Image-based multiplex immune profiling of cancer tissues: translational implications. A report of the International Immuno-oncology Biomarker Working Group on Breast Cancer

Recent advances in the field of immuno-oncology have brought transformative changes in the management of cancer patients. The immune profile of tumours has been found to have key value in predicting disease prognosis and treatment response in various cancers. Multiplex immunohistochemistry and immunofluorescence have emerged as potent tools for the simultaneous detection of multiple protein biomarkers in a single tissue section, thereby expanding opportunities for molecular and immune profiling while preserving tissue samples. By establishing the phenotype of individual tumour cells when distributed within a mixed cell population, the identification of clinically relevant biomarkers with high-throughput multiplex immunophenotyping of tumour samples has great potential to guide appropriate treatment choices. Moreover, the emergence of novel multi-marker imaging approaches can now provide unprecedented insights into the tumour microenvironment, including the potential interplay between various cell types. However, there are significant challenges to widespread integration of these technologies in daily research and clinical practice. This review addresses the challenges and potential solutions within a structured framework of action from a regulatory and clinical trial perspective. New developments within the field of immunophenotyping using multiplexed tissue imaging platforms and associated digital pathology are also described, with a specific focus on translational implications across different subtypes of cancer. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Pitfalls in machine learning-based assessment of tumor-infiltrating lymphocytes in breast cancer: A report of the International Immuno-Oncology Biomarker Working Group on Breast Cancer

The clinical significance of the tumor-immune interaction in breast cancer is now established, and tumor-infiltrating lymphocytes (TILs) have emerged as predictive and prognostic biomarkers for patients with triple-negative (estrogen receptor, progesterone receptor, and HER2-negative) breast cancer and HER2-positive breast cancer. How computational assessments of TILs might complement manual TIL assessment in trial and daily practices is currently debated. Recent efforts to use machine learning (ML) to automatically evaluate TILs have shown promising results. We review state-of-the-art approaches and identify pitfalls and challenges of automated TIL evaluation by studying the root cause of ML discordances in comparison to manual TIL quantification. We categorize our findings into four main topics: (1) technical slide issues, (2) ML and image analysis aspects, (3) data challenges, and (4) validation issues. The main reason for discordant assessments is the inclusion of false-positive areas or cells identified by performance on certain tissue patterns or design choices in the computational implementation. To aid the adoption of ML for TIL assessment, we provide an in-depth discussion of ML and image analysis, including validation issues that need to be considered before reliable computational reporting of TILs can be incorporated into the trial and routine clinical management of patients with triple-negative breast cancer. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Spatial analyses of immune cell infiltration in cancer: current methods and future directions: A report of the International Immuno-Oncology Biomarker Working Group on Breast Cancer

Modern histologic imaging platforms coupled with machine learning methods have provided new opportunities to map the spatial distribution of immune cells in the tumor microenvironment. However, there exists no standardized method for describing or analyzing spatial immune cell data, and most reported spatial analyses are rudimentary. In this review, we provide an overview of two approaches for reporting and analyzing spatial data (raster versus vector-based). We then provide a compendium of spatial immune cell metrics that have been reported in the literature, summarizing prognostic associations in the context of a variety of cancers. We conclude by discussing two well-described clinical biomarkers, the breast cancer stromal tumor infiltrating lymphocytes score and the colon cancer Immunoscore, and describe investigative opportunities to improve clinical utility of these spatial biomarkers. © 2023 The Pathological Society of Great Britain and Ireland.

The tale of TILs in breast cancer: A report from The International Immuno-Oncology Biomarker Working Group

The advent of immune-checkpoint inhibitors (ICI) in modern oncology has significantly improved survival in several cancer settings. A subgroup of women with breast cancer (BC) has immunogenic infiltration of lymphocytes with expression of programmed death-ligand 1 (PD-L1). These patients may potentially benefit from ICI targeting the programmed death 1 (PD-1)/PD-L1 signaling axis. The use of tumor-infiltrating lymphocytes (TILs) as predictive and prognostic biomarkers has been under intense examination. Emerging data suggest that TILs are associated with response to both cytotoxic treatments and immunotherapy, particularly for patients with triple-negative BC. In this review from The International Immuno-Oncology Biomarker Working Group, we discuss (a) the biological understanding of TILs, (b) their analytical and clinical validity and efforts toward the clinical utility in BC, and (c) the current status of PD-L1 and TIL testing across different continents, including experiences from low-to-middle-income countries, incorporating also the view of a patient advocate. This information will help set the stage for future approaches to optimize the understanding and clinical utilization of TIL analysis in patients with BC.

