Impact of primary tumor size/horizontal extent on survival in colorectal cancer

125

Background: Pathologic staging in colorectal cancer (CRC) is crucial in patient management. Data regarding the impact of size/horizontal tumor extent is limited, contradictory and currently excluded from the American Joint Committee on Cancer (AJCC) staging model. However, a previously published SEER analysis showed that AJCC stages I and IIIA have similar 2- and 5- year survival rates, and worse rates for stage II. Using the largest cohort to date, we report the impact of primary tumor size on CRC survival. Methods: Data were obtained from all US hospitals that contributed to the National Cancer Database (NCDB) between 2010 and 2015. Univariate and multivariate analyses were performed to identify factors associated with patient outcome. Kaplan-Meier analysis and Cox proportional hazards models were used to assess the association between tumor/patient characteristics and overall survival (OS). Results: A total of 61,145 patients were identified with a similar gender distribution (M/F:50.9%/49.1%). The mean age was 62.7years (SD+/-14.1) and 82% were non-Hispanic Whites. Majority had colon primary (82.7%) and 82.4% had microsatellite stable (MSS) disease. Distribution across stages I-IV was 20.1%, 32.1%, 34.7% and 13.2% respectively. Among the total study population, AJCC stage correlated closely with OS on multivariate analysis (HR 1.49, 2.29, 8.38 for stages II to IV compared to stage I), while the distinguishing power for tumor size was relatively mild (HR 1.19 and 1.33 for 5-10 cm and >5cm compared to <5cm). Among patients with stage II disease, tumors >10cm were associated with worse survival compared to those <5cm (HR 1.2; 1.03-1.39; p=0.22). Stage III disease also had differential survival rates; patients with tumors 5-10cm (HR 1.21; 1.14-1.28; p<0.001) and >10cm (HR 1.57; 1.37-1.80; p<0.001) had worse survival than those <5cm. Patients with stage II who did not receive adjuvant chemotherapy (CTX) had worse survival outcomes (HR 1.29; 1.08-1.55; p=0.005) compared to stage III disease who did. Accounting for tumor size, there was no statistically significant survival differences between stage I patients and stages II and III patients who received adjuvant chemotherapy. Conclusions: Tumors larger than 10cm have inferior outcomes among patients in the same AJCC stages. Stage II patients without adjuvant CTX did worse than stage III with CTX. Further studies are needed to clarify the role of tumor size in staging models. [Table: see text]

Is adjuvant chemotherapy beneficial for stage II-III goblet cell carcinoid/goblet cell adenocarcinoma of the appendix?

BACKGROUND

Goblet cell carcinoma (GCC), formerly known as goblet cell carcinoid, of the appendix constitutes less than 14% of all primary appendiceal neoplasms. Surgical resection is the main treatment and the role of adjuvant chemotherapy (AC) is not established. This study aims to evaluate the impact of AC in stage II-III appendiceal GCC.

METHODS

Patients with pathological stage II and III GCC who underwent surgical resection between 2006 and 2015 were identified from the National Cancer Database (NCDB) using ICD-O-3 morphology and topography codes: 8243/3 (goblet cell carcinoid) and C18.1. Patients treated with neoadjuvant systemic and/or radiation therapy and adjuvant radiation were excluded. Univariate and multivariable analyses were conducted, and Kaplan-Meier Curves were used to compare overall survival (OS) based on treatment received with Log-rank test.

RESULTS

A total of 619 patients were identified. 54.4% males and 89.0% Caucasian; median age 56 (range, 23-90) years. Distribution across pathological stages II-III was 82.7% (N = 512) and 17.3% (N = 107) respectively. AC was administered in 9.4% (N = 48) of stage II and 47.7% (N = 51) of stage III patients. For stage II patients, AC was not associated with better OS in univariate (HR 0.32; 95% CI 0.04-2.34; p = 0.261) or multivariable analyses (HR 0.29; 95% CI 0.04-2.12; p = 0.221). By contrast, in stage III patients, AC was associated with better OS in univariate (HR 0.35; 95% CI 0.17-0.71; p = 0.004) and multivariable analyses (HR 0.25; 95% CI 0.07-0.88; p = 0.031). In the entire cohort 5-year OS for patients that received AC was 85.5% (74.0%, 92.1%) versus 82.7% (77.5%, 86.8%) (p = 0.801) with no AC. For stage II patients, 5-year OS was 96.9% with AC vs. 89.1% with no AC (p = 0.236). For stage III patients, 5-year OS was 77.1% with AC vs. 42.8% with no AC (p = 0.003).

CONCLUSION

AC was associated with improved OS in patients with pathological stage III GCC of the appendix, but not with pathological stage II.

Perioperative therapy in metastatic colorectal cancer: Pattern of use and survival outcomes

BACKGROUND

Multimodality therapy of metastatic colorectal cancer (mCRC) is currently considered the standard of care. The aim of this study was to evaluate the impact of perioperative therapy on surgical resection in mCRC.

METHODS

The National Cancer Database was analyzed for affected patients between 2004 and 2013. Univariate and multivariate analyses were done to identify factors associated with patient outcomes. Kaplan-Meier analysis and Cox proportional hazards models were used for the association between patient characteristics and survival.

