account for a small proportion of tumors, and most mesotheliomas not clearly attributable to asbestos exposure are spontaneous (idiopathic).

Unusual progression of renal cell carcinoma with carcinomatosis peritoneii and Krukenberg tumour and alopecia with sunitinib therapy in young female.

BACKGROUND: Sunitinib is a multiple receptor tyrosine kinase inhibitor (TKI) used for the treatment of renal cell carcinoma (RCC). It increases the median survival considerably with minimum side effects. Alopecia is one of the rare side effects. Metastasis to the ovary is also rare. We report a case of RCC metastasizing to the ovary developing alopecia early on starting sunitinib. CASE PRESENTATION: A 22-year-old hypothyroid girl underwent right radical nephrectomy for T2N0 RCC. Histopathology was clear cell carcinoma. Six months later, she presented with right iliac fossa pain, imaging revealed metastasis to the ileocolic junction and the ovary, an exploratory laparotomy was carried out and, after debulking, the patient was started on sunitinib. Four weeks after the start of the  treatment, she developed alopecia. She was continued with sunitinib therapy till progression. CONCLUSIONS: The present case shows a rare metastasis to the ovary and early onset of rare adverse event of alopecia on starting sunitinib therapy. In the presence of confounding factors like hypothyroidism and dandruff, establishing this as an adverse reaction of sunitinib is difficult. This case had a unique metastatic spread with involvement of the bowel, ovary and peritoneal carcinomatosis. Use of adjuvant TKI's after resection of primary tumour in nonmetastatic setting may reduce metastatic rates and increase progression-free survival.

Carcinogenicity of multi-walled carbon nanotubes: challenging issue on hazard assessment.

OBJECTIVES: This report reviews the carcinogenicity of multi-walled carbon nanotubes (MWCNTs) in experimental animals, concentrating on MWNT-7, a straight fibrous MWCNT. METHODS: MWCNTs were administered to mice and rats by intraperitoneal injection, intrascrotal injection, subcutaneous injection, intratracheal instillation and inhalation. RESULTS: Intraperitoneal injection of MWNT-7 induced peritoneal mesothelioma in mice and rats. Intrascrotal injection induced peritoneal mesothelioma in rats. Intratracheal instillation of MWCNT-N (another straight fibrous MWCNT) induced both lung carcinoma and pleural mesothelioma in rats. In the whole body inhalation studies, in mice MWNT-7 promoted methylcholanthrene-initiated lung carcinogenesis. In rats, inhalation of MWNT-7 induced lung carcinoma and lung burdens of MWNT-7 increased with increasing concentration of airborne MWNT-7 and increasing duration of exposure. CONCLUSIONS: Straight, fibrous MWCNTs exerted carcinogenicity in experimental animals. Phagocytosis of MWCNT fibers by macrophages was very likely to be a principle factor in MWCNT lung carcinogenesis. Using no-observed-adverse-effect level-based approach, we calculated that the occupational exposure limit (OEL) of MWNT-7 for cancer protection is 0.15 µg/m3 for a human worker. Further studies on the effects of the shape and size of MWCNT fibers and mode of action on the carcinogenicity are required.

Differential Susceptibility of Human Pleural and Peritoneal Mesothelial Cells to Asbestos Exposure.

Malignant mesothelioma (MM) is an aggressive cancer of mesothelial cells of pleural and peritoneal cavities. In 85% of cases both pleural and peritoneal MM is caused by asbestos exposure. Although both are asbestos-induced cancers, the incidence of pleural MM is significantly higher (85%) than peritoneal MM (15%). It has been proposed that carcinogenesis is a result of asbestos-induced inflammation but it is not clear what contributes to the differences observed between incidences of these two cancers. We hypothesize that the observed differences in incidences of pleural and peritoneal MM are the result of differences in the direct response of these cell types to asbestos rather than to differences mediated by the in vivo microenvironment. To test this hypothesis we characterized cellular responses to asbestos in a controlled environment. We found significantly greater changes in genome-wide expression in response to asbestos exposure in pleural mesothelial cells as compared to peritoneal mesothelial cells. In particular, a greater response in many common genes (IL-8, ATF3, CXCL2, CXCL3, IL-6, GOS2) was seen in pleural mesothelial cells as compared to peritoneal mesothelial cells. Unique genes expressed in pleural mesothelial cells were mainly pro-inflammatory (G-CSF, IL-1ß, IL-1α, GREM1) and have previously been shown to be involved in development of MM. Our results are consistent with the hypothesis that differences in incidences of pleural and peritoneal MM upon exposure to asbestos are the result of differences in mesothelial cell physiology that lead to differences in the inflammatory response, which leads to cancer.

Case report: peritoneal mesothelioma from asbestos in hairdryers.