Automated assessment of Ki-67 in breast cancer: the utility of digital image analysis using virtual triple staining and whole slide imaging

AIMS

Precise evaluation of proliferative activity is essential for the stratified treatment of luminal-type breast cancer (BC). Immunohistochemical staining of Ki-67 has been widely used to determine proliferative activity and is recognised to be a useful prognostic marker. However, there remains discussion concerning the methodology. We aimed to develop an automated and reliable Ki-67 assessment approach for invasive BC.

MATERIALS AND RESULTS

A retrospective study was designed to include two cohorts consisting of 152 and 261 consecutive patients with luminal-type BC. Representative tissue blocks following surgery were collected, and three serial sections were stained automatically with Ki-67, pan-cytokeratin and p63. The whole slides were scanned digitally and aligned using VirtualTripleStaining - an extension to the VirtualDoubleStaining™ technique provided by Visiopharm software. The aligned files underwent automated invasive cancer detection, hot-spot identification and Ki-67 counting. The automated scores showed a significant positive correlation with the pathologists' scores (r = 0.82, P < 0.0001). Among selected patients with curative surgery and standard adjuvant therapies (n = 130), the digitally assessed low Ki-67 group (<20%) demonstrated a significantly better prognosis (breast cancer-specific survival, P = 0.030; hazard ratio = 0.038) than the high Ki-67 group.

CONCLUSIONS

Digital image analysis yielded similar results to the scores determined by experienced pathologists. The prognostic utility was verified in our cohort, and an automated process is expected to have high reproducibility. Although some pitfalls were confirmed and thus need to be monitored by laboratory staff, the application could be utilised for the assessment of BC.

The path to a better biomarker: application of a risk management framework for the implementation of PD-L1 and TILs as immuno-oncology biomarkers in breast cancer clinical trials and daily practice

Immune checkpoint inhibitor therapies targeting PD-1/PD-L1 are now the standard of care in oncology across several hematologic and solid tumor types, including triple negative breast cancer (TNBC). Patients with metastatic or locally advanced TNBC with PD-L1 expression on immune cells occupying ≥1% of tumor area demonstrated survival benefit with the addition of atezolizumab to nab-paclitaxel. However, concerns regarding variability between immunohistochemical PD-L1 assay performance and inter-reader reproducibility have been raised. High tumor-infiltrating lymphocytes (TILs) have also been associated with response to PD-1/PD-L1 inhibitors in patients with breast cancer (BC). TILs can be easily assessed on hematoxylin and eosin-stained slides and have shown reliable inter-reader reproducibility. As an established prognostic factor in early stage TNBC, TILs are soon anticipated to be reported in daily practice in many pathology laboratories worldwide. Because TILs and PD-L1 are parts of an immunological spectrum in BC, we propose the systematic implementation of combined PD-L1 and TIL analyses as a more comprehensive immuno-oncological biomarker for patient selection for PD-1/PD-L1 inhibition-based therapy in patients with BC. Although practical and regulatory considerations differ by jurisdiction, the pathology community has the responsibility to patients to implement assays that lead to optimal patient selection. We propose herewith a risk-management framework that may help mitigate the risks of suboptimal patient selection for immuno-therapeutic approaches in clinical trials and daily practice based on combined TILs/PD-L1 assessment in BC. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Correlation between 18F-FDG uptake on PET/MRI and the level of tumor-infiltrating lymphocytes (TILs) in triple-negative and HER2-positive breast cancer

PURPOSE

The tumor microenvironment is related to the metabolism of cancer cells and local immune reactions. Previous studies have established TILs could be a significant prognostic factor, especially for triple-negative breast cancers (TNBC) and human epithelial growth factor receptor 2 (HER2)-positive breast cancers. We explore the association between metabolic information on PET/MRI with TILs in TNBC and HER2-positive breast cancer.

METHOD

We retrospectively reviewed the cases of 55 women with triple-negative or HER2-positive invasive ductal carcinomas who had undergone ¹⁸F-FDG PET/MRI without neo-adjuvant treatment for pre-operative evaluation. FDG uptake was quantified as standardized uptake value (SUV) max. The existence of peritumoral edema on PET/MRI was also recorded. The TIL score of the breast cancers was defined histologically on the basis of the proportion of the area infiltrated by lymphocytes, and classified as low (<10 %), intermediate (10-50 %), and high (>50 %). The association between PET/MRI findings and TILs was assessed using Kruskal-Wallis test and Wilcoxon signed-rank test.