RESULTS

About 61,940 patients with mCRC were identified. Mean age = 63.4 years (SD ± 14). About 69% had a colon primary and 32% had only one metastatic site. Only 49% of those who underwent surgery for both primary and metastatic sites received postoperative chemotherapy (p < .001). Negative prognostic factors included no chemotherapy received (hazard ratio [HR], 2.32; 2.27-2.37; p < .001), more than three metastatic sites (HR, 2.28; 2.09-2.48; p < .001), year of diagnosis between 2004 and 2008 (HR, 1.71; 1.15-1.20; p < .001) and colon tumor location with right worse than left-sided (HR, 1.21; 1.19-1.24; p < .001). Five-year overall survival for resection of the primary and metastatic site (28.2%) was higher than for no surgical treatment (4.7%).

CONCLUSION

Perioperative therapy was associated with improved survival, following resection of metastatic sites or primary tumor.

Survival outcome of adjuvant chemotherapy in deficient mismatch repair stage III colon cancer

BACKGROUND

The prognostic impact of DNA mismatch repair (MMR) status remains controversial in patients with stage III colon cancer who are treated with adjuvant chemotherapy (AC). The aim of this study was to evaluate the survival outcome of AC in deficient mismatch repair (dMMR)/microsatellite instable (MSI) stage III CC.

METHODS

Patients with pathological stage III CC between 2010 and 2013 were identified from the National Cancer Database using International Classification of Diseases for Oncology (3rd Edition) morphology and topography codes 8140, 8480, and C18.0-18.8. Patients with pathologic stage T3N2, T4N1, or T4N were considered high risk; patients with stage T3N1 were considered low risk. Univariate and multivariable analyses were conducted, and Kaplan-Meier analysis and Cox proportional hazards models were used to identify the association between AC and overall survival (OS).

RESULTS

A total of 9226 patients with pathological stage III CC were identified, of which 2384 (25.8%) were MSI-high (MSI-H) and met the inclusion criteria of the final analysis. MSI-low (MSI-L) patients (n = 6842) were excluded. There was a preponderance of women (55.0% [n = 1311]), and 76.6% (n = 1825) of patients were non-Hispanic white. The median age was 65 years (range, 19-90 years). The primary sites were the cecum (29.7% [n = 707]), ascending colon (26.0% [n = 620]), sigmoid colon (17.2% [n = 410]), and transverse colon (10.8% [n = 257]). The most common tumor grade was moderately differentiated (n = 50.4% [1202]), followed by poorly differentiated (34.1% [n = 813]) and well differentiated (5.1% [n = 121]). High-risk pathologic stage III CC (T4N1, TxN2) constituted 51.0% (n = 1215) of the study population. High-risk stage III was associated with worse OS compared with low-risk stage III on univariate (P < .001) analysis and displayed a similar trend on multivariable analysis, without a statistically significant difference. Multiagent AC was associated with improved OS compared with no treatment on univariate (P < .001) and multivariable (P < .001) analysis. When stratified by risk status, multiagent AC was associated with improved OS compared with no treatment for high-risk (P < .001) and low-risk (P < .001) stage III disease.

CONCLUSION

Adjuvant chemotherapy is associated with better OS in stage III dMMR/MSI-H CC. An enhanced benefit was shown for high-risk stage III disease.

Nonsurgical Management of Rectal Cancer

Neoadjuvant chemoradiotherapy followed by surgical resection is the standard of care for locally advanced rectal adenocarcinoma. Up to one third of patients achieve pathologic complete response (CR) with neoadjuvant therapy. Promising disease-free and overall survival outcomes have been reported in patients who achieve clinical CR after neoadjuvant therapy without surgical resection. Furthermore, patients who have local recurrence have acceptable disease control outcomes with salvage resection. With consideration of morbidities associated with surgical resection and similar clinical outcomes, interest in nonsurgical management of low rectal cancers has emerged. Randomized clinical trials are being conducted to evaluate a nonsurgical approach in rectal cancer. Lack of consensus on the definition of clinical CR, molecular biomarkers, and standardized nonsurgical management protocols is a significant barrier for routine clinical implementation of a nonsurgical management approach. This article aims to provide a concise review of the clinical experience and practical approach to the nonsurgical management of locoregional rectal adenocarcinoma.

Adjuvant concurrent chemoradiotherapy in extrahepatic cholangiocarcinoma

4583

Background: Resected cholangiocarcinomas are rare and have high relapse rates. Adjuvant chemotherapy is the standard of care (BiLCAP Trial). Adjuvant radiation therapy benefit is not well defined. This study aims to evaluate survival outcomes of the effect of adjuvant chemoradiotherapy compared to chemotherapy in extrahepatic cholangiocarcinoma (EHC) using the National Cancer Database (NCDB). Methods: Patients with resected EHC between 2004 and 2013 were identified from the NCDB using ICD-O-3 histology and topography codes: 8140, 8160, 8161, 8162 and C24.0. Patients with neoadjuvant therapy were excluded from this analysis. Univariate and multivariable analyses were conducted, and Kaplan-Meier Curves were used to compare overall survival (OS) based on treatment received. Results: A total of 236 EHC patients were identified. Males comprised 60.6% and 88.1% were Caucasian. Median age was 64 (range, 31-84) years. The majority were distal (72.0%, N = 157) followed by perihilar (20.6%, N = 45), hilar (6.4%, N = 14) and cystic (0.9%, N = 2). Distribution across stages I-III was 28.8% (N = 68), 56.8% (N = 134), and 14.4% (N = 34), consecutively. Adjuvant chemotherapy was given in 37.7% (N = 89) and adjuvant chemoradiotherapy in 62.3% (N = 147). The median dose of radiation was 50.4 Gy. Adjuvant chemoradiotherapy was mostly given in regional node positive disease (p = 0.016) and negative surgical margin (p = 0.002) compared to regional node negative disease and positive surgical margin, respectively. The use of adjuvant chemoradiotherapy was associated with improved OS compared to chemotherapy alone in univariate (HR 0.64; 95% CI 0.44-0.93; p = 0.019) and multivariable analysis (HR 0.65; 95% CI 0.44-0.96; p = 0.030). Median survival and 1 year-OS for patients that received chemoradiotherapy was 33.8 months (95% CI 28, NA) and 87.7% (80.9%, 92.1%) compared to chemotherapy alone which was 23.8 months (95% CI 18.9, 35.4) and 75.5% (64.9%, 83.3%). Conclusions: Adjuvant chemoradiotherapy was associated with improved survival in patients with resected EHC compared to chemotherapy alone. This conclusion warrants further prospective studies to confirm these results.

