Retroperitoneal soft-tissue sarcomas: Radiotherapy experience from a tertiary cancer center and review of current evidence

Background

Surgery remains to be the main therapeutic approach for retroperitoneal sarcomas (RPS) although evidence supports that complementary radiotherapy increases local-control and survival. We present a multidisciplinary management and experience of a tertiary cancer center in the treatment of RPS and analyze current evidence of radiotherapy efficacy.

Patients and methods

We retrospectively reviewed 19 patients with primary or relapsed RPS treated between November 2009 and October 2018. Multidisciplinary approach comprised complete resection in 15 patients (79%) achieving resection R0 in 11 patients (58%), R1 in 4 patients (21%) and R2 in 2 patients (10%). Seven patients (37%) underwent a preoperative radiation (PRORT), 10 patients (53%), post-operative radiation (PORT) and 2 patients (10%), received radiotherapy exclusively. Ten patients (53%) received adjuvant chemotherapy.

Results

With a median follow-up of 24 months (2-114 months), actuarial rates of loco-regional relapse free survival (LRFS) at 1, 2 and 3 years were 77%, 77% and 67%, respectively. Actuarial rates of distant-metastases-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) at 1, 2 and 3 years were 100%, 100% and 80% for DMFS; 94%, 77% and 67% for DFS and 100%, 91% and 91% for OS, respectively. Only surgical margins (negative vs. positive) showed significance for 3y-LRFS: 100% vs. 34.3%, p = 0.018. Treatment tolerance was acceptable with no acute or late toxicity higher than grade 2.

Conclusions

Complementary radiotherapy appears to be useful and well tolerated for the multidisciplinary management of RPS. Presence of positive surgical margins seems to be the most relevant prognostic factor through the follow-up.

The Role of Clusterin in Carcinogenesis and its Potential Utility as Therapeutic Target

Clusterin is a glycoprotein that has been implicated in many processes, including apoptosis, cell cycle regulation and DNA repair. Since clusterin expression has also been associated with tumorigenesis and the progression of various malignancies including prevalent tumors like prostate, colon, bladder and breast, this protein has been proposed as a good candidate for future treatments. There have been numerous studies conducted in cell lines and xenograft models with successful results that, in general, justify the use of clusterin as a therapeutic target. However, it is still necessary to continue with these studies in order to achieve a better understanding of the role of this protein in carcinogenesis and to determine those specific situations in which its therapeutic use may be more favorable. In this review, we will make a brief description of clusterin structure and genetics, its implication in tumorigenesis and cancer progression and its prognosis utility. Finally, we will analyze the effects of clusterin inhibition in different types of cancer.

Abstract P1-14-10: Final results of neoadjuvant trial of bevacizumab (B) and trastuzumab (T) in combination with weekly paclitaxel (P) as neoadjuvant treatment in HER2-positive breast cancer: A phase II trial (AVANTHER)

Background: B in combination with T has shown meaningful activity in patients (pts) with metastatic HER2-positive breast cancer. Pathological complete response (pCR) was defined as the absence of invasive disease at the time of histological study and there is a relationship between pCR and disease-free survival (DFS) and overall survival (OS). The complete pathological response rate is between 9 to 34% of patients receiving primary treatment prior to surgery with chemotherapy and when the Herceptin was administrated, a pCR of 39% was reached.

AVANTHER is a Phase II trial of preoperative systemic therapy combining B with T and P in a weekly regimen in HER2 positive breast cancer to assess safety and efficacy of the combination.

Methods: Pts with centrally-confirmed HER2− positive (IHC 3+ or FISH positive) breast cancer (stage II or III including locally advanced) received neoadjuvant chemotherapy (NC) with weekly P (80mg/m2/week) for 12 weeks in combination with weekly T (4mg/kg loading dose and 2 mg/kg maintenance) and B (15mg/kg every 3 weeks) for 4 cycles. After surgery all pts received T (1 year) and liposomal doxorubicin plus cyclophosphamide every 3 weeks (4 cycles); primary endpoint was rate of pathological complete response (pCR) in breast and axilla. For all patients, a tissue sample at baseline as well as at surgery was collected for biomarker analyses.

Results: A total of 44 pts have been enrolled. Median tumor size: 3.9 cm. Nine (21%) pts had stage IIA; 19 (45%) stage IIB; 10 (24%) stage IIIA and 4 (10%) stage IIIB. Twenty-nine (69%) pts had estrogen positive receptors.

Data from surgery of 42 patients from a total of 44 patients enrolled were presented in this abstract, but the final results will be present in the symposium. pCR was achieved in 18 (42.9%) pts. Safety and tolerability were good, with rare adverse events of grade 3 [1 (2.4%) episode of severe hypertension, 1 (2,4%) mucosal inflammation].

We presented the results of relationship between magnetic resonance imaging (MRI) and pCR that is one of the secondary objectives of the study.

100% of the patients without pathologic response had stable disease at resonance imaging. Of all patients who had pCR only 55.6% had complete radiological response.

Conclusions: These data show that the combination of P with T and B without an anthracycline for 12 weeks is very effective as NC in HER2 positive breast cancer pts with a high rate of pCR and minimal side effects.

And the MRI is useful for identifying the persistence of residual disease however it only predicts half of the complete pathological responses

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-14-10.