Preoperative radiation, surgical margins, and local control of extremity sarcomas of soft tissues

Postoperative radiation boost does not improve local recurrence rates in extremity soft tissue sarcomas

INTRODUCTION

The standard of care for extremity soft tissue sarcomas continues to be negative-margin limb salvage surgery. Radiotherapy is frequently used as an adjunct to decrease local recurrence. No differences in survival have been found between preoperative and postoperative radiotherapy regimens. However, it is uncertain if the use of a postoperative boost in addition to preoperative radiotherapy reduces local recurrence rates.

METHODS

This retrospective review evaluated patients who received preoperative radiotherapy (n = 49) and patients who received preoperative radiotherapy with a postoperative boost (n = 45). The primary endpoint analysed was local recurrence, with distant metastasis and death due to sarcoma analysed as secondary endpoints. Wilcoxon rank-sum test and either χ(2) or Fisher's exact test were used to compare variables. Multivariable regression analyses were used to take into account potential confounders and identify variables that affected outcomes.

RESULTS

No differences in the proportion or rate of local recurrence, distant metastasis or death due to sarcoma were observed between the two groups (P > 0.05). The two groups were similarly matched with respect to demographics such as age, race and sex and tumour characteristics including excision status, tumour site, size, depth, grade, American Joint Committee on Cancer stage, chemotherapy receipt and histological subtype (P > 0.05). The postoperative boost group had a larger proportion of patients with positive microscopic margins (62% vs 10%; P < 0.001).

CONCLUSION

No differences in rates of local recurrence, distant metastasis or death due to sarcoma were found in patients who received both pre- and postoperative radiotherapy when compared with those who received only preoperative radiotherapy.

Neoadjuvant treatment with preoperative radiotherapy for extremity soft tissue sarcomas: long-term results from a single institution in Turkey

BACKGROUND

To assess the long term clinical outcome of preoperative radiotherapy with or without chemotherapy followed by limb sparing surgery in patients with non-metastatic soft tissue sarcomas (STS) of the extremities.

MATERIALS AND METHODS

Sixty patients with locally advanced STS were retrospectively analyzed. The median tumor diameter was 12 cm. All patients were treated with preoperative radiotherapy delivered with two different fractionation schedules (35Gy/10fr or 46-50Gy/23-25fr). Neoadjuvant chemotherapy was added to 44 patients with large and/or high grade tumors. Surgery was performed 2-6 weeks after radiotherapy. Chemotherapy was completed up to 6 courses after surgery in patients who had good responses.

RESULTS

Median follow-up time was 67 months (8-268 months). All of the patients had limb sparing surgery. The 5-year local control (LC), disease free (DFS) and overall survival (OSS) rates for all of the patients were 81%, 48.1% and 68.3% respectively. 5-year LC, DFS and cause specific survival (CSS) were 81.7%, 47%, 69.8%, and 80%, 60%, 60% in the chemoradiotherapy and radiotherapy groups, respectively. On univariate analysis, patients who were treated with hypofractionation experienced significantly superior LC, DFS and CSS rates with similar rates of late toxicity when compared with patients who were treated with conventional fractionation and statistical significance was retained on multivariate analysis.

CONCLUSIONS

Treatment results are consistent with the literature. As neoadjuvant chemoradiotherapy provides effective LC and CSS with acceptable morbidity, it should be preferred for patients with large and borderline resectable STS.

Long-term outcome after local recurrence of soft tissue sarcoma: a retrospective analysis of factors predictive of survival in 135 patients with locally recurrent soft tissue sarcoma

BACKGROUND

The aim of this study was to identify prognostic indicators of survival in patients with locally recurrent soft tissue sarcoma (STS) through a long-term follow-up.

METHODS

We retrospectively assessed the relationship between post-recurrence survival (PRS) and potential prognostic factors in 135 patients who had experienced local recurrence, which was suitable for further surgical treatment. The median follow-up time after initial recurrence was 12.3 years (95% confidence interval (CI): 10.4-14.2 years).

RESULTS

The 5-year estimate of the PRS rate was 53.1% (95% CI: 44.3-61.2%) for the entire series. Patients with negative margins after the final surgery experienced improved survival compared with patients with positive margins (5-year survival: 46.7% (35.2-57.5%) vs 35.5% (23.4-47.8%); P=0.01). In a multivariate analysis, the significant prognostic indicators for PRS were histologic grade, tumour site, time to initial recurrence, the number of recurrences and the surgical margin status attained at the last resection.

CONCLUSIONS

Complete surgical resection with microscopically clear margins is desirable in patients with locally recurrent STS. However, when achieving clear surgical margins will require major functional impairment of the extremity, a radical surgical approach should be weighed for the patient in each case.

Surgical procedures and prognostic factors for local recurrence of soft tissue sarcomas

BACKGROUND

Patients with local recurrence of soft tissue sarcomas are predisposed to future recurrences because treatment is challenging and complicated by prior therapy. This study investigated clinical outcomes following surgical procedures for locally recurrent soft tissue sarcomas and risk factors for re-recurrence and metastasis.

METHODS

A retrospective analysis was conducted with 105 patients (52 males, 53 females) who underwent surgical procedures for local recurrence without distant metastasis of soft tissue sarcoma between 1987 and 2009. Patient follow-up ranged from 1 to 12 years (mean 4.9 years).

RESULTS

Overall 5- and 10-year survival rates were 83.4 and 67.7%, respectively. Twenty-one patients (20.0%) had additional local recurrences, and 23 (21.9%) had distant metastases. Amputation rate was 10.5% at the time of surgical procedures and 17.1% at final follow-up. Locations deep within muscles in the upper limb or trunk and surgical margins <1 cm wide were risk factors for further local recurrence. Locations deep within muscles, tumor sizes >10 cm, high-grade malignancy, and local recurrence after radical surgery were risk factors for distant metastasis.

CONCLUSIONS

Surgical margin and location were independent prognostic factors for local control, and a wider margin was especially important for recurrent tumors located in the trunk and upper extremity. For high-grade sarcomas with local recurrence after radical surgery, new approaches are needed to prevent distant metastases.

Does postoperative infection after soft tissue sarcoma resection affect oncologic outcomes?

BACKGROUND AND OBJECTIVES

Prior studies have demonstrated postoperative infection may confer a survival benefit after osteosarcoma resection. Our aim was to determine whether infection after soft tissue sarcoma resection has similar effects on metastasis, recurrence and survival.