Provider Recommendations for Phase I Clinical Trials Within a Shared Decision-Making Model in Phase I Cancer Clinical Trial Discussions

PURPOSE

Debate continues over whether explicit recommendations for a clinical trial should be included as an element of shared decision making within oncology. We aimed to determine if and how providers make explicit recommendations in the setting of phase I cancer clinical trials.

METHODS

Twenty-three patient/provider conversations about phase I trials were analyzed to determine how recommendations are made and how the conversations align with a shared decision-making framework. In addition, 19 providers (9 of whose patient encounters were observed) were interviewed about the factors they consider when deciding whether to recommend a phase I trial.

RESULTS

We found that providers are comprehensive in the factors they consider when recommending clinical trials. The two most frequently stated factors were performance status (89%) and patient preferences (84%). Providers made explicit recommendations in 19 conversations (83%), with 12 of those being for a phase I trial (12 [63%] of 19). They made these recommendations in a manner consistent with a shared decision-making model; 18 (95%) of the 19 conversations during which a recommendation was made included all steps, or all but 1 step, of shared decision making, as did 11 of the 12 conversations during which a phase I trial was recommended. In 7 (58%) of these later conversations, providers also emphasized the importance of the patient's opinion.

CONCLUSION

We suggest that providers not hesitate to make explicit recommendations for phase I clinical trials, because they are able to do so in a manner consistent with shared decision making. With further research, these results can be applied to other clinical trial settings.

A cost analysis of managing cancer-related pain among hospitalized US cancer patients

7079

Background: Pain is a common symptom of cancer, affecting patients' function and quality of life. It is also a common cause of hospitalization for cancer patients. The aim of this study was to evaluate the cost of in-hospital pain management among US cancer patients. Methods: A retrospective analysis of data from all US hospitals that contributed to the National Inpatient Sample for 2011-2015 was conducted. All cancer patients admitted for pain management were included in the analysis. Main outcomes were factors significantly associated with hospital length of stay, total charge per hospital stay, and in-hospital mortality. Weighted chi-square test was used for categorical covariates and univariate analysis was performed using a logistic model. Results: 122,776 patient discharges were identified. Mean age was 59.3 years and 52.3% were female. 65.9% stayed in the hospital for longer than 72 hours, with a median total hospital charge of $48,156. Conversely, the median total hospital charge for those spending less than 72 hours on admission was $15,966. Median total charge per hospital stay was similar among insured and uninsured/self-pay patients ($32,879 vs. $32,323; p=0.013), but higher in patients without metastatic disease ($33,315 vs. $29,369; p<0.001). It was also higher in those with the highest income quartile when compared with lowest income patients ($38,223 vs. $30,047; p<0.001). Co-morbid medical illnesses were more prevalent in those with longer hospital stay (15 vs. 12; p<0.001) and the overall in-hospital mortality rate was 8.2%. There was no significant difference in median total hospital charges between those who died in, or those discharged from the hospital ($33,746 vs. $32,795; p<0.001). On multivariate analyses, gender, race, insurance status, diagnosis of metastatic cancer, age, number of co-morbid medical illnesses, year of diagnosis, and median income were significant predictors of length of stay. Race, insurance payor, metastatic cancer, age, and number of co-morbid medical illnesses were significant predictors of total hospital charges, after adjusting for other covariates. Conclusions: In-patient pain management of cancer patients is associated with significant health care costs. Optimization of outpatient pain management strategies could significantly lower the cost of care for cancer.

Pharmacokinetics and safety following a single oral dose of niraparib in patients with moderate hepatic impairment

6054

Background: Niraparib is approved for the maintenance treatment of adult patients (pts) with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in a complete or partial response to platinum-based chemotherapy, or with similar cancers but advanced, associated with homologous recombination deficiency (HRD) and have been treated with ³3 prior chemotherapy regimens. Niraparib is extensively metabolized in the liver and eliminated via both hepatobiliary and renal routes. Objectives of this study included characterization of niraparib pharmacokinetics (PK) and safety in pts with normal hepatic function vs. pts with moderate hepatic impairment. Methods: This phase I, open-label, parallel-group, single-dose study enrolled pts with advanced solid tumors into 2 groups: normal hepatic function and moderately impaired hepatic function, defined as bilirubin >1.5 to 3 times the upper limit of normal and any aspartate aminotransferase elevation. Pts received a single 300-mg dose and underwent PK sampling for 7 days. Exposure parameters included maximum concentration (Cmax), area under the concentration-time curve calculated to last measured concentration (AUClast), and extrapolated to infinity (AUCinf). PK parameters were determined using a non-compartmental analysis in WinNonlin. Results: Seventeen pts were enrolled; 9 with normal hepatic function and 8 with hepatic impairment. Niraparib Cmax was 7% lower in pts with moderate hepatic impairment compared with pts with normal hepatic function (Table). Overall exposure was increased in pts with moderate hepatic impairment, with niraparib AUClast and AUCinf increased 45% and 60%, respectively. Safety data during the PK phase of the study is consistent with the known profile for niraparib. Conclusions: Pts with moderate hepatic impairment experienced increased niraparib exposure which did not noticeably alter the toxicity profile in this population. Clinical trial information: NCT03359850. [Table: see text]

