sarcoma.jpg (3923 bytes)

 Treatment of Sarcoma

The best, current information on treatment is from the NCCN guidelines (go here). In general patients are treated with surgery often combined with radiation (go here) and often chemotherapy (go here).

for the role of radiation   go here  and side effects of radiation here

Typical radiation dose and technique from RTOG 0630, the fields are smaller than before, in the older RTOG trials (RTOG 95-14) the radiation fields were much larger (go here and here).

the most effective chemotherapy drugs include adriamycin, ifosfamide or DTIC, with some newer drugs (e.g. Gleevac (Imatinib) or Sutent (Sunitinib) for GIST tumors, go here). for a discussion of adjuvant chemotherapy go here


for a discussion of retroperitoneal sarcoma go here.

other reviews on treatments go: here, here, here, here, here

Traditionally, sarcomas have been divided into two broad categories depending on whether they arise in soft tissue or bone.Sarcomas constitute 1% of newly diagnosed adult malignancies and 15% of pediatric cancers. Most cases of sarcoma have no identifiable risk factor. with the exception of primitive neuroectodermal tumor (PNET), and rhabdomyosarcoma, clinical decisions regarding the treatment of soft tissue sarcomas place unique emphasis on the assessment of tumor grade rather than the histologic subclassification. Although patients with high-grade sarcomas are more likely to respond to chemotherapy, their probability and duration of recurrence-free survival is lower than those of patients with low-grade tumors Involvement of draining lymph nodes by sarcoma is unusual. In one series of 323 patients with nonmetastatic sarcoma, only 5% developed nodal metastases at any time in their clinical course. The incidence is highest in patients with synovial cell, epithelioid, clear cell, vascular, and rhabdomyosarcomas.
 

The treatment of patients who present with localized soft tissue sarcomas is primarily surgical, with an important role for adjuvant radiation therapy in selected cases. Many soft tissue tumors are surrounded by a pseudocapsule, giving the false appearance that all of the tumor has been resected after the surgeon “shells out” all visible disease. The local recurrence rate after such a marginal excision has been reported to be in the range of 80%. At the other extreme, the benchmark for local control of extremity soft tissue sarcomas is amputation above the level of the proximal joint. Such therapy reduces local recurrence rates to 10% to 20%.
Despite optimal locoregional therapy, more than 50% of patients with high-grade soft tissue sarcomas can be expected to develop recurrent disease, predominantly from distant metastases. In an effort to reduce the incidence of systemic relapse, multiple studies of adjuvant chemotherapy have been conducted. Trials in patients with advanced disease have thus far identified only two drugs with single-agent response rates of greater than 25%: doxorubicin and ifosfamide. Response rates to doxorubicin are clearly dose dependent. Regimens using constant infusion rather than bolus doxorubicin have documented a lower rate of cardiotoxicity. Nonetheless, significant cardiac morbidity can still follow such treatment. Several trials have suggested that dacarbazine improves the response to single-agent doxorubicin, particularly in leiomyosarcomas, albeit at the expense of significant gastrointestinal toxicity.
Of 12 randomized studies comparing adjuvant chemotherapy vs surgery alone for extremity sarcomas, one trial still reports a survival advantage, and several report a delay in relapse for the patients treated with adjuvant chemotherapy. Among eight randomized studies examining the effect of adjuvant chemotherapy in patients with nonextremity sarcomas, none have demonstrated a survival advantage, and in fact, one has shown a detrimental effect. Overall, the efficacy of adjuvant chemotherapy in soft tissue sarcoma remains unproven.
In an effort to avoid such debilitating procedures, surgeons have moved toward wide excisions in which the tumor is removed in continuity with a 2- to 3-cm margin of normal surrounding tissue. Although the local failure rate of such limb-sparing procedures when used alone is approximately 50%, acceptable rates of local failure (5% to 10%) can be achieved by the addition of high-dose external beam radiation (55 to 70 Gy). The benefit of adjuvant radiation therapy following a wide excision appears primarily in patients with tumors of high and intermediate grade. In patients with bulky tumors (> 15 cm), some centers use preoperative radiation therapy or chemotherapy to either render an unresectable tumor resectable or reduce the high risk of local recurrence in such large tumors.