Tumor size increase following preoperative radiation of soft tissue sarcomas does not affect prognosis

Abstract

Our results indicate that a 20% increase in tumor size following preoperative radiotherapy did not result in a worse outcome for patients when compared to those who had stable or decrease local tumor size following preoperative radiotherapy.

Preoperative radiotherapy of soft-tissue sarcomas: surgical and radiologic parameters associated with local control and survival

“…Reduction of tumour volume on the other hand obviously reflects the response to treatment, although intratumoural bleeding may contribute to a stable or increasing volume and MRI sequences specific for the detection of tissue haemorrhage may be useful in this setting. Two previous studies failed to show any significance of tumour volume increase on survival [ 5 , 6 ], and tumour volume reduction may be a more accurate marker. Tumour response using the RECIST criteraia was not prognostic, most probably because they are more blunt and minor volume changes are not recorded as a response.…”

“…Tumour necrosis may be an objective measure of the effect of preoperative radiotherapy but there is no proof of its validity as a prognostic factor [ 4 ]. The use of radiologic measures is also questionable [ 5 – 7 ].…”

Neoadjuvant Treatment Options in Soft Tissue Sarcomas

“…The analysis of 99 patients with STS treated with neoadjuvant or palliative RT has shown that in 58 patients, the tumor volume changed significantly with a volume increase in the majority of cases [111]. Moreover, a decrease in tumor size may be correlated with the presence of viable sarcoma cells, whereas "pseudoprogressing" tumors might be related to an extensive pathological response [79,112]. Thus, conventional response evaluation criteria in solid tumors (RECIST 1.1) should not be used to assess the response to neoadjuvant treatment in STS, except for myxoid liposarcomas.…”

Conventional Modalities and Novel, Emerging Imaging Techniques for Musculoskeletal Tumors

“…23 In particular, sarcomas are challenging because an increase in size often does not indicate poor response to therapy. 24 Often, preoperative radiotherapy causes hemorrhage or necrosis leading to tumor enlargement. An increase in tumor size (≤ 20%) observed after radiotherapy but prior to surgery has not been associated with worse outcomes.…”

“…An increase in tumor size (≤ 20%) observed after radiotherapy but prior to surgery has not been associated with worse outcomes. 24 PET/CT can also be used to guide biopsy. Soft-tissue sarcomas are often heterogenous on MRI, with areas of necrosis or myxoid components.…”