Ueberroth, Benjamin E.

365 Background: Automated scalp cooling (ASC) is utilized in breast cancer patients to reduce chemotherapy-induced alopecia. Nursing staff and patient perspectives on ASC are limited regarding impact on care delivery and outcomes. Methods: A survey-based study of patient and chemotherapy nurse perspectives of ASC was conducted at three multi-regional Mayo Clinic sites. One-time surveys were sent to breast cancer patients and nurses for self-reporting of the ASC experience. Patients were identified via ICD-10 codes for breast cancer with subsequent chart review to confirm relevant chemotherapy regimen and ASC use. Chemotherapy nurses were identified by their respective chemotherapy unit nurse managers. Patient survey responses were compared between groups that did or did not use ASC by use of Pearson chi-square test for frequency data and the Kruskal-Wallis rank sum test for continuous measures. P values <0.05 were considered statistically significant. Results: Surveys were sent to 181 nurses with 61 (33.7%) completing them. Nurses reported ASC administration to 10-50 patients (n=43, 63.9%) or ≥50 patients (n=18, 29.5%). Most felt they had little or no technical support available (67.2%), witnessed scheduling difficulties (52.5%), were distressed by workload intensity (52.5%), and did not receive adequate training (67.2%). Most felt that ASC demanded greater nursing time compared to other duties (57.4%). Most would not recommend ASC to a friend or family member (88.6%). Surveys were sent to chemotherapy patients with 93 of 465 (20.0%) ASC patients and 56 of 341 (16.4%) without ASC (control) completing them. Controls were significantly more likely to experience hair loss, shave their head, and wear a wig (all p<0.001). There was no significant difference between groups for the EORTC QLQC30, EORTC BR23, and Body Image Scale results or frequency of headaches. Patients who used ASC for less than half of their chemotherapy sessions reported significantly more cold discomfort ( p=0.040) and dizziness ( p=0.003). Time investment (33.3%) and side effects (31.2%) were the most frequent burdens cited. Conclusions: Most nurses indicated that ASC increased nursing workload compared with other duties, and they lacked adequate training and technical support. Increasing formal nurse education and access to technical support documents and live technical support may be options for improving nursing satisfaction with ASC. Patient responses suggest qualitative effectiveness of ASC in reducing hair loss. While those with ASC were less likely to shave or use a wig, this did not translate to significant differences in quality of life or psychosocial body image compared to controls. Cold discomfort and dizziness were the most frequent side effects among those with lower utilization of ASC.

Background: For patients with resected stage III colon cancer, 6 months of adjuvant fluoropyrimidine-based chemotherapy has been the standard of care. The IDEA collaboration aimed to evaluate whether 3 months of adjuvant chemotherapy was noninferior to 6 months. Despite failing to meet its primary endpoint, the subgroup analyses demonstrated noninferiority based on regimen and treatment duration when a risk-stratified approach was used. Patients and Methods: To evaluate the impact of the results of the IDEA collaboration, we evaluated adjuvant chemotherapy prescribing practice patterns, including planned adjuvant treatment regimen and duration from January 1, 2016, to January 31, 2021. The time period was selected to evaluate chemotherapy prescribing patterns prior to the abstract presentation of the IDEA collaboration in June 2017 and after full manuscript publication in March 2018. Results: A total of 399 patients with stage III colon cancer who received adjuvant chemotherapy were included in the analysis. A significant increasing trend for use of 3 months of adjuvant chemotherapy was observed after presentation of the IDEA abstract (P<.001). A significant change in CAPOX (capecitabine/oxaliplatin) prescribing was also observed, increasing from 14% of patients prior to presentation of the IDEA abstract to 48% after presentation (P<.001). Comparing 3 months of CAPOX with 6 months of FOLFOX (fluorouracil/leucovorin/oxaliplatin), 3 months of CAPOX use also steadily increased over time (adjusted odds ratio [aOR], 1.28; 95% CI, 1.20–1.37; P<.001). Among subgroups of interest, no differences in adoption of CAPOX were observed. The adoption of 3 months of CAPOX was similar in patients with low-risk cancer (aOR, 1.27; 95% CI, 1.17–1.37) and those with high-risk cancer (aOR, 1.31; 95% CI, 1.16–1.47). Conclusions: Despite the IDEA collaboration failing to demonstrate noninferiority of 3 months’ duration of adjuvant therapy compared with 6 months, the findings have influenced practice prescribing patterns, favoring CAPOX and a shorter duration of planned adjuvant treatment.