RESULTS

There were 14 high TIL, 20 intermediate TIL and 21 low TIL lesions. Higher values of SUVmax were found in the high and intermediate TIL group as compared to the low TIL group (P = 0.013). On the other hand, the lesions with peritumoral edema in the low TIL group tended to show high SUVmax (P = 0.014).

CONCLUSIONS

¹⁸F-FDG uptake on PET/MRI correlated with TIL levels in patients with TNBC and HER2-positive breast cancer. This finding suggests that preoperative PET/MRI may be useful as a non-invasive tool for guiding the treatment plan.

Diffuse distribution of tumor-infiltrating lymphocytes is a marker for better prognosis and chemotherapeutic effect in triple-negative breast cancer

PURPOSE

High-density tumor-infiltrating lymphocytes (TILs) are a prognostic marker for triple-negative breast cancer (TNBC). However, lymphocytic infiltration is heterogeneous in its pattern. We aimed to explore the utility of TIL distribution patterns against TIL density for predicting TNBC prognosis and chemotherapeutic effects.

METHODS

Primary invasive TNBC cases were retrieved from a single institutional cohort, and archived samples were reviewed by two board-certificated pathologists. We used 154 consecutive surgical specimens from patients with standard adjuvant therapy, and 80 biopsies taken before primary systemic chemotherapy. The average density of stromal TILs was scored at 10% intervals, while the distribution pattern of TILs was evaluated as diffuse or non-diffuse. The association between TILs and prognosis or pathological complete response (pCR) was statistically analyzed.

RESULTS

A diffuse pattern of TILs at primary surgery correlated with better prognosis (relapse-free survival [RFS], hazard ratio [HR] 3.71, 95% confidence interval [CI] 1.60-8.57; overall survival [OS], HR 3.87, 95% CI 1.46-10.27), as well as high TIL density (≥ 50%; RFS, HR 4.51, 95% CI 2.06-9.90; OS, HR 3.28, 95% CI 1.32-8.14). Diffuse TIL pattern and nodal status were independent prognostic factors in multivariate analysis. Diffuse TIL pattern upon biopsy was associated with higher pCR rate (diffuse, 46%; non-diffuse, 21%; P = 0.032). All high TIL cases had diffuse patterns and the best outcome. Interobserver concordance was moderate (k = 0.53-0.55; distribution pattern) to good (weighted k = 0.67-0.69; density), and it was faster to assess the distribution pattern than to assess the density of TIL.

CONCLUSIONS

Showing similar clinical impacts to the TIL density, diffuse TILs could be a predictive marker for better prognosis and higher pCR. The assessment of TIL distribution pattern is simple, faster, and practical. Heterogeneous tumor immunity may contribute to further stratification of TNBC treatment.

Prognostic significance of tumor-infiltrating lymphocytes may differ depending on Ki67 expression levels in estrogen receptor-positive/HER2-negative operated breast cancers

BACKGROUND

The prognostic significance of tumor-infiltrating lymphocytes (TILs) has been established in breast cancers with estrogen receptor (ER)-negative and human epithelial growth factor receptor 2 (HER2)-negative or HER2-positive subtypes; however, its utility concerning the ER + /HER2 - subtype remains unclear.

METHODS

We evaluated the prognostic value of TILs by analyzing 717 invasive breast cancer operation cases. TILs were classified into three groups based on the proportion of area within the tumor: low ( < 10%), intermediate (10-50%), and high ( > 50%). Disease-free survival (DFS) and overall survival (OS) were calculated according to TIL levels.

RESULTS

Although there was no significant association between TIL levels and DFS or OS in all patients, high TILs were significantly associated with favorable DFS in Ki67-high (n = 238, p = 0.035) but not in Ki67-low (n = 470, p = 0.46) breast cancers. Multivariable analysis showed that high TILs were a significant and independent factor for DFS (HR 0.34; 95% CI 0.10-0.87; p = 0.023) among the Ki67-high group. In the ER + /HER2 - subtype, high-TILs showed favorable DFS in the Ki67-high group, although this was not statistically significant (p = 0.48); in contrast, unfavorable DFS was observed in the Ki67-low group (p = 0.027).

