Systemic Therapy for Melanoma: ASCO Guideline Update

PURPOSE

To provide guidance to clinicians regarding the use of systemic therapy for melanoma.

METHODS

American Society of Clinical Oncology convened an Expert Panel and conducted an updated systematic review of the literature.

RESULTS

The updated review identified 21 additional randomized trials.

UPDATED RECOMMENDATIONS

Neoadjuvant pembrolizumab was newly recommended for patients with resectable stage IIIB to IV cutaneous melanoma. For patients with resected cutaneous melanoma, adjuvant nivolumab or pembrolizumab was newly recommended for stage IIB-C disease and adjuvant nivolumab plus ipilimumab was added as a potential option for stage IV disease. For patients with unresectable or metastatic cutaneous melanoma, nivolumab plus relatlimab was added as a potential option regardless of BRAF mutation status and nivolumab plus ipilimumab followed by nivolumab was preferred over BRAF/MEK inhibitor therapy. Talimogene laherparepvec is no longer recommended as an option for patients with BRAF wild-type disease who have progressed on anti-PD-1 therapy. Ipilimumab- and ipilimumab-containing regimens are no longer recommended for patients with BRAF-mutated disease after progression on other therapies.This full update incorporates the new recommendations for uveal melanoma published in the 2022 Rapid Recommendation Update.Additional information is available at www.asco.org/melanoma-guidelines.

Phase I study of trifluridine/tipiracil in combination with gemcitabine (gem) and nab-paclitaxel (nab-P) in patients (pts) with advanced pancreatic ductal adenocarcinoma (PDAC)

731

Background: The incidence of PDAC is on the rise and it is predicted to be the 2nd leading cause of cancer related mortality in the next decade. Most patients present with advanced disease at diagnoses with limited systemic treatment options. Fluoropyrimidines are active in PDAC. Lonsurf (L) is an orally administered combination of a thymidine-based nucleic acid analogue, trifluridine, and a thymidine phosphorylase inhibitor, tipiracil hydrochloride. Preclinical data demonstrate Lonsurf may have activity in 5-FU resistant malignancies. This phase I study combines Gem, nab-P, and L. Methods: Gem and nab-P are dosed on days 1 and 15 IV on a 28 day cycle. L (20-30mg/m2) is dosed twice daily on days 2-6 and 16-20 (table 1). Dose escalation is by 3+3 design. Key eligibility include pts with untreated locally advanced or metastatic PDAC, ECOG 0-1, and adequate hepatic and bone marrow function. Results: 14 pts (median age 62 yrs [range 43-74]) have been enrolled. Dose was initiated at DL1. The first 3 pts were treated without DLT. DL2 exceeded the MTD with 1 patient experiencing grade 3 infection (cholangitis). Dose expansion to 7 patients was completed at DL 1 with no further DLTs. The RP2D is Gem 800mg/m2, Nab-P 100mg/m2, and L 25mg/m2. Of the 10 patients with evaluable disease, 2 (20%) had PR and 7 (70%) had SD. Pts were on study a median of 14 months (range 4 -31+). Most common grade 3/4 AEs include fatigue (46%,) neutropenia (38%), anemia (31%) anorexia (15%), nausea (15%), vomiting (15%), abdominal pain (15%), hyperglycemia (15%). No grade 5 events occurred. Conclusions: The RP2D is Gem 800mg/m2, Nab-P 100mg/m2, and L 25mg/m2. This combination was well tolerated with expected toxicities of myelosuppression with prolonged responses seen. Clinical trial information: NCT04046887 . [Table: see text]

Impact of acceptance and commitment therapy on physical and psychological symptoms in advanced gastrointestinal cancer patients and caregivers: Secondary results of a pilot randomized trial

