Clinical characteristics of patients with undergoing unplanned excisions of malignant soft tissue tumors

Introduction Malignant soft tissue tumors are rare tumors representing <1% of all malignancies. As these tumors are rare, it is not uncommon that malignant soft tissue tumor excision is performed without the required preoperative imaging, staging, or wide resection margins for sarcomas. The purpose of this study was to investigate the characteristics of patients with undergoing unplanned excisions. Risk factors for tumor recurrence and mortality in patients treated with unplanned excisions were also analyzed. Methods Forty-nine patients who underwent unplanned excision at other hospitals and additional wide excision at our hospital between January 2002 and December 2018 were identified. Among them, 42 patients with follow-up for more than 1 year were included in this retrospective study. The relationships between sex, age, tumor depth, histological grade, location, size, surgical margin at additional wide excision, residual tumor, reconstruction, kind of hospital where the primary excision was done (sarcoma vs non-sarcoma center), preoperative examination, chemotherapy, radiation therapy, and oncological outcomes were statistically analyzed. Results Mean patient age was 57.3 years (15–85 years) and the mean observation period was 72.5 months (14–181 months). This analysis showed 53.8% tumors that underwent unplanned excisions were small (<5 cm) and 70.7% tumors were superficial. Multivariate analysis revealed that a positive margin during additional wide excision was significantly associated with a lower 5-year LRFS ( p < 0.01). Conclusion Most of the tumors underwent unplanned excisions were small (<5 cm) and superficial. Surgeons should be aware that a positive margin during additional wide excision is an independent risk factor for local recurrence.

Radiomics of diffusion-weighted MRI compared to conventional measurement of apparent diffusion-coefficient for differentiation between benign and malignant soft tissue tumors

Diffusion-weighted imaging (DWI) is proven useful to differentiate benign and malignant soft tissue tumors (STTs). Radiomics utilizing a vast array of extracted imaging features has a potential to uncover disease characteristics. We aim to assess radiomics using DWI can outperform the conventional DWI for STT differentiation. In 151 patients with 80 benign and 71 malignant tumors, ADCmean and ADCmin were measured on solid portion within the mass by two different readers. For radiomics approach, tumors were segmented and 100 original radiomic features were extracted on ADC map. Eight radiomics models were built with training set (n = 105), using combinations of 2 different algorithms—multivariate logistic regression (MLR) and random forest (RF)—and 4 different inputs: radiomics features (R), R + ADCmin (I), R + ADCmean (E), R + ADCmin and ADCmean (A). All models were validated with test set (n = 46), and AUCs of ADCmean, ADCmin, MLR-R, RF-R, MLR-I, RF-I, MLR-E, RF-E, MLR-A and RF-A models were 0.729, 0.753 0.698, 0.700, 0.773, 0.807, 0.762, 0.744, 0.773 and 0.807, respectively, without statistically significant difference. In conclusion, radiomics approach did not add diagnostic value to conventional ADC measurement for differentiating benign and malignant STTs.

Recurrent Nodular Fasciitis of the Vulva

All vulvar malignancies comprise only 2% of vulvar lesions, since 98% of vulvar neoplasms are benign. Nodular Fasciitis of the vulva present a diagnostic dilemma due in part to the rare nature of these disorders and similarities malignant soft tissue tumors, so publishing descriptions of these entities are essential

Accumulation of genome-wide somatic loss of heterozygosity (LOH) as a prominent feature of advanced malignant soft tissue tumors and association with the BRCAness status, suppression of immune responses, and lower survival rates.

11533 Background: Malignant soft tissue tumor is a rare cancer with few therapeutic options. Recent genomic analysis revealed widespread CNA and the cumulative burden of cancer-related pathogenic germline mutations/variants, their clinical and therapeutic significance were unknown. Methods: We recruited 155 patients with advanced malignant soft tissue tumors (135 female and 20 male, mean age 51 at analysis, 100 LMS, 19 LPS, 4 ESS, 3 UPS, 3 AS, 3 MPT, 3 GIST and others) with confirmed metastasis/recurrence and information on familial cancer burden. Whole exome sequencing was performed in both blood and tumor samples as described in 2018ASCO. The copy number of BRCA2 gene was determined by the MLPA method. Tumor immune microenvironment was assessed by immunohistochemistry. The MSI status was analysed by PCR. Results: We analyzed the LOH status in 595 COSMIC genes and found that genome-wide accumulation of somatic LOH of polygenic germline mutations/variants. Patients with more than 33% LOH genes (n=102) in the total of somatic and LOH mutations showed significantly lower OS rates compared with those (n=53) with less LOH genes (5-year survival rates; 49 vs 75%, p=0.010), which constitute 78% of LMS (n=78/100) and 26% of LPS (n=5/19). Total of 41 patients (26%, n=41/155) including 33 LMS (33%, n=33/100) showed LOH in the BRCA2 locus with hemizygous VUS. Those patients with BRCA2 LOH (n=41) showed significantly lower OS rates compared with those without BRCA2 LOH (n=114) (5-year survival rates; 43 vs. 64%, p=0.019). Neither TMB nor the MSI status was associated with LOH. In contrast, accumulation of somatic LOH (mean LOH values of 71.7 vs. 15.7%) was clearly and negatively associated with CD8+T-cell immune infiltrates (T-cells; 44±23 vs 555±180/mm2, n=7, p=0.016), CD20+B-cell accumulation in tertiary lymphoid structures (TLS) (TLS; 0.57±0.43 vs. 20.1±6.1/tumor, n=7, p=0.008) and low levels of neutrophil-to-lymphocyte ratio (NLR) (NLR; 3.63±0.45 vs. 1.71±0.17, n=7, p=0.002), hallmarks of the immunological response to tumors. Conclusions: This study suggests that in advanced malignant soft tissue tumors, accumulation of genome-wide LOH of germline mutations/variants is associated with the BRCAness status and suppression of the immune responses to tumors, and thus influences therapeutic response and survival of the patients.