Pathologic necrosis following neoadjuvant radiotherapy or chemoradiotherapy is prognostic of poor survival in soft tissue sarcoma

Rethinking tumor viability as prognostic factor in soft tissue sarcoma

Background

Histopathologic assessment of tumor viability has emerged as a potential predictive factor of outcomes in various cancers. This study evaluates the prognostic significance of viability in high-grade soft tissue sarcoma while accounting for different adjuvant regimens and clinical variables.

Methods

A retrospective chart review was conducted on 147 patients surgically treated for high-grade soft tissue sarcoma between 2010 and 2021 at a single institution. Perioperative, clinical and surveillance data were collected. Tumor viability was determined through histopathologic analysis by a board-certified pathologist.

Results

No significant differences in clinical variables were observed between groups with ≤10 % and >10 % tumor viability. Neoadjuvant treatments, tumor grade, size, and depth did not independently affect tumor viability. There was no statistically decreased risk of local recurrence in the group with ≤10 % viability compared to the group with >10 % viability (HR = 1.19, 95 % CI [0.57,2.50]) (p = 0.64). Margin status was the only variable that significantly increases the risk of LR on multivariate analysis.

Conclusion

This cohort suggests that neoadjuvant radiotherapy, chemotherapy, or their combination did not influence tumor viability predictably. Notably, tumors without neoadjuvant treatment exhibited a high rate of necrosis, potentially confounding the interpretation of treatment effect. Other factors such as tumor type may play a more significant role in the cause of tumor necrosis than originally thought. Pathologic tissue response continues to offer value for the management of STS, but these findings underscore the need for further investigation into tumor viability in soft tissue sarcoma, targeting specific treatments analyzed in large collaborative studies.

Rethinking the Prognostic Role of Necrosis in Soft-Tissue Sarcoma: Multidisciplinary Insights from the Sarcoma Academy

Background: Soft-tissue sarcomas (STSs) represent a heterogeneous group of malignancies with widely varying treatment responses and biological behaviors. While spontaneous necrosis (present at diagnosis) is recognized in established sarcoma grading systems, the prognostic significance of therapy-induced necrosis remains uncertain. Inconsistent definitions, methodological variability, and clinical confounders further complicate the interpretation of necrosis as an independent prognostic marker. Methods: This communication synthesizes findings from an international, multidisciplinary webinar hosted by the Sarcoma Academy, critically assessing the utility of therapy-induced necrosis in STS management. Discussions encompassed surgical, pathological, oncological, and radiological perspectives, emphasizing how necrosis is defined, measured, and contextualized in patient care. Results: Heterogeneity in STS subtypes, varied treatment protocols, and sampling inconsistencies challenge the prognostic value of post-treatment necrosis. While substantial necrosis may sometimes signal effective therapy, it can also reflect the tumor's aggressive nature. The panel underscored the utility of measuring the percentage of viable tumor cells, rather than necrosis alone, to obtain a more standardized and reproducible measure of therapy response. Emerging approaches-such as radiomics, molecular profiling, immune-based analyses, and real-world evidence (RWE) protocols-offer promising avenues for refining prognostication and guiding personalized therapy in STS. Conclusions: A focus solely on therapy-induced necrosis is insufficient to predict outcomes in STS. Instead, a multidisciplinary framework-combining standardized pathology protocols, quantification of viable tumor cells, advanced imaging, and innovative clinical trial designs-can better capture both treatment effects and underlying tumor biology. Future collaborative studies and hybrid trial methodologies are needed to determine which STS subgroups gain the most from intensified treatments aimed at maximizing necrosis, and how to balance such interventions with surgical considerations, toxicity, and overall patient well-being.

The mitotic rate as a prognostic biomarker after preoperative radiotherapy for high-grade limb/trunk soft tissue sarcoma

PURPOSE

Currently there is no generally accepted standardized approach for the pathological evaluation of soft tissue sarcoma (STS) histology appearance after preoperative radiotherapy (PORT). This study aimed to investigate the prognostic value of pathological appearance after PORT for patients with high-grade limb/trunk STS.

METHODS

A cohort of 116 patients with high-grade STS of the limb/trunk treated with PORT followed by resection were evaluated. Patient characteristics, imaging tumor morphology (size, volume), and histopathology (mitotic and necrosis rate, viable cell, hyalinization/fibrosis cytopathic effect) were reviewed and reassessed. Disease free survival (DFS) and overall survival (OS) were calculated using the Kaplan-Meier method, and the hazard ratio was derived from Cox proportional hazard models. Two predictive nomograms were calculated based on significant predictors identified.