Patients with advanced gastrointestinal cancer often experience high symptom burden, which is associated with heightened distress in both patients and their family caregivers. Few interventions have been tested to jointly address patient and caregiver symptoms in advanced gastrointestinal cancer. In a randomized pilot trial, telephone-based, dyadic acceptance and commitment therapy (ACT) was found to be feasible in this population. The present secondary analyses examined the impact of this intervention on patient and caregiver physical and psychological symptoms. Patients and caregivers (N = 40 dyads) were recruited from clinics in Indianapolis, Indiana and randomized to either six weeks of telephone-based ACT or education/support, an attention control condition. Outcomes were assessed at baseline and at 2 weeks and 3 months post-intervention. Study group differences in outcomes were not statistically significant. However, when examining within-group change, only ACT patients experienced moderate reductions in pain severity and interference at 2 weeks post-intervention (effect size [ES]=-0.47; -0.51) as well as moderate reductions in depressive symptoms at 2 weeks (ES=-0.42) and 3 months (ES=-0.41) post-intervention. ACT caregivers experienced moderate reductions in sleep disturbance (ES=-0.56; -0.49) and cognitive concerns (ES=-0.61; -0.85) across follow-ups. Additionally, caregivers in both conditions experienced moderate reductions in fatigue (ES=-0.38 to -0.70) and anxiety (ES=-0.40 to -0.49) across follow-ups. Findings suggest that ACT may improve certain symptoms in dyads coping with advanced gastrointestinal cancer and warrant replication in a larger trial.

Acceptance and commitment therapy for patient fatigue interference and caregiver burden in advanced gastrointestinal cancer: Results of a pilot randomized trial

BACKGROUND

Fatigue often interferes with functioning in patients with advanced cancer, resulting in increased family caregiver burden. Acceptance and commitment therapy, a promising intervention for cancer-related suffering, has rarely been applied to dyads coping with advanced cancer.

AIM

To examine the feasibility, acceptability, and preliminary efficacy of acceptance and commitment therapy for patient-caregiver dyads coping with advanced gastrointestinal cancer. Primary outcomes were patient fatigue interference and caregiver burden.

DESIGN

In this pilot trial, dyads were randomized to six weekly sessions of telephone-delivered acceptance and commitment therapy or education/support, an attention control. Outcomes were assessed at baseline and at 2 weeks and 3 months post-intervention.

SETTING/PARTICIPANTS

Forty patients with stage III-IV gastrointestinal cancer and fatigue interference and family caregivers with burden or distress were recruited from two oncology clinics and randomized.

RESULTS

The eligibility screening rate (54%) and retention rate (81% at 2 weeks post-intervention) demonstrated feasibility. At 2 weeks post-intervention, acceptance and commitment therapy participants reported high intervention helpfulness (mean = 4.25/5.00). Group differences in outcomes were not statistically significant. However, when examining within-group change, acceptance and commitment therapy patients showed moderate decline in fatigue interference at both follow-ups, whereas education/support patients did not show improvement at either follow-up. Acceptance and commitment therapy caregivers showed medium decline in burden at 2 weeks that was not sustained at 3 months, whereas education/support caregivers showed little change in burden.

CONCLUSIONS

Acceptance and commitment therapy showed strong feasibility, acceptability, and promise and warrants further testing.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04010227. Registered 8 July 2019, https://clinicaltrials.gov/ct2/show/NCT04010227?term=catherine+mosher&draw=2&rank=1.

Acceptance and commitment therapy for fatigue interference in advanced gastrointestinal cancer and caregiver burden: protocol of a pilot randomized controlled trial

BACKGROUND

Fatigue interference with activities, mood, and cognition is one of the most prevalent and bothersome concerns of advanced gastrointestinal (GI) cancer patients. As fatigue interferes with patient functioning, family caregivers often report feeling burdened by increasing responsibilities. Evidence-based interventions jointly addressing cancer patient fatigue interference and caregiver burden are lacking. In pilot studies, acceptance and commitment therapy (ACT) has shown promise for addressing symptom-related suffering in cancer patients. The current pilot trial seeks to test a novel, dyadic ACT intervention for both advanced GI cancer patients with moderate-to-severe fatigue interference and their family caregivers with significant caregiving burden or distress.

METHODS

A minimum of 40 patient-caregiver dyads will be randomly assigned to either the ACT intervention or an education/support control condition. Dyads in both conditions attend six weekly 50-min telephone sessions. Outcomes are assessed at baseline as well as 2 weeks and 3 months post-intervention. We will evaluate the feasibility, acceptability, and preliminary efficacy of ACT for improving patient fatigue interference and caregiver burden. Secondary outcomes include patient sleep interference and patient and caregiver engagement in daily activities, psychological flexibility, and quality of life. We will also explore the effects of ACT on patient and caregiver physical and mental health service use.

DISCUSSION

Findings will inform a large-scale trial of intervention efficacy. Results will also lay the groundwork for further novel applications of ACT to symptom interference with functioning and caregiver burden in advanced cancer.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT04010227 . Registered 8 July 2019.