CONCLUSIONS

In Ki67-high breast cancers, high TILs were associated with favorable DFS, irrespective of subtype, but increasing TIL levels correlated with worse DFS in the Ki67-low group with the ER + /HER2 - subtype. These results highlight variation in TIL prognostic significance between Ki67-high and -low breast cancers, particularly for the ER + /HER2 - subtype.

Prospective Cohort Study of Congenital Cytomegalovirus Infection during Pregnancy with Fetal Growth Restriction: Serologic Analysis and Placental Pathology

OBJECTIVE

To investigate prospectively the prevalence of congenital cytomegalovirus (CMV) infection and the pathologic features of the placenta in cases of fetal growth restriction (FGR).

STUDY DESIGN

Forty-eight pregnant women who were diagnosed with FGR during pregnancy were enrolled for 15 months. Maternal CMV serologic tests, pathologic examinations of the placenta, and newborn urinary CMV-DNA polymerase chain reaction tests were performed in all the cases. The clinical characteristics and laboratory findings of the pregnant women and their newborns were collected. Biomarkers for inflammation, angiogenesis, and placental hormones were measured in the maternal serum at FGR diagnosis or in the neonatal urine at birth.

RESULTS

One of the 48 cases with FGR was a congenital CMV infection. CMV antigen was detected in the placenta of 7 cases with FGR. The change rate of the estimated fetal body weight was significantly lower in FGR cases with placental CMV detection. Placental villitis was observed more frequently in FGR cases with placental CMV detection. Human placental lactogen was significantly decreased in FGR cases with placental CMV detection. Increased C-reactive protein and serum amyloid A levels in the maternal serum were observed more frequently in FGR cases with placental CMV detection. Newborn urine β-2 microglobulin levels were significantly higher in FGR cases with placental CMV detection.

CONCLUSIONS

Serologic tests for maternal CMV, the change rate of the estimated fetal body weight, analysis of several biomarkers, and placental pathologic examinations might be helpful in comprehensively predicting the possibility of congenital CMV infection.

Abstract P2-08-35: A significance of SUVmax levels on FDG-PET as a prognostic factor may be mediated by local immune environment of breast cancer

(Background) SUVmax levels (maximum radioactivity concentration per a pixel) on FDG-PET reflect glucose uptake and it is clinically useful as a prognostic factor. It is reported that breast cancer with high levels of SUVmax causes insufficient glucose concentration in stromal tissue, which results in suppressed cytotoxic T-lymphocytes function. These data may indicate that the prognostic significance of SUVmax levels is influenced by local immune environment of breast cancer. The aim of this study is to investigate whether local immune responses of breast cancer affect correlation of SUVmax levels and prognosis.

(Method) The 278 invasive breast cancer patients were recruited who underwent surgery at Hyogo College of Medicine Hospital and whose SUVmax levels in the breast were examined before surgery or neo-adjuvant therapy. The cutoff value of SUVmax levels was set at 3.585. Tumor infiltrate lymphocytes (TILs) were evaluated as a local immune response and the distributions of TILs were divided into three groups, inflamed (intra-tumoral lymphocytes, Inf), immune excluded (peri-tumoral lymphocytes, IE) and immune desert (very few lymphocytes, ID). During follow-up period (median 39 months), 21 patients relapsed.

(Results) Relapse free survival (RFS) in the SUVmax-high group was significantly worse than in the SUVmax–low group (p=0.0026). There was no correlation between TILs distribution patterns and RFS. In the IE+ID group (175 patients) SUVmax levels were not correlated with prognosis, but in the Inf group (103 patients) RFS of SUVmax-high was significantly worse than of SUVmax-low (p=0.0051). In the multivariate analysis including nodal status and nuclear grade, SUVmax levels of the Inf group was an independent prognostic factor.

(Discussion and conclusion) SUVmax levels in primary lesions were correlated with prognosis only in the Inf group and were not in the IE+ID group. A significance of SUVmax levels as a prognostic factor may be diverse depending on the local immune environment of breast cancer. A novel therapeutic strategy such as inducing suppression of glucose uptake in cancer cells is suggested for breast cancer with immune inflamed.

Citation Format: Fujimoto Y, Higuchi T, Watanabe T, Hida AI, Imamura M, Kitajima K, Miyoshi Y. A significance of SUVmax levels on FDG-PET as a prognostic factor may be mediated by local immune environment of breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-35.

An autopsy case of epignathus (immature teratoma of the soft palate) with intracranial extension but without brain invasion: case report and literature review

Background

Epignathus is a rare congenital orofacial teratoma infrequently associated with intracranial extension. Intracranial extension of an epignathus indicates a poor prognosis; however, only a small number of such cases have been reported. While there have been some studies reporting cases of epignathus expanding directly into the cranium, others have reported no communication between an epignathus and an intracranial tumor.

Case presentation

A fetus at gestational week 27 was suspected of having an epignathus with intracranial tumor as shown by ultrasonographic and magnetic resonance imaging. The fetus was stillborn and an autopsy was performed. An epignathus measuring 12 × 6 × 6 cm and weighing 270 g protruded from the mouth, with its base on the soft palate. An intracranial tumor weighing 14 g was located at the middle intracranial fossa and connected to the epignathus through the right side of the sella turcica. The intracranial tumor was encapsulated, and there was no invasion into the brain. Histologically, both the epignathus and intracranial tumor were immature teratomas, with neural and pulmonary components that were especially immature as compared to those of the internal organs and brain tissues of the fetus.

Conclusion

There have been several reports of epignathus and intracranial tumors that did not communicate; therefore, careful evaluation is needed when a fetus is suspected of having an epignathus extending into an intracranial lesion. Our case supports the findings that an epignathus can directly expand into the cranium. Moreover, this is a rare case of an epignathus in which the intracranial lesion was encapsulated and did not invade the brain. These rare but important findings will provide additional, potential therapeutic strategies for gynecologists, neurosurgeons, and pathologists.

Abundant tumor infiltrating lymphocytes after primary systemic chemotherapy predicts poor prognosis in estrogen receptor-positive/HER2-negative breast cancers

PURPOSE

The therapeutic effect of systemic treatment for breast cancer (BC) generally depends on its intrinsic subtypes. In addition, tumor infiltrating lymphocytes (TILs) are considered to be an independent factor for tumor shrinkage and disease prognosis. High TILs at baseline or after primary systemic chemotherapy are reported to be associated with better survival in triple-negative or human epithelial growth factor receptor 2 (HER2)-positive BCs. However, the prognostic value of TILs in estrogen receptor (ER)-positive and HER2-negative (ER+/HER2-) BC is still controversial.

METHODS

We assessed TIL score (low, intermediate, and high) before and after primary systemic chemotherapy in every subtype of BC, and compared the clinical outcomes. Biopsy specimens of 47 triple-negative, 58 HER2+ and 91 ER+/HER2- BCs were used to assess TILs before treatment. To assess TILs after treatment, we examined residual invasive carcinoma in surgically resected samples of 28 triple-negative, 30 HER2+ and 80 ER+/HER2- BCs.

RESULTS

A high TIL score in triple-negative BC before treatment resulted in a significantly higher proportion of pathological complete response (pCR). In contrast, ER+/HER2- BC exhibited fewer instances of pCR than other subtypes. Although not statistically significant, ER+/HER2- cases with a high TIL score also tended to achieve pCR (p = 0.088). Moreover, we revealed that low TIL BCs after chemotherapy, but not at baseline, had significantly better relapse-free survival in ER+/HER2- BC (p = 0.034).

CONCLUSION

Pathological examination of TILs after treatment may be a surrogate marker for prognosis in ER+/HER2- BC.

Clinicopathologic analysis of IgG4-related skin disease

IgG4-related disease is a recently recognized systemic syndrome characterized by mass-forming lesions with lymphoplasmacytic infiltration, increase in the number of IgG4(+) cells in affected tissues and elevation of serum IgG4 levels. In 2009, we were the first to report skin lesions in patients with IgG4-related disease, but no large case series has been reported and clinicopathological findings remain unclear. To clarify these features, we herein report 10 patients (9 men and 1 woman; median age, 64 years; age range, 46-81 years) with IgG4-related skin disease. All patients had erythematous and itchy plaques or subcutaneous nodules on the skin of the head and neck, particularly in the periauricular, cheek, and mandible regions, except for one patient, whose forearm and waist skin were affected. In addition, eight patients had extracutaneous lesions: these were found on the lymph nodes in six patients, the lacrimal glands in three patients, the parotid glands in three patients, and the kidney in one patient. Histologically examined extracutaneous lesions were consistent with IgG4-related disease; five of six lymph node lesions showed progressively transformed germinal centers-type IgG4-related lymphadenopathy. Cases of IgG4-related skin disease were classified into two histological patterns: those exhibiting a nodular dermatitis pattern and those with a subcutaneous nodule pattern. The infiltrate was rich in plasma cells, small lymphocytes, and eosinophils; the majority of the plasma cells were IgG4(+). The IgG4(+) cell count was 49-396 per high-power field (mean±s.d., 172±129), with an IgG4(+)/IgG(+) cell ratio ranging from 62 to 92%. Serum IgG4 levels were elevated in all examined patients. In conclusion, patients with IgG4-related skin disease had uniform clinicopathology. Lesions were frequently present on the skin of the periauricular, cheek, and mandible regions, and were frequently accompanied by IgG4-related lymphadenopathy.