BACKGROUND: The relationship between mesothelioma and exposure to asbestos is well established. As a result, the use of asbestos in buildings, construction sites, and mines, as well as the implications of disease for the workers has received considerable attention. However, asbestos was also used in household equipment and consumer products, including hairdryers. PURPOSE: To examine one case of peritoneal mesothelioma in a hairdresser and review the relevant literature on asbestos exposure from hairdryers. METHODS: The subject's medical and occupational records were obtained and reviewed and a physical examination was performed. RESULTS: The results indicate that the subject developed peritoneal mesothelioma from her occupational exposure to asbestos containing hairdryers in accordance with the literature. CONCLUSION: Hairdryers are possible sources of asbestos exposure in patients with mesothelioma, and the asbestos exposure risk is higher for those who use hairdryers occupationally.

Gene expression of mesothelioma in vinylidene chloride-exposed F344/N rats reveal immune dysfunction, tissue damage, and inflammation pathways.

A majority (∼80%) of human malignant mesotheliomas are asbestos-related. However, non-asbestos risk factors (radiation, chemicals, and genetic factors) account for up to 30% of cases. A recent 2-year National Toxicology Program carcinogenicity bioassay showed that male F344/N rats exposed to the industrial toxicant vinylidene chloride (VDC) resulted in a marked increase in malignant mesothelioma. Global gene expression profiles of these tumors were compared to spontaneous mesotheliomas and the F344/N rat mesothelial cell line (Fred-PE) in order to characterize the molecular features and chemical-specific profiles of mesothelioma in VDC-exposed rats. As expected, mesotheliomas from control and VDC-exposed rats shared pathways associated with tumorigenesis, including cellular and tissue development, organismal injury, embryonic development, inflammatory response, cell cycle regulation, and cellular growth and proliferation, while mesotheliomas from VDC-exposed rats alone showed overrepresentation of pathways associated with pro-inflammatory pathways and immune dysfunction such as the nuclear factor kappa-light-chain-enhancer of activated B cells signaling pathway, interleukin (IL)-8 and IL-12 signaling, interleukin responses, Fc receptor signaling, and natural killer and dendritic cells signaling, as well as overrepresentation of DNA damage and repair. These data suggest that a chronic, pro-inflammatory environment associated with VDC exposure may exacerbate disturbances in oncogene, growth factor, and cell cycle regulation, resulting in an increased incidence of mesothelioma.

Iron overload as a major targetable pathogenesis of asbestos-induced mesothelial carcinogenesis.

Few people expected that asbestos, a fibrous mineral, would be carcinogenic to humans. In fact, asbestos is a definite carcinogen in humans, causing a rare but aggressive cancer called malignant mesothelioma (MM). Mesothelial cells line the three somatic cavities and thus do not face the outer surface, but reduce the friction among numerous moving organs. MM has several characteristics: extremely long incubation period of 30-40 years after asbestos exposure, difficulty in clinical diagnosis at an early stage, and poor prognosis even under the current multimodal therapies. In Japan, 'Kubota shock' attracted considerable social attention in 2005 for asbestos-induced mesothelioma and, thereafter, the government enacted a law to provide the people suffering from MM a financial allowance. Several lines of recent evidence suggest that the major pathology associated with asbestos-induced MM is local iron overload, associated with asbestos exposure. Preclinical studies to prevent MM after asbestos exposure with iron reduction are in progress. In addition, novel target genes in mesothelial carcinogenesis have been discovered with recently recognized mesothelioma-prone families. Development of an effective preventive strategy is eagerly anticipated because of the long incubation period for MM.

Iron overload signature in chrysotile-induced malignant mesothelioma.

Exposure to asbestos is a risk for malignant mesothelioma (MM) in humans. Among the commercially used types of asbestos (chrysotile, crocidolite, and amosite), the carcinogenicity of chrysotile is not fully appreciated. Here, we show that all three asbestos types similarly induced MM in the rat peritoneal cavity and that chrysotile caused the earliest mesothelioma development with a high fraction of sarcomatoid histology. The pathogenesis of chrysotile-induced mesothelial carcinogenesis was closely associated with iron overload: repeated administration of an iron chelator, nitrilotriacetic acid, which promotes the Fenton reaction, significantly reduced the period required for carcinogenesis; massive iron deposition was found in the peritoneal organs with high serum ferritin; and homozygous deletion of the CDKN2A/2B/ARF tumour suppressor genes, the most frequent genomic alteration in human MM and in iron-induced rodent carcinogenesis, was observed in 92.6% of the cases studied with array-based comparative genomic hybridization. The induced rat MM cells revealed high expression of mesoderm-specific transcription factors, Dlx5 and Hand1, and showed an iron regulatory profile of active iron uptake and utilization. These data indicate that chrysotile is a strong carcinogen when exposed to mesothelia, acting through the induction of local iron overload. Therefore, an intervention to remove local excess iron might be a strategy to prevent MM after asbestos exposure.

Cancer incidence within a cohort occupationally exposed to asbestos: a study of dose--response relationships.