Impact of tumor side on clinical outcomes in stage II and III colon cancer with known microsatellite instability status

4068

Background: Microsatellite instability high (MSI-H) status indicates better prognosis in early stage colon cancer (CC) compared to microsatellite stable (MSS). However, the impact of tumor side, left side (L) versus right side (R), is not described on clinical outcomes based on MSI status. Methods: Patients with pathological stage II and III primary adenocarcinoma of the colon between 2010 and 2015 were identified in the National Cancer Database (NCDB) using ICD-O-3 morphology and topography codes: 8140-47, 8210-11, 8220-21, 8260-63, 8480-81, 8490 and C18.0, 18.2,18.3, 18.5,18.6, 18.7. Univariate (UVA) and multivariable (MVA) survival analyses were conducted, and Kaplan-Meier Curves were used to compare overall survival (OS) based on tumor location and treatment received with Log-rank test. Results: A total of 35,071 patients with stage II (n = 17,629) and III (n = 17,442) CC were identified. 51.3% female; 81.5% Caucasian; median age 66 (range, 18-90). Majority of stage II and III tumors were R, 61.2% (n = 10,794) and 56.0% (n = 9,763). MSI-H was more common in stage II compared to III, 23.3% (n = 4,115) vs 18.2% (n = 3,171) (p < 0.0001). Survival was better in stage II MSI-H compared to MSS, 5 year-OS 75.1% vs 71.8% (p = 0.0057). However, stage III CC survival was better in MSS compared to MSI-H, 5-year OS 60.5% vs 58.0% (p < 0.001). In stage II MSI-H CC R was more common than left, 78.3 % (n = 3223) vs 21.7% (n = 892). There was no significant difference in survival between stage II MSI-H L vs R (5-year OS 76.2% vs 74.7%, p = 0.1578). Stage II MSS CC R was more common than L, 56.0% (n = 7571) vs 44.0% (n = 5943), and survival was better in L vs R (5-year OS 73.2% vs 70.8%, p = 0.0029). Stage III MSI-H CC was more common in R than L, 75.6% (n = 2397) vs 24.4% (n = 774) and survival was better in L (5-year OS 62.5% vs 56.5%, p = 0.0026). Stage III MSS CC was more common in R than L, 51.6% (n = 7366) vs 48.4% (n = 6905), and survival was better in L vs R (5-year OS 67.0% vs 54.4%, p < 0.001). Conclusions: Survival was better in left sided tumors compared to right in stage II MSS, stage III MSS and stage III MSI-H CC.

Blood-based next-generation sequencing analysis of neuroendocrine neoplasms

Background: Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplasms that span from well-differentiated neuroendocrine tumors (NETs) to highly aggressive neoplasms classified as neuroendocrine carcinomas (NECs). The genomic landscape of NENs has not been well studied. The aim of this study is to confirm the feasibility of next generation sequencing (NGS) testing circulating tumor DNA (ctDNA) in patients with NENs and characterize common alterations in the genomic landscape.

Results: Of the 320 NEN patients, 182 (57%) were male with a median age of 63 years (range: 8-93) years. Tumor type included pancreatic NET (N = 165, 52%), gastrointestinal NEC (N = 52, 16%), large cell lung NEC (N = 21, 7%), nasopharyngeal NEC (N = 16, 5%) and NEC/NET not otherwise specified (N = 64, 20%). ctDNA NGS testing was performed on 338 plasma samples; 14 patients had testing performed twice and 2 patients had testing performed three times. Genomic alterations were defined in 280 (87.5%) samples with a total of 1,012 alterations identified after excluding variants of uncertain significance (VUSs) and synonymous mutations. Of the 280 samples with alterations, TP53 associated genes were most commonly altered (N = 145, 52%), followed by KRAS (N = 61, 22%), EGFR (N = 33, 12%), PIK3CA (N = 30, 11%), BRAF (N = 28, 10%), MYC (N = 28, 10%), CCNE1 (N = 28, 10%), CDK6 (N = 22, 8%), RB1 (N = 19, 7%), NF1 (N = 19, 7%), MET (N = 19, 7%), FGFR1 (N = 19, 7%), APC (N = 19, 7%), ERBB2 (N = 16, 6%) and PTEN (N = 14, 5%).

Conclusions: Evaluation of ctDNA was feasible among individuals with NEN. Liquid biopsies are non-invasive methods that can provide personalized options for targeted therapies in NEN patients.

Patients and Methods: Molecular alterations in 338 plasma samples from 320 patients with NEN were evaluated using clinical-grade NGS of ctDNA (Guardant360^®) across multiple institutions. The test detects single nucleotide variants in 54-73 genes, copy number amplifications, fusions, and indels in selected genes.