Systemic Therapy for Melanoma: ASCO Guideline

PURPOSE

To provide guidance to clinicians regarding the use of systemic therapy for melanoma.

METHODS

ASCO convened an Expert Panel and conducted a systematic review of the literature.

RESULTS

A systematic review, one meta-analysis, and 34 additional randomized trials were identified. The published studies included a wide range of systemic therapies in cutaneous and noncutaneous melanoma.

RECOMMENDATIONS

In the adjuvant setting, nivolumab or pembrolizumab should be offered to patients with resected stage IIIA/B/C/D BRAF wild-type cutaneous melanoma, while either of those two agents or the combination of dabrafenib and trametinib should be offered in BRAF-mutant disease. No recommendation could be made for or against the use of neoadjuvant therapy in cutaneous melanoma. In the unresectable/metastatic setting, ipilimumab plus nivolumab, nivolumab alone, or pembrolizumab alone should be offered to patients with BRAF wild-type cutaneous melanoma, while those three regimens or combination BRAF/MEK inhibitor therapy with dabrafenib/trametinib, encorafenib/binimetinib, or vemurafenib/cobimetinib should be offered in BRAF-mutant disease. Patients with mucosal melanoma may be offered the same therapies recommended for cutaneous melanoma. No recommendation could be made for or against specific therapy for uveal melanoma. Additional information is available at www.asco.org/melanoma-guidelines.

A phase II trial of cabozantinib and erlotinib for patients with EGFR and c-Met co-expressing metastatic pancreatic adenocarcinoma (PDAC)

e16764

Background: Both EGFR and the c-MET receptors are overexpressed in a majority of PDACs. Inhibition of both receptors simultaneously may be required for anti-tumor activity. Erlotinib, an EGFR inhibitor, has modest activity in metastatic PDAC and is approved by the FDA in combination with gemcitabine. Cabozantinib is a tyrosine kinase inhibitor targeting AXL, FLT-3, KIT, MER, MET, RET, ROS1, TIE-2, TRKB, TYRO3, and VEGFR-1, -2, and -3. Preclinical data suggests that the addition of cabozantinib to erlotinib leads to tumor shrinkage and improvement in survival in a KPC PDAC mouse model compared to gemcitabine alone. This phase II study tests this hypothesis in patients with metastatic PDAC that co-express c-MET and EGFR. Methods: Key eligibility includes patients (pts) with metastatic PDAC with EGFR and c-MET overexpression (as determined by centrally tested IHC of 2+ or greater) that have progression on one prior chemotherapy regimen. Patients were treated with cabozantinib (40mg daily) and erlotinib (100mg daily) continuously. This dosing is based on previous combination data in NSCLC. This is a single arm two-stage phase II study with a primary endpoint of overall response rate. Secondary endpoints include of PFS, DCR and OS. Results: From October 2017 to October 2019, 43 pts were screened with 7 pts (median age 62 [range 51-76)] enrolled and treated on study. Pts had a median of 1 line of prior systemic chemotherapy. Most common reason for screen failure was due to lack of co-expression of c-MET and EGFR. EGFR IHC expression was +2 in 4 pts, +3 in 3 pts; c-MET IHC expression was +2 in 5 pts and +3 in 2 pts. Most common any-grade adverse events attributable to cabozantinib and erlotinib include: diarrhea (71%), AST increase (43%), fatigue (43%), nausea (43%), and rash (43%). Only one grade 3 event of fatigue occurred. All pts had clinical and/or radiographic progression within 1-2 months after initiating study therapy. Conclusions: The combination of cabozantinib and erlotinib was well tolerated with manageable toxicity. Due to lack of clinical responses, this study has been terminated due to futility. Clinical trial information: NCT03213626 .

Phase II study of fluorouracil (FU), leucovorin (LV), and nanoliposomal irinotecan (nal-IRI) in previously treated advanced biliary tract cancer (NAPOLI-2)

