Okuno, Scott H.

Objectives: Extraskeletal osteosarcoma (EO) is a malignant neoplasm that produces osteoid, bone, and chondroid material without direct attachment to bone or periosteum. Surgical resection is the mainstay of treatment; the role of chemotherapy is not well defined. Therefore, we evaluated the impact of chemotherapy in the survival of patients with EO. Methods: All EO patients seen at Mayo Clinic between 1990 and 2014 were assessed. Forty-three patients were included after all archived pathology slides were reviewed to confirm the diagnosis of EO. Results: Of 43 patients, 37 patients had localized disease and 6 patients had metastatic disease at diagnosis. Chemotherapy was used in 73% and 75% of patients, respectively. Chemotherapy was predominantly anthracycline based, and included platinum in 22 patients (84%). Median overall survival (OS) and progression-free survival (PFS) were 50 months (95% confidence interval, 25-99), and 21 months (95% confidence interval, 13-not reached), respectively. There was a trend towards longer OS and PFS in patients who received chemotherapy. Those who received platinum-based therapy had remarkably prolonged OS (median, 182 vs. 18 mo; 5-year, 61% vs. 0%; P=0.01) and PFS (median, not reached vs. 10 mo; 5-year, 56% vs. 0%; P=0.005). Baseline characteristics were similar in the platinum and nonplatinum group. In patients who received chemotherapy, relapse/recurrence rate was lower in the platinum-based group (41%) as opposed to the nonplatinum-based group (100%; P=0.02). In the neoadjuvant setting, the overall response rate of platinum-containing regimens was 27%. Conclusions: Our results suggest a clinical benefit when platinum-based chemotherapy is incorporated in the management of patients with EO. We plan to validate this further with an expanded multicenter analysis.

404 Background: Testicular sarcomas represent less than 1% of all testicular tumors in adults. Because of their rarity, little is known about the features and outcomes of these tumors. We present an analysis of the prognosis and survival predictors in patients with testicular sarcomas from the Surveillance, Epidemiology, and End Results Program (SEER). Methods: Using the SEER registry, we identified adults with testicular sarcomas between 1980 and 2013. Cases were identified using a combination of ICD-O-3 site and histology codes. The JMP and SEER*STAT 8.3.2 were used for statistical analysis. Overall survival (OS) was analyzed using the Kaplan-Meier method. The prognostic effect of variables was studied using Cox proportional hazards models. Results: We identified 264 patients with testicular sarcomas with a median follow-up time of 9.2 years. The median age at diagnosis was 55 years (range 15-94) and the median tumor size was 6.6 cm (range 0.7-45). 20% of patients with documented staging presented with de novo metastatic disease. Rhabdomyosarcomas were the most common histology (37%). The median OS was 129 months (95%; CI 85-180). OS rates at 1 year and 5 years were 85% and 62% respectively. 53% of deaths were related to cancer. 1-year OS rates for localized, locally advanced and metastatic disease were 91%, 93% and 53% (P<0.0001). Variables that were significant for survival in univariate analysis included age, histology, stage, and surgical resection. Factors that negatively affected survival in multivariate analysis were age >55 years (HR 2; 95% CI, 1.1-3.7), advanced stage (HR 4.8; 95% CI, 2.7-8.4) and surgical unresectability (HR 3.7; 95% CI, 1.1-9.3). Patients with rhabdomyosarcoma had favorable outcomes compared to other histologies (59% vs 17% alive at 10 years, P=0.01). Conclusions: Testicular sarcomas are rare entities with overall good prognosis after surgical resection. Patients presenting with distant metastases, however, have worse outcomes with only about 50% of the patients alive at 1 year. Rhabdomyosarcomas are the most common histology encountered and have relatively better survival. Younger age, earlier stage and surgical resection are factors associated with significantly better outcomes.

179 Background: GISTs arise from interstitial cells of Cajal anywhere within the gastrointestinal tract, but those of the esophagus and GEJ are exceedingly rare ( < 1% of cases). Our aim was to characterize clinicopathological features and outcomes of esophageal and GEJ GISTs and compare survival with a population-based registry (SEER). Methods: 28 cases were identified using the Mayo Clinic Cancer Registry from 1997 to 2016, and 378 cases from the SEER 18 registry from 2000 to 2013. Mayo cases were re-reviewed by Mayo pathologists. We analyzed patient characteristics, tumor location, TNM staging, mitotic index, molecular diagnostics, IHC staining, and histomorphology. JMP software was used to calculate time to recurrence (TTR) and overall survival (OS) utilizing Kaplan-Meier and log-rank. Results: At Mayo, 60% of tumors arose in the distal esophagus. Mean tumor size was 5.73 cm. 42% of cases were low grade. None had nodal involvement. Five cases were metastatic at diagnosis, all to the liver. 86.7% had spindle cell morphology. IHC staining was positive for KIT in 92%, followed by CD34 (52%), DOG-1 (24%), and actin (16%). Mutational analysis was done on 10 cases and KIT mutation was found in 8 cases; 2 were wild-type. Two-thirds of patients underwent surgery, mostly esophagectomy. 14 patients received adjuvant imatinib. Median time to diagnosis from symptom onset was 2 months; median time to surgery from diagnosis was 1 month. Of 10 patients with complete follow-up, 2 had recurrences: 1at the anastomotic site and 1 in the liver. Median TTR from surgery was 36.5 months. Median follow-up time was 31.5 months. Median OS from diagnosis for the Mayo cohort was 129.5 months (95% CI 55.7-x). SEER cohort median OS was 81 months (95% CI 63-101), and females had superior OS compared to males (HR 0.67; 95% CI 0.48-0.93, p = 0.016). Conclusions: Patients undergoing surgical resection for esophageal and GEJ GISTs had a favorable prognosis, but recurrences occurred. The superior OS seen in the Mayo cohort suggests early resection and adjuvant imatinib may improve outcomes.