Nonbacterial Thrombotic Endocarditis and Widespread Skin Necrosis in Newly Diagnosed Lung Adenocarcinoma

Nonbacterial thrombotic endocarditis (NBTE) is a rare entity most commonly diagnosed postmortem with rates in autopsy series ranging from 0.9 to 1.6%. A 63-year-old female with past medical history of hypertension and mitral valve prolapse presented to the hospital with shortness of breath, headache, and necrotic skin lesions on her hands and feet. Computed tomography (CT) scan of her chest demonstrated a pulmonary embolus in the right lower lung segmental artery and right upper lobe lobar to segmental pulmonary artery, a mass-like consolidation in the left upper lung field impeding the hilum. CT scan of the abdomen demonstrated metastatic disease in liver and bone and bilateral femoral deep vein thrombosis. Transesophageal echocardiography revealed severe mitral regurgitation with two small mobile plaques on the mitral valve and two immobile plaques on the descending aorta. Magnetic resonance imaging of the brain was consistent with subacute infarcts and metastatic disease. Bronchoscopy was performed and pathology revealed primary adenocarcinoma of the lung. She was treated with anticoagulation and systemic chemotherapy. The patient and family elected to proceed with hospice due to her clinical decline, poor performance status, and poor prognosis after a prolonged hospital stay. Underlying malignancy is detected in approximately 40–85% of patients with NBTE. Lung cancer is the most frequently associated malignancy followed by pancreatic, stomach, breast, and ovarian cancer. Widespread necrotic skin lesions as presenting symptoms of primary lung adenocarcinoma are rare. In the present case, the diagnosis of necrotic skin lesions and NBTE preceded that of the neoplastic disease. Necrotic skin lesions and NBTE can be the first manifestations of an occult malignancy causing extensive multi-organ infarcts. NBTE can present with such extensive skin lesions as a first presenting sign of malignancy. To the best of our knowledge, this is the first case to present with such extensive skin lesions as the first presenting symptom of lung adenocarcinoma.

Impact of high-risk features for stage II adenocarcinoma of the appendix

795

Background: Clinico-pathological high risk features are frequently utilized in adjuvant chemotherapy (AC) decisions in stage II colorectal cancer and their utility in stage II appendiceal adenocarcinoma (AA) is less established. The aim of this study is to determine the impact of high risk features on clinical outcomes and whether high risk features are predictive of AC benefit in stage II AA. Methods: Patients with pathological stage II AA between 2010 and 2015 were identified from the National Cancer Database (NCDB) using ICD-O-3 morphology and topography codes: 8140, 8480 and C18.1. High risk stage II AA was defined as having at least one of the following clinicopathological features: T4 tumor, < 12 lymph nodes examined, poorly differentiated histology, positive margins, or lymphovascular invasion. Patients with none of these features were defined as low-risk. Results: A total of 1,040 patients were identified. 51.0% males, 84.5% Caucasian; median age 61 (range, 19-90). 46.4% were determined to have high-risk stage II AA. High-risk status was associated with worse OS compared to low-risk in univariate (HR 1.55; 95% CI 1.18-2.02; p = 0.001) and multivariable analyses (HR 1.36; 95% CI 1.03-1.79; p = 0.028). High-risk stage II AA patients had significantly worse 5-year OS compared to low-risk patients (67.1% vs. 74.5%, p = 0.0013). AC was administered in 34.4% (n = 166) of high-risk patients and in 36.5% (n = 203) of low-risk patients. Among high-risk patients, AC was not associated with better OS in univariate (HR 0.86; 95% CI 0.59-1.26; p = 0.722) and multivariable analyses (HR 1.35; 95% CI 0.90-2.04; p = 0.324) compared to no AC. Similarly, among low-risk patients, AC was not associated with better OS in univariate (HR 0.92; 95% CI 0.60-1.39; p = 0.813) and multivariable analyses (HR 1.27; 95% CI 0.81-2.02; p = 0.334) compared to no AC. For high-risk patients, 5-year OS was 68.3% in patients that received AC vs. 66.5% in patients that did not (p = 0.722). For low-risk patients, 5-year OS was 74.0% in patients that received AC vs. 76.3% in patients that did not (p = 0.813). Conclusions: High-risk stage II AA patients had significantly worse 5-year OS compared to low-risk patients. AC did not improve survival regardless of high risk features in stage II AA.

Is adjuvant chemotherapy beneficial for stage II-III goblet cell tumors of the appendix?