METHODS

A retrospective review was conducted; 396 patients treated surgically for a soft tissue sarcoma between 2000 and 2008 were identified. Relevant oncologic data were collected. Fifty-six patients with a postoperative infection were compared with 340 patients without infection. Hazard ratios and overall cumulative risk were evaluated.

RESULTS

There was no difference in survival, local recurrence or metastasis between patients with or without a postoperative infection. Patients were evenly matched for age at diagnosis, gender, smoking status, and diabetes status. Tumor characteristics did not differ between groups in tumor size, location, depth, grade, margin status, stage, and histologic subtype. There was no difference in utilization of chemotherapy or radiation therapy between groups. From our competing risk model, only positive margin status significantly impacted the risk of local recurrence. An increase in tumor size corresponded to an increased risk of metastasis and death.

CONCLUSIONS

Postoperative infection neither conferred a protective effect, nor increased the risk of adverse oncologic outcomes after soft tissue sarcoma resection.

Neoadjuvant treatment of soft tissue sarcoma

PURPOSE

The aim of this study was to evaluate disease-free survival (DFS), overall survival and toxicity of patients who underwent preoperative therapy for soft tissue sarcoma.

MATERIALS AND METHODS

The data of 38 consecutive patients affected by soft tissue sarcoma were retrospectively analysed. Six (15.8 %) patients were treated only with neoadjuvant radiotherapy, and 32 (84.2 %) with neoadjuvant chemo-radiation therapy. Surgery was performed within 4-6 weeks after the completion of neoadjuvant treatment.

RESULTS

Median follow-up was 4.9 years (range 1-13.7 years). All patients received preoperative external beam radiotherapy (RT). Most patients (84.2 %) underwent neoadjuvant chemotherapy treatment associated with radiotherapy. After neoadjuvant treatment, the majority of patients underwent wide excision (32 out of 38) and five patients had marginal surgery; only one patient underwent amputation. Local recurrence was observed in only two patients (5.2 %). Fourteen (36.8 %) patients experienced metastatic relapse. At the time of our analysis 13 patients (34.2 %) had died due to metastatic spread of the disease. In our series, DFS in relation to distant metastases (DM) showed a significant result for lower limb involvement (p = 0.038) and marginal excision (p = 0.024), both predictors of a worse DFS, histology was statistically significant although it was not possible to evaluate the risk for specific histology due to the small number of events in the different subtypes.

CONCLUSIONS

The results obtained from our study are encouraging with regard to the feasibility and efficacy of preoperative RT in the treatment of soft tissue sarcoma in view of the results obtained in terms of local control, limb sparing and safety.

A non-comparative phase II study of dose intensive chemotherapy with doxorubicin and ifosfamide followed by high dose ICE consolidation with PBSCT in non-resectable, high grade, adult type soft tissue sarcomas

The objective was to determine the role of dose intensive induction chemotherapy in patients with soft tissue sarcomas (STS) that were considered unresectable. Treatment consisted of 2-3 cycles of doxorubicin (Dox) and ifosfamide (Ifo) followed by high dose chemotherapy with ifosfamide, carboplatin, etoposide (HD-ICE) plus peripheral blood stem cell transplantation (PBSCT). 30 out of 631 consecutive patients, median age 46 years (21-62), with high grade STS were included. 29 patients completed at least 2 cycles of Dox/Ifo. HD-ICE was withheld because of progressive disease (PD) in 5 patients, neurotoxicity in 6 cases, insufficient peripheral blood stem cell (PBSC) mobilization, complete remission (CR) and refusal in 1 patient each. HD-ICE was associated with non-haematological grade III toxicity including emesis, mucositis, fever, neurotoxicity, and transaminase level elevation. Two additional patients attained a partial response after HD-ICE. Overall, 24 of 30 (80%) patients underwent surgery, with complete tumor resections in 19 patients (63% of all patients, 79% of the operated subgroup); however, 2 of these required amputation. After a median follow up period of 50 months in surviving patients (range, 26-120), 5-year PFS and OS rates were 39% and 48%, respectively. Induction chemotherapy plus consolidation HD-ICE is generally feasible, but is associated with significant neurotoxicity. The advantage of HD-ICE over conventional dose chemotherapy plus external beam radiation therapy (EBRT) in non-resectable disease remains unproven.

Head and neck sarcomas: a comprehensive cancer center experience

Head/neck sarcomas are rare, accounting for about 1% of head/neck malignancies and 5% of sarcomas. Outcomes have historically been worse in this group, due to anatomic constraints leading to difficulty in completely excising tumors, with high rates of local recurrence. We retrospectively analyzed cases of head/neck soft tissue sarcomas (STS) and osteogenic sarcomas managed in a multi-disciplinary setting at Fox Chase Cancer Center from 1999–2009 to describe clinicopathologic characteristics, treatment, outcomes, and prognostic factors for disease control and survival. Thirty patients with STS and seven patients with osteogenic sarcoma were identified. Most STS were high grade (23) and almost all were localized at presentation (28). Common histologies were synovial cell (6), rhabdomyosarcoma (5), angiosarcoma (4), liposarcoma (4) and leiomyosarcoma (3). The type of primary therapy and disease outcomes were analyzed. Cox proportional hazards regression analysis was performed to identify predictors of disease-free survival (DFS) and overall survival (OS). The HR and 95% CI for Cox model and median DFS/OS analyzed by Kaplan-Meier curves were calculated.

Quantitative Segmentation of Fluorescence Microscopy Images of Heterogeneous Tissue: Application to the Detection of Residual Disease in Tumor Margins

Purpose

To develop a robust tool for quantitative in situ pathology that allows visualization of heterogeneous tissue morphology and segmentation and quantification of image features.

Materials and Methods

Tissue excised from a genetically engineered mouse model of sarcoma was imaged using a subcellular resolution microendoscope after topical application of a fluorescent anatomical contrast agent: acriflavine. An algorithm based on sparse component analysis (SCA) and the circle transform (CT) was developed for image segmentation and quantification of distinct tissue types. The accuracy of our approach was quantified through simulations of tumor and muscle images. Specifically, tumor, muscle, and tumor+muscle tissue images were simulated because these tissue types were most commonly observed in sarcoma margins. Simulations were based on tissue characteristics observed in pathology slides. The potential clinical utility of our approach was evaluated by imaging excised margins and the tumor bed in a cohort of mice after surgical resection of sarcoma.