TPS593

Background: Biliary tract cancers (BTCs) are rare and aggressive malignancies. The current standard of care for advanced BTC is gemcitabine (GEM) plus cisplatin . Although there is no established second-line treatment, regimens such as FOLFOX, XELOX, FOLFIRI, XELIRI, GEM, and capecitabine have activity. Nal-IRI contains IRI free base encapsulated in liposome nanoparticles which shelter IRI from conversion to its active metabolite (SN-38) and increase intratumoral levels of SN-38 compared with IRI. FU/LV/nal-IRI has shown overall survival benefit and acceptable toxicity in patients (pts) with metastatic pancreatic adenocarcinoma following GEM-based therapy in the NAPOLI-1 trial. Methods: This is a single arm, open label, multicenter phase II study of pts with advanced BTC previously treated with gemcitabine plus platinum chemotherapy. Pts will receive nal-IRI 70 mg/m2 IV over 90 minutes, LV 400 mg/m2 IV over 30 minutes, and FU 2400 mg/m2 over 46 hours, every 14 days. The primary objective is to determine progression-free survival (PFS) rate at 4 months (4mo) using RECIST v. 1.1 criteria and central radiology review. Response assessments will occur using imaging every 8 weeks. All pts who receive at least 1 dose of the study treatment will be eligible for the primary analysis. We will substitute pts who screen fail or do not begin treatment. Median PFS reported for pts receiving second-line 5-FU doublet chemotherapy is 3 months with a PFS4mo of 30%. FU/LV/nal-IRI would be of interest if it could increase the PFS4mo to 50% or higher. We will use a 2-stage Simon Minimax design. Using a one-sided α of 0.05 and 80% power, 39 pts will be required to detect a difference in PFS4mo between 30% and 50%. Assuming a dropout rate of 10%, 44 pts will be enrolled across the 5 study sites. Enrollment began in Q2 2019. Clinical trial information: NCT04005339.

Clinical Assessment of 5-Fluorouracil/Leucovorin, Nab-Paclitaxel, and Irinotecan (FOLFIRABRAX) in Untreated Patients with Gastrointestinal Cancer Using UGT1A1 Genotype-Guided Dosing

PURPOSE

5-Fluorouracil (5-FU)/leucovorin, irinotecan, and nab-paclitaxel are all active agents in gastrointestinal cancers; the combination, FOLFIRABRAX, has not been previously evaluated. UDP Glucuronosyltransferase 1A1 (UGT1A1) clears SN-38, the active metabolite of irinotecan. UGT1A1*28 polymorphism reduces UGT1A1 enzymatic activity and predisposes to toxicity. We performed a trial to assess the safety and tolerability of FOLFIRABRAX with UGT1A1 genotype-guided dosing of irinotecan.

PATIENTS AND METHODS

Patients with previously untreated, advanced gastrointestinal cancers received FOLFIRABRAX with prophylactic pegfilgrastim every 14 days. UGT1A1 *1/*1, *1/*28, and *28/*28 patients received initial irinotecan doses of 180, 135, and 90 mg/m2, respectively. 5-FU 2,400 mg/m2 over 46 hours, leucovorin 400 mg/m2, and nab-paclitaxel 125 mg/m2 were administered. Doses were deemed tolerable if the dose-limiting toxicity (DLT) rate during cycle 1 was ≤35% in each genotype group. DLTs were monitored using a sequential procedure.

RESULTS

Fifty patients enrolled, 30 pancreatic, 9 biliary tract, 6 gastroesophageal, and 5 others. DLTs occurred in 5 of 23 (22%) *1/*1 patients, 1 of 19 (5%) *1/*28 patients, and 0 of 7 *28/*28 patients. DLTs were all grade 3: diarrhea (3 patients), nausea (2 patients), and febrile neutropenia (1 patient). The overall response rate was 31%. Response rates in pancreatic, gastroesophageal, and biliary tract cancers were 34%, 50%, and 11%, respectively. Eighteen patients (36%) received therapy for at least 24 weeks.

CONCLUSIONS

FOLFIRABRAX with genotype-guided dosing of irinotecan is tolerable in patients with advanced gastrointestinal cancer and UGT1A1*1*1 or UGT1A1*1*28 genotypes. Too few *28/*28 patients were enrolled to provide conclusive results. Responses occurred across multiple tumor types.

Chronic inflammatory demyelinating polyradiculoneuropathy secondary to immune checkpoint inhibitors in melanoma patients

IMPORTANCE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an autoimmune neurological disorder that is characterized by symmetrical progressive worsening or relapsing weakness and numbness of the limbs. There are no reliable diagnostic tests or definitive diagnostic criteria, and the diagnosis remains one of excluding other cases of polyneuropathy. Typical treatment for CIDP includes corticosteroids, intravenous immunoglobulin (IVIG), and plasma exchange. Little is known about CIDP as a treatment complication of immune checkpoint inhibitors (ipilimumab and nivolumab). This report will be helpful in increasing awareness and knowledge about this unique entity.