RESULTS

The 5-year DFS and OS were 52.9% and 70.3%, respectively. Tumor size before (HR:1.07, 95%CI: 1.01-1.14) and after PORT (HR:1.08, 95%CI: 1.01-1.14), tumor volume (HR:1.06, 95%CI: 1.01-1.12), mitotic rate after PORT (HR: 1.06, 95%CI: 1.02-1.11), mitotic rate change after PORT (HR:1.04, 95%CI:1.00-1.09) were independent risk factors for DFS. Tumor size before (HR:1.08, 95%CI: 1.03-1.14) and after PORT (HR:1.09, 95%CI: 1.04-1.15), tumor volume (HR:1.05, 95%CI: 1.01-1.09), mitotic rate after PORT (HR: 1.09, 95%CI: 1.04-1.13), mitotic rate change after PORT (HR:1.05, 95%CI:1.01-1.09) were independent risk factors for OS. The C-index of pathologic predictive nomogram based on mitotic rate for DFS and OS were 0.67 and 0.73, respectively. The C-index of morphology-pathology predictive nomogram for OS was 0.79.

CONCLUSION

Tumor size before and after PORT, tumor volume, mitotic rate after PORT, mitotic rate change after PORT were independent risk factors for DFS and OS in high-grade STS patients treated with PORT. The mitotic rate, independent of tumor morphology, showed its potential as a prognostic biomarker for pathologic evaluation in patients treated with PORT.

What Is the Prognostic Value of the Pathologic Response after Neoadjuvant Radiotherapy in Soft Tissue Sarcoma? An Institutional Study Using the EORTC-STBSG Response Score

Background/Objectives: The relationship between pathologic findings in soft tissue sarcoma (STS) after neoadjuvant treatment and oncological outcomes remains uncertain due to varying evaluation methods and cut-off values. This study aims to assess pathologic findings after neoadjuvant radiotherapy in STS using the EORTC-STBSG response score and evaluate its prognostic value. Methods: Clinical and outcome data from 44 patients were reviewed. Resected specimens were re-evaluated to measure viable cells, necrosis, fibrosis, and hyalinization. Local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and overall survival (OS) were analyzed using Kaplan-Meier survival analysis. Cox proportional hazards regression was used for univariate and multivariate analyses to correlate outcomes with pathologic response. Results: The median percentages of viable cells, necrosis, and fibrosis/hyalinization were 20%, 11%, and 40%, respectively. A pathologic complete response (pCR), defined as ≤5% viable cells, was achieved in 25% of cases. Local recurrence occurred in 33% of cases, with a significantly higher rate of 64% after R1 resection compared to 22% after R0 resection. Distant metastases were observed in 42% of patients, primarily in the lungs. The 3-year rates for LRFS, DMFS, and OS were 65%, 54%, and 67%, respectively. A correlation between outcomes and tumor size, grade and histological subtype was observed. Classifying pathologic response by the EORTC-STBSG score failed to show an association with outcomes. Patients achieving pCR showed lower risk of LR and improved OS. Conclusions: While the EORTC-STBSG score did not show a prognostic value, resection specimens with ≤5% viable cells were linked to improved LRFS and OS.

Preoperative Ultrahypofractionated Radiation Therapy for Soft Tissue Sarcomas: Low Rate of Wound Complications

Purpose

Normofractionated preoperative radiation therapy (nRT) with 50 Gy applied in 25 fractions represents the most widely used radiation therapy (RT) regimen in combined local treatment of soft tissue sarcomas (STSs). STSs are characterized by a low α/β ratio of 4 to 5 Gy, which may translate into a higher sensitivity for hypofractionation. Increasing data from cohorts and phase 2 trials on ultrahypofractionated RT (uhRT) regimens are available. We prospectively assessed our preoperative uhRT sarcoma patient cohort with a focus on short-term wound complications (WCs).

Methods and Materials

This is a prospective registry analysis of a single-center patient cohort, treated from 03.2020 to 10.2023 with uhRT (25 Gy in 5 fractions in 1 week). The same radiation oncologists (G.S./C.G.) and surgeon (B.F.) performed the treatment (61/61 and 58/60), as well as the same reference pathologist (B.B.) confirmed all histopathologic diagnoses. WC (according to CAN-NCIC-SR2 trial) and intermediate local control (LC) rates were assessed and compared with outcome data of a previously published cohort of 67 extremity/trunk sarcoma patients treated with nRT by the same authors (7% WC, 98% LC at 3 years).

Results

After a mean/median follow-up of 19/19 months (range, 0-46), LC at 1.5 years was 94%. Surgery was performed at a mean/median of 20/16 days (range, 4-60) after uhRT completion. WC were observed in 7/60 operated patients (12%), and in 5/51 (10%) extremity/trunk lesions. Early tolerance was excellent, limited to G0 to G1, even in 3 patients with prior RT to the same region. Clear resection margins were achieved in 55/60 patients (92%). Pathologic necrosis of ≥95% was reported in 5% and 75% achieved less than 50% necrosis.

Conclusions

These results show low rates of WC and high LC for uhRT and are comparable with our previously published nRT data. This study supports the routine use of preoperative uhRT for STS.

