Development of a Multi-Institutional Prediction Model for Three-Year Survival Status in Patients with Uterine Leiomyosarcoma (AGOG11-022/QCGC1302 Study)

Prognostic value of mitotic count in leiomyosarcoma: A comprehensive monocentric retrospective study

BACKGROUND

Leiomyosarcomas (LMSs) include heterogeneous entities with different clinical courses not entirely predicted by known prognostic factors. In particular, the value of mitotic count as independent prognostic factor in LMS has been poorly investigated.

METHODS

We retrospectively analyzed all patients with a diagnosis of LMS who accessed to our Institution from June 1999 to May 2022 for which mitotic count was numerically expressed within the pathology report. Univariate and multivariate analyses were conducted to explore the prognostic value of mitotic count along with other clinical and histological variables.

RESULTS

We identified 121 eligible patients, with a median follow-up of 91.03 months (range 0.62-275.2 months). Median progression-free survival (mPFS) was 16.7 months, and median overall survival (mOS) was 105.6 months. In univariate analysis, mitotic count showed a significant impact on PFS and OS, with an hazard ratio per mitotic unit of 1.03 (1.01-1.04, p < 0.001) and 1.03 (1.01-1.04, p = 0.007), respectively. Similar results were found for locally advanced and metastatic patients, separately. Other significant prognostic factors for PFS were stage at diagnosis, performance status, tumor size and Ki-67, while differentiation, necrosis, grade, stage at diagnosis, tumor size, performance status and age at diagnosis were identified for OS. In multivariate analysis, the only significant factors were mitotic count and the presence of metastases at diagnosis for PFS, whereas the same two factors plus age at diagnosis were identified for OS.

CONCLUSION

Mitotic count represented the most important histological prognostic factor for OS and PFS in localized and metastatic LMS.

Establishment of a staging system for visceral sarcoma

BACKGROUND

Visceral sarcoma is a rare malignancy with a poor prognosis. However, there is no recommended prognostic staging system for the malignant disease.

METHOD

We analyzed the data of patients diagnosed with primary soft tissue sarcoma (STS) of the abdomen and thoracic visceral organs between 2006 and 2017 at our hospital. Prognostic factors (size, tumor grade, and lymph node metastasis) were analyzed in our cohort (n = 203) and the SEER validation cohort (n = 5826).

RESULTS

Tumor size, grade, and lymph node metastasis were important prognostic factors for visceral sarcoma in both our and the SEER cohorts. Based on these prognostic factors, we established a new staging system for visceral sarcoma, by which patients could be stratified into clinically meaningful and non-overlapping stages in both our cohort and the SEER validation series. Moreover, the area under the curve (AUC) value of the staging system for 5-year survival was 0.84 (95% CI: 0.78-0.89) in our series and 0.80 (95% CI: 0.79-0.81) in SEER series, respectively. In addition, compared with the widely used FIGO staging system for female genital sarcoma, the visceral sarcoma staging system could more effectively and reliably stratify patients into four different prognostic groups.

CONCLUSIONS

The visceral sarcoma staging system is applicable for STS of the abdomen and thoracic visceral organs and is better than the current FIGO staging system for female genital sarcoma and should be incorporated into the AJCC Cancer Staging Manual.

Development and validation of tumor-size-stratified prognostic nomograms for patients with uterine sarcoma: A SEER database analysis

BACKGROUND

Tumor-size-stratified analysis on the prognosis of uterine sarcoma is insufficient. This study aimed to establish the tumor-size-stratified nomograms to predict the 3- and 5-year overall survival (OS) of patients with uterine sarcoma.

METHODS

The data analyzed in this study were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. We collected data from patients with uterine sarcoma diagnosed between 2004 and 2015. According to the median tumor size of 7.8 cm, the enrolled patients were divided into two tumor size (TS) groups: TS <7.8 cm and TS ≥7.8 cm. Patients in each group were randomly divided into the training and validation cohorts with a ratio of 7:3. Chi-square test was used to compare differences between categorical variables. Multivariate Cox regression models were used to identify significant predictors. We calculated the concordance index (C-index) and the area under the receiver operating characteristics curve (AUC) to validate the nomograms.

RESULTS

Compared with TS <7.8 cm group, TS ≥7.8 cm group had more patients of 45-64 years group, higher black race prevalence, higher proportion of myometrium tumor, higher stage, and higher grade; In the TS <7.8 cm training cohort, six variables (age, race, marital status, tumor primary site, stage, and grade) were identified as significantly associated with OS in multivariate analysis. However in the TS ≥7.8 cm training cohort, only four variables (surgery on primary site, tumor size, stage, and grade) were significantly identified; The C-index of two nomograms were 0.80 and 0.73 in training cohorts, respectively, and the AUC values for 3- and 5-year OS predictions in training cohorts were all above 0.80. Similar results were observed in validation cohorts.

CONCLUSIONS

This study found that the significant prognostic factors were different between two tumor size groups of uterine sarcoma patients. The tumor-size-stratified nomograms, which we constructed and validated, might be useful to predict the probability of survival for patients with uterine sarcoma.