OBSERVATIONS

We describe two cases of CIDP secondary to treatment with combined ipilimumab and nivolumab in patients with metastatic melanoma that were successfully treated with prednisone and IVIG. Conclusion and Relevance: This report illustrates that treatment with immune checkpoint inhibitors can lead to CIDP that can be successfully treated with complete resolution of symptoms. CIDP secondary to checkpoint inhibitors may have unique features such as low-grade lymphocytic pleocytosis on CSF evaluation as well as severe neuropathic pain as an early presenting symptom. Additionally, it is interesting to note that both patients presented in this report remained melanoma-free on follow-up more than 16 months later.

Phase 1 study of EUS-guided photodynamic therapy for locally advanced pancreatic cancer

BACKGROUND AND AIMS

Locally advanced pancreatic cancer (LAPC) has a poor prognosis. There are limited data describing the use of photodynamic therapy (PDT) for pancreatic cancer in humans. We hypothesized that EUS-guided PDT for LAPC is safe, technically feasible, and produces a dose- and time-dependent increasing degree of image-defined tumor necrosis.

METHODS

In a single-center, prospective, dose-escalation phase 1 study, patients with treatment-naïve LAPC received intravenous porfimer sodium (Concordia Laboratories Inc, St Michael, Barbados) followed 2 days later by EUS-PDT. EUS-PDT was performed by puncture with a 19-gauge needle and insertion of a 1.0-cm light diffuser (Pioneer Optics, Bloomfield, Conn) and illumination with a 630-nm light (Diomed Inc, Andover, Mass). A CT scan 18 days after PDT was done to assess for change in pancreatic necrosis. Nab-paclitaxel (125 mg/ m² intravenously) and gemcitabine (1000 mg /m² intravenously) were initiated 7 days after CT and given weekly for 3 of 4 weeks (1 cycle) until disease progression or unacceptable toxicity.

RESULTS

Twelve patients (mean age, 67 ± 6 years; 8 male) with tumors (mean diameter, 45.2 ± 12.9 mm) in the head and/or neck (8) or body and/or tail (4) underwent EUS-PDT. Compared with baseline imaging, increased volume and percentage of tumor necrosis were observed in 6 of 12 patients (50%) after EUS-PDT. The mean overall increases in volume and percentage necrosis were 10 ± 26 cm³ (P = .20) and 18% ± 22% (P = .016), respectively. After a median follow-up of 10.5 months (range, 1.0-37.4 months), median progression-free (PFS) and overall survival (OS) were 2.6 months (95% confidence interval, 0.7, not estimable) and 11.5 months (95% confidence interval, 1.1, 16.9), respectively. Surgical resection was attempted in 2 patients, and pathology showed a complete response (n = 1) and residual 2-mm tumor (n = 1). There were 8 serious adverse events and none related to EUS or EUS-PDT.

CONCLUSION

EUS-PDT for LAPC appears to be safe and produces measurable imaged-defined tumor necrosis. Phase 2 studies are warranted. (Clinical trial registration number: NCT01770132.).

Neoadjuvant therapy duration and outcome of patients with resectable and borderline resectable pancreatic ductal adenocarcinoma (PDAC)

436

Background: Neoadjuvant chemotherapy (NA CT) may improve surgical selection for resectable (R) PDAC, and margin negative resection in borderline resectable (BR) PDAC. Optimal duration of NA CT is unknown, as is the role of XRT with modern chemotherapy. We compared survival outcomes by duration of NA CT and NA CT + XRT. Methods: Patients with R or BR PDAC who underwent NA CT with or without XRT and followed by curative resection were included in this analysis. Data was extracted from an IRB approved pancreatic cancer database at Indiana University. Disease Free (DFS) and Overall (OS) survival were calculated from the surgery date and compared between: 1) < 3 v ≥ 3 months NA CT and 2) NA CT with/without XRT. Results: Between Summer 2008 and Summer 2018, 116 patients received NA CT with or without XRT and completed surgical resection. Median (range) age was 63 years (36, 84), stages were R=47%, BR=53%. Most patients received modified FOLFIRINOX or FOLFIRINOX (59 %), or gemcitabine/nab-paclitaxel (13%) and 24% received XRT. There were four (3 %) pathologic complete responders, all in the ≥ 3 mo NA CT + XRT group. Percent node positive was lower in NA CT + XRT versus NA CT only (median 0% vs 7.4%, p < 001), but did not differ by duration of NA CT. With a median (range) follow-up time of 13.7 mo (0.7, 83.0), median OS was 22.5 mo (19.5, 29.8) with < 3 mo NA CT versus 16.3 (12.2, 18.9) with ≥ 3 mo NA CT (p = 0.02) and was 22.6 mo (17.0, 82.9) with NA CT + XRT versus 19.5 (13.1, 22.5) in NA CT only (p = 0.03). There was no difference in DFS by duration of NA CT or XRT. Conclusions: In this study, patients who received a shorter course of chemotherapy and radiation had improved mOS when calculated from the surgery date. While this unexpected results could reflect selection bias of therapy, further analysis will account for tumor stage at diagnosis, perioperative complications and use propensity score adjustment to examine/adjust for possible treatment selection bias.