Evaluation of pathological response to neoadjuvant chemotherapy in locally advanced cervical cancer

Neoadjuvant chemotherapy (NACT) is a viable therapeutic option for women diagnosed locally advanced cervical cancer (LACC). However, the factors influencing pathological response are still controversial. We collected pair specimens of 185 LACC patients before and after receiving NACT and conducted histological evaluation. 8 fresh tissues pre-treatment were selected from the entire cohort to conducted immune gene expression profiling. A novel pathological grading system was established by comprehensively assessing the percentages of viable tumor, inflammatory stroma, fibrotic stroma, and necrosis in the tumor bed. Then, 185 patients were categorized into either the good pathological response (GPR) group or the poor pathological response (PPR) group post-NACT, with 134 patients (72.4%, 134/185) achieving GPR. Increasing tumor-infiltrating lymphocytes (TILs) and tumor-infiltrating lymphocytes volume (TILV) pre-treatment were correlated with GPR, with TILV emerging as an independent predictive factor for GPR. Additionally, CIBERSORT analysis revealed noteworthy differences in the expression of immune makers between cPR and non-cPR group. Furthermore, a significantly heightened density of CD8 + T cells and a reduced density of FOXP3 + T cells were observed in GPR than PPR. Importantly, patients exhibiting GPR or inflammatory type demonstrated improved overall survival and disease-free survival. Notably, stromal type was an independent prognostic factor in multivariate analysis. Our study indicates the elevated TILV in pre-treatment specimens may predict a favorable response to NACT, while identifying stromal type in post-treatment specimens as an independent prognostic factor. Moreover, we proposed this pathological grading system in NACT patients, which may offer a more comprehensive understanding of treatment response and prognosis.

Preoperative sequential chemotherapy and hypofractionated radiotherapy combined with comprehensive surgical resection for high-risk soft tissue sarcomas: a retrospective study

Introduction

The management of soft tissue sarcomas presents considerable therapeutic challenges. This study was designed to assess the efficacy of neoadjuvant sequential chemotherapy and hypofractionated radiotherapy in conjunction with extensive surgical resection for the treatment of high-risk soft tissue sarcomas.

Materials and methods

We performed a retrospective review of 31 high-risk soft tissue sarcoma patients treated at our institution from June 2021 to June 2023. The cohort consisted of 21 males and 10 females with a mean age of 55.7 years and included both initial and recurrent disease presentations. Our treatment regimen comprised two to three cycles of neoadjuvant chemotherapy coupled with hypofractionated radiotherapy, delivered at 5 Gy per fraction to a total dose of 25-35 Gy across 5-7 days, prior to surgical resection aimed at achieving wide margins. Data collection was systematic, covering surgical outcomes, chemoradiotherapy-related complications, and prognostic factors.

Results

All patients completed the prescribed course of neoadjuvant chemoradiotherapy. 29% patients experienced grade 3+ chemotherapy toxicity, necessitating a reduction or interruption in their chemotherapy regimen. Limb preservation was accomplished in 30 patients finally. Response evaluation using RECIST 1.1 criteria post-neoadjuvant therapy revealed 9.7% with PD, 58.1% with SD, 29% with a PR, and 3.2% with a CR, culminating in an ORR of 32.2%. Postoperative complications included superficial wound infections in four patients and deep incisional infections in another four. 6 patients had developed metastasis, and 3 patients were still alive. Two experienced local recurrence. One-year DFS was 79.3%, with a one-year OS rate of 89.6%.

Conclusion

Neoadjuvant sequential chemotherapy and hypofractionated radiotherapy followed by extensive surgical resection represents an effective treatment paradigm for high-risk soft tissue sarcomas. This multimodal approach not only facilitates tumor reduction but also significantly reduces the risks of local recurrence and distant metastasis.

The Effect of chemo- and radiotherapy on tumor necrosis in soft tissue sarcoma- does it influence prognosis?

BACKGROUND

Soft tissue sarcomas (STSs) are a heterogeneous group of tumors. Wide surgical resection is standard, often combined with neoadjuvant chemotherapy, radiotherapy, or both. Studies have shown the predictive value of tumor necrosis in bone sarcoma (BS); however, the role of necrosis in STS after neoadjuvant therapies is still unclear. This study aimed to investigate the role of chemo- and radiotherapy in the formation of tumor necrosis and to evaluate the influence of tumor necrosis on overall survival and local recurrence-free survival. Data from BS patients and patients who did not receive neoadjuvant therapy were compared.

METHODS

A total of 779 patients with STS or BS were treated surgically. In all patients, tumor-specific factors such as type, size, or grading and the type of adjuvant therapy were documented. Local recurrence (LR), the diagnosis of metastatic disease, and survival during follow-up were evaluated.

