Molecular diagnostics in soft tissue sarcomas and gastrointestinal stromal tumors

Identification of common factors among fibrosarcoma, rhabdomyosarcoma, and osteosarcoma by network analysis

Sarcoma cancers are uncommon malignant tumors, and there are many subgroups, including fibrosarcoma (FS), which mainly affects middle-aged and older adults in deep soft tissues. Rhabdomyosarcoma (RMS), on the other hand, is the most common soft-tissue sarcoma in children and is located in the head and neck area. Osteosarcomas (OS) is the predominant form of primary bone cancer among young adults, primarily resulting from sporadically random mutations. This frequently results in the dissemination of cancer cells to the lungs, commonly known as metastasis. Mesodermal cells are the origin of sarcoma cancers. In this study, a rather radical approach has been applied. Instead of comparing homogenous cancer types, we focus on three main subtypes of sarcoma: fibrosarcoma, rhabdomyosarcoma, and osteosarcoma, and compare their gene expression with normal cell groups to identify the differentially expressed genes (DEGs). Next, by applying protein-protein interaction (PPI) network analysis, we determine the hub genes and crucial factors, such as transcription factors (TFs), affected by these types of cancer. Our findings indicate a modification in a range of pathways associated with cell cycle, extracellular matrix, and DNA repair in these three malignancies. Results showed that fibrosarcoma (FS), rhabdomyosarcoma (RMS), and osteosarcoma (OS) had 653, 1270, and 2823 differentially expressed genes (DEGs), respectively. Interestingly, there were 24 DEGs common to all three types. Network analysis showed that the fibrosarcoma network had two sub-networks identified in FS that contributed to the catabolic process of collagen via the G-protein coupled receptor signaling pathway. The rhabdomyosarcoma network included nine sub-networks associated with cell division, extracellular matrix organization, mRNA splicing via spliceosome, and others. The osteosarcoma network has 13 sub-networks, including mRNA splicing, sister chromatid cohesion, DNA repair, etc. In conclusion, the common DEGs identified in this study have been shown to play significant and multiple roles in various other cancers based on the literature review, indicating their significance.

Retrospective analysis of primary intraosseous malignancies in mandible and maxilla in a population of Taiwanese patients

BACKGROUND/PURPOSE

Due to the rarity and diversity of primary intraosseous malignancies in jawbones, we aimed to evaluate the clinicopathological features and discuss the findings of our collected cases with the literatures.

METHODS

Twenty-nine patients (2000-2020) diagnosed with primary central malignancies of jawbones were selected from the database of Oral Pathology Department in our institution. Clinical features, radiographic appearance, and histopathological diagnosis of the 29 cases were analyzed.

RESULTS

Twenty-nine patients aged between 19 and 84 years (average, 57.4 years) with a male to female ratio of 1.2:1 were included. The most frequent site was the mandibular body and ramus, followed by the posterior maxilla and mandibular symphysis. The most common diagnosis was osteogenic sarcoma (n = 13), followed by odontogenic carcinoma (n = 7), hematologic malignancies (n = 5), salivary gland malignancies (n = 2), and neurogenic sarcomas (n = 2). The most frequent symptoms were swelling, pain, paresthesia of lower lip, and mobile tooth. Radiographically, they usually presented as ill-defined osteolytic to osteoblastic lesions depending on the amount of ossification. Wide excision comprising partial maxillectomy and segmental mandibulectomy were the most common therapeutic methods.

CONCLUSION

Despite the rarity of primary central malignancies in jawbones, the clinical features may mimic infectious process or benign lesions. Detailed history-taking, clinical and imaging examination and awareness of the patient's signs and symptoms combining with the histopathological inspection are important for early diagnosis and improved prognosis. The current data contributes a useful basis for clinical investigation regarding intraosseous malignancies occurring in the jawbones.