Results

Simulation experiments revealed that SCA+CT achieved the lowest errors for larger nuclear sizes and for higher contrast ratios (nuclei intensity/background intensity). For imaging of tumor margins, SCA+CT effectively isolated nuclei from tumor, muscle, adipose, and tumor+muscle tissue types. Differences in density were correctly identified with SCA+CT in a cohort of ex vivo and in vivo images, thus illustrating the diagnostic potential of our approach.

Conclusion

The combination of a subcellular-resolution microendoscope, acriflavine staining, and SCA+CT can be used to accurately isolate nuclei and quantify their density in anatomical images of heterogeneous tissue.

Surgical margins and handling of soft-tissue sarcoma in extremities: a clinical practice guideline

QUESTIONS

In limb salvage surgery for extremity soft-tissue sarcoma (sts), what is an adequate surgical margin?What is the appropriate number of samples to take from the margins of a surgical resection specimen?What is the appropriate handling of surgical resection specimens?

BACKGROUND

Surgery is the primary treatment for extremity sts. The combination of radiotherapy with surgery allows for limb salvage by using radiation to biologically "sterilize" microscopic extensions of tumour and to spare neurovascular and osseous structures. Adjuvant chemotherapy in sts-except for rhabdomyosarcoma and Ewing sarcoma-continues to be controversial.

METHODS

The medline and embase databases (1975 to June 2011) and the Cochrane Library were searched for pertinent studies. The Web sites of the main guideline organizations and the American Society of Clinical Oncology conference proceedings (2007-2010) were also searched.

RESULTS AND CONCLUSIONS

Thirty-three papers, including four guidelines, one protocol, and one abstract, were eligible for inclusion. The data suggest that patients with clear margins have a better prognosis, but no prospective studies have indicated how wide margins should be. In limb-salvage surgery for extremity sts, the procedure should be planned to achieve a clear margin. However, to preserve functionality, surgery may result in a very close (<1 cm) or even microscopically positive margin. In this circumstance, the use of preoperative or postoperative radiation should be considered. No studies described the optimal number of tissue sections required to assess adequacy of excision nor the appropriate handling of surgical resection specimens. The Sarcoma Disease Site Group made its recommendations based on expert opinion and consensus.

Planned preservation surgery for soft tissue sarcomas adjacent to critical structures

BACKGROUND

Whether to preserve or sacrifice critical structures (bone, major vessels and major nerves) adjacent to soft tissue sarcomas is still controversial. Referring to characteristic imaging and intraoperative findings, we perform planned preservation surgery for these critical structures. The aim of this study was to investigate the clinical outcome of soft tissue sarcomas adjacent to critical structures and to validate this procedure.

METHODS

Of 202 cases of soft tissue sarcomas surgically treated at our department of orthopedic surgery from 2004 to 2010, 57 cases (28 %) whose tumors were adjacent to the critical structures were studied. There were 36 men and 21 women. In 32 cases critical structures were preserved, and in 25 resected together with the tumor. The oncological outcome and histological surgical margin were analyzed.

RESULTS

The overall survival and local recurrence-free survival rates at 5 years were 75.9 and 83.2 %. In 26 of the 32 (81 %) preserved cases histologically the surgical margin was negative, and in 17 (53 %) radiotherapy could be avoided. Neither overall survival (p = 0.9669) nor local recurrence-free survival (p = 0.7819) differed significantly between two groups.

CONCLUSIONS

When soft tissue sarcomas are located adjacent to bone or major vessels, by meticulously detaching the periosteum or neurovascular sheath referring to characteristic imaging and intraoperative findings, a histologically negative surgical margin can be achieved in the majority, allowing avoidance of postoperative radiotherapy. Planned preservation surgery provided no significant adverse effect on survival or local recurrence rates, validating this procedure.

Prognostic variables in patients with primary soft tissue sarcoma of the extremity and trunk treated with neoadjuvant radiotherapy or neoadjuvant sequential chemoradiotherapy

BACKGROUND

Neoadjuvant radiotherapy (NRT) is an effective strategy to treat soft tissue sarcomas (STS). However, the role of neoadjuvant chemoradiotherapy (NCRT) remains to be determined.

METHODS

From May 1999 to July 2010, 112 patients with localized STS of the extremity and trunk who were treated with NRT or NCRT followed by surgery were retrospectively reviewed. Clinical outcomes including overall survival (OS), disease-free survival (DFS), and distant metastasis free survival (DMFS) were calculated using Kaplan-Meier survival analyses. Prognostic variables were determined by univariate (UVA) and multivariate analyses (MVA).

RESULTS

Median follow-up was 37 months. Median RT dose was 50 Gy. Forty-nine patients received NCRT. Overall limb-preservation rate was 99% and local control was 97%. The estimated 3-year OS, DFS, and DMFS were 86%, 68%, and 72%, respectively. Age was the only variable to predict for OS, DFS and DMFS on UVA. Age ≥ 70 predicted for poor OS, stage III disease predicted for poor DFS and DMFS, and the addition of chemotherapy predicted for improved DMFS on MVA.

CONCLUSIONS

Excellent rates of local control and limb-preservation were observed in patients with primary STS treated with neoadjuvant therapy followed by surgery. Neoadjuvant sequential chemotherapy followed by radiotherapy may be considered for young patients with stage III STS.

A novel imaging system permits real-time in vivo tumor bed assessment after resection of naturally occurring sarcomas in dogs

BACKGROUND

Treatment of soft tissue sarcoma (STS) includes complete tumor excision. However, in some patients, residual sarcoma cells remain in the tumor bed. We previously described a novel hand-held imaging device prototype that uses molecular imaging to detect microscopic residual cancer in mice during surgery.

QUESTIONS/PURPOSES

To test this device in a clinical trial of dogs with naturally occurring sarcomas, we asked: (1) Are any adverse clinical or laboratory effects observed after intravenous administration of the fluorescent probes? (2) Do canine sarcomas exhibit fluorescence after administration of the cathepsin-activated probe? (3) Is the tumor-to-background ratio sufficient to distinguish tumor from tumor bed? And (4) can residual fluorescence be detected in the tumor bed during surgery and does this correlate with a positive margin?

METHODS

We studied nine dogs undergoing treatment for 10 STS or mast cell tumors. Dogs received an intravenous injection of VM249, a fluorescent probe that becomes optically active in the presence of cathepsin proteases. After injection, tumors were removed by wide resection. The tumor bed was imaged using the novel imaging device to search for residual fluorescence. We determined correlations between tissue fluorescence and histopathology, cathepsin protease expression, and development of recurrent disease. Minimum followup was 9 months (mean, 12 months; range, 9-15 months).