RESULTS

A total of 565 patients with STS and 214 with BS were investigated. In STS, 24.1% G1 lesions, 34.1% G2 lesions, and 41.8% G3 lesions were observed. Two hundred twenty-four of the patients with STS and neoadjuvant therapy had either radiotherapy (RTx) (n = 80), chemotherapy (CTx) (n = 93), or both (n = 51). Three hundred forty-one had no neoadjuvant therapy at all. In STS, tumor necrosis after neoadjuvant treatment was significantly higher (53.5%) than in patients without neoadjuvant therapy (15.7%) (p < 0.001). Patients with combined neoadjuvant chemo-/radiotherapy had substantially higher tumor necrosis than those with radiotherapy alone (p = 0.032). There was no difference in tumor necrosis in patients with combined chemo-/radiotherapy and chemotherapy alone (p = 0.4). The mean overall survival for patients with STS was 34.7 months. Tumor necrosis did not influence survival in a subgroup of G2/3 patients. In STS with no neoadjuvant therapy and grading of G2/3, the correlation between necrosis and overall survival was significant (p = 0.0248). There was no significant correlation between local recurrence (LR) and necrosis.

CONCLUSION

STS shows a broad spectrum of necrosis even without neoadjuvant chemo- or radiotherapy. After CTx or/and RTx necrosis is enhanced and is significantly pronounced with a combination of both. There is a trend toward higher necrosis with CTx than with RTx. Grading substantially influences the necrosis rate, but necrosis in soft-tissue sarcoma following neoadjuvant therapy does not correlate with better survival or a lower local recurrence rate, as in bone sarcomas.

Moderate hypofractionated radiation therapy and pathologic response for soft tissue sarcomas (STS) of limbs and trunk: experience from a tertiary cancer center

BACKGROUND

Preoperative radiation therapy following by limb-sparing or conservative surgery is a standard approach for limb and trunk STS. Data supporting hypofractionated radiotherapy schedules are scarce albeit biological sensitivity of STS to radiation would justify it. We sought to evaluate the impact of moderate hypofractionation on pathologic response and its influence on oncologic outcomes.

MATERIAL AND METHODS

From October 2018 to January 2023, 18 patients with limb or trunk STS underwent preoperative radiotherapy at a median dose of 52.5 Gy (range 49.5-60 Gy) in 15 fractions of 3.5 Gy (3.3-4 Gy) with or without neoadjuvant chemotherapy. A favorable pathologic response (fPR) was considered as ≥ 90% tumor necrosis on specimen examination.

RESULTS

All patients completed planned preoperative radiotherapy. Eleven patients (61.1%) achieved a fPR, and 7 patients (36.8%) a complete pathologic response with total disappearance of tumor cells. Nine patients (47%) developed grade 1-2 acute skin toxicity, and 7 patients (38.8%) had wound complications on follow-up. With a median follow-up of 14 months (range 1-40), no cases of local relapse were observed, and actuarial 3-year overall survival (OS) and distant metastases-free survival (DMFS) are 87% and 76.4%, respectively. In the univariate analysis, the presence of a favorable pathologic response (fPR) was associated with improved 3-year OS (100% vs. 56.03%, p = 0.058) and 3-year DMFS (86.91% vs. 31.46%, p = 0.002). Moreover, both complete or partial RECIST response and radiological stabilization of the tumor lesion showed a significant association with higher rates of 3-year distant metastasis-free survival (DMFS) (83% vs. 83% vs. 56%, p < 0.001) and 3-year overall survival (OS) (100% vs. 80% vs. 0, p = 0.002).

CONCLUSIONS

Preoperative moderate hypofractionated radiation treatment for STS is feasible and well tolerated and associates encouraging rates of pathologic response that could have a favorable impact on final outcomes.

Outcomes After Preoperative Chemoradiation With or Without Pazopanib in Non-Rhabdomyosarcoma Soft Tissue Sarcoma: A Report From Children's Oncology Group and NRG Oncology

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.ARST1321 was a phase II study designed to compare the near complete pathologic response rate after preoperative chemoradiation with/without pazopanib in children and adults with intermediate-/high-risk chemotherapy-sensitive body wall/extremity non-Rhabdomyosarcoma Soft Tissue Sarcoma (ClinicalTrials.gov identifier: NCT02180867). Enrollment was stopped early following a predetermined interim analysis that found the rate of near complete pathologic response to be significantly greater with the addition of pazopanib. As a planned secondary aim of the study, the outcome data for this cohort were analyzed. Eight-five eligible patients were randomly assigned to receive (regimen A) or not receive (regimen B) pazopanib in combination with ifosfamide and doxorubicin + preoperative radiotherapy followed by primary resection at week 13 and then further chemotherapy at week 25. As of December 31, 2021, at a median survivor follow-up of 3.3 years (range, 0.1-5.8 years), the 3-year event-free survival for all patients in the intent-to-treat analysis was 52.5% (95% CI, 34.8 to 70.2) for regimen A and 50.6% (95% CI, 32 to 69.2) for regimen B (P = .8677, log-rank test); the 3-year overall survival was 75.7% (95% CI, 59.7 to 91.7) for regimen A and 65.4% (95% CI, 48.1 to 82.7) for regimen B (P = .1919, log-rank test). Although the rate of near complete pathologic response was significantly greater with the addition of pazopanib, outcomes were not statistically significantly different between the two regimens.