Abstract Background Radium (Ra)‐223 is an established treatment option for patients with metastatic castrate‐resistant prostate cancer (mCRPC) who have symptomatic bone metastases without soft tissue disease. Studies have indicated genetic aberrations that regulate DNA damage response (DDR) in prostate cancer can increase susceptibility to treatments such as poly ADP‐ribose polymerase inhibitors and platinum‐based therapies. This study aims to evaluate mCRPC response to Ra‐223 stratified by tumor genomics. Methods This is a retrospective study of mCRPC patients who received Ra‐223 and genetic testing within the Mayo Clinic database (Arizona, Florida, and Minnesota) and Tulane Cancer Center. Patient demographics, genetic aberrations, treatment responses in terms of alkaline phosphatase (ALP) and prostate‐specific antigen (PSA), and survival were assessed. Primary end points were ALP and PSA response. Secondary end points were progression‐free survival (PFS) and overall survival (OS) from time of first radium treatment. Results One hundred and twenty‐seven mCRPC patients treated with Ra‐223 had germline and/or somatic genetic sequencing. The median age at time of diagnosis and Ra‐223 treatment was 61.0 and 68.6 years, respectively. Seventy‐nine (62.2%) had Gleason score ≥ 8 at time of diagnosis. 50.4% received prior docetaxel, and 12.6% received prior cabazitaxel. Notable alterations include TP53 (51.7%), BRCA 1/2 (15.0%), PTEN (13.4%), ATM (11.7%), TMPRSS2‐ERG (8.2%), RB deletion (3.4%), and CDK12 (1.9%). There was no significant difference in ALP or PSA response among the different genetic aberrations. Patients with a TMPRSS2‐ERG mutation exhibited a trend toward lower OS 15.4 months (95% confidence interval [CI] 10.0−NR) versus 26.8 months (95% CI 20.9−35.1). Patients with an RB deletion had a lower PFS 6.0 months (95% CI 1.28−NR) versus 9.0 months (95% CI 7.3−11.1) and a lower OS 13.9 months (95% CI 5.2−NR) versus 26.5 months (95% CI 19.8−33.8). Conclusions Among mCRPC patients treated with Ra‐223 at Mayo Clinic and Tulane Cancer Center, we did not find any clear negative predictors of biochemical response or survival to treatment. TMPRSS2‐ERG and RB mutations were associated with a worse OS. Prospective studies and larger sample sizes are needed to determine the impact of genetic aberrations in response to Ra‐223.

92 Background: Since the publication of the MOSAIC trial, stage III CC has been treated with a six-month (mo) regimen of FOLFOX (fluorouracil, leucovorin, and oxaliplatin) or CAPOX (capecitabine and oxaliplatin). Recently, the IDEA collaboration challenged this practice by demonstrating that the 3-year rate of disease-free survival (DFS) was non-inferior to 6mo of treatment (Rx) when given for low risk CC (83.1 vs. 83.3%) and resulted in significantly lower rates of grade 2 and higher neuropathy. In high risk (T4, N2) patients (pts) the DFS of 3mo of CAPOX was equivocal to 6mo (64.1 vs. 64.0%), while 3mo of FOLFOX was inferior to 6mo (61.5 vs. 64.7%). We hypothesized that trends in prescribing would favor shorter courses of Rx with a preference towards CAPOX given its efficacy across both high and low risk CC. Methods: We performed a retrospective analysis of stage III CC pts from 4 institutions. We evaluated prescribing patterns of 3mo or 6mo of Rx and CAPOX vs. FOLFOX over a period of 5 years from Jan 2016 to Jan 2021, a time period that traverses before and after the release of IDEA. Logistic and multinomial logistic regression models, with a linear time trend, were used to estimate the percentage of pts receiving CAPOX vs. FOLFOX and the combination of Rx and duration, respectively, while adjusting for baseline characteristics. The prescribing patterns in important subgroups were examined by incorporating the interaction term in the models. Results: A total of 366 pts met inclusion criteria. From 2016-2021, there was a significant increase per quarter in patients treated with CAPOX when compared to FOLFOX (OR 1.16 95% CI 1.11 – 1.21, p <.001). Prior to IDEA, 78.3% of pts received 6mo FOLFOX and 7.4% received 3mo CAPOX. Two years after IDEA, only 17.3% of pts were on 6mo FOLFOX compared to 67.5% of pts on 3mo CAPOX (Table). At present, high risk pts are more likely to receive 6mo FOLFOX (47.8%) than 3mo of FOLFOX (3.9%), 3mo CAPOX (25.8%), or 6mo CAPOX (22.4%). Low risk pts are more likely to receive 3mo of CAPOX (67.9%) than other Rx. Conclusions: Our findings suggest that since IDEA, physician practice has significantly changed in favor of CAPOX and shorter courses of Rx. The use of CAPOX has significantly increased overall, presumably due to its efficacy across all risk groups and relatively reduced toxicity.[Table: see text]