RESULTS

Fluorescence was apparent from all 10 tumors and ranged from 3 × 10(7) to 1 × 10(9) counts/millisecond/cm(2). During intraoperative imaging, normal skeletal muscle showed no residual fluorescence. Histopathologic assessment of surgical margins correlated with intraoperative imaging in nine of 10 cases; in the other case, there was no residual fluorescence, but tumor was found at the margin on histologic examination. No animals had recurrent disease at 9 to 15 months.

CONCLUSIONS

These initial findings suggest this imaging system might be useful to intraoperatively detect residual tumor after wide resections.

CLINICAL RELEVANCE

The ability to assess the tumor bed intraoperatively for residual disease has the potential to improve local control.

Prognostic factors of extremity soft tissue sarcoma in adults. A single institutional analysis

PURPOSE

To analyse the prognostic factors for patients treated with limb sparing surgery and radiation for extremity soft tissue sarcoma (E-STS).

PATIENTS AND METHODS

Medical records of 87 patients with limb sparing surgery and radiation for E-STS were reviewed retrospectively. Disease-free survival (DFS) and disease-specific survival (DSS) were estimated and factors potentially influencing these outcomes were analysed.

RESULTS

With a mean follow-up of 69months, most recurrences occurred within the first 2years. Extent of resection margin was found to improve DFS (P=0.002) and DSS (P=0.002). Brachytherapy combined with external beam radiotherapy (EBRT) improved DFS (P=0.034) and DSS (P=0.019). Tumor size (<10cm) was related to DSS (P=0.043) and its relation to DFS was almost significant (P=0.057). Short time interval between surgery and radiotherapy (≤50days) had an impact only on DSS (P=0.030).

CONCLUSION

Extent of resection margin and use of brachytherapy combined with EBRT seem to improve the prognosis of E-STS. Small tumor size and short time interval between radiotherapy and surgery seem also to improve the outcome of E-STS. This study was limited by inadequate power and low number of recurrences. Larger randomised studies are needed to confirm these results.

Neoadjuvant chemoradiotherapy for patients with high-risk extremity and truncal sarcomas: a 10-year single institution retrospective study

BACKGROUND

Patients with large, high-grade extremity and truncal soft tissue sarcomas (STS) are at considerable risk for recurrence. A regimen of pre-operative chemotherapy consisting of mesna, adriamycin, ifosfamide and dacarbazine (MAID), interdigitated with radiotherapy (RT), followed by resection and post-operative chemotherapy with or without RT, has demonstrated high rates of local and distant control. The goal of this study is to assess outcomes in a recent cohort of patients treated on this regimen.

METHODS

We retrospectively reviewed records of 66 consecutive patients with STS of the extremity or trunk who were treated with the aforementioned regimen from May 2000 to April 2011. Clinicopathologic characteristics and patient outcomes were analysed.

RESULTS

Sixty-six patients were analysed and were equally divided between grade 2 and 3 tumours. Margins were negative in 57 (89%) patients and positive in seven (11%) patients. At a median follow-up of 46 months, there were six (9%) locoregional and 20 (30%) distant recurrences. The locoregional and distant 5-year recurrence-free survival (RFS) rates were 91% and 64%, respectively. The 5-year overall (OS) and disease-specific survival rates were 86% and 89%, respectively. There were no treatment-related deaths or secondary myelodysplasias. Thirty-four (52%) patients had grade 3 or 4 acute haematologic chemotherapy-related toxicity. There were no statistically significant predictors of OS or RFS.

CONCLUSIONS

For a contemporary cohort of patients with high-risk extremity and truncal STS, a regimen of neoadjuvant chemoradiotherapy and surgery continues to result in high rates of survival with tolerable short- and long-term toxicity.

Critical study of resection margins in adult soft-tissue sarcoma surgery

INTRODUCTION

Resection margins constitute a recognized risk factor for local recurrence, but their impact on survival is less clear.

HYPOTHESIS

Infiltrative proliferation and satellite nodules are prognostic factors for local and systemic aggressiveness.

TYPE OF STUDY

Retrospective cohort study.

PATIENTS AND METHODS

In 105 patients under curative treatment, resection quality was assessed on UICC criteria (R0/R1) and on a modified version (R0M/R1M) taking account of proliferation contours and satellite nodules for narrow margins (<1mm). Uni- and multi-variate analysis was performed, and Kaplan-Meier survival curves were compared on log-rank.

RESULTS

Mean 5-year local recurrence-free survival (LRFS) was 0.64 [0.52-0.76] after R1 surgery, 0.9 [0.85-0.95] after R0, 0.64 [0.519-0.751] after R1M and 0.92 [0.87-0.96] after R0M. Resection type according to R classification correlated with disease-free survival (DFS) (P=0.028), but not with metastasis-free survival (MFS) (P=0.156). Resection type according to RM classification correlated with DFS and MFS. Multivariate analysis disclosed correlations between LRFS rate and RM resection type (HR 6.77 [1.78-25.7], P=0.005), DFS rate and RM resection type (HR 2.83 [1.47-5.43], P=0.001) and grade (HR=3.17 [1.38-7.27], P=0.003), and MFS and grade (HR=3.96 [1.50-10.5], P=0.006).

DISCUSSION

The microscopic aspect of the proliferation contours and presence of satellite nodules were confirmed as prognostic factors for local and systemic aggressiveness. They impact both disease-free survival and metastasis-free survival in case of margins less than 1mm. Their systematic consideration may help identify patients with elevated systemic risk.

LEVEL OF EVIDENCE

IV.

Risk factors for local recurrence and metastasis in soft tissue sarcomas of the extremity

OBJECTIVES

We reviewed our institution's experience in treating soft tissue sarcomas of the extremity to identify factors associated with local recurrence, metastasis, and overall survival, to identify patients who may benefit from intensification of therapy.

METHODS

A retrospective analysis was performed for patients who underwent both limb-sparing surgery and external beam radiotherapy for extremity sarcoma. Those who had gross residual disease or who presented with recurrent or metastatic disease were excluded. The Kaplan-Meier product limit and multivariate Cox regression were used to estimate local failure-free probability, distant failure-free probability, and overall survival along with associations with patient, tumor, and treatment characteristics.