The Prognostic Relevance of MRI Characteristics in Myxofibrosarcoma Patients Treated with Neoadjuvant Radiotherapy

To improve local control, neoadjuvant radiotherapy (nRT) followed by surgery is the standard of care in myxofibrosarcoma (MFS) because of its infiltrative growth pattern. Nevertheless, local recurrence rates are high. Data on prognostic factors for poor clinical outcomes are lacking. This retrospective study thus investigates the prognostic relevance of magnetic resonance imaging (MRI) characteristics before and after nRT in 40 MFS patients, as well as their association with disease-free survival (DFS) and overall survival (OS). A vascular pedicle, defined as extra-tumoral vessels at the tumor periphery, was observed in 12 patients (30.0%) pre-nRT and remained present post-nRT in all cases. Patients with a vascular pedicle had worse DFS (HR 5.85; 95% CI 1.56-21.90; p = 0.009) and OS (HR 9.58; 95% CI 1.91-48.00; p = 0.006). An infiltrative growth pattern, referred to as a tail sign, was observed in 22 patients (55.0%) pre-nRT and in 19 patients (47.5%) post-nRT, and was associated with worse DFS post-nRT (HR 6.99; 95% CI 1.39-35.35; p = 0.019). The percentage of tumor necrosis estimated by MRI was increased post-nRT, but was not associated with survival outcomes. The presence of a tail sign or vascular pedicle on MRI could support the identification of patients at risk for poor clinical outcomes after nRT.

Correlation of radiological and histopathological response after neoadjuvant radiotherapy in soft tissue sarcoma

BACKGROUND

The aim of this study was to assess the association between radiological and histopathological response after neoadjuvant radiotherapy (nRT) in soft tissue sarcoma (STS), as well as the prognostic value of the different response evaluation methods on the oncological outcome.

METHODS

A retrospective cohort of patients with localized STS of the extremity and trunk wall, treated with nRT followed by resection were included. The radiological response was assessed by RECIST 1.1 (RECIST) and MR-adapted Choi (Choi), histopathologic response was evaluated according to the EORTC-STBSG recommendations. Oncological outcome parameters of interest were local recurrence-free survival (LRFS), disease metastases-free survival (DMFS), and overall survival (OS).

RESULTS

For 107 patients, complete pre- and postoperative pathology and imaging datasets were available. Most tumors were high-grade (77%) and the most common histological subtypes were undifferentiated pleomorphic sarcoma/not otherwise specified (UPS/NOS, 40%), myxoid liposarcoma (MLS, 21%) and myxofibrosarcoma (MFS, 16%). When comparing RECIST to Choi, the response was differently categorized in 58%, with a higher response rate (CR + PR) with Choi. Radiological responders showed a significant lower median percentage of viable cells (RECIST p = .050, Choi p = .015) and necrosis (RECIST p < .001), and a higher median percentage of fibrosis (RECIST p = .005, Choi p = .008), compared to radiological non-responders (SD + PD). RECIST, Choi, fibrosis, and viable cells were not significantly associated with altered oncological outcome, more necrosis was associated with poorer OS (p = .038).

CONCLUSION

RECIST, Choi and the EORTC-STBSG response score show incongruent results in response evaluation. The radiological response was significantly correlated with a lower percentage of viable cells and necrosis, but a higher percentage of fibrosis. Apart from necrosis, radiological nor other histopathological parameters were associated with oncologic outcomes.

PET-CT in the Evaluation of Neoadjuvant/Adjuvant Treatment Response of Soft-tissue Sarcomas: A Comprehensive Review of the Literature

➢

In soft-tissue sarcomas (STSs), the use of positron emission tomography-computed tomography (PET-CT) through a standardized uptake value reduction rate correlates well with histopathological response to neoadjuvant treatment and survival.

➢

PET-CT has shown a better sensitivity to diagnose systemic involvement compared with magnetic resonance imaging and CT; therefore, it has an important role in detecting recurrent systemic disease. However, delaying the use of PET-CT scan, to differentiate tumor recurrence from benign fluorodeoxyglucose uptake changes after surgical treatment and radiotherapy, is essential.

➢

PET-CT limitations such as difficult differentiation between benign inflammatory and malignant processes, inefficient discrimination between benign soft-tissue tumors and STSs, and low sensitivity when evaluating small pulmonary metastases must be of special consideration.

Extent of tumor fibrosis/hyalinization and infarction following neoadjuvant radiation therapy is associated with improved survival in patients with soft-tissue sarcoma

Introduction

Current standard of care for most intermediate and high‐grade soft‐tissue sarcomas (STS) includes limb‐preserving surgical resection with either neoadjuvant radiation therapy (NRT) or adjuvant radiation therapy. To date, there have been a few studies that attempt to correlate histopathologic response to NRT with oncologic outcomes in patients with STS.