Objectives This study sought to better characterize patient characteristics, treatment options, and outcomes for osteoclast-like giant cell carcinoma of the pancreas, a rare subtype of pancreatic adenocarcinoma. Methods This is a retrospective study of all patients with osteoclast-like giant cell carcinoma of pancreatic origin treated at Mayo Clinic from 2000 to present. Baseline patient characteristics, treatment modalities utilized, and outcomes were compiled. Overall survival (OS) and progression-free survival were assessed using Kaplan-Meier analysis with a significance level of P ≤ 0.05. Results Fifteen patients met criteria for inclusion. Four patients had distant metastases at diagnosis, the remaining 11 with locoregional disease. Median OS for the entire cohort was 11 months. Metastatic disease was associated with significantly shorter OS (3.5 vs 14.1 months; P = 0.005). Three patients had no evidence of disease at time of analysis; all 3 were treated with complete resection followed by adjuvant chemotherapy. Conclusions Osteoclast-like giant cell carcinoma of the pancreas is an aggressive malignancy with poor prognosis. For patients with locoregional disease, surgical resection followed by adjuvant chemoradiation may play a role in extended disease-free survival. Metastatic disease presents a challenging entity to treat with little data to support any effective chemotherapy regimens.

Abstract Introduction Recent classification of neuroendocrine neoplasms has defined well-differentiated high-grade neuroendocrine tumors (NET G3) as a distinct entity from poorly differentiated neuroendocrine carcinoma. The optimal treatment for NET G3 has not been well-described. This study aimed to evaluate metastatic NET G3 response to different treatment regimens. Materials and Methods This was a retrospective study of patients with NET G3 within the Mayo Clinic database. Patients’ demographics along with treatment characteristics, responses, and survival were assessed. Primary endpoints were progression-free survival (PFS) and overall survival. Secondary endpoints were objective response rate (ORR) and disease control rate (DCR). Results Treatment data was available in 30 patients with median age of 59.5 years at diagnosis. The primary tumor was mostly pancreatic (73.3%). Ki-67 index was ≥55% in 26.7% of cases. Treatments included capecitabine + temozolomide (CAPTEM) (n = 20), lutetium 177 DOTATATE (PRRT; n = 10), Platinum-etoposide (EP; n = 8), FOLFOX (n = 7), and everolimus (n = 2). CAPTEM exhibited ORR 35%, DCR 65%, and median PFS 9.4 months (95% confidence interval, 2.96–16.07). Both EP and FOLFOX showed similar radiographic response rates with ORR 25.0% and 28.6%; however, median PFS durations were quite distinct at 2.94 and 13.04 months, respectively. PRRT had ORR of 20%, DCR of 70%, and median PFS of 9.13 months. Conclusion Among patients with NET G3, CAPTEM was the most commonly used treatment with clinically meaningful efficacy and disease control. FOLFOX or PRRT are other potentially active treatment options. EP has some activity in NET G3, but responses appear to be short-lived. Prospective studies evaluating different treatments effects in patients with NET G3 are needed to determine an optimal treatment strategy. Implications for Practice High-grade well-differentiated neuroendocrine tumors (NET G3) are considered a different entity from low-grade NET and neuroendocrine carcinoma in terms of prognosis and management. The oral combination of capecitabine and temozolomide is considered a good option in the management of metastatic NET G3 and may be preferred. FOLFOX is another systemic option with reasonable efficacy. Similar to other well-differentiated neuroendocrine tumors, peptide receptor radionuclide therapy seems to have some efficacy in these tumors.

e17587 Background: Radium (Ra)-223 has become the cornerstone treatment in patients with metastatic castrate-resistant prostate cancer (mCRPC) with bone metastases. Ra-223 has been shown to suppress abnormal bone formation by inducing DNA double-strand breaks in tumor cells. This can reduce skeletal-related events, as well as improve survival and quality of life. Studies have indicated mutations that regulate DNA damage response in prostate cancer as susceptible to PARP inhibitors and platinum-based therapies. This study aims to evaluate mCRPC response to Ra-223 stratified by tumor genomics. Methods: This is a retrospective study of mCRPC patients who received Ra-223 and genetic testing within the Mayo Clinic database (Arizona, Florida, and Minnesota). Patient demographics, genetic mutations, treatment responses in terms of alkaline phosphatase (ALP) and prostate-specific antigen (PSA), and survival were assessed. Primary end points were progression-free survival (PFS) and overall survival (OS) from time of first radium treatment. Results: 239 mCRPC patients treated with Ra-223 were identified. Germline and/or somatic genetic sequencing was available in 50 patients, who had a median age of 61 years at time of diagnosis and 68 years at time of Ra-223 treatment. Median Gleason score at time of diagnosis was 8.0. 100% of patients received prior androgen deprivation therapy. 72% received prior docetaxel, and 18% received prior cabazitaxel. Notable mutations included TP53 (45.2%), TMPRSS2-ERG (28.6%), PTEN (26.2%), BRCA1/2 (14.3%), ATM (9.3%), CDK12 (7.1%), and Rb (4.9%). TMPRSS2-ERG was the second most commonly found mutation, with median OS 12.7 mo versus 15.4 mo in patients without TMPRSS2-ERG mutations (p = 0.099). In patients with CDK12 mutations (2 of 28 tested positive), PFS was 10.4 mo versus 5.6 mo in patients without CDK12 mutations (p = 0.157). The assessment of ALP and PSA response to radium treatment stratified by genetic mutation did not reach statistical significance. Conclusions: Among mCRPC patients treated with Ra-223 at Mayo Clinic, TMPRSS2-ERG was the second most commonly found genetic mutation and had observed worse survival outcomes that approached statistical significance. Prospective studies and increased sample sizes are needed to determine the impact of genetic mutations in response to Ra-223.

e16752 Background: Undifferentiated osteoclast-like giant cell carcinoma of the pancreas is an aggressive malignancy only described by a few case reports in the literature. In this study, we sought to better characterize this entity by examining patients seen at Mayo Clinic. Methods: This study identified patients with osteoclast-like giant cell carcinoma of the pancreas using Mayo Clinic databases (MN, AZ, FL) from the year 2000 to present. Patient demographics, genetic data, and treatment modalities were reviewed. Kaplan-Meier analysis was used to evaluate median overall survival (mOS) for the cohort as well as mOS and mPFS for treatment subgroups. Results: 15 patients were identified (9 female, 6 male). Median age at diagnosis was 59 years and mOS for all patients was 11.0 mos (95% CI 6.2-15.7 mos). 3 patients (20%) had metastatic disease at diagnosis with the liver being the most common site (n = 3). Metastatic disease was associated with significantly shorter OS (3.5 vs. 14.1 mos, p = 0.005; HR 7.98 [95% CI 1.43-44.4]) compared to locoregional disease (LRD). 4 patients underwent genetic testing. The most common mutation was CDKN2A (n = 3), followed by TP53 (n = 2) and KRAS (n = 2). 13/15 patients had detailed follow-up information. 6/7 patients undergoing chemotherapy received a gemcitabine-based regimen as first line: with capecitabine (n = 2), with nab-paclitaxel (n = 2), or as monotherapy (n = 2). 1 patient received FOLFIRINOX. In patients with LRD and adequate follow-up (n = 11), 8/11 underwent surgical resection and had longer OS compared to those without resection (17.0 vs. 8.4 mos, p = 0.09). No surgical patients received neoadjuvant chemotherapy. 5/8 received adjuvant chemotherapy, 2 did not undergo chemotherapy, and 1 was lost to follow-up after surgery. PFS from time of surgery was 15.3mos (95% CI 5.0-25.6mos). 6 patients (40%) were alive at time of analysis; all 6 underwent surgical resection. Conclusions: Osteoclast-like giant cell carcinoma of the pancreas is a rare malignancy with a poor prognosis, even when diagnosed at an early stage. OS for patients of all stages in this study was less than 1 year suggesting prognosis may be even worse than that of pancreatic adenocarcinoma. The optimal therapy remains unknown but most patients received similar chemotherapy as in adenocarcinoma. Patients with LRD amenable to surgical resection experienced a PFS over 1 year from surgery, possibly associated with OS benefit, however overall prognosis is poor. Further study is warranted on a larger scale to better understand disease course and treatment options.