OBJECTIVES: The aim of our study was to analyse the dose-response relationship between occupational asbestos exposure and risk of cancer. METHODS: Our study was a retrospective morbidity study based on 2024 subjects occupationally exposed to asbestos, conducted over the period 1 January 1978 to 31 December 2004. Analysis of the dose-response relationship between occupational asbestos exposure, as a time-dependant variable, and risk of cancer was performed using a Cox model. In order to account for the effect of latency, we conducted the analysis with a lag of 10 years. RESULTS: 285 cases of cancers were observed in our cohort. The relative risk of pleuro-peritoneal mesothelioma, lung cancer and colorectal cancer associated with asbestos exposure, adjusted for age as a time-dependant variable and for sex, was correlated with exposure intensity (or average exposure level, AEL). The risk of cancer, whatever the anatomical site, did not increase with the duration of exposure to asbestos. CONCLUSION: While confirming the established relationship between asbestos exposure and pleuropulmonary and peritoneal cancers, this study also suggests a causal relationship between asbestos exposure and colorectal cancer.

Carbon nanotubes induce granulomas but not mesotheliomas.

BACKGROUND: Different types of carbon nanotubes may represent toxic hazards due to their size distribution and massive surface area. They may adsorb other toxic agents that can consequently be transported into the body. Hence the aim of this study was to confirm or reject the hypothesis of carcinogenicity of two types of carbon nanotubes. MATERIALS AND METHODS: Well-defined single-walled and multi-walled carbon nanotubes were studied in a specific animal model for mesothelioma induction. RESULTS: Short-term pilot studies were published on the asbestos fibre-like mesothelioma-inducing effects of carbon nanotubes based on the proposed mechanistic correlation on health effects of fibres of the same size. Our results with a simple in vivo, peritoneal exposure model refute such an interpretation. The present studies with rats indicate that early granuloma formation does not lead to the development of mesotheliomas during chronic exposure of peritoneal mesothelium to either single- or multi-walled carbon nanotubes of varied size. CONCLUSION: Due to the limited toxicity data on carbon nanotubes, these results may be particularly important for risk assessment purposes.

Homozygous deletion of CDKN2A/2B is a hallmark of iron-induced high-grade rat mesothelioma.

In humans, mesothelioma has been linked to asbestos exposure, especially crocidolite and amosite asbestos, which contain high amounts of iron. Previously, we established a rat model of iron-induced peritoneal mesothelioma with repeated intraperitoneal injections of iron saccharate and an iron chelator, nitrilotriacetate. Here, we analyze these mesotheliomas using array-based comparative genomic hybridization (aCGH) and gene expression profiling by microarray. Mesotheliomas were classified into two distinct types after pathologic evaluation by immunohistochemistry. The major type, epithelioid mesothelioma (EM), originated in the vicinity of tunica vaginalis testis, expanded into the upper peritoneal cavity and exhibited papillary growth and intense podoplanin immunopositivity. The minor type, sarcomatoid mesothelioma (SM), originated from intraperitoneal organs and exhibited prominent invasiveness and lethality. Both mesothelioma types showed male preponderance. SMs revealed massive genomic alterations after aCGH analysis, including homozygous deletion of CDKN2A/2B and amplification of ERBB2 containing region, whereas EMs showed less genomic alterations. Uromodulin was highly expressed in most of the cases. After 4-week treatment, iron deposition in the mesothelia was observed with 8-hydroxy-2'-deoxyguanosine formation. These results not only show two distinct molecular pathways for iron-induced peritoneal mesothelioma, but also support the hypothesis that oxidative stress by iron overload is a major cause of CDKN2A/2B homozygous deletion.

Biological agents involved in malignant mesothelioma: relevance as biomarkers or therapeutic targets.

Malignant mesothelioma (MM) is a rare, highly aggressive tumor that arises from the surface serosal cells (pleural, peritoneal and pericardial cavities). Epidemiological and clinical data show that there is an association between asbestos exposure and MM development, even if the exact mechanism whereby asbestos induces MM is unknown. The continuing identification and elucidation of the molecular defects involved in mesothelioma pathogenesis and progression should lead to better disease control and greater therapeutic options in the near future. Goal of this article is to summarize the most recent advances in molecular pathogenesis of mesothelioma with particular emphasis on genes that could be considered as biomarkers or therapeutic targets and discuss possible clinical implications of these findings.

[Effect of peptone blocking asbestos-induced carcinogenesis in rats].

Regular intraperitoneal administration of peptone to rats was initiated immediately and 12 months after intraperitoneal thrice injection of crokidolite UICC in a dose of 20 mg. The rate of peritoneal mesotheliomas was 37.8% after co-administration of peptone and crokidolite, 25.6% following 12 months of crokidolite injection, and 72.1% after use of crokidolite alone. The effect of peptone administration is accounted for by the action of macrophages on transformed mesothelial cells and mesothelioma cells.