Citations

PURPOSE: The 21st Century Cures Act mandates the immediate release of clinical information (IRCI) to patients. Immediate sharing of sensitive test results to patients with cancer might have serious unintended consequences for patients and providers. METHODS: A 22-question REDCap survey was designed by the Association of American Cancer Institutes Physician Clinical Leadership Initiative Steering Committee to explore oncology providers' opinions on IRCI policy implementation. It was administered twice in 2021 with a 3-month interval. A third survey with a single question seeking providers' opinions about their adaptation to the IRCI mandate was administered 1 year later to those who had responded to the earlier surveys. The data were analyzed using descriptive statistics such as chi-squared or Fisher's exact tests for categorical variables. The survey was sent to all Association of American Cancer Institutes cancer center members. In the first or second administration, 167 practitioners answered the survey; 31 responded to the third survey. RESULTS: Three quarters of the providers did not favor the new requirement for IRCI and 62% encountered questions from patients about results being sent to them without provider interpretation. Only half of the hospitals had a plan in place to deal with the new IRCI requirements. A third survey, for longitudinal follow-up, indicated a more favorable trend toward adoption of IRCI. CONCLUSION: IRCI for patients with cancer was perceived negatively by academic oncology providers after its implementation. It was viewed to be associated with higher levels of patient anxiety and complaints about the care delivered. Providers preferred to discuss test results with patients before release.

TPS780 Background: Pancreatic adenocarcinoma is an aggressive malignancy with a limited number of therapeutic options. One subset of patients (up to 15%) carries germline and/or somatic mutations in homologous recombination repair genes, most notably BRCA1, BRCA2 and PALB2 amongst others, that confer sensitivity to PARP inhibition. Combinations of PARP inhibitors with anti-PD1 immunotherapy have shown activity in breast and ovarian cancer and have not yet been thoroughly studied in pancreatic cancer. Methods: We designed a single-arm phase 2 investigator-initiated study utilizing the combination of niraparib, a highly selective PARP inhibitor and a dostarlimab, an anti PD1 antibody, in the subset of pancreatic cancer patients with germline or somatic mutations in BRCA1/2, PALB2, BARD1, RAD51C, or RAD51D. Additional inclusion criteria include metastatic pancreatic adenocarcinoma, receipt of a platinum agent in 1st or 2nd line unless contraindicated, and at least 1 but not more than 2 prior lines of systemic therapy not including maintenance. Prior PARP inhibition is allowed, but not immediately prior to enrollment. Exclusion criteria include active unstable autoimmune disease or prior malignancy requiring active treatment within 2 years. Patients are treated with niraparib 200 mg orally once daily on days 1 through 21 of a 21 day cycle. Dostarlimab is administered IV 500 mg every 3 weeks for the 1st 4 cycles and then 1000 mg IV every 6 weeks subsequently. The primary endpoint of the study is the disease control rate at 12 weeks using standard iRECIST criteria. Twenty patients will be enrolled to ensure 19 evaluable. The design has 80% power to detected improvement in disease control rate from 25-50% with significance level of 0.10. Descriptive factors include gene mutated for inclusion, germline/somatic, and platinum refractoriness. Given the size of the study along with genetic heterogeneity there will be no interim analysis. Patients are being enrolled at 3 Mayo clinic sites in Rochester Minnesota, Phoenix Arizona, Jacksonville Florida. To date, 13 patients have been enrolled across all 3 sites. Full accrual is anticipated by early 2023. Correlative studies include genomic characterization of baseline tumors, assessment of immune infiltration of tumor microenvironment, tumor collection for organoid/xenograft, and serial circulating cell-free DNA and immune biomarkers. Trial Identifiers: NCT04493060, Mayo: MC1841. Supported by Glaxo Smith Kline. Clinical trial information: NCT04493060 .