Methods

Using our institutional database, we identified 58 patients who received NRT followed by surgical resection for primary intermediate or high‐grade STS and 34 patients who received surgical resection without NRT but did receive adjuvant radiation therapy or did not receive any radiation therapy. We analyzed four histologic parameters of response to therapy: residual viable tumor, fibrosis/hyalinization, necrosis, and infarction (each ratiometrically determined). Data were stratified into two binary groups. Unadjusted, 5‐ and 10‐year overall survival, and relapsed‐free survival (RFS) were calculated using the Kaplan–Meier method.

Results

Analysis of pathologic characteristics showed that patients treated with NRT demonstrate significantly higher tumor infarction, higher tumor fibrosis/hyalinization, and a lower percent viable tumor compared with patients not treated with NRT (p < 0.0001). Based on Kaplan–Meier curve analysis and multivariate cox proportional hazard model for OS and RFS, patients treated with NRT and showing >12.5% tumor fibrosis/hyalinization have significantly higher overall survival and recurrence‐free survival at 5 and 10 years.

Discussion and Conclusion

We have identified three histopathologic characteristics—fibrosis, hyalinization, and infarction—that may serve as predictive biomarkers of response to NRT for STS patients. Future prospective studies will be needed to confirm this association.

Long-Term Follow-Up of Patients Receiving Neoadjuvant Treatment Modalties for Soft Tissue Sarcomas of the Extremities

BACKGROUND

Neoadjuvant treatment modalities in soft tissue sarcoma (STS) of the extremities have become more popular in recent years, but because of the rarity and heterogeneity of STS, there are yet few studies on the long-term impact of neoadjuvant treatment modalities, especially in terms of neoadjuvant radiochemotherapy.

METHODS

The study enrolled 136 patients with primary STS of the extremities who underwent surgery with curative intent or neoadjuvant therapy, followed by surgery in a 15-year period. Neoadjuvant treatment consisted of radiotherapy (RT) with 60 Gy and in most cases simultaneous chemotherapy (CTx) with ifosfamide (1.5 g/m²/d, d1-5, q28) and doxorubicine (50 mg/m²/d, d3, q28). We investigated the clinical, (post)-operative and histopathological data and the oncological follow-up as well. The median follow-up period was 82 months (range 6-202).

RESULTS

A total of 136 patients (M:F = 73:63) with a mean age of 62 years (range; 21-93) was observed. Seventy-four patients (54.4%) received neoadjuvant therapy (NT), 62 patients (45.6%) received primary surgery (PS). When receiving NT, patients with high-risk STS had a lower risk to develop distant metastasis (p = 0.025). Age, histological type, tumor size and surgical margins (R0 vs. R1) had no influence on any survival rates. There was an association between NT and the occurrence of postoperative complications (p = 0.001). The 5-year local recurrence free survival (LRFS), metastasis free survival (MFS), disease free survival (DFS) and overall survival (OS) rate of the whole cohort was 89.9%, 77.0%, 70.6% and 72.6%; whereas the 5-year LRFS, MFS, DFS and OS rate was 90.5%, 67.2%, 64.1% and 62.8% for the NT group and 89.5%, 88.3%. 78.4% and 83.8% for the PS group.

CONCLUSIONS

Multimodal treatment strategies in patients with STS of extremities lead to excellent oncological outcomes. Patients with high-risk STS had a significantly better MFS when receiving NT than patients with low-risk STS. NT was associated with a higher probability of postoperative but well-manageable complications.

Impact of histological subtype on radiological and pathological response after neoadjuvant radiotherapy in soft tissue sarcoma

BACKGROUND

Evaluation of response to neoadjuvant radiotherapy (NART) does not consider soft tissue sarcoma (STS) heterogeneity. We aimed to investigate radiological and pathological response of 4 major histotypes.

METHODS

Extremity or trunk STS patients who received 50 Gy NART between 2009 and 2020 were retrospectively included. Relative variation in tumor size (RVTS) and pathological response were reported in the overall population and in undifferentiated pleomorphic sarcoma (UPS), myxofibrosarcoma (MFS), myxoid liposarcoma (MLS) and synovial sarcoma (SS) patients to identify response modalities of each histotype.

RESULTS

Among the 121 included patients, 49, 19, 13 and 11 presented UPS, MFS, MLS and SS. Median RVTS were 0% (IQR -18-+18), +8% (IQR 0-+24), -12% (IQR -20-3) and -11% (IQR -15-9), respectively (p = 0.001). Median viable cells were 10%, 60%, 20% and 70% (p = 0.007). In overall population, pathological complete response and median necrosis were 27.7% and 10% without significant correlation to histotype (p = 0.18 and 0.06). Nineteen (38.8%) UPS specimens presented cysts that were emptied during the sampling process and distorted the microscopic response evaluation. Infiltrative growth pattern was observed in 28% and 38.9% UPS and MFS patients. Five (38.5%) MLS presented mature adipocytes without proven prognostic value. Cysts were observed in 36% of SS specimens. In the absence of initial tumor limits, the great viable cellularity of SS may be overestimated by their nodular aspect.

