Limb-sparing treatment with surgery and intraoperative radiotherapy (IORT) for a second local recurrence of myxoid liposarcoma in the popliteal region, after previous surgery and high-dose radiation

Development of machine learning model algorithm for prediction of 5-year soft tissue myxoid liposarcoma survival

BACKGROUND

Predicting survival in myxoid liposarcoma (MLS) patients is very challenging given its propensity to metastasize and the controversial role of adjuvant therapy. The purpose of this study was to develop a machine-learning algorithm for the prediction of survival at five years for patients with MLS and externally validate it using our institutional cohort.

METHODS

Two databases, the surveillance, epidemiology, and end results program (SEER) database and an institutional database, were used in this study. Five machine learning models were created based on the SEER database and performance was rated using the TRIPOD criteria. The model that performed best on the SEER data was again tested on our institutional database.

RESULTS

The net-elastic penalized logistic regression model was the best according to our performance indicators. This model had an area under the curve (AUC) of 0.85 when compared to the SEER testing data and an AUC of 0.76 when tested against institutional database. An application to use this calculator is available at https://sorg-apps.shinyapps.io/myxoid_liposarcoma/.

CONCLUSION

MLS is a soft-tissue sarcoma with adjunct treatment options that are, in part, decided by prognostic survival. We developed the first machine-learning predictive algorithm specifically for MLS using the SEER registry that retained performance during external validation with institutional data.

Surgical Outcomes and Prognostic Factors of Myxoid Liposarcoma in Extremities: A Retrospective Study

Objectives

To evaluate treatments and prognostic factors for the myxoid liposarcoma in extremities.

Methods

We retrospectively reviewed 34 patients histologically diagnosed with myxoid liposarcoma arising in the extremities, treated in our hospital from 2010 to 2017. We recorded tumor locations, max diameter, operations, complications, radiation, chemotherapy, survival, recrudescence, and metastases. Overall survival, treatments, and prognostic factors were subsequently analyzed.

Results

The mean age of 34 patients with myxoid liposarcoma in extremities was 49.1 years, and the mean follow‐up period was 65.1 months. The median survival time was 190 months. Five of 14 patients accepted recrudescence resection and two patients of 20 patients who underwent primary tumor resection or unplanned operation died of tumor progression. Although no statistical difference was found (X² = 3.331, P = 0.068), the lower mortality was confirmed in the patients who accepted primary tumor resection or unplanned operation. Eleven patients with a tumor diameter of 8.6 ± 4.7 cm accepted wide resection, while 23 patients with 17.2 ± 8.8 cm tumors accepted marginal resection. Statistical difference was found between the size of tumors with relatively wide resection and those with relatively marginal resection (F = 9.130, P = 0.005). No recurrence or metastasis occurred in patients who accepted wide resection, while 14 patients presented with local recurrence and 8 patients developed distant metastases among the 23 patients with marginal resection. Seven patients died of metastases, while one patient lived with metastases. No significant difference in survival was found between different surgical methods (X² = 0.9460, P = 0.3307). The average diameter of eight patients with distant metastases was 21.7 cm, which was considerable larger than the 12.1 cm of patients without metastasis. This difference was proven significant upon the statistical analysis (F = 9.412, P = 0.004).

Conclusions

Wide resection achieved good local control but was not unambiguously superior in long‐term survival. Myxoid liposarcoma tumors with larger diameters were more difficult to be submitted to wide resection and were more likely to present with distant metastasis.

Intraoperative radiotherapy electron boost followed by moderate doses of external beam radiotherapy in resected soft-tissue sarcoma of the extremities

PURPOSE

To analyze the patterns of failure and the toxicity profile of intraoperative electron beam radiotherapy (IOERT) after resection of soft tissue sarcomas of the extremities (STS).

PATIENTS AND METHODS

Forty-five patients with extremity STS were treated with IOERT and moderate-dose postoperative radiotherapy (45-50 Gy). Twenty-six patients were treated for primary disease (PD) and 19 patients for an isolated recurrence (ILR). Tumor size was >5 cm (maximum diameter) in 36 patients (80%), and high-grade histology in PD patients was present in 14 patients (54%). In nine patients, IOERT was used alone, due to previous irradiation or patient refusal. Chemotherapy (neoadjuvant and/or adjuvant) was mainly given to high-grade tumors.

RESULTS

Nine patients relapsed in the extremity (20%), and 12 patients in distant sites (28%). Actuarial local control at 5 years was 88% for patients with negative/close margins and 57% for patients presenting positive margins (P=0.04). Five patients (11%) developed neuropathy associated with the treatment. Extremity preservation was achieved in 40 patients (88%). With a median follow-up of 93 months (range: 27-143 months) for the patients at risk, 25 patients remain alive (a 7-year actuarial survival rate of 75% for PD and 47% for ILR; P=0.01).

CONCLUSIONS

IOERT combined with moderate doses of external beam irradiation yields high local control and extremity preservation rates in resected extremity STS. Peripheral nerves in the IOERT field are dose-limiting structures requiring a dose compromise in the IOERT component to avoid severe neurological damage.

Clinico-pathological data and prognostic factors in completely resected AJCC stage I-III liposarcomas

BACKGROUND

In general, although biological behavior and prognosis of liposarcomas (LPS) are more favorable compared with most other soft tissue sarcomas (STS), prognosis can vary widely depending on tumor characteristics, especially histological subtype and tumor grade.

PATIENTS AND METHODS

All consecutive, completely resected stage I-III LPS (as determined by the American Joint Committee on Cancer staging guidelines), treated at the Groningen University Hospital from 1977-2000, were analyzed.

RESULTS

A total of 69 patients, 35 males and 34 females, median age 51 (range 11-80) years, were reviewed. After a median follow-up of 71 (range 5-231) months, the overall local recurrence and metastasis rate at five years after diagnosis were 27% and 16%, respectively. Retroperitoneal localization was a significant negative prognostic factor regarding local recurrence; dedifferentiation, grade II-III, and deep location regarding distant metastasis; and dedifferentiation, grade II-III, stage II-III, size >20 cm and non-radical resection regarding survival.

CONCLUSIONS

LPS have a relatively mild biologic behavior, with the exception of very large, deeply located, dedifferentiated and/or grade II-III LPS. Radical resection is important for disease-specific survival. LPS have a relatively mild biologic behavior, with the exception of very large, deeply located, dedifferentiated and/or grade II-III LPS.