Soft Tissue Sarcomas Treatment

Soft tissue sarcomas (STSs) gather over 80 histological entities, with even more molecularsubsets, characterized by low to very low incidence in all populations. STSs are ubiquitous in theirsite of origin and are often managed with multimodality treatment.The typical wide excision is followed by radiotherapy (RT) as the standard treatment of high-grade(G2–3), deep, cm lesions. There is no consensus on the current role of adjuvant Ch. Study resultsare conflicting, in the presence of negative results from the largest studies, though data are availablefrom smaller studies suggesting that adjuvant Chemotherapy (ChT)might improve, or at least delay,distant and local recurrence in high-risk patients. ChT was used as neoadjuvant treatment, aiming ata local benefit facilitating surgery, in addition to the systemic one. randomized trial showed nodifferences between three (preoperative) and five (pre- and postoperative) courses of full-dose ChTin high-risk STS patients. subsequent trial compared preoperative ChT with full-dose epirubicinplus ifosfamide versus histology-driven ChT. This trial was closed slightly in advance becausethree interim analyses showed statistically significant benefit in terms of both RFS and OS infavor of neoadjuvant therapy with epirubicin and ifosfamide.In case of advanced and metastatic STS the decision making is complex, depending ondiverse presentations and histologies, and should always be multidisciplinary.Metachronous(disease-free interval more than year), resectable lung metastases without extrapulmonary diseaseare managed with surgery as standard treatment, if complete excision of all lesions is feasible. ChTmay be added to surgery as an option, considering the prognostic factors (a short previousrecurrence-free interval and high number of lesions are adverse factors, encouraging the additionof ChT). ChT is preferably given before surgery to assess tumor response and thus modulatetreatment In cases where lung metastases are synchronous, in the absence of extrapulmonary disease,standard treatment is ChT Surgery of completely resectable residual lung metastases may beoffered as an option, especially when tumor response is achieved.Surgery, ablations or RT of extrapulmonary metastases may be an option without ChT inhighly selected cases (e.g. some patients with myxoid liposarcoma, solitary fibrous tumor).Standard ChT is based on anthracyclines as the first-line treatment. There is no formaldemonstration that multi-agent ChT is superior to single-agent ChT with doxorubicin alone in termsof OS. However, higher response rate can be expected, in particular, in number of sensitivehistological types, according to several, although not all, randomized clinical trials .Therefore,multi-agent ChT with adequate-dose anthracyclines plus ifosfamide may be the treatment of choice,particularly in subtypes sensitive to ifosfamide, when tumor response is felt to be potentiallyadvantageous and patient performance status is good. Recently, relatively small phase II studytested the combination of doxorubicin with an antibody directed against platelet-derived growthfactor receptor alpha (PDGFRA), olaratumab, and showed statistically significant higher OS incomparison with doxorubicin alone, though with lower and non-statistically significant benefit inPFS and response rate. The mechanisms for the added value of the combination of doxorubicin witha PDGFRA inhibitor are not fully understood. The standard arm in the phase II and III studies wasdoxorubicin alone, so it must be clarified whether the combination is superior to doxorubicin andifosfamide.A phase III study compared single-agent doxorubicin with the combination of gemcitabineand docetaxel as an upfront treatment in advanced STS patients of all types. The combination failedto show any improvement in PFS and objective response rate (ORR) and is not generallyrecommended as first-line therapy for advanced STS patients. Angiosarcoma is highly sensitive totaxanes, which can be treatment option in this histological subtype. An alternative is gemcitabine,possibly in combination with docetaxel. Doxorubicin plus dacarbazine is an option for multi-agent,first-line ChT of LMS, in which the activity of ifosfamide is far less convincing in availableretrospective evidence, or of solitary fibrous tumors. Imatinib is standard medical therapy for thoserare patients with dermatofibrosarcoma protuberans who are not amenable to non-mutilatingsurgery or with metastases deserving medical therapy. Similarly, imatinib and nilotinib are active intenosynovial giant cell tumors. After failure of anthracycline-based ChT, or the impossibility to useit, the following criteria may apply, although high-level evidence is lacking: Patients who have already received ChT may be treated with ifosfamide, if they did not progress on it previously. Highdose ifosfamide (14 g/m2) may be an option also for patients who have already received standarddose (9 g/m2) ifosfamide Trabectedin is an option for second line and beyond and is approved foradvanced previously treated STS. It has proved effective in LMS and liposarcoma In myxoidliposarcoma, high antitumor activity has been reported, with early radiological tissue densitychanges. peculiar pattern of tumor response has been reported, with an early phase of tissuechanges preceding tumor shrinkage. Clinical benefit with trabectedin was also demonstrated inother histological types. randomized trial showed benefit in PFS averaging months forpazopanib given until progression to advanced, previously treated STS patients (excludingliposarcomas). Thus, it is an option in non-adipogenic STS. randomized phase III trial showedthat eribulin was superior to dacarbazine in patients with liposarcomas and LMS.The mediandifference OS was months, but subgroup analysis showed that it reached months inliposarcomas. This led to the regulatory approval of eribulin for liposarcomas. One trial showed thatgemcitabine/docetaxel is more effective than gemcitabine alone as second-line ChT, with specialreference to LMS and undifferentiated pleomorphic sarcoma, but these data have not beenconfirmed (equivalence in response rate, PFS and OS) in second randomized trial conducted inLMS only; in both trials, toxicity was superior with the combination of docetaxel and gemcitabine.Gemcitabine was also shown to have antitumor activity in LMS and angiosarcoma as singleagent. The combination of dacarbazine and gemcitabine was shown to improve the OS and PFSover dacarbazine in randomized trial. Dacarbazine has some activity as second-line therapy(mostly in LMS and solitary fibrous tumor). In randomized placebo-controlled phase II trial,regorafenib improved PFS for patients with doxorubicin-pretreated, advanced STS. No survivaladvantage was observed in the liposarcoma cohort. post hoc exploratory analysis showedimproved quality adjusted survival in comparison with placebo. Regorafenib should be consideredas an option, if available, in doxorubicin pretreated advanced, non-adipogenic STS patients .RTshould be used as palliative resource in all cases as appropriate to the clinical need (e.g. bonelesions at risk of fracture).With reference to selected histological types, there is anecdotal evidenceof activity of several molecular targeted agents, building on consistent preclinical data and smallretrospective cohort studies. Examples are: Mammaliantarget of rapamycin (mTOR) inhibitors in malignant perivascular epithelioid cell tumours(PEComas), which are often associated with the loss of tuberous sclerosis complex 1/2 (TSC1/TSC2) Sirolimus activity in epithelioid aemangioendothelioma Crizotinib ininflammatory myofibroblastic tumour associated with anaplastic lymphoma kinase (ALK)translocations. Sunitinib and cediranib in alveolar soft part sarcoma, where the molecular target isyet unclear; and Sunitinib in solitary fibrous tumors, where the molecular target is as yet unclear.