CONCLUSION

After NART, we highlighted disparate response of UPS, frequent progression of MFS, and confirmed MLS and SS radiosensitivity. Response must be interpreted with caution and consider the histotype-specific patterns.

Apatinib with doxorubicin and ifosfamide as neoadjuvant therapy for high-risk soft tissue sarcomas: a retrospective cohort study

BACKGROUND

There is a need to establish an effective neoadjuvant therapy for soft tissue sarcomas (STSs). We previously showed that apatinib, administered in combination with doxorubicin-based chemotherapy, improves the efficacy of treatment. This study aimed to clarify the effectiveness and safety of apatinib combined with doxorubicin and ifosfamide (AI) neoadjuvant chemotherapy for STSs.

METHODS

This retrospective study included patients with STS who received neoadjuvant therapy and surgery between January 2016 and January 2019. The patients were divided into two treatment groups: AI + apatinib group and AI group (doxorubicin + ifosfamide).

RESULTS

The study included 74 patients (AI + apatinib: 26, AI: 48) with STS. There were significant between-group differences in objective response rates (53.85% vs. 29.17%, p = 0.047) and the average change in target lesion size from baseline (-40.46 ± 40.30 vs. -16.31 ± 34.32, p = 0.008). The R0 rate (84.62% vs. 68.75%; p = 0.170) and 2-year disease-free survival (73.08% vs. 62.50%, p = 0.343) were similar across groups. Finally, the rates of neoadjuvant therapy-related adverse effects and postoperative complications were similar in both groups (p > 0.05).

CONCLUSION

Apatinib plus doxorubicin and ifosfamide regimen is safe and effective as neoadjuvant therapy for patients with STS. However, the significantly improved preoperative ORR observed after neoadjuvant therapy did not translate into a significantly improved R0 rate and 2-year DFS. Prospective, well-powered studies are warranted to determine the long-term efficacy and optimal application of these protocols.

Complete pathological response to neoadjuvant treatment is associated with better survival outcomes in patients with soft tissue sarcoma: Results of a retrospective multicenter study

BACKGROUND

Locally advanced soft tissue sarcoma (STS) management may include neoadjuvant or adjuvant treatment by radiotherapy (RT), chemotherapy (CT) or chemoradiotherapy (CRT) followed by wide surgical excision. While pathological complete response (pCR) to preoperative treatment is prognostic for survival in osteosarcomas, its significance for STS is unclear. We aimed to evaluate the prognostic significance of pCR to pre-operative treatment on 3-year disease-free survival (3y-DFS) in STS patients.

METHODS

This is an observational, retrospective, international, study of adult patients with primary non-metastatic STS of the extremities and trunk wall, any grade, diagnosed between 2008 and 2012, treated with at least neoadjuvant treatment and surgical resection and observed for a minimum of 3 years after diagnosis. The primary objective was to evaluate the effect of pCR. (≤5% viable tumor cells or ≥95% necrosis/fibrosis) on 3y-DFS. Effect on local recurrence-free survival (LRFS), distant recurrence-free survival (MFS) overall survival (OS) at 3 years was also analyzed. Statistical univariate analysis utilized chi-square independence test and odds ratio confidence interval (CI) estimate, multivariate analysis was performed using LASSO.

RESULTS

A total of 330 patients (median age 56 years old, range:19-95) treated by preoperative RT (67%), CT (15%) or CRT (18%) followed by surgery were included. pCR was achieved in 74/330 (22%) of patients, of which 56/74 (76%) had received RT. 3-yr DFS was observed in 76% of patients with pCR vs 61% without pCR (p < 0.001). Multivariate analysis showed that pCR is statistically associated with better MFS (95% CI, 1.054-3.417; p = 0.033), LRFS (95% CI, 1.226-5.916; p = 0.014), DFS (95% CI, 1.165-4.040; p = 0.015) and OS at 3 years (95% CI, 1.072-5.210; p = 0.033).

CONCLUSIONS

In a wide, heterogeneous STS population we showed that pCR to preoperative treatment is prognostic for survival.

Modern Management of High-risk Soft Tissue Sarcoma With Neoadjuvant Chemoradiation: A Single-center Experience

OBJECTIVE

Neoadjuvant chemoradiation (NA-CRT), followed by resection of high-risk soft tissue sarcoma (STS), may offer good disease control and toxicity outcomes. We report on a single institution's modern NA-CRT experience.

MATERIALS AND METHODS

Delay to surgical resection, resection margin status, extent of necrosis, tumor cell viability, presence of hyalinization, positron emission tomography (PET)/computed tomography data, and treatment toxicities were collected. Using the Kaplan-Meier survival analysis, 5-year overall survival, disease-free survival, distant metastasis-free survival, and local control (LC) were estimated. Clinicopathologic features and PET/computed tomography avidity changes were assessed for their potential predictive impact using the log-rank test.