796

Background: Goblet cell tumors (GCT) of the appendix are very rare tumors constituting 2.5%-5% of all primary appendiceal neoplasms. Role of adjuvant chemotherapy (AC) is not established for GCT. This study aims to evaluate the impact of AC in stage II-III appendiceal GCT. Methods: Patients with pathological stage II and III GCT who underwent surgical resection between 2006 and 2015 were identified from the National Cancer Database (NCDB) using ICD-O-3 morphology and topography codes: 8243/3, 8245/3 and C18.1. Patients treated with neoadjuvant systemic and/or radiation therapy and adjuvant radiation were excluded. Univariate and multivariable analyses were conducted, and Kaplan-Meier Curves were used to compare overall survival (OS) based on treatment received with Log-rank test. Results: A total of 1,046 patients were identified. 53.7% males and 89.0% Caucasian; median age 56 (range, 20-90) years. Distribution across pathological stages II-III was 83.6% (N = 874) and 16.4% (N = 172) consecutively. 8.3% (N = 73) of stage II and 50.6% (N = 87) of stage III patients received AC. In the total cohort, AC was not associated with better OS compared to no AC in univariate analysis (HR 1.84; 95% CI 1.26-2.67; p = 0.001) or multivariable analysis (HR 0.94; 95% CI 0.57-1.52; p = 0.790). For stage II patients, AC was not associated with better OS in univariate (HR 1.24; 95% CI 0.60-2.57; p = 0.562) or multivariable analyses (HR 1.67; 95% CI 0.76-3.64; p = 0.199). Similarly, in stage III patients, AC was not associated with better OS in univariate (HR 0.78; 95% CI 0.48-1.29; p = 0.340) or multivariable analyses (HR 0.55; 95% CI 0.28-1.04; p = 0.067). In the entire cohort 5-year OS for patients that received AC was 83.9% (80.3%, 86.9%) versus 70.7% (60.9%, 78.5%) (p = 0.001) with no AC. For stage II patients, 5-year OS was 77.3% with AC vs. 87.7% with no AC (p = 0.562). For stage III patients, 5-year OS was 64.8% with AC vs. 54.4% with no AC (p = 0.340). Conclusions: AC was not associated with improved 5-year OS in patients with pathological stage II and III GCT compared to no AC.

Clinicopathological features and survival outcomes of rare histologic variants of gallbladder cancer

BACKGROUND

Adenocarcinoma (AC) is the most common histological type in gallbladder carcinoma (GBC). Squamous cell carcinoma (SCC), adenosquamous carcinoma (ASC), and papillary carcinoma (PC) are rare histologic variants of GBC.

METHODS

Patients with AC, SCC, ASC, and PC of the gallbladder between 2004 and 2013 were identified from the National Cancer Database. Univariate and multivariate analyses were performed, and Kaplan-Meier curves were used to compare overall survival (OS) based on histological subtype.

RESULTS

A total of 5956 patients ≥18 years of age were included in the final analysis. Most patients (n = 5398; 90.6%) had AC compared with variant histologies. PC (n = 227; 3.8%) was the most common variant, followed by ASC (n = 216; 3.6%) and SCC (n = 115; 1.9%); 70.3% were female and 78.9% Caucasian. The median age was 70 (range, 25-90) years. Surgical resection was performed in 77.7% of AC, 53.0% of SCC, 88.9% of ASC, and 96.9% of PC (P < .001). Systemic therapy after surgery was administered in 25.1% of AC, 18.3% of SCC, 35.7% of ASC, and 19.4% of PC (P = .001). In multivariate analysis, multiagent chemotherapy was associated with improved OS in all histologies except for SCC and PC (p < .001), and adjuvant systemic therapy was associated with improved OS in ASC and AC (P < .001).

CONCLUSION

Survival differs between the gallbladder variants. Except for SCC, GBC variants underwent surgical resection more often than AC. Adjuvant systemic therapy was associated with improved OS in ASC and AC.

Clinical and molecular markers of immune checkpoint inhibitor (ICI) response in dMMR colorectal cancer (CRC) patients (pts)

225

Background: ICIs induce durable responses in dMMR CRC patients. However, clinical and molecular biomarkers of response to ICIs have not been well-established. In this study, we investigated impact of specific MMR gene loss, BRAF V600E mutation and clinical characteristics of pts on clinical outcomes of ICIs. Methods: Pts were eligible if they had confirmed dMMR CRC by IHC or MSI-H by PCR and received ICIs between 01/01/2012 and 05/01/2019 at Winship Cancer Institute of Emory University, Mayo Clinic, Vanderbilt or Stanford University. Due to the functional dependency, the groups were categorized as protein loss of MLH1+PMS2 vs MSH2+MSH6. Log-rank test, Cox hazard model and Fisher’s exact test were used for survival outcomes, the best response and the distribution of variables among the subgroups. Results: A total of 66 pts with dMMR CRC were identified and BRAF status was available for 41 pts. ORRs in MLH1+PMS2 and MSH2+MSH6 groups were 72.9% and 56.5% respectively (P = 0.189). At 2 years, PFS rates were 55.6% and 78.2% for MLH1+PMS2 and MSH2+MSH6 groups respectively (P < 0.001). Pts with BRAF V600E mutations had significantly worse outcomes as compared to pts with wild-type BRAF (2-year PFS rate of 35.0% and 73.3% respectively; P < 0.001). Notably pts < 65 had better 2-year disease control rates when compared to > 65 (71.1% and 41.5% respectively; P < 0.001). We also observed worse 2-year PFS rates in pts with liver metastases (P = 0.014). CRC side and tumor volume did not impact 2-year PFS rates in our cohort. Conclusions: Our data suggest that pts with loss of function in MSH2+MSH6 may have better 2 year-PFS rates compared pts with MLH1+PMS2 even though ORR favored MLH1+PMS2 group suggesting that ORR may not reflect the durability of ICI response in dMMR CRC patients. Consistently, pts with BRAF V600E mutation which is associated with MLH1 promoter methylation had significantly worse 2-year PFS rates. Overall, our findings suggest that BRAFV600E mutation, the affected MMR proteins, pt age, and site of metastasis may impact durability of ICI response in dMMR CRC patients.