PURPOSE Oxaliplatin-based adjuvant chemotherapy in patients with stage III colon cancer (CC) for 6 months remains a standard in high-risk stage III patients. Data are lacking as to whether early discontinuation of all treatment (ETD) or early discontinuation of oxaliplatin (EOD) could worsen the prognosis. MATERIALS AND METHODS We studied the prognostic impact of ETD and EOD in patients with stage III CC from the ACCENT/IDEA databases, where patients were planned to receive 6 months of infusional fluorouracil, leucovorin, and oxaliplatin or capecitabine plus oxaliplatin. ETD was defined as discontinuation of treatment and EOD as discontinuation of oxaliplatin only before patients had received a maximum of 75% of planned cycles. Association between ETD/EOD and overall survival and disease-free survival (DFS) were assessed by Cox models adjusted for established prognostic factors. RESULTS Analysis of ETD and EOD included 10,447 (20.9% with ETD) and 7,243 (18.8% with EOD) patients, respectively. Compared with patients without ETD or EOD, patients with ETD or EOD were statistically more likely to be women, with Eastern Cooperative Oncology Group performance status ≥ 1, and for ETD, older with a lower body mass index. In multivariable analyses, ETD was associated with a decrease in disease-free survival and overall survival (hazard ratio [HR], 1.61, P < .001 and HR, 1.73, P < .001), which was not the case for EOD (HR, 1.07, P = .3 and HR, 1.13, P = .1). However, patients who received < 50% of the planned cycles of oxaliplatin had poorer outcomes. CONCLUSION In patients treated with 6 months of oxaliplatin-based chemotherapy for stage III CC, ETD was associated with poorer oncologic outcomes. However, this was not the case for EOD. These data favor discontinuing oxaliplatin while continuing fluoropyrimidine in individuals with significant neurotoxicity having received > 50% of the planned 6-month chemotherapy.

Abstract Background: Associations between candidate germline genetic variants and treatment outcome of oxaliplatin, a drug commonly used for patients with colorectal cancer, have been reported but not robustly established. This study aimed to construct polygenic hazard scores (PHSs) as predictive markers for oxaliplatin treatment outcome by using a supervised principal component approach (PCA). Methods: Genome-wide association analysis for overall survival, including interaction terms (SNP*treatment type) was carried out using two phase III trials, 3,098 resected stage III colon cancer (rCC) patients of NCCTG N0147 and 506 metastatic colorectal cancer (mCRC) patients of NCCTG N9741, separately. SNPs showing interaction with genome-wide significance (P &lt; 5 × 10–8) were selected for PCA to derive a PHS. PHS interaction with treatment was included in Cox regression models to predict outcome. Replication of prediction models was performed in an independent cohort, DACHS. Results: The two PHSs based on the first two principal components of selected SNPs (15SNPs for rCC and 13SNPs for mCRC) were used to construct interaction terms with treatment type and included in models adjusted for clinical covariables. However, in the DACHS study, the addition of the two PHS terms to clinical models did not improve the prediction error in either patients with rCC or mCRC. PHS interaction was also not replicated. Conclusions: The PHSs derived using principal components efficiently combined multiple predictive SNPs for estimating likelihood of benefit from oxaliplatin versus other treatment but could not be replicated. Impact: These results highlight the potential but also challenges in generating evidence for a predictive polygenic score for oxaliplatin efficacy.