RESULTS

From 2011 to 2018, 37 consecutive cases of localized high-risk STS were identified. Twenty-nine patients underwent ifosfamide-based NA-CRT to a median dose of 50 Gy before en bloc resection. At a median follow-up of 40.3 months, estimated 5-year overall survival was 86.1%, disease-free survival 70.2%, distant metastasis-free survival 75.2%, and LC 86.7%. Following NA-CRT, a median reduction of 54.7% was observed in tumor PET avidity; once resected, median tumor necrosis of 60.0% with no viable tumor cells was detected in 13.8% of the cases. Posttreatment resection margins were negative in all patients, with 27.6% having a margin of ≤1 mm. Delays of over 6 weeks following the end of radiation treatment to surgical resection occurred in 20.7% cases and was suggestive of inferior LC (92.8% vs. 68.6%, P=0.025).

CONCLUSIONS

This single-institution series of NA-CRT demonstrates favorable disease control. Delay in surgical resection was associated with inferior LC, a finding that deserves further evaluation in a larger cohort.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Pre- or postoperative radiotherapy for soft tissue sarcomas

Sarcomas are rare tumours arising from mesenchymal tissue. A multimodal management in an expert centre combining surgery and radiotherapy is the current standard of care for localized soft-tissue sarcomas of the extremities, to enable limb-sparing strategies. The delivery of pre- radiotherapy or postoperative radiotherapy offers similar local control and survival rates but the toxicity profile is quite different: preoperative radiotherapy increases the risk of wound complications and postoperative radiotherapy affects long-term functional outcomes. While postoperative radiotherapy has long been the rule, especially in Europe, technical improvements with image-guided- and intensity-modulated radiotherapy associated with a better management of postoperative wounds has tended to change practices with more frequent preoperative radiotherapy. More recently the possibilities of a hypofractionated regimen or potentiation by nanoparticles to increase the therapeutic index plead in favour of a preoperative delivery of radiotherapy. The aim of this paper is to report pros and cons of pre- and post-operative radiotherapy for soft-tissue sarcomas.

Neoadjuvant Chemoradiation Compared With Neoadjuvant Radiation Alone in the Management of High-Grade Soft Tissue Extremity Sarcomas

Purpose

Patients with large, high-grade soft tissue sarcomas are commonly treated with aggressive limb preservation regimens. This study aimed to assess cancer control outcomes of patients treated with neoadjuvant chemoradiation (CRT) compared with radiation therapy (RT) alone.

Methods

We reviewed records of patients with high-grade extremity or trunk soft tissue sarcomas ≥5 cm who were treated with neoadjuvant radiation with or without chemotherapy. Patient and disease characteristics were compared using t test and χ² tests. Standardized mortality ratio weighted method was used to compare overall survival (OS), local control, and disease-free (DFS) survival. Acute radiation and surgical toxicity were reported.

Results

In the study, 64 patients (34 CRT and 30 RT) treated between 1997 and 2015 were analyzed. In the RT group compared with the CRT group, the patient population was older, with a median age of 65 versus 50 years (P < .001), and more likely to have cardiovascular disease (CVD; 30% vs 0%, P < .001). At a median follow-up of 41 months, after adjusting for propensity score of receiving RT, the 3-year LC was 87.3% versus 86.1%, DFS was 58.5% versus 56.6%, and OS was 75.6% versus 69.0% for the CRT and RT groups, respectively (P > .05). Acute dermatitis occurred in 18% versus 3% and surgical complications occurred in 32% versus 17% of CRT and RT patients, respectively.

Conclusions

In this study, patients receiving RT alone were more likely to be older and have comorbid cardiovascular disease. When controlling for baseline differences, neoadjuvant CRT and RT provided similar rates of LC, DFS, and OS.

The role of radiation therapy and margin width in localized soft-tissue sarcoma: Analysis from the US Sarcoma Collaborative

BACKGROUND AND OBJECTIVES

Soft-tissue sarcomas (STSs) are often treated with resection and radiation (RT)±chemotherapy. The role of RT in decreasing resection width to achieve local control is unclear. We evaluated RT on margin width to achieve local control and local recurrence (LR).

METHODS

From 2000 to 2016, 514 patients with localized STS were identified from the US Sarcoma Collaborative database. Patients were stratified by a margin and local control was compared amongst treatment groups.

RESULTS

LR was 9% with positive, 4.2% with ≤1 mm, and 9.3% with >1 mm margins (P = .315). In the ≤1 mm group, LR was 5.7% without RT, 0% with preoperative RT, and 0% with postoperative RT (P < .0001). In the >1 mm group, LR was 10.2%, 0%, and 3.7% in the no preoperative and postoperative RT groups, respectively (P = .005). RT did not influence LR in patients with positive margins. In stage I-III and II-III patients, local recurrence-free survival was higher following RT (P = .008 and P = .05, respectively).

CONCLUSIONS

RT may play a larger role in minimizing LR than margin status. In patients with positive margins, RT may decrease LR to similar rates as a negative margin without RT and may be considered to decrease the risk of LR with anticipated close/positive margins.