A Brief Overview and Update on Major Molecular Genomic Alterations in Solid, Bone and Soft Tissue Tumors, Hematopoietic As Well As Lymphoid Malignancies

CONTEXT.—

Recent advances in comprehensive genomic profiling by next-generation sequencing have uncovered the genomic alterations at the molecular level for many types of tumors; as such, numerous small specific molecules that target these alterations have been developed and widely used in the management of these cancers.

OBJECTIVE.—

To provide a concise molecular genomic update in solid, bone and soft tissue tumors, hematopoietic as well as lymphoid malignancies; discuss its clinical applications; and familiarize practicing pathologists with the emerging cancer biomarkers and their diagnostic utilities.

DATA SOURCES.—

This review is based on the National Comprehensive Cancer Network guidelines and peer-reviewed English literature.

CONCLUSIONS.—

Tumor-specific biomarkers and molecular/genomic alterations, including pan-cancer markers, have been significantly expanded in the past decade thanks to large-scale high-throughput technologies and will continue to emerge in the future. These biomarkers can be of great value in diagnosis, prognosis, and/or targeted therapy/treatment. Familiarization with these emerging and ever-changing tumor biomarkers will undoubtedly aid pathologists in making accurate and state-of-the-art diagnoses and enable them to be more actively involved in the care of cancer patients.

Primary Gastrointestinal Stromal Tumor Mimicking as Gynecologic Mass: Characteristics, Management, and Prognosis

BACKGROUND

Primary gastrointestinal stromal tumor (GIST)-mimicking gynecologic masses are easily misdiagnosed. This study aimed to investigate the clinicopathological features, management, and prognosis of primary GIST mimicking as gynecologic mass.

METHODS

Clinicopathological and survival data of GIST mimicking as gynecologic mass admitted to our center from January 2005 to December 2017 were retrospectively analyzed.

RESULTS

Thirty-eight patients were included. The most common primary tumor site was the jejunoileum (n = 33, 86.9%), and 33 patients (86.9%) were classified as high recurrence risk. The short-term outcomes of operative incision length (P = 0.004), time to gas passage (P = 0.002), and hospital stay (P = 0.012) with laparoscopy-assisted resection were significantly shorter than those with open resection, showing no significant differences of long-term outcomes. With a median follow-up of 56 mo for 31 patients (81.6%), 18 (58.1%) received adjuvant therapy with imatinib. The 5-year disease-free survival and disease-specific survival of pelvic high-risk GIST was 37.0% and 48.3%, respectively; both were significantly lower than those of the other female high-risk group (both P < 0.05).

CONCLUSIONS

GIST mimicking as gynecologic mass is not uncommon, most originate from the jejunoileum and have a high risk of recurrence. Laparoscopy-assisted resection may be preferable for more favorable short-term outcomes. Compared with the other female high-risk GIST, pelvic high-risk GIST has a significantly worse prognosis; a longer duration of adjuvant therapy with imatinib than recommended may be beneficial.

The Role of Precision Medicine in the Diagnosis and Treatment of Patients with Rare Cancers

Rare cancers pose unique challenges for patients and their physicians arising from a lack of information regarding the best therapeutic options. Very often, a lack of clinical trial data leads physicians to choose treatments based on small case series or case reports. Precision medicine based on genomic analysis of tumors may allow for selection of better treatments with greater efficacy and less toxicity. Physicians are increasingly using genetics to identify patients at high risk for certain cancers to allow for early detection or prophylactic interventions. Genomics can be used to inform prognosis and more accurately establish a diagnosis. Genomic analysis may also expose therapeutic targets for which drugs are currently available and approved for use in other cancers. Notable successes in the treatment of previously refractory cancers have resulted. New more advanced sequencing technologies, tools for interpretation, and an increasing array of targeted drugs offer additional hope, but challenges remain.

Adult genitourinary sarcoma: Clinical characteristics and survival in a series of patients treated at a high-volume institution

OBJECTIVES

To report our institutional experience in the management of adult genitourinary sarcoma.