RESULTS

One hundred eighty-eight patients were included in the analysis. Twenty-five (13%) and 46 (24%) experienced local and distant recurrence, respectively. Patients with high/intermediate-grade tumors [hazard ratio (HR)=5.63, 95% confidence interval (CI): 1.27-24.89, P=0.023] or with multifocally positive margins (HR=4.27, 95% CI: 1.20-15.24, P=0.026) were more likely to fail locally. Those with a preceding local recurrence (HR=8.58, 95% CI: 3.87-19.04, P<0.0001), high/intermediate-grade tumors (HR=5.68, 95% CI: 1.28-25.25, P=0.023), or no secondary reexcision (HR=2.5, 95% CI: 1.09-5.74, P=0.031) were more likely to develop metastasis. Patients with local recurrence (HR=3.6, 95% CI: 1.77-7.29, P<0.001), metastasis (HR=16.0, 95% CI: 7.93-32.31, P<0.0001), or without secondary reexcision (HR=3.2, 95% CI: 1.27-8.09, P=0.014) had decreased overall survival.

CONCLUSIONS

Patients whose tumor grade or margin status put them at high risk for local failure should be considered for intensification of therapy. Those with a local recurrence should be considered for increased surveillance or systemic therapy, as local failure is associated with subsequent metastasis and decreased survival.

Intraoperative detection and removal of microscopic residual sarcoma using wide-field imaging

BACKGROUND: The goal of limb-sparing surgery for a soft tissue sarcoma of the extremity is to remove all malignant cells while preserving limb function. After initial surgery, microscopic residual disease in the tumor bed will cause a local recurrence in approximately 33% of patients with sarcoma. To help identify these patients, the authors developed an in vivo imaging system to investigate the suitability of molecular imaging for intraoperative visualization. METHODS: A primary mouse model of soft tissue sarcoma and a wide field-of-view imaging device were used to investigate a series of exogenously administered, near-infrared (NIR) fluorescent probes activated by cathepsin proteases for real-time intraoperative imaging. RESULTS: The authors demonstrated that exogenously administered cathepsin-activated probes can be used for image-guided surgery to identify microscopic residual NIR fluorescence in the tumor beds of mice. The presence of residual NIR fluorescence was correlated with microscopic residual sarcoma and local recurrence. The removal of residual NIR fluorescence improved local control. CONCLUSIONS: The authors concluded that their technique has the potential to be used for intraoperative image-guided surgery to identify microscopic residual disease in patients with cancer. Cancer 2012. © 2012 American Cancer Society.

Extremity soft tissue sarcoma resections: how wide do you need to be?

BACKGROUND

Sarcomas require a wide margin of resection including a cuff of normal tissue to minimize the risk of local recurrence. The amount of tissue that constitutes a wide margin is unclear in the literature.

QUESTIONS/PURPOSES

We therefore determined whether a close resection margin for soft tissue sarcoma resulted in an increased incidence of locally recurrent disease and whether additional factors, including radiation therapy, outside biopsies, and tumor biology, affected the risk of local recurrence.

METHODS

We retrospectively reviewed 117 patients with soft tissue sarcomas resected with negative margins from 2001 to 2007. Gross specimens were inked and the closest macroscopic margins were sent for microscopic examination. Resection margins were categorized as less than 1 mm, 1-5 mm, or greater than 5 mm. We evaluated additional factors that might influence local recurrence, including radiation therapy, outside biopsies, sarcoma type, grade, and stage at presentation, and development of metastatic disease.

RESULTS

Four of 117 patients (3.4%) developed local recurrence. The incidence of local recurrence was similar in patients with less than 1-mm margins and greater than 1-mm margins: two of 45 patients (4.4%) and two of 64 patients (3.1%), respectively. Due to the low number of local recurrences, quantitative margin extent and the other factors evaluated did not affect local recurrence.

CONCLUSIONS

The extent of a margin necessary to prevent local recurrence of soft tissue sarcoma remains unclear as the power of our study was limited by the low number of local recurrences. Relatively low local recurrence rates can be achieved even with close margins.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Long-term follow-up of patients treated with neoadjuvant chemotherapy and radiotherapy for large, extremity soft tissue sarcomas

BACKGROUND

Patients with large, high-grade, extremity soft tissue sarcomas (STS) are at significant risk for distant recurrence and death. A regimen of preoperative chemotherapy consisting of mesna, Adriamycin (doxorubicin), ifosfamide, and dacarbazine (MAID), interdigitated with radiotherapy (RT) and followed by resection and postoperative chemotherapy with or without RT, has demonstrated high rates of local and distant control. We report the long-term follow-up data on 48 patients treated with this regimen compared to an historical matched-control patient population.

METHODS

Adult patients with high-grade extremity STS ≥ 8 cm were treated with 3 cycles of preoperative chemotherapy combined with 44 Gy of RT followed by surgery. Three cycles of postoperative MAID were planned. For patients with positive surgical margins, 16 Gy of RT was delivered postoperatively.

RESULTS

Patients received the MAID/RT regimen from 1989 through 1999. After a median follow-up of 9.3 years in surviving patients in the MAID group and 13.2 years in surviving patients in the control group, the 7-year disease-specific and overall survival rates were 81% and 50% (P = .004) and 79% and 45% (P = .003) for the MAID and control patients, respectively. Five of 11 patients in the MAID group and 7 of 25 control patients died of sarcoma ≥5 years after treatment. One patient in the MAID group developed a fatal myelodysplasia at 53 months.

CONCLUSIONS

For patients with high-risk, extremity STS, the significant survival benefits conferred by an intense regimen of neoadjuvant chemoradiotherapy and surgery are sustained even with long-term follow-up.

The significance of a marginal excision after preoperative radiation therapy for soft tissue sarcoma of the extremity

BACKGROUND

Marginal excision of soft tissue sarcoma (STS), defined as resection through the tumor pseudocapsule or surrounding reactive tissue, increases the likelihood of local recurrence and necessitates re-excision or postoperative radiation. However, its impact after preoperative radiation therapy (RT) remains unclear. This study therefore investigated the significance of marginal margins in patients treated with preoperative RT for extremity STS, reporting long-term local control and limb preservation endpoints.

METHODS

The records of 317 adults at the University of Florida with nonmetastatic extremity STS treated from 1980 to 2008 with preoperative RT as part of a limb conservation strategy were reviewed. The median follow-up was 4.7 years (8.3 years for living patients). The median tumor size was 10 cm (range, 2-36 cm), and 86% were high grade. The median RT dose was 50.4 Gy (range, 12.5-57.6 Gy). Margins were classified as wide/radical (n = 105), marginal (n = 179), contaminated (n = 15), positive (n = 17), or unknown (n = 1). Endpoints were local control (LC), amputation-free survival (AFS), cause-specific survival (CSS), and overall survival (OS).

RESULTS

Five-year CSS and OS rates were 62% and 59%, respectively. Five-year LC and AFS was 93% and 89%, respectively. AFS by margin status was 64%, 83%, 97%, and 92% for positive, contaminated, marginal, and wide/radical margins, respectively (P<.005). Marginal excision following preoperative RT resulted in equivalent LC and AFS compared with wide/radical margins.

CONCLUSIONS

Marginal resection after preoperative RT does not compromise LC or AFS in extremity STS. This finding may be related to radiosterilization of tumor cells within the reactive zone following preoperative RT.

Reconstructive treatment of soft tissue sarcoma of the upper extremity

Limb-sparing surgery is currently the cornerstone of treatment for most patients with soft-tissue sarcoma of the upper extremity. To achieve the best outcome, the reconstructive surgeon must be part of a multidisciplinary team and is required to have a thorough understanding of the whole treatment concept. This article provides an update for the current surgical management of patients with soft tissue sarcoma of the upper extremity. Relevant nonsurgical aspects are also highlighted.

Multidisciplinary management of soft tissue sarcomas

Musculoskeletal sarcomas are a heterogeneous group of malignant neoplasms derived from connective tissue. Sarcomas represent about 1% of cancer in adults. The annual incidence in adults in Europe is around 14,000 new cases of soft tissue sarcomas (STS) and 4,800 new cases of bone sarcomas. Musculoskeletal tumours arise anywhere in the body, although lower extremities are the most common site of appearance, followed by upper extremities, trunk, retroperitoneum and head and neck area. Adequate management of STS is a stimulating challenge for oncologists. The aim of treatment should be focused on four main aspects: improving survival, avoiding local recurrence, maximising organ function and, finally, minimising morbidity. Surgery, radiotherapy and, sometimes though increasingly, chemotherapy are the pillars on which rests the modern treatment of sarcomas. The optimal management of musculoskeletal tumour requires a multidisciplinary integration of these different approaches in treatment planning right from the initial diagnoses. Referring patients to qualified centres should be desirable to achieve the maximum probability of control and even cure for STS.

Recurrence patterns and survival for patients with intermediate- and high-grade myxofibrosarcoma

PURPOSE

Myxofibrosarcoma (MFS) is a rare sarcoma with a predilection for multiple local recurrences (LR), for which optimal treatment has not been defined. We reviewed our experience to determine the impact of surgery and radiation therapy (RT) on pattern of recurrence, limb salvage, and overall survival (OS).

METHODS AND MATERIALS

Between 1995 and 2005, 36 patients with localized intermediate- or high-grade MFS were treated at our institution. Data on clinicopathologic features, treatments, and patient outcomes were reviewed and analyzed.

RESULTS

Median age was 72.5 years (range, 42-96 years). Median tumor size was 7.5 cm, and 34 tumors (94%) were high grade. All patients underwent surgery at our institution, including re-resections in 20 patients (56%) after initial surgery elsewhere. Margins were microscopically positive in 9 patients (25%). RT was given to 28 patients (78%) pre - and/or postoperatively. After a median follow-up of 3.5 years (range, 0.4-12.4 years), 11 patients (31%) developed LR. There were no significant predictors for LR on univariate analysis, including margin status or use of RT. Limb salvage was ultimately achieved in only 5 of 11 LRs (45%) because of multiple subsequent LRs. Distant recurrence (DR) occurred in 6 patients (17%). Median and 4-year OS were 96 months and 65%, respectively. Seven patients (19%) died of tumor-related causes, 6 of whom had DRs. On univariate analysis, tumor size was associated with OS.

CONCLUSIONS

Despite aggressive surgery and RT, intermediate- and high-grade MFS are associated with a high rate of LR that adversely affects limb preservation. More aggressive local treatment strategies are necessary.

The significance of size change of soft tissue sarcoma during preoperative radiotherapy

AIM

To assess the significance of change in tumour size during preoperative radiotherapy in patients with soft tissue sarcoma (STS).

METHODS

A retrospective review of 91 cases with STS was performed. Inclusion criteria were localised extremity and truncal STS with measurable disease, older than 18 years, treated with preoperative radiotherapy and wide local excision, in the period between January 1966 and December 2005. Patients with head and neck STS, or who received neoadjuvant chemotherapy were excluded. A difference in excess of 10% of the greatest tumour diameter of the pre-radiotherapy and the post-radiotherapy MRI scans was considered as change in tumour size.

RESULTS

Increase in tumour size was noted in 28 patients (31%) (Group 1). No change or decrease in size was observed in 63 patients (Group 2). There were no significance differences in local control or overall survival rates between the 2 groups. The estimated overall actuarial local recurrence free, event-free and overall survival rates were 90.5%, 64.4%, 62.9% in Group 1, and 85.7%, 60.8%, 68.9% in Group 2 respectively.

CONCLUSION

Increase in tumour size during preoperative radiotherapy for soft tissue sarcoma does not seem to associate with inferior local tumour control or compromise survival. Lack of reduction in tumour size is not necessarily a sign of lack of response to preoperative radiotherapy.

Positive surgical margins in soft tissue sarcoma treated with preoperative radiation: is a postoperative boost necessary?

PURPOSE

For patients with an extremity soft tissue sarcoma (STS) treated with preoperative radiotherapy and surgically excised with positive margins, we retrospectively reviewed whether a postoperative radiation boost reduced the risk of local recurrence (LR).

METHODS AND MATERIALS

A total of 216 patients with positive margins after resection of an extremity STS treated between 1986 and 2003 were identified from our institution's prospectively collected database. Patient demographics, radiation therapy parameters including timing and dose, classification of positive margin status, reasons for not administering a postoperative boost, and oncologic outcome were collected and evaluated.

RESULTS

Of the 216 patients with a positive surgical margin, 52 patients were treated with preoperative radiation therapy alone (50 Gy), whereas 41 received preoperative radiation therapy plus a postoperative boost (80% received 16 Gy postoperatively for a total of 66 Gy). There was no difference in baseline tumor characteristics between the two groups. Six of 52 patients in the group receiving preoperative radiation alone developed a LR compared with 9 of 41 in the boost group. Five-year estimated LR-free survivals were 90.4% and 73.8%, respectively (p = 0.13).

