The Contemporary Role of the Use of Radiation Herapy in the Management of Sarcoma

[Surgery and postoperative radiation therapy in primary retroperitoneal sarcomas: experience of the cancer centre Alexis-Vautrin]

PURPOSE

Surgical resection remains the standard treatment for patients with resectable retroperitoneal sarcomas. The aim of this study was to retrospectively analyse the outcomes of patients with primary retroperitoneal sarcoma.

PATIENTS AND METHODS

We analysed data of 50 patients with primary retroperitoneal sarcoma who underwent curative-intent resection from 1975 to 2008. External beam radiotherapy and chemotherapy were delivered postoperatively. Demographics, surgical, pathological variables and chemo/radiation therapy were analysed as prognosis factors.

RESULTS

There were 22 males and 28 females (mean age 54 ± 13 years). Surgery required visceral resections in 30 patients. There were 16 leiomyosarcomas, 25 liposarcomas and eight other sub-types. Twenty-one patients had clear surgical margins. Twenty-eight patients received postoperative external beam radiotherapy (median 45 Gy) and 15 received chemotherapy. At the end of the follow-up (median 55 months), local recurrence occurred in 39% (n=14) among R0/R1 resection group (n=36). Postoperative external beam radiotherapy tends to increase the time of local recurrence from surgery (27 vs. 13 months, P=0.05). The overall survival rates were 81%, 55% and 46% at 1, 3 and 5 years, respectively. Although R0 resection (P=0.01), well tumour differentiation (P=0.004) and postoperative external beam radiotherapy (P=0.02) significantly influenced overall survival in univariate analysis, only R0 resection was an independent prognostic factor in a multivariate analysis.

CONCLUSION

We confirm the pre-eminence of radical surgery with negative margins as major prognostic factor and the benefit of postoperative radiotherapy.

Effect of transforming growth factor-1 on bone regeneration in critical-sized bone defects after irradiation of host tissues

OBJECTIVE

To determine whether sustained release of transforming growth factor (TGF)-beta1 from a gelatin hydrogel would enhance bone regeneration in critical-sized long-bone defects and overcome inhibitory effects of preoperative irradiation.

ANIMALS

24 adult New Zealand White rabbits.

PROCEDURE

Rabbits were allocated to 2 groups. Twelve rabbits received localized megavoltage radiation to the right ulna by use of a cobalt 60 teletherapy unit, and 12 rabbits received no irradiation. Then, a 1.5-cm defect was aseptically created in the right ulna of each rabbit. Gelatin hydrogel that contained 5 microg of adsorbed recombinant-human (rh)TGF-beta1 was placed in the defect of 12 rabbits (6 irradiated and 6 nonirradiated), and the other 12 rabbits received hydrogel without rhTGF-beta1. Rabbits were euthanatized 10 weeks after surgery. New bone formation within the defect was analyzed by use of nondecalcified histomorphometric methods. A 1-way ANOVA was used to compare differences among groups.

RESULTS

New bone formation within the defect was significantly greater in TGF-beta1-treated rabbits than in rabbits treated with hydrogel carrier alone. Local delivery of rhTGF-beta1 via a hydrogel carrier in irradiated defects resulted in amounts of bone formation similar to those for nonirradiated defects treated by use of rhTGF-beta1.

CONCLUSIONS AND CLINICAL RELEVANCE

Local delivery of TGF-beta1 by use of a hydrogel carrier appears to have therapeutic potential for enhancing bone formation in animals after radiation treatments.

IMPACT FOR HUMAN MEDICINE

This technique may be of value for treating human patients at risk for delayed bone healing because of prior radiation therapy.

The effect of host tissue irradiation on large-segment allograft incorporation

Therapeutic radiation delivered to bone and the adjacent local tissues before allograft limb-salvage surgery has been associated with poor graft incorporation and higher numbers of clinical complications. Our objective was to determine the effect of preoperative radiation therapy on specific histologic, molecular and structural parameters of large-segment, bone allograft incorporation in a canine model. Skeletally mature dogs received a total of 0, 25, or 50 Gy of radiation to the foreleg (radius and ulna) delivered in 2-Gy fractions during a 5-week period before reconstruction of a 3.5-cm defect in the radius. The dogs were sacrificed at postoperative day 150. Nondestructive four-point bending was done on the harvested allograft-host bone immediately after euthanasia and specimens were compared using biomechanical, histomorphometric, immunohistochemical, and in situ reverse transcription polymerase chain reaction techniques. Preoperative irradiation significantly impaired allograft incorporation as determined by radiographic healing scores, histomorphometry, and frequency of nonunions. Biochemical differences included diminished bone morphogenetic protein-2 and bone morphogenetic protein-4 protein levels and messenger ribonucleic acid expression. Vascular endothelial growth factor expression was not altered. These data suggest that bone morphogenetic protein-2 and bone morphogenetic protein-4 signaling at the allograft-host junction is altered after preoperative fractionated radiation and provides a plausible albeit partial mechanistic explanation for radiation-mediated delays in allograft incorporation.

Soft tissue sarcoma of the upper extremity

Soft tissue sarcomas of the upper extremities are rare and hand surgeons typically encounter only one or two undiagnosed soft tissue sarcomas during their careers. It is incumbent on the physician to review repeatedly the characteristics of these tumors and remain suspicious, because these lesions typically are misdiagnosed and treatment is delayed. The most common soft tissue sarcomas of the upper extremity are the epithelioid sarcoma, synovial cell sarcoma, and malignant fibrous histiocytoma. Limb salvage surgery is the treatment of choice for soft tissue sarcomas to preserve upper extremity function. Following wide tumor resection, adjuvant therapies such as chemotherapy, external beam radiation therapy, and brachytherapy may lessen local recurrence rates, but their effect on overall survival remains unclear.

Surgical resection and radiotherapy for primary retroperitoneal soft tissue sarcoma

METHODS AND MATERIALS

Forty-five patients were consecutively treated for primary retroperitoneal soft tissue sarcoma with surgery in combination with radiation therapy in the same institution. The median follow-up time was 53 months (7-108).

RESULTS

Seventeen (38%) patients had clear microscopic margins (R0 resection), 26 patients (58%) had gross complete surgical excision (R1 resection) and two patients (4%) had a macroscopic residual disease (R2 resection). External radiotherapy doses ranged from 40.8 to 59.4 Gy (mean and median: 49 Gy). Seventeen patients underwent intraoperative radiation therapy (IORT). Moreover, 11 patients received chemotherapy. The overall 1-, 2-, and 5-year survival for all 45 patients were 93, 85 and 60%, respectively. The 1-, 2-, and 5-year locoregional relapse-free rate for the whole group was 91, 70 and 40%, respectively. In univariate analysis, quality of surgery was the only variable to show a significant effect for overall survival (P=0.0386) and for local control (P=0.0059). Tumor size and tumor grade had no statistically significant effect. For the patients receiving IORT+external beam radiation therapy, no difference was observed for survival or locoregional control. The most frequent acute side effects treatment complications were radiation-induced nausea or vomiting (42%) and moderate enteritis (30%). Significant late morbidity was observed for two patients.

CONCLUSIONS

This study confirms the feasibility of external postoperative radiotherapy with an acceptable level of toxicity. However, the high rate of local relapses (especially in field of radiation) does not demonstrate the usefulness of radiotherapy at the level of dose used and further preferably randomized studies should be planned.