PURPOSE The recommended duration of adjuvant fluoropyrimidine and oxaliplatin chemotherapy for patients with stage III colon cancer is based on tumor classification into clinically low-risk (T1-3 N1) and high-risk (T4 or N2) groups. We determined whether Immunoscore can enhance prognostication within these risk groups. MATERIALS AND METHODS Patients with stage III colon carcinomas (N = 600) were randomly selected from the infusional fluorouracil, leucovorin, and oxaliplatin arm of adjuvant trial NCCTG N0147 (Alliance for Clinical Trials in Oncology). Tumors were evaluated for Immunoscore that quantifies CD3+ and CD8+ T-cell densities in the tumor center and invasive margin by digital image analysis. Disease-free survival (DFS) by Immunoscore was analyzed using a multivariable Cox regression model in each risk group with adjustment for covariates including KRAS, BRAF V600E, and mismatch repair status. RESULTS Of 559 cancers with Immunoscore data, 299 (53.5%) were classified as clinically low-risk (T1-3 N1) and 260 (46.5%) as clinically high-risk (T4 and/or N2). Among patients with low-risk tumors, those with Immunoscore-Low versus Immunoscore-High tumors had significantly worse 5-year DFS rates (77.5% v 91.8%; hazard ratio, 1.70; 95% CI, 1.03 to 2.79; P = .037). Among patients with high-risk tumors, those with Immunoscore-Low versus Immunoscore-High tumors also had significantly worse DFS (55.3% v 70.3%; hazard ratio, 1.65; 95% CI, 1.11 to 2.47; P = .013). Tumors that were low-risk/Immunoscore-Low had similar outcomes as did tumors that were high-risk/Immunoscore-High ( P = .174). Prognostication was significantly improved in multivariable models where Immunoscore was added to clinical risk parameters and limited biomarkers (likelihood ratio test P = .0003). CONCLUSION Immunoscore can refine patient prognosis beyond clinical risk group classification, suggesting its potential utility for adjuvant decision making.

4130 Background: KRAS is mutationally activated in over 90% of pancreatic ductal adenocarcinoma (PDAC). Compared to pts with KRAS mutation, KRAS wild-type (wt) PDAC seem to have better response to therapy and may harbor potentially actionable molecular alterations. Here, we analyze the molecular profile and clinical outcome of a cohort of pts with KRAS wt PDAC. Methods: A retrospective review was conducted on pts with PDAC who underwent CLIA-certified Next Generation Sequencing (NGS) testing at Mayo Clinic between December 1, 2018 and December 1, 2021. Pts with KRAS wt PDAC with available reports were included. Their genomic drivers, RNA expression, demographics, disease characteristics, therapies offered, and clinical outcome data were collected. The study was approved by the institutional IRB. Results: Of the 241 eligible pts, 8% (19) has KRAS wt PDAC. Among those, 2 pts had no mutation identified by the gene/molecular panel used. Of the 17 pts (89%) with identified alterations, mutations found in ³ 2 pts were TP53 (53%), CDKN2A (16%) and CDKN2B/ERBB2/PTEN/MSH3/RNF43/FBXW7/KMT2D/GNAS (11% each). Chromosomal rearrangements were identified in 5 (26%): CADPS2-BRAF, GP2-ERBB2, PTPRK-RSPO3, EML4-NTRK3 and TFG-MET. RNA expression results were available in 12 pts: common overexpression were ERBB2 (27%) and MET/NRAS/MYC/CCDN1/CCNE1/AR (18% each); and the under-expression MGMT (18%). Among the 13 pts with available MSI status via NGS, 2 (11%) were MSI-high (both had high TMB [28.4 and 23.7 m/MB]) while all others were TMB < 10 m/MB. The median age at diagnosis was 61 years (68% males). 8/19 (42%) were Stage IV at diagnosis with 15/19 (79%) pts ultimately diagnosed with metastatic disease. Among metastatic pts, median lines of treatment received was 2.5 (range:0-4). 4 pts received FOLFIRINOX (FFX), 2 gemcitabine/ nab-paclitaxel (GP) and tumor response were comparable to previously reported results. 1 received 1st-line pembrolizumab and remained on therapy at the time of analysis. The median length of follow up from diagnosis was 29 months. A patient with TFG-MET re-arrangement previously progressed on FFX and GP was treated using a MET inhibitor, and achieved significant CA19-9 drop and pancreas tumor shrinkage at 1st restaging, with ongoing response. Conclusions: The molecular profile of KRAS wt PDAC is highly heterogeneous and difficult to generalize. Novel approaches (e.g., basket trials) are needed to develop therapy for this rare PDAC subgroup.