Integrating therapies for surgical adult soft tissue sarcoma patients

Sarcomas are an uncommon group of over 50 different individual histological malignancies arising from mesenchymal (non-epithelial or connective) tissues. Overall, they constitute 1% of human malignancies with an annual incidence rate of fewer than 5 patients per million. Sarcoma may arise from any mesenchymal cell lineages including fat, muscle, or other connective tissues. Due to the rarity of these groups of malignancies, many subtypes were, and still today, are managed as a single entity. This review focused on soft tissue sarcomas with an emphasis on how to integrate therapies for patients with this rare disorder. The role for surgical resection in cure and palliation as well as the relative benefits of adjuvant therapies such as chemotherapy and radiation therapy are discussed.

The impact of research presented at annual gastrointestinal cancers symposium

757

Background: The Gastrointestinal (GI) Cancers Symposium provides a multidisciplinary forum to both present research and gain expertise in the management of GI cancers. We conducted a study to understand the research trends, publication rate and the overall impact of research presented. Methods: A bibliometric review of the conference proceedings of the Symposium from 2013-2015 was undertaken. Data collected on each abstract included author number, demographic information of the presenting author, presentation type, cancer type, research focus (multidisciplinary treatment; prevention, diagnosis and screening; translational research) and research design. A PubMed search was used to determine overall and specific publication data. Descriptive statistics were compiled. Chi-square was used to compare groups. Results: The number of abstracts presented has increased (584 in 2013, 652 in 2014 and 794 in 2015). Fraction of oral presentations by year were similar (2.0%, 2.1% and 1.8%). Median number of authors per abstract was 9 (range 1-20). The subject area in all three years was dominated by multidisciplinary treatment (mean 58.6%), followed by translational research (mean 25.5%) and lastly Prevention, Diagnosis and Screening (mean 15.8%). The most common study design was observational (mean 43.5%), followed by case series (mean 27%), clinical trial (mean 19.8%) and other (mean 9.2%). Overall, 51.5%, 46.9% and 40.4% of the abstracts presented in 2013, 2014 and 2015 were published. The median time to publication was 14.5 months (range 0-49 months). The majority of published abstracts were published in journals with impact factor (IF) < 5 (mean 66.5%) and a small percentage (mean 8.4%) of abstracts were published in high impact journals (IF > 10). Abstracts selected for oral presentation were associated with publication in a journal with high IF (p < 0.001). The presenting author was more commonly male (70%) and a medical oncologist (61.5%). Conclusions: Overall participation is increasing in the Symposium. Selection for oral presentation appeared to be a good marker for both publication and higher impact. Prevention, diagnosis, and screening studies were under-represented and clinical trials were also relatively uncommon.

Safety and tolerability of 5-FU, irinotecan (IRI), and nab-paclitaxel (FOLFIRABRAX) with genotype-guided dosing of IRI in previously untreated patients with advanced gastrointestinal (GI) malignancies

423

Background: 5-FU, IRI, and nab-paclitaxel (NP) are active in advanced GI cancers; the combination (FOLFIRABRAX) has not been evaluated. UGT1A1 clears SN-38, the active metabolite of IRI. UGT1A1*28 polymorphism reduces enzymatic activity and predisposes to severe IRI toxicity. Dose adjustment in patients with this allele may be warranted. Primary objective: to determine the dose-limiting toxicity (DLT) rate of FOLFIRABRAX with genotype-guided dosing of IRI. Secondary objectives included determining objective response rates (ORR) in GI cancers. Methods: Pts with previously untreated GI cancers and ECOG performance status 0/1 received FOