Clinicopathological assessment of T1 soft tissue sarcomas

Not every knee tumour is a ganglion - retrospective analysis of benign and malign tumour entities around the knee

BACKGROUND

Due to a lack of routine, there is often uncertainty regarding diagnostics of tumours around the knee joint. This study aimed to provide knowledge about the frequency, distribution and diagnostic algorithm of different bone and soft tissue tumour entities of the knee at a large referral university hospital in Germany.

METHODS

Retrospective, longitudinal, single-centre study that reviewed adult patients from 2010 until 2020 with a suspected tumours diagnosis around the knee at a university cancer centre. Inclusion criteria were adults with true bone or soft-tissue tumours in the knee joint and in its adjacent compartments. Suspected diagnosis, histological tumour entity, localization and its surgical treatment by biopsy, resection, osteosynthesis or tumour endoprosthesis were investigated.

RESULTS

A total number of 310 adult patients were included with a mean age of 54.2 ± 18.8 years. In total 160 (51.6%) soft-tissue tumours (69/43.1% benign; 74/46.2% malignant; 17/10.6% intermediate), 92 (29.6%) primary bone tumours (46/50% benign; 39/42.3% malignant; 7/7.6% intermediate), 36 (11.6%) metastases and 22 (7.1%) lymphomas were detected. 171 (55.1%) tumours were classified as malignant. Suspected diagnosis was matched with histology in 74.5% (231/310) of all cases. In 6 cases a primarily suspected benign diagnosis turned out to be malignant. The majority of primary bone tumours was cartilage derived (63.1%;58/92) and located in the distal 2/3 of the femur, whereas intracapsular tumours of the knee joint were rare (13.0%). Soft-tissue tumours were located primarily in the middle third of the thigh (36.8%). The MRI was the diagnostic tool of choice in 98.1% of soft tissue tumours and 82.6% bone tumours.

CONCLUSION

Awareness is crucial for detecting rare and malignant tumours around the knee, with adipocytic tumours being the most common soft tissue tumour and chondrogenic tumours as the most prevalent malignant bone tumour. Accurate diagnosis of bone tumours necessitates radiographs and frequently an additional MRI scan, while soft tissue tumours require mandatory MRI scans. Incorrectly diagnosing a tumour can have severe consequences, emphasizing the need for histological confirmation in all cases. Additionally, malignant tumours within joint capsules in adults are infrequent.

Is no additional excision after unplanned excision with positive margins justified in patients with small (≤5 cm) high-grade soft-tissue sarcoma?: Analysis from the Bone and Soft Tissue Tumor registry in Japan

BACKGROUND

This study aimed to elucidate the clinical outcomes of patients with small (≤5 cm) high-grade soft tissue sarcoma, who underwent unplanned excision with positive surgical margin, using data from the Bone and Soft Tissue Tumor registry in Japan.

METHODS

We examined 174 patients (101 males and 73 females; mean age, 59 years) with primary non-metastatic soft tissue sarcoma. The tumor size was ≤5 cm, and tumor histological grade was high in all patients. The mean follow-up duration was 50 months.

RESULTS

Unplanned excision with R1 and R2 margins was reported in 115 (66%) and 59 patients (34%), respectively. After unplanned excision, immediate additional excision was performed in 154 patients, whereas no additional excision was performed in the remaining 20. Of the 154 patients who underwent additional excision, wide surgical margin resection was achieved in 140 patients, while marginal and intralesional resections were achieved in 10 and 3 patients, respectively. Additionally, 93 patients (60%) underwent reconstruction after additional excision. During the last follow-up, 8 patients died of the disease, 22 developed distant metastasis, and 14 reported local recurrence. The 5-year disease-specific survival rate and 5-year metastasis-free survival rate was 93.5% and 85%, respectively. Tumor depth and additional excision after unplanned excision showed statistical significance in the multivariate analysis. The 5-year metastasis-free survival rate was 89.1% in patients with additional excision and 39.2% in those without. Univariate analysis showed an association between additional excision and local control. The 5-year local recurrence-free survival was significantly worse in patients without additional excision after unplanned excision (52.6%) than in those with additional excision (92.8%).

CONCLUSION

If unplanned excision is performed in patients with small high-grade soft tissue sarcoma, additional excision is recommended for preventing metastasis, along with necessary preparations for reconstruction.

Minimal Increase in Survival Throughout the Years in Patients with Soft Tissue Sarcoma with Synchronous Metastases: Results of a Population-Based Study

BACKGROUND

Treatment options for patients with metastatic soft tissue sarcoma (STS) have increased in the last decade. We aimed to examine whether this is associated with improved overall survival (OS) in patients with STS with synchronous metastases.