PURPOSE: A meta-analysis of six North Central Cancer Treatment Group (NCCTG) trials involving patients receiving their first ever fluorouracil (5-FU)–based chemotherapy was undertaken to explore the association of sex with reports of the incidence and severity of stomatitis. PATIENTS AND METHODS: Data were obtained on a total of 731 patients (402 men and 329 women). Comparisons of incidence and severity rates and average stomatitis across sex were performed using standard binomial testing and t tests, respectively. Logistic regression analysis and a weighted analysis using data summarized to study level served as evidence of cross-validation. RESULTS: Women reported stomatitis both more often and with greater severity than did men. The incidence of any stomatitis for women was 63% versus 52% for men (P = .002). The incidence of severe or very severe stomatitis for men and women was 22% and 12%, respectively (P = .0006). On average, women reported stomatitis of roughly 0.4 points higher than men on a 0 to 4 ordinal scale (P < .00001). Comparison of results across treatment and placebo arms was carried out to validate the initial findings. Logistic regression modelling further confirmed the results conditional on the presence of a number of potentially confounding covariates. Women were also 11% more likely than men to experience leukopenia of common toxicity criteria grade ≥ 1, (70% v 59%, respectively; P < .00001) and grade 3+ (18% v 11%, respectively; P = .004). CONCLUSION: More women than men reported 5-FU–induced stomatitis. The precise mechanism resulting in different degrees of stomatitis across sex is not evident.

PURPOSE: The p27kip1 protein (p27) is a cyclin-dependent kinase inhibitor that has been shown to be an independent prognostic factor in a variety of human neoplasms. Low expression of p27 tends to occur in more aggressive neoplasms. The role of p27 as an independent prognostic factor in the spectrum of myxoid and round-cell liposarcomas has not been examined. MATERIALS AND METHODS: Forty-seven cases of myxoid and round-cell liposarcomas were examined. Clinicopathologic features and immunohistochemical expression of p27 and Ki-67 antigen were studied in all cases. Survival analysis was performed using the log-rank test and the Cox multivariate regression model. RESULTS: The male:female ratio was 1.4:1, and the mean age at diagnosis was 45 years. The tumors were located in the lower extremities (94%) and retroperitoneum (6%). The median tumor size was 13.5 cm. The median follow-up was 6.3 years, and the overall 5- and 10-year survival rates were 76% and 67%, respectively. Low expression of p27 was identified in 34 cases (72%) and correlated with decreased metastasis-free (P = .026) and overall survival (P = .008). In a multivariate analysis, only round-cell differentiation and low expression of p27 independently predicted decreased metastasis-free and overall survival. CONCLUSION: p27 expression predicts the clinical behavior of myxoid and round-cell liposarcomas, even in neoplasms with few or no round-cell differentiation.

Background:Myoepithelioma of the soft tissues is a rare entity and little is known about how best to manage locally recurrent and high-grade disease. Here, we retrospectively examined outcomes of surgery, chemotherapy, and radiation therapy (RT) for treatment of low-grade and high-grade myoepithelioma of soft tissues.Methods:We reviewed 20 cases of myoepithelioma of soft tissues seen at Mayo Clinic between 1994 and 2014. The effect of histologic grade and therapies received on relapse and survival were assessed.Results:We identified 13 patients with low-grade disease and 7 patients with high-grade disease. We found that low-grade disease was frequently effectively managed with surgical resection alone, whereas high-grade disease frequently metastasized and was often fatal. The 5-year event-free survival was 88% (confidence interval, 46%-98%) for low-grade disease versus 36% (confidence interval, 7%-75%;P=0.04) for high-grade disease. The relapse rate in low-grade disease was 29% at 5 years versus 64% (P=0.04) in high-grade disease. No significant responses to chemotherapy were noted, however, excellent responses to perioperative RT were seen.Conclusions:Surgery continues as the primary modality of treatment for myoepithelioma of soft tissues. Our study did not show a clear benefit of chemotherapy in the metastatic disease setting, but supports the use of perioperative RT in the management of high-grade disease; further investigation is warranted.