Pancreatic serous microcystic adenoma with extensive oncocytic change

Herein is reported a case of pancreatic serous microcystic adenoma with extensive oncocytic change in a 73-year-old woman. Histologically the tumor consisted of numerous small cysts, separated by thin or broad fibrous septa. These cysts were lined with uniform cells having abundant eosinophilic granular cytoplasm, which was negatively or weakly stained with PAS. Immunohistochemically, the cyst-lining cells were positive for cytokeratin (CK) 7, CK19, MUC1, MUC6, alpha-inhibin, and neuron-specific enolase (NSE), and negative for CK8, CK20, MUC2, and MUC5AC; these immunoprofiles coincide with those of serous microcystic adenoma. Immunostaining with anti-mitochondrial antibody showed dense granular positivity in the cytoplasm, which suggested an oncocytic phenotype. Thus, this case is considered a variant of serous microcystic adenoma characterized by extensive oncocytic change. To the authors' knowledge no similar case has been reported in the literature. It may pose problems in the differential diagnosis of the cystic pancreatic tumors with oncocytic change, but can be diagnosed on histology and immunohistochemistry.

Saccharated colloidal iron enhances lipopolysaccharide-induced nitric oxide production in vivo

We investigated the effects of iron on the production of nitric oxide (NO), inducible NO synthase (iNOS), and plasma cytokines induced by lipopolysaccharide (LPS) in vivo. Male Wistar rats were preloaded with a single intravenous injection of saccharated colloidal iron (Fesin, 70 mg iron/kg body weight) or normal saline as a control, and then given an intraperitoneal injection of LPS (5.0 mg/kg body weight). Rats, preloaded with iron, had evidence of both iron deposition and strong iNOS induction in liver Kupffer cells upon injection of LPS; phagocytic cells in the spleen and lung had similar findings. LPS-induced NO production in iron-preloaded rats was significantly higher than control rats as accessed by NO-hemoglobin levels measured by ESR (electron spin resonance) and NOx (nitrate plus nitrite) levels. Western blot analysis showed that iron preloading significantly enhanced LPS-induced iNOS induction in the liver, but not in the spleen or lung. LPS-induced plasma levels of IL-6, IL-1beta, and TNF-alpha were also significantly higher in iron-preloaded rats as shown by ELISA, but IFN-gamma levels were unchanged. We conclude that colloidal-iron phagocytosed by liver Kupffer cells enhanced LPS-induced NO production in vivo, iNOS induction in the liver, and release of IL-6, IL-1beta, and TNF-alpha.

Effects of phlebotomy on the growth of ferric nitrilotriacetate-induced renal cell carcinoma

The ferric nitrilotriacetate-induced carcinogenesis model is unique in that reactive oxygen species-free radicals are involved in the carcinogenic process. But the effects of iron-withdrawal in the progression of renal cell carcinoma are not well understood. We performed repeated phlebotomies on animals that had been administered ferric nitrilotriacetate in the initiation stage of renal cell carcinoma (phlebotomy group), and compared the development of renal tumors with those not receiving repeated phlebotomies (non-phlebotomy group). Ferric nitrilotriacetate-treated male Wistar rats were randomly divided into 2 groups: a phlebotomy group (21 rats) and a non-phlebotomy group (17 rats). Ten age-adjusted normal rats were also observed as a normal group. Hematocrit was maintained under 25% in the phlebotomy group. Hematocrit levels in the normal group and in the non-phlebotomy group were not significantly different. As a result, the incidence of renal cell carcinoma was not significantly different between phlebotomy and non-phlebotomy animals. However, the total weight of the renal cell carcinoma was significantly heavier in the animals from non-phlebotomy group than in those from the phlebotomy group (23.64 g +/- 18.54 vs. 54.40 g +/- 42.40, P < 0.05). The present study demonstrated that phlebotomy after the administration of ferric nitrilotriacetate did not reduce the incidence of renal cell carcinoma. In addition, we showed that iron withdrawal at the promotion stage of carcinogenesis will retard tumor growth.