PATIENTS AND METHODS

Patients diagnosed with STS and synchronous metastases from 1989 to 2014 were queried from The Netherlands Cancer Registry. Trends in OS were assessed by the Kaplan-Meier method and log-rank test in time intervals of 5 years, for the whole study population and in subgroups for liposarcomas, leiomyosarcoma, and other STS subtypes. A multivariable Cox regression analysis was performed to identify characteristics prognostic for OS.

RESULTS

Median OS of the 1,393 identified patients did not improve significantly over the years from 5.8 months in 1989-1994 to 8.1 months in 2010-2014, but there was an evident trend. Median OS was prolonged in the subgroups of liposarcomas (3.6 to 9.3 months), leiomyosarcomas (11.3 to 14.6 months), and other STS subtypes (5.7 to 6.3 months), although there were no significant improvements in OS over the years. Primary tumor site in one of the extremities and surgery in an academic center had a favorable effect on OS, whereas significant negative predictors were no treatment, elderly age, STS subtype other than liposarcoma or leiomyosarcoma, high or unknown grade, and nodal involvement.

CONCLUSION

Although overall survival of patients with STS with synchronous metastases in this nationwide and "real-life" population has improved over the years, the improvement was not statistically significant, despite new treatment options.

IMPLICATIONS FOR PRACTICE

Treatment of patients with metastatic soft tissue sarcoma (STS) has changed in the past years, with new drugs such as trabectedin (2007) and pazopanib (2012) becoming available. By using data from the nationwide Netherlands Cancer Registry, the impact of these changes in treatment policies on survival is analyzed in a "real-life" population of patients with STS with synchronous metastases, rather than in a strictly selected trial population. Unfortunately, overall survival improved only minimally and not significantly for these patients diagnosed from 1989 to 2014. Hopefully, the advent of novel treatment options, such as eribulin and olaratumab, will further improve the outcome of this patient group.

Preoperative Factors Associated with Infiltrative Histologic Growth Patterns in Extremity Soft Tissue Sarcoma

Soft tissue sarcoma (STS) with an infiltrative histologic growth pattern, when compared to STS with an expansile pattern, may pose difficulties in local control. Preoperative assessment of the presence of infiltrative histologic growth pattern would be helpful in deciding treatment strategies. A review of 144 patients who underwent surgery for extremity STS was performed. Microscopically, the histologic growth pattern was defined as infiltrative if the penetration of the tumor cells into the surrounding tissue was observed. Possible clinicopathologic factors that might be associated with infiltrative histologic growth pattern were investigated with regard to patient demographics, tumor characteristics, and MRI findings. Of the 144 tumors, 71 (49%) showed infiltrative histologic growth pattern. On multivariate analysis, histological subtypes other than liposarcoma (OR = 4.57, p = 0.02) and infiltrative border on MRI (OR = 2.48, p = 0.01) were independent factors associated with infiltrative histologic growth pattern. Predictive index based on these two factors showed a significant improved accuracy (ROC-AUC = 0.647) for predicting infiltrative histologic growth pattern compared to either factor alone. Our data suggests that liposarcoma histology and tumor border on MRI can predict histologic growth pattern in extremity STS.

Clinicopathological characteristics and prognostic factors of T1 (≤5 cm) soft tissue sarcoma -- a comparative study with T2 (>5 cm) soft tissue sarcoma

BACKGROUND

T1 (≤5 cm) soft tissue sarcoma (STS) may represent a distinct subgroup with different biological characteristics resulting in favorable outcomes, when compared with T2 (>5 cm) STS. However, only few studies focusing on T1 STS have been reported.

METHODS

A retrospective review was conducted on 373 patients (163 with T1 STS [T1 group] and 210 with T2 STS [T2 group]) who underwent surgical removal of STS. Clinicopathologic characteristics and prognostic factors for local recurrence and disease-specific survival (DSS) of T1 STS was investigated and compared with those of T2 STS.

RESULTS

T1 group was younger (p = 0.004), had fewer metastases at initial presentation (p < 0.001), more previous unplanned excisions (p < 0.001), more synovial sarcomas (p = 0.024), fewer liposarcomas (p < 0.001), lower histological grade (p = 0.013), and fewer deep-seated tumors (p < 0.001) than T2 group. For local recurrence, older age (p = 0.008), previous unplanned excision (p = 0.012), and malignant peripheral nerve sheath tumor subtype (p = 0.014) independently predicted poor prognosis in the T2 group whereas only anatomical site of lower extremity (p = 0.046) was a favorable prognostic factor in the T1 group. For DSS, higher histologic grade (p = 0.037) and larger tumor size (p = 0.020) predicted poor prognosis in T2 group whereas only older age (p = 0.005) was prognostic in the T1 group.

CONCLUSIONS

Clinicopathological characteristics and prognostic factors of T1 STS differed from those of T2 STS. Established prognostic factors for STS were of limited value for T1 STS. These findings suggest the necessity of a different assessment strategy for T1 STS.