3525 Background: Tumor-infiltrating lymphocytes (TILs) are significantly associated with clinical outcomes in patients with colon cancer. However, the potential for a differential effect of TILs on prognosis based on primary tumor sidedness has not been studied. We determined the interaction between TILs and tumor sidedness in relationship to disease-free survival (DFS). Methods: We analyzed data on TIL densities by primary tumor sidedness in 1532 stage III colon carcinomas from participants in a phase III trial of FOLFOX-based adjuvant chemotherapy (NCCTG N0147). TIL densities were dichotomized as low or high (≤3 /HPF) based on an optimized cutoff previously identified for DFS in this cohort. Right-sided tumors were defined as proximal to the splenic flexure. Analysis of TILs and sidedness with DFS were examined using Kaplan-Meier methodology and multivariable Cox regression. Results: Overall, tumors with high vs low TILs had the best DFS [HRadj: 0.58 (95%CI: 0.45-0.74); Padj <0.0001]. The association of TIL densities with 5-yr DFS differed significantly by primary tumor sidedness ( Pinteraction (adj) = 0.045). Among right-sided tumors, high vs low TILs were significantly associated with improved DFS ( Padj <0.0001)[Table]. Among left-sided tumors, however, DFS did not differ significantly for high vs low TILs ( Padj =0.173)[Table]. Similar results for TILs and DFS by sidedness were found for pMMR cancers. We then analyzed our data in low risk (T1-3, N1) and high risk (T4 and/or N2) tumors. Among low risk tumors, high vs low TILs was significantly associated with improved 5-yr DFS only in right-sided tumors ( Padj =0.006) [Table]. Among high risk tumors, high vs low TILs were significantly associated with better DFS in both right-sided ( Padj<0.001) and left-sided ( Padj =0.024) tumors. Conclusions: Overall, tumors with high TIL densities had significantly better DFS in right-sided but not left-sided cancers. Among low risk patients, the association of high TILs with better DFS was limited to right-sided tumors. These findings suggest that TILs should be interpreted by sidedness for prognostication. ClinicalTrials.gov Identifier: NCT00079274 . [Table: see text]

Abstract Background This North Central Cancer Treatment Group (NCCTG) N064A (Alliance) phase II trial evaluated upfront chemoradiotherapy incorporating the EGFR inhibitor panitumumab, followed by gemcitabine and panitumumab for unresectable, non-metastatic pancreatic cancer. Methods The treatment consisted of fluoropyrimidine and panitumumab given concurrently with radiotherapy followed by gemcitabine and panitumumab for 3 cycles followed by maintenance panitumumab. The primary endpoint was the 12-month overall survival (OS) rate and secondary endpoints included confirmed response rate (RR), OS, progression-free survival (PFS), and adverse events. Enrollment of 50 patients was planned and the study fully accrued. Results Fifty-two patients were enrolled, but only 51 were treated and included in the analysis. The median age of patients was 65 years and 54.9% were women. Twenty-two patients received at least 1 cycle of systemic therapy following radiotherapy, but 29 patients received chemoradiotherapy only without receiving subsequent chemotherapy after completion of chemoradiotherapy. The overall RR was 5.9% (95% CI: 1.2%-16.2%). The 12-month OS rate was 50% (95% CI: 38%-67%) which fell short of the per-protocol goal for success (51.1%). The median PFS was 7.4 months (95% CI: 4.5-8.6) and the median OS was 12.1 months (95% CI 7.9-15.9). Grade 3 or higher adverse events were reported by 88%. Conclusion The combination of panitumumab, chemotherapy, and external beam radiation therapy was associated with very high rates of grades 3-4 toxicities and survival results did not meet the trial’s goal for success. This regimen is not recommended for further study (ClinicalTrials.gov Identifier NCT00601627).