Radiation as a single modality treatment in localized pancreatic cancer

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Background: Locally advanced pancreatic cancer (LAPC) is managed with multimodality therapy. A subset of patients with LAPC are not good candidates for aggressive treatment. The aim here is to evaluate the outcomes of single modality radiation therapy for LAPC using the National Cancer Database (NCDB). Methods: Data was obtained between years 2004 and 2013. Pancreatic ductal adenocarcinoma (PDAC) patients with unresectable local disease were identified excluding patients who received chemotherapy or surgery. Univariate and multivariable analyses identified factors associated with patient outcome. Kaplan-Meier analysis and Cox proportional hazards models were used for patient characteristics and overall survival (OS). Results: A total of 6,590 patients were included; 480 (6.9%) received radiation therapy only and 6470 (93.1%) received no treatment. Mean age was 73.5 (range, 28‐90) years, with the majority being White (N = 5685; 83.2%) and female (N = 3779; 54.4%). Poorly differentiated histology and tumors ≥ 4 cm ( > T3 stage) accounted for 47.8% and 52.7%, respectively. The median dose of radiation was 39.6 Gy. Stereotactic body radiation (SBRT) was given in 64 patients and external-beam/Intensity modulated radiotherapy (IMRT) in 416 patients. Charlson-Deyo score of +1 was seen in 34.4% of patients who received no treatment, 32.8% of patients who received SBRT and in 29.8% of patients who received external-beam IMRT. Radiation therapy was associated with improved OS compared to no treatment in univariate and multivariable analyses controlling for sex, Charlson-Deyo score, age, tumor size, amongst other covariates. Median OS for patients who received SBRT, external-beam/IMRT or no radiation was 8.6, 6.7 and 3.4 months; respectively (P < 0.001). There is a significant difference in 12-month OS for the SBRT cohort (31.9%; 95% CI 20.9%-43.5%) compared to patients who received no radiation (15.1%; 95% CI 14.2%-16.0%), similarly seen on multivariable analysis (HR 0.50; 95% CI 0.38-0.65; P < 0.001). Conclusions: The current study is the first to evaluate the efficacy of radiation as single modality therapy in LAPC. The results suggest a potential benefit for radiation therapy alone, in comparison to no treatment.

A phase II study of niraparib in combination with EGFR inhibitor panitumumab in patients with advanced colorectal cancer

TPS269

Background: Panitumumab (Pmab) is a recombinant monoclonal antibody that binds specifically to the human epidermal growth factor receptor (EGFR), and is indicated for metastatic colorectal carcinoma (mCRC). EGFR inhibition induces synthetic lethality with poly ADP ribose polymerase inhibitors (PARPi) by attenuating DNA repair pathways. This susceptibility to PARPi-induced cell death by EGFR inhibition is associated with deficient Non-homologous end joining (NHEJ), and Homologous recombination (HR) mediated DNA repair and persistence of DNA damage. Furthermore, efficacy of PARPi (such as niraparib) is highly correlated with platinum sensitivity. Cancer cell sensitivity and resistance to both PARPi and platinum have been associated with loss and restoration of HR DNA repair, indicating similar mechanisms of anticancer activity and resistance. Platinum sensitivity in CRC could therefore predict for anticancer properties of PARPi when utilized in the setting of synthetic lethality. Combining PARP and EGFR inhibition has the potential to confer synergistic benefit, while ameliorating resistance mechanism to PARPi. This study aims to evaluate the activity of the combination of niraparib and Pmab in RAS wildtype (WT) mCRC. Methods: Eligible patients for the trial include advanced, RAS WT mCRC who have been intolerant of, progressed on, or failed at least one line of systemic chemotherapy. Those currently on first line oxaliplatin-containing regimen are allowed on the trial if they have remained stable or better (PR or CR) for at least 4 months on that line of treatment, and are being considered for maintenance therapy as standard of care. Patients must also be 18 years old, ECOG PS 0-1 and measurable disease per RECIST 1.1. A safety run-in cohort of 6 eligible patients, and additional 20 patients with the same inclusion criteria will be enrolled. Pmab dose - 6 mg/kg IV on days 1 & 15 of each 28-day cycle; Niraparib - 200mg or 300mg (based on body weight and platelet count) orally continuously. Primary endpoint: clinical benefit rate (CR +PR + SD). Biomarker analysis includes skin biopsies evaluated for p-Caspace-3, PARP, p-MAPK, Ki-67, and p27. The study was activated in Sept. 2019. Clinical trial information: NCT03983993.

Phase Ib trial of pembrolizumab and XL888 in patients with advanced gastrointestinal malignancies: Results of the dose-escalation phase

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Background: XL888 is a selective inhibitor of heat shock protein 90 (HSP90). It modulates several oncogenic signaling pathways, and the tumor microenvironment. In preclinical models, XL888 potentiates efficacy of PD-1 inhibition. We report the results of the dose escalation (DE) portion of a phase Ib trial of combined XL888 and pembrolizumab (P) in advanced gastrointestinal adenocarcinomas. Methods: XL888 was administered orally (PO) in three dose levels of 45 (DL1), 90 (DL2), 60 (only if DLT on DL2) mg twice weekly with P 200 mg IV on day 1, in 21-day cycles. Eligible patients included stage IV or locally advanced unresectable gastrointestinal adenocarcinomas with at least one prior therapy (patients with colorectal (CRC) adenocarcinoma must have received oxaliplatin, irinotecan, and fluoropyrimidine), age ≥18 years, ECOG PS 0-1, adequate organ function, no prior anti-PD-1 or anti-PD-L1 agent. The primary endpoint was recommended phase II dose (RP2D), while secondary endpoints included safety and tolerability. Pre-treatment and on-treatment correlative peripheral blood specimens were collected. Results: A total of 14 patients were enrolled in the DE phase. 9 male, median age 66.5. Diagnoses included CRC (6), pancreatic adenocarcinoma (5), biliary tract cancer (1), ampullary (1), and duodenal (1). Two patients were ineligible for assessing the primary endpoint (DL2) due to biliary stent obstruction and sepsis. One DLT (grade 3 autoimmune hepatitis) was observed on DL2. We enrolled three patients on DL3. Five additional patients were subsequently enrolled on DL2 with no additional DLT. Three patients (1 duodenal, 2 CRC) had prolonged stable disease (6, 9 and 15 cycles). The most common treatment-related toxicities included autoimmune hepatitis (G3; n = 1), retinopathy (G2; n = 2), nausea (G2; n = 1), constipation (G2; n = 1), and diarrhea (G2; n = 3). Conclusions: The XL888 and pembrolizumab combination had an acceptable safety profile and the RP2D of XL888 was 90 mg twice weekly combined with P 200 mg, every 3 weeks. The dose expansion portion and a robust series of immunologic correlative laboratory studies for this study is ongoing. Clinical trial information: NCT03095781.

