Differences between peritoneal and pleural mesothelioma in Lombardy, Italy

Diagnosis and treatment of malignant retroperitoneal mesothelioma: A case report

RATIONALE

Malignant peritoneal mesothelioma (MPM) is a rare clinical disease. Although there are several reports describing intraperitoneal mesothelioma of the lung, liver, and intestine, retroperitoneal mesothelioma is, to our knowledge, very rare and rarely reported. In recent years, our best clinical protocols for the treatment and diagnosis of retroperitoneal mesothelioma have not been proven and the diagnosis and treatment are challenging.

PATIENT CONCERNS

A 37-year-old Chinese woman complained of bilateral low back pain for a month, with obvious symptoms of low back pain on the left side. To treat low back pain, retroperitoneal masses were found during physical examination. The patient consulted a urological specialist for further treatment.

DIAGNOSIS

After the operation, pathological biopsy confirmed retroperitoneal epithelioid diffuse mesothelioma.

INTERVENTIONS

After exclusion of surgical contraindications, the patient underwent laparoscopic retroperitoneal lesion resection under tracheal intubation and general anesthesia, and the operation was successful.

OUTCOMES

On the tenth day after surgery, the patient vital signs were stable, and he was discharged.

LESSONS

Patients with malignant peritoneal mesothelioma may have no typical clinical symptoms, and the diagnosis is based on pathological and immunohistochemical examination. In selected patients, surgical cell reduction and intraoperative intraperitoneal heat chemotherapy have become the first choice of treatment, which can achieve ideal therapeutic effects and prolong survival.

RhoA and vigilin are candidates for immunohistochemical markers for epithelioid malignant mesothelioma

Diagnostic markers of malignant mesothelioma (MM) have been extensively investigated. Immunohistochemistry (IHC) markers, such as calretinin, have been used for pathologic diagnosis. However, more diagnostic markers are required to improve the specificity and sensitivity of pathologic diagnosis. This study proposed two proteins as diagnostic markers for epithelioid MM. One is RhoA, an MM mutation-susceptible locus-derived protein, and another is vigilin, a lung small cell carcinoma marker. IHC was performed using 93 MM (epithelioid, 71 cases; sarcomatoid, 13 cases; and biphasic, 9 cases), 64 lung adenocarcinoma (LAC), 60 lung squamous cell carcinoma (LSC), and 14 normal mesothelial (NM) tissues. The majority of epithelioid MM cases were positive for both RhoA and vigilin, whereas both IHCs showed lower stainability in biphasic and sarcomatoid MM. Besides, both IHCs showed significantly higher stainability for RhoA and vigilin in epithelioid MM than in LAC and LSC (p < 0.05). Chi-square tests showed that both RhoA and vigilin IHC positive rate in epithelioid MM was not significantly different from that of calretinin (p > 0.05). In the differential diagnosis of MM from lung cancer, the accuracy and specificity of RhoA, vigilin, and calretinin staining were almost equivalent. Further, H-score test showed that there was no significant difference between RhoA versus calretinin and vigilin versus calretinin in IHC positivity in epithelioid MM (p > 0.05). In conclusion, RhoA and vigilin may be candidates for immunohistochemical markers for epithelioid MM.

Asbestos Exposure in Patients with Malignant Pleural Mesothelioma included in the PRIMATE Study, Lombardy, Italy

The PRIMATE study is an Italian translational research project, which aims to identify personalized biomarkers associated with clinical characteristics of malignant pleural mesothelioma (MPM). For this purpose, characteristics of MPM patients with different degrees of asbestos exposure will be compared to identify somatic mutations, germline polymorphism, and blood inflammatory biomarkers. In this framework, we assessed exposure to asbestos for 562 cases of MPM extracted from the Lombardy region Mesothelioma Registry (RML), for which a complete interview based on a standardized national questionnaire and histopathological specimens were available. Exposure assessment was performed: (1) through experts' evaluation (considered as the gold standard for the purpose of this study), according to the guidelines of the Italian National Mesothelioma Registry (ReNaM) and (2) using a job-exposure matrix (SYN-JEM) to obtain qualitative (ever/never) and quantitative estimates of occupational asbestos exposure (cumulative exposure expressed in fibers per mL (f/mL)). The performance of SYN-JEM was evaluated against the experts' evaluation. According to experts' evaluation, occupational asbestos exposure was recognized in 73.6% of men and 23.6% of women; furthermore, 29 men (7.8%) and 70 women (36.9%) had non-occupational exposure to asbestos. When applying SYN-JEM, 225 men (60.5%) and 25 women (13.2%) were classified as occupationally exposed, with a median cumulative exposure higher for men (1.7 f/mL-years) than for women (1.2 f/mL-years). The concordance between the two methods (Cohen’s kappa) for occupational exposure assessment was 0.46 overall (0.41 in men, and 0.07 in women). Sensitivity was higher in men (0.73) than in women (0.18), while specificity was higher in women (0.88) than in men (0.74). Overall, both methods can be used to reconstruct past occupational exposure to asbestos, each with its own advantages and limitations.