CONCLUSIONS

We found that including the postoperative radiation boost after preoperative radiation and a margin-positive excision did not provide an advantage in preventing LR for patients treated with external beam radiotherapy. Given that higher radiation doses placed patients at greater risk for late complications such as fracture, fibrosis, edema, and joint stiffness, judicious avoidance of the postoperative boost while maintaining an equivalent rate of local control can reduce the risk of these difficult-to-treat morbidities.

[Surgical treatment of musculoskeletal soft tissue sarcomas]

Treatment of soft tissue sarcomas requires an individual plan which considers interdisciplinary recommendations and the various clinical situations. Anatomical region, histological grading and typing, and tumor size necessitate adjusted methods of reconstruction. The biopsy should be performed at the institution where the patient is treated. In general surgical resection of the tumor will be the treatment of choice. Adjuvant therapies are applied according to anatomical region and size and grading of the tumor. Surgery alone is recommended only in small (<5 cm), superficial, low-grade sarcomas. Sarcomas larger than 5 cm in diameter should be treated by surgery and radiotherapy, achieving excellent results, although in high-grade sarcomas more than 50% of patients still will experience metastatic disease. In case of locally recurrent disease, surgical revision with tumor-free resection margins followed by radiotherapy should be the aim. This applies even for patients who had had radiotherapy after the first excision. In this case brachytherapy is a good modality of tissue-sparing treatment.

Adjuvant electrochemotherapy in veterinary patients: a model for the planning of future therapies in humans

The treatment of soft tissue tumors needs the coordinated adoption of surgery with radiation therapy and eventually, chemotherapy. The radiation therapy (delivered with a linear accelerator) can be preoperative, intraoperative, or postoperative. In selected patients adjuvant brachytherapy can be adopted. The goal of these associations is to achieve tumor control while maximally preserving the normal tissues from side effects. Unfortunately, the occurrence of local and distant complications is still elevated. Electrochemotherapy is a novel technique that combines the administration of anticancer agents to the application of permeabilizing pulses in order to increase the uptake of antitumor molecules. While its use in humans is still confined to the treatment of cutaneous neoplasms or the palliation of skin tumor metastases, in veterinary oncology this approach is rapidly becoming a primary treatment. This review summarizes the recent progresses in preclinical oncology and their possible transfer to humans.

Local recurrence of deep-seated, high-grade, soft tissue sarcoma: 459 patients from the Scandinavian Sarcoma Group Register

This study was based on 459 adult patients with deep, high-grade, soft tissue sarcoma of extremities or trunk wall reported to the Scandinavian Sarcoma Group Register (1986-1993). All patients had their definitive surgery for primary tumor at a sarcoma center. The median follow-up was 7.5 (3-12) years. 204 patients are still alive. 68 patients had amputations and 391 underwent limb-sparing surgery. Among 183 patients with intralesional or marginal margins after limb-sparing surgery, 65% had postoperative radiotherapy and 9% of the 198 patients with wide margins. The local recurrence rate after limb-sparing surgery was 26%. The rate with an intralesional or marginal margin was 39% without postoperative radiotherapy versus 24% when radiotherapy was given. It was 25% after a wide margin, and no recurrences were noted among the 10 patients with a compartmental surgical margin. Among patients with a wide margin, a subset fulfilling criteria for a myectomy was defined. The local recurrence rate was 26% among these 62 and there was no advantage of myectomy over other wide margins. More radical surgical margins would improve the local recurrence rate, but this can hardly be achieved in center-operated patients without increasing the amputation rate. Instead, increased use of radiotherapy in all patients with inadequate margins, and to a larger extent in those with wide margins will improve local control.

Evaluating surgery quality in soft tissue sarcoma

To identify pertinent indicators for oncologic outcomes in assessing surgery in soft tissue sarcomas, only local recurrences are considered here. Functional outcomes and treatment morbidity, equally important end-points for evaluating surgery quality, are less frequently reported and are not taken into account in this review. Herein, we review recent publications reporting indicators of surgery quality in soft tissue sarcoma treatment. Local recurrence-free interval is the major end-point in evaluating the quality of surgery. Disease-free survival should not be used because the risk factors for metastases are different from those for local recurrence. Five-year local recurrence-free estimations for limb and trunk wall sarcoma should be below 20%, and best approach 10%. The risk of local recurrence depends on tumour biology (i.e. grade) and quality of surgery as defined by the quality of margins. Better than margin width as measured on the tumour specimen, margin quality determined consensually between surgeons and pathologists is the best indicator for local outcome. Quality of margin should be expressed according the UICC residual disease definitions (R0: in sano, R1: microscopic residual disease, R2: macroscopic residual disease). Other important indicators for surgery quality are treatment in specialised centres, a planned, organised surgery, and treatment within a multidisciplinary team. Soft tissue sarcoma should also be treated in specialised centres. Surgery quality depends on obtained margins that are determined best by close collaboration between the surgeon and the pathologist.

Standardized approach to the treatment of adult soft tissue sarcoma of the extremities

Soft tissue sarcomas are very rare tumors. Available data are based on only a few prospective randomized trials. Most studies are retrospective, reviewing the results of single institutions. Furthermore, universally accepted treatment protocols for adult patients are lacking. Several prognostic factors have been identified, including grading, tumor size and development of metastatic disease; however, the relevance of other important aspects in the treatment of patients with soft tissue sarcomas remains unknown or subject to controversy. The main issues concern: which surgical margin width is safe from an oncological perspective? Does local recurrence influence survival? Can systemic chemotherapy improve prognosis? Is radiotherapy necessary in every case? Should it be applied pre-, post- or intraoperatively? What is the value of assessing the response after neoadjuvant therapy? These topics are examined in this review.

Long-term outcomes in extremity soft tissue sarcoma after a pathologically negative re-resection and without radiotherapy

BACKGROUND

The purpose was to define the rate of local recurrence (LR) and identify prognostic factors for LR in patients with extremity soft-tissue sarcoma (STS) treated with limb-sparing surgery and a pathologically negative re-resection specimen without radiotherapy (RT).

METHODS

A review of the prospective sarcoma database identified 200 patients with primary, nonmetastatic, extremity STS treated with limb-sparing surgery between June 1982 and December 2002 who had a pathologically confirmed negative re-resection. None of the patients had adjuvant RT. Univariate and multivariate analyses were performed to determine clinicopathologic factors associated with LR.