The impact of inflammatory biomarkers, BMI, and sarcopenia on survival in advanced hepatocellular carcinoma treated with immunotherapy

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Background: Sarcopenia and inflammation are independently associated with worse survival in cancer patients. This study aims to determine the impact of inflammatory biomarkers, BMI and sarcopenia on survival in advanced hepatocellular carcinoma (HCC) patients treated with immunotherapy. Methods: We performed a retrospective review of advanced HCC patients treated with immunotherapy-based therapies at Winship Cancer Institute between 2015 and 2019. Baseline computed tomography and magnetic resonance imaging scans were collected at mid-L3 level, assessed for skeletal muscle density using SliceOmatic (TomoVision, version 5.0) and converted to skeletal muscle index (SMI) by dividing it by height (m)2. Gender-specific sarcopenia was defined by median value of SMI. The optimal cut for continuous inflammation biomarker was determined by bias-adjusted log-rank test. Overall Survival (OS) was set as primary outcome and Cox proportional hazard model was performed. Results: 57 patients were included; 77.2% male, 52.6% Caucasian, 58.5% ECOG PS 0-1, 80.7% Child Pugh A. Treatment was second line and beyond in 71.9%. The median follow-up time was 6 months. Sarcopenia cut-off for males and females was SMI of 43 and 39, respectively. 49.1% of patients had sarcopenia. Median OS was 5 vs. 14.3 months in sarcopenic vs. non-sarcopenic patients (p=0.054). Median OS was 5 and 17.5 months in patients with BMI <25 and BMI ≥25 respectively (p=0.034). Median OS was 3.6 and 14.3 months for patients with neutrophil to lymphocyte ratio (NLR) ≥ 5.15 vs. NLR < 5.15 (p<0.001). In multivariable Cox regression model, higher baseline NLR was associated with worse OS (HR: 4.17, 1.52-11.39, p=0.005). Gender specific sarcopenia showed a trend of worse OS (HR: 1.71, 0.73-4.00, p=0.215) but was not statistically significant. BMI<25 was associated with worse OS (HR: 2.73, 1.15-6.53, p=0.023). In the association with PFS, neither baseline BMI nor gender specific sarcopenia showed statistical significance. Conclusions: Baseline BMI and NLR may predict OS after immunotherapy treatment. After controlling for baseline Child Pugh Score and NLR, gender specific sarcopenia was not associated with OS significantly.

A Phase I Study of Safety, Pharmacokinetics, and Pharmacodynamics of Concurrent Everolimus and Buparlisib Treatment in Advanced Solid Tumors

PURPOSE

Concurrent inhibition of mTOR and PI3K led to improved efficacy in preclinical models and provided the rationale for this phase I study of everolimus and buparlisib (BKM120) in patients with advanced solid tumor.

PATIENTS AND METHODS

We used the Bayesian Escalation with Overdose Control design to test escalating doses of everolimus (5 or 10 mg) and buparlisib (20, 40, 60, 80, and 100 mg) in eligible patients. Pharmacokinetic assessment was conducted using blood samples collected on cycle 1, days 8 and 15. Pharmacodynamic impact on mTOR/PI3K pathway modulation evaluated in paired skin biopsies collected at baseline and end of cycle 1.

RESULTS

We enrolled 43 patients, median age of 63 (range, 39-78) years; 25 (58.1%) females, 35 (81.4%) Caucasians, and 8 (18.6%) Blacks. The most frequent toxicities were hyperglycemia, diarrhea, nausea, fatigue, and aspartate aminotransferase elevation. Dose-limiting toxicities observed in 7 patients were fatigue (3), hyperglycemia (2), mucositis (1), acute kidney injury (1), and urinary tract infection (1). The recommended phase II dose (RP2D) for the combination was established as everolimus (5 mg) and buparlisib (60 mg). The best response in 27 evaluable patients was progressive disease and stable disease in 3 (11%) and 24 (89%), respectively. The median progression-free survival and overall survival were 2.7 (1.8-4.2) and 9 (6.4-13.2) months. Steady-state pharmacokinetic analysis showed dose-normalized maximum concentrations and AUC values for everolimus and buparlisib in combination to be comparable with single-agent pharmacokinetic.

CONCLUSIONS

The combination of everolimus and buparlisib is safe and well-tolerated at the RP2D of 5 and 60 mg on a continuous daily schedule.