Malignant Peritoneal Mesothelioma with Latent Tuberculosis Infection

Malignant peritoneal mesothelioma (MPM) is a rare malignant tumor with peritoneal thickening. Tuberculous peritonitis also shows peritoneal thickening, so differentiating between the two is important but difficult if latent tuberculosis infection (LTBI) is present. We herein report a patient with MPM and LTBI. A 79-year-old man was diagnosed with peritoneal thickening on computed tomography. Interferon gamma release assay (IGRA) results were positive, suggesting tuberculous peritonitis. He underwent a laparoscopic omental biopsy and was diagnosed with MPM, which can occur together with LTBI. If peritoneal thickening is observed, an IGRA should be performed early, and the possibility of LTBI should be considered.

Establishment and characterization of a new malignant peritoneal mesothelioma cell line, KOG-1, from the ascitic fluid of a patient with pemetrexed chemotherapy resistance

Malignant peritoneal mesothelioma (MPeM) is a rare and aggressive form of malignant mesothelioma. Sufficient biological tools for studying the functional characteristics of this cancer have not been developed. Therefore, in this study, a novel human cancer cell line, KOG-1, was established from ascites fluids isolated from a 39-year-old Japanese woman with pemetrexed-resistant MPeM. Cells were dendritic or linear immediately after thawing, showed a jigsaw puzzle-like and spindle arrangement during growth, and formed monolayers without contact inhibition in two-dimensional (2D) culture. The population doubling time was 13.7 h. Karyotypic and molecular genetic analyses showed that chromosome numbers ranged from 62 to 142, with a peak of 73 with complicated copy number alterations. No germline BAP1 pathogenic variant was detected. Cells expressed various tumor markers of mesothelioma, such as calretinin, podoplanin, and Wilms tumor 1 (WT-1). Drug sensitivity and resistance testing with a set of 36 drugs using 2D and three-dimensional (3D) culture models demonstrated that KOG-1 cells showed high and low sensitivity to pemetrexed under 2D and 3D culture conditions, respectively, whereas control ovarian cancer cell lines showed low sensitivity to pemetrexed under both culture conditions. This newly established cell line will be a valuable biological resource to expand the feasibility of functional studies as well as drug testing for potential therapeutic purposes in MPeM.

Gender differences in pleural mesothelioma occurrence in Lombardy and Piedmont, Italy

BACKGROUND

Higher mesothelioma rates in men (vs women) reflect more frequent and more intense asbestos exposure. We assessed the impact of exposure difference between genders on age-specific rates of pleural mesothelioma (PM) occurrence using data from two Italian regions.

METHODS

We used data from the Lombardy and Piedmont mesothelioma registries (period 2000-2016, age 45-74 years) to compare rates of PM in men and women and to estimate the rate advancement period (RAP).

RESULTS

Based on 3384 cases (2405 men, 979 women) in Lombardy and 2042 (1389 men, 653 women) in Piedmont, the rate ratio was 2.81 (90% confidence interval: 2.61-3.03) in Lombardy and 2.39 (2.17-2.62) in Piedmont. In both regions RAP ranged from 7 to 10 years (at age 45 and 63 in men, respectively).

CONCLUSION

Men showed more than twofold increased PM rates and reached the same incidence as women 7-10 years earlier. RAP can be a useful measure of exposure impact on premature disease occurrence.

Peritoneal mesothelioma and asbestos exposure: a population-based case-control study in Lombardy, Italy

OBJECTIVES

Asbestos is the main risk factor for peritoneal mesothelioma (PeM). However, due to its rarity, PeM has rarely been investigated in community-based studies. We examined the association between asbestos exposure and PeM risk in a general population in Lombardy, Italy.

METHODS

From the regional mesothelioma registry, we selected PeM cases diagnosed in 2000-2015. Population controls (matched by area, gender and age) came from two case-control studies in Lombardy on lung cancer (2002-2004) and pleural mesothelioma (2014). Assessment of exposure to asbestos was performed through a quantitative job-exposure matrix (SYN-JEM) and expert evaluation based on a standardised questionnaire. We calculated period-specific and gender-specific OR and 90% CI using conditional logistic regression adjusted for age, province of residence and education.

RESULTS

We selected 68 cases and 2116 controls (2000-2007) and 159 cases and 205 controls (2008-2015). The ORs for ever asbestos exposure (expert-based, 2008-2015 only) were 5.78 (90% CI 3.03 to 11.0) in men and 8.00 (2.56 to 25.0) in women; the ORs for definite occupational exposure were 12.3 (5.62 to 26.7) in men and 14.3 (3.16 to 65.0) in women. The ORs for ever versus never occupational asbestos exposure based on SYN-JEM (both periods) were 2.05 (90% CI 1.39 to 3.01) in men and 1.62 (0.79 to 3.27) in women. In men, clear positive associations were found for duration, cumulative exposure (OR 1.33 (1.19 to 1.48) per fibres/mL-years) and latency.

CONCLUSIONS

Using two different methods of exposure assessment we provided evidence of a clear association between asbestos exposure and PeM risk in the general population.

Peritoneal mesothelioma mortality in Italy: Spatial analysis and search for asbestos exposure sources

BACKGROUND

This study is part of a national plan of epidemiological surveillance of malignant mesothelioma (MM) mortality in Italy. The paper shows the results of malignant peritoneal mesothelioma (MPeM) mortality study in Italian Regions and municipalities.

METHODS

National Bureau of Statistics data for MPeM municipal mortality (ICD-10, Code C45.1) were analyzed in the time-window 2003-2014: mortality standardized rates (reference Italian population, census 2011), temporal trends of the annual national rates, Standardized Mortality Ratios and a municipal clustering analysis were performed.

RESULTS

747 deaths for MPeM were recorded (0.10/100,000): 464 in men (0.14/100,000) and in 283 women (0.07/100,000). No significant MPeM mortality temporal trend was found. Seventeen municipalities showed excesses of mortality for MPeM in at least one gender and/or overall population. Four clusters in male population, and one in women were identified.

CONCLUSIONS

The study identifies some areas where remediation activities and/or health care actions may be warranted.

Incidence and survival of peritoneal malignant mesothelioma between 1989 and 2015: A population-based study

BACKGROUND

Peritoneal malignant mesothelioma is a rare disease for which few population-based studies are available. The aim of this study was to describe the evolution of the incidence and survival of peritoneal malignant mesothelioma in France between 1989 and 2015, using data derived from the French network of cancer registries.

METHODS

Age world-standardized incidence rates and overall survival were calculated using data from 16 French cancer registries. Log-linear Poisson regression analysis was used to estimate the average annual percentage change in incidence rates. Overall survival was performed using age-adjusted Cox proportional hazards model.

RESULTS

In French men, the incidence has increased quietly over the reporting period from 0.07 to 0.10 with a maximum of 0.16 per 100,000 persons-years in 2001-2003. For women, the increase in incidence has been lower than for men over the period 1989-2015, ranging from 0.04 to 0.11. A better prognosis was associated with a diagnosis made after 2000 (HR = 1.76; p = 0.013), the epithelioid histological type (p = 0.003), and the fact of being a woman, which has a 5-year risk of death half that of men (HR = 0.55; p = 0.001), regardless of age, diagnosis period or histology.

CONCLUSION

Our results are similar to those currently available for other countries. In France, peritoneal mesothelioma remains a rare and fatal cancer with a small increase in the incidence rate since 1989 and a median survival of 1 year; it seemed to develop equally in women and men over this period of time.

A case from India of pleural malignant mesothelioma probably due to domestic and environmental asbestos exposure: a posthumous report

India is the largest consumer of asbestos in the world. There is no report from India of mesothelioma related to asbestos. The case is a 42-year-old man who died of pleural mesothelioma. He was exposed to asbestos domestically and from the environment since birth. Two of his close family members worked in a factory that used asbestos. The living quarter of the family was within the premises of the factory. Asbestos waste was strewn on the grounds surrounding the quarters. After decades of legal battles by workers and families exposed to asbestos, Indian courts have ordered remedial measures and compensation to people, who are exposed to asbestos at work and the environment. Mesothelioma, currently in epidemic proportions in the west where asbestos production was banned in the 1990s, could rise to alarming levels in the next decades in India if the legal remedial measures are not implemented soon.