RESULTS

With a median follow-up of 82 months the 5-year actuarial LR rate was 9%. Factors associated with higher LR rates on univariate and multivariate analysis were older age, stage III presentation, and histology. The 5-year LR rate was 5% for those<50 compared with 15% for those>or=50 (P=.001). For patients with stage III the LR rate was 26% versus 7% for those with stage I/II (P<.001). On multivariate analysis only age>or=50 (relative risk [RR] 3.3; P=.02) and stage III disease (RR 3.4; P=.01) remained significant predictors for LR. When the cohort of patients was divided into 3 groups based on the number of risk factors present, the 5-year LRs were as follows: no risk factors (stage I/II and<50 years old) 4%, 1 risk factor (stage III or>or=50) 12%, and 2 risk factors (stage III and>or=50) 31% (P<.01).

CONCLUSIONS

Patients with a pathologically negative re-excision represent a heterogeneous group. Whereas the overall rate of local recurrence at 5 years was 9% for the entire cohort, patients with older age and/or stage III disease had a higher rate of LR. Therefore, treatment decisions especially with regard to adjuvant RT should be individualized and not be based solely on the finding of a negative re-resection.

Results of limb-salvage surgery with vascular reconstruction for soft tissue sarcoma in the lower extremity: comparison between only arterial and arterovenous reconstruction

BACKGROUND

Reports on vascular reconstruction in conjunction with limb salvage techniques for soft tissue sarcomas in the lower extremity have been published. The aim of this study was to investigate the necessity for venous reconstruction by comparing the results of arterial reconstruction alone and those of arteriovenous reconstruction.

METHODS

Twenty-five (6.7%) of 373 patients underwent vascular resections for lower limb soft tissue sarcomas. Only arterial reconstruction was performed for 12 patients. Arteriovenous reconstruction was performed for 13 patients. The clinical results, complications, and postoperative function were compared between only arterial reconstruction group and arteriovenous reconstruction group.

RESULTS

Limb salvage was achieved in 92% of all cases. No local recurrence has been observed. Nineteen patients (76%) are continuously free of disease. Histopathologic examination of the specimens showed that blood vessels had been infiltrated in 24%. The mean Musculoskeletal Tumor Society score was 70%. There were no significant differences in complication rate and postoperative function between two groups.

CONCLUSIONS

Wide resection with vascular reconstruction for patients of soft tissue sarcomas involving major vessels in the lower limb provide long term local control and limb salvage. This study could not indicate the usefulness of additional venous reconstruction after vascular resection in the lower extremity.

Sarcoma

Sarcomas comprise a heterogeneous group of mesenchymal neoplasms. They can be grouped into 2 general categories, soft tissue sarcoma and primary bone sarcoma, which have different staging and treatment approaches. This review includes a discussion of both soft tissue sarcomas (malignant fibrous histiocytoma, liposarcoma, leiomyosarcoma, synovial sarcoma, dermatofibrosarcoma protuberans, angiosarcoma, Kaposi sarcoma, gastrointestinal stromal tumor, aggressive fibromatosis or desmoid tumor, rhabdomyosarcoma, and primary alveolar soft-part sarcoma) and primary bone sarcomas (osteosarcoma, Ewing sarcoma, giant cell tumor, and chondrosarcoma). The 3 most important prognostic variables are grade, size, and location of the primary tumor. The approach to a patient with a sarcoma begins with a biopsy that obtains adequate tissue for diagnosis without interfering with subsequent optimal definitive surgery. Subsequent treatment depends on the specific type of sarcoma. Because sarcomas are relatively uncommon yet comprise a wide variety of different entities, evaluation by oncology teams who have expertise in the field is recommended. Treatment and follow-up guidelines have been published by the National Comprehensive Cancer Network (www.nccn.org).

Clinical significance of margin status in postoperative radiotherapy for extremity and truncal soft-tissue sarcoma

PURPOSE

To evaluate whether adjuvant radiotherapy (RT) in extremity and truncal soft-tissue sarcoma (STS) patients with microscopically positive or close margins after excision can achieve comparable local control to that of excision with negative margin plus RT.

METHODS AND MATERIALS

A total of 150 patients (111 extremity and 39 trunk cases) treated with conserving surgery and adjuvant RT was analyzed. All surgical margins were classified as being a negative margin or a positive or close margin based on pathologic margin width. RT was delivered with a shrinking-field technique in 150 patients (median, 63 Gy).

RESULTS

All patients were divided into two groups: (A) excision with negative margins plus RT (n = 56) and (B) excision with positive or close margins plus RT (n = 94). Overall, the 5-year local failure-free survival in all patients was 72.9%, and no significant differences were found between the two groups (Group A, 74.7%; Group B, 71.6%). High tumor grade was found to be a significant predictor of local failure. However, Group A was superior to Group B in distant metastasis-free survival (p = 0.02). No significant differences were shown in overall survival between the two groups.

CONCLUSIONS

In our series, margin status did not predict for LF when adjuvant RT was used. We believe that when adjuvant RT is used, re-resection may not be necessary for selected patients with positive or close pathologic margins in the management of extremity and truncal STS patients.

[Soft tissue carcinoma. Epidemiology, diagnostics and therapy]

The treatment of soft tissue sarcoma requires an individually tailored, multimodal therapy due to the high variability in the clinical situation. Resection is the usual treatment for patients with superficial, low grade tumors with a diameter of <5 cm. For intermediate grade, differentiated lesions, resection with negative resection edges combined with radiotherapy attains an almost 80% total survival rate. For patients with high grade sarcoma of >5 cm, local control can be attained by resection and radiotherapy, however every second patient will develop metastases. Patients with a local recurrence should consider a new resection. Radiotherapy is the more effective the lower the remaining postoperative tumor burden.

Patterns of tumor response in canine and feline cancer patients treated with electrochemotherapy: preclinical data for the standardization of this treatment in pets and humans

Electrochemotherapy (ECT) is a novel anticancer therapy that is currently being evaluated in human and pet cancer patients. ECT associates the administration of an anti-tumor agent to the delivery of trains of appropriate waveforms. The increased uptake of chemotherapy leads to apoptotic death of the neoplasm thus resulting in prolonged local control and extended survival. In this paper we describe the histological features of a broad array of spontaneous tumors of companion animals receiving pulse-mediated chemotherapy. Multivariate statistical analysis of the percentage of necrosis and apoptosis in the tumors before and after ECT treatment, shows that only a high percentage of necrosis and apoptosis after the ECT treatment were significantly correlated with longer survivals of the patients (p < 0.0001 and p = 0.004, respectively). Further studies on this topic are warranted in companion animals with spontaneous tumors to identify new molecular targets for electrochemotherapy and to the develop new therapeutical protocols to be translated to humans.