e16702 Background: There are only a few reports examining the treatment patterns for poorly differentiated rectal/anal NEC. In this study, we sought to report treatment and survival outcomes for patients with NEC of the anus and rectum seen at Mayo Clinic. Methods: We identified patients with a primary NEC of the anus or rectum using Mayo Clinic databases (Minnesota, Arizona, Florida) from the year 2000 to present. NEC identified within polyps on colonoscopy was excluded from this study. Patients’ demographics were compiled. Kaplan Meier analyses were performed to evaluate overall survival (OS) for all patients, as well as subgroups with locoregional disease (LRD) and metastatic disease at diagnosis. Progression free survival (PFS) was also evaluated for patients with LRD treated with chemoradiation therapy (CRT). Results: 38 patients with NEC of the anus/rectum were identified with a median age of 55.5 years. 23 patients (61%) had metastatic disease at diagnosis and 15 (39%) had LRD. The most common site of metastasis was the liver (n = 20). Patients with metastatic disease at presentation had significantly shorter OS compared to patients with LRD (median OS 10.4 vs. 18.9 months, p = 0.039; HR 2.46, 95% CI [1.001-6.050]). 34 total patients received chemotherapy (ORR 11.8%), with platinum + etoposide (EP) being the most common first-line chemotherapy (n = 26). 10 of 15 patients with LRD received CRT (9 with EP and 1 with 5-FU) with median PFS of 6.3 months (95% CI 2.3-16.5 months), a 1-year PFS rate of 20%, and median OS of 18.6 months (95% CI 13.5-23.7 months). 2/10 received induction chemotherapy prior to CRT with 6/10 undergoing primary tumor resection (1 prior to CRT and 5 after CRT). Only 3 CRT patients were living at time of analysis (all underwent surgical resection), 2 without any active disease, 1 who achieved complete response with CRT then suffered recurrence and is still undergoing treatment. Conclusions: NEC of the anus and rectum is an aggressive malignancy with most patients experiencing metastatic disease at presentation and poor response to chemotherapy at all stages. Even those with LRD experience a very poor prognosis with OS of 18.9 months from diagnosis. For LRD, most patients underwent CRT with only a short-lived response (median PFS 6.3 months). Those achieving sustained response also underwent surgical resection. Overall, prognosis is poor for all stages and further study on a large scale is warranted to better characterize this rare, aggressive malignancy.

e16691 Background: Recent WHO classification of NET has defined high-grade well-differentiated NET (NET G3) as a distinct entity that is clinically different from neuroendocrine carcinoma. The optimal treatment for NET G3 has not been well-described. This study aims to evaluate NET G3 response to different treatment regimens. Methods: This is a retrospective study of NET G3 patients within the Mayo Clinic database (Arizona, Florida, and Minnesota). Patient demographics along with treatment responses and survival were assessed. Primary end points were progression-free survival (PFS) and objective response rate (ORR) by RECIST 1.1 criteria. Results: 71 patients with NET G3 were identified. Systemic treatment data was available in 30 patients who had a median age of 59.5 years at time of diagnosis. The primary tumor was most commonly pancreatic (73.3%). Ki 67 index was ≥55% in 26.7% of cases. 56.7% of cases had > 1 metastatic site. Treatment regimens included: capecitabine+temozolomide (CAPTEM) (n = 20), somatostatin analog (SSA) (n = 14), carboplatin/cisplatin+etoposide (EP) (n = 7), everolimus (n = 2), FOLFOX (n = 7), and lutetium Lu 177 DOTATATE (PRRT) (n = 10). CAPTEM was the most commonly used regimen (10 first-line, and 10 second-line) with ORR of 35%, disease control rate (DCR) of 65%, and median PFS of 9.4 months. The table summarizes the treatment data and responses rates for the various therapies used. Conclusions: Among NET G3 patients treated at Mayo Clinic, CAPTEM was found to be the most commonly used treatment with reasonable efficacy and disease control. Other treatment options include SSA, PRRT, FOLFOX, and EP. Prospective studies evaluating different treatments effects in NET G3 patients are needed to determine an optimal treatment strategy. [Table: see text]