METHODS

This was a retrospective analysis of data on adult genitourinary sarcoma treated at the West China Hospital, Sichuan University, Chengdu, Sichuan, China from 1985 to 2010. Clinicopathological parameters were analyzed to determine their impact on overall, recurrence-free and metastasis-free survivals.

RESULTS

A total of 46 women and 142 men were included, with a median age of 42 years. Of these, 152 cases were high-grade. The most common site was the paratesticular region. Surgical resection was carried out in 155 patients (82.4%), with negative margin in 106. After a minimum follow up of 5 years, 20 patients (11.6%) survived disease-free, 14 (8.1%) were alive with disease and 138 (80.2%) died of disease. Survival rates at 1, 3 and 5 years were 91.3%, 64.0% and 47.7%. In univariate analyses, liposarcoma, high grade, metastasis at diagnosis, a lack of surgical resection and positive margin were predictive of unfavorable survival. In multivariate analyses, high grade, a lack of surgical resection and chemotherapy were independent predictors of poor survival.

CONCLUSIONS

Adult genitourinary sarcoma is an aggressive malignancy, usually presenting at advanced stage, with a high incidence of recurrence and metastasis. Complete resection and selective combination of chemotherapy and radiotherapy might constitute the optimal treatment for this disease.

Advanced soft-tissue sarcoma and treatment options: critical appraisal of trabectedin

Soft-tissue sarcomas (STS) are a heterogeneous group of rare solid tumors of mesenchymal origin. This paper reviews the current status of systemic treatment in advanced and metastatic soft tissue sarcomas, with an emphasis on trabectedin. Trabectedin is a unique type of chemotherapeutic agent with multiple potential mechanisms of action. We discuss the putative mechanisms, as well as the toxicity and administration schedules of trabectedin, followed by its efficacy in first-line systemic therapy and beyond first-line systemic therapy.

miR-135b, a key regulator of malignancy, is linked to poor prognosis in human myxoid liposarcoma

Myxoid/round cell (RC) liposarcomas (MLS) were originally classified into two distinct populations based on histological differences; a myxoid component and a RC component. It is notable that, depending on an increase of the RC component, the prognosis significantly differs. Hence, the RC component is associated with metastasis and poor prognosis. However, the molecular mechanisms that contribute to the malignancy of the RC component still remain largely unknown. Here, we report microRNA-135b (miR-135b), a key regulator of the malignancy, highly expressed in the RC component and promoting MLS cell invasion in vitro and metastasis in vivo through the direct suppression of thrombospondin 2 (THBS2). Decreased THBS2 expression by miR-135b increases the total amount of matrix metalloproteinase 2 (MMP2) and influences cellular density and an extracellular matrix structure, thereby resulting in morphological change in tumor. The expression levels of miR-135b and THBS2 significantly correlated with a poor prognosis in MLS patients. Overall, our study reveals that the miR-135b/THBS2/MMP2 axis is tightly related to MLS pathophysiology and has an important clinical implication. This work provides noteworthy evidence for overcoming metastasis and improving patient outcomes, and sheds light on miR-135b and THBS2 as novel molecular targets for diagnosis and therapy in MLS.

Significance of circulating tumor cells in soft tissue sarcoma

Circulating tumor cells can be detected from the peripheral blood of cancer patients. Their prognostic value has been established in the last 10 years for metastatic colorectal, breast, and prostate cancer. On the contrary their presence in patients affected by sarcomas has been poorly investigated. The discovery of EpCAM mRNA expression in different sarcoma cell lines and in a small cohort of metastatic sarcoma patients supports further investigations on these rare tumors to deepen the importance of CTC isolation. Although it is not clear whether EpCAM expression might be originally present on tumor sarcoma cells or acquired during the mesenchymal-epithelial transition, the discovery of EpCAM on circulating sarcoma cells opens a new scenario in CTC detection in patients affected by a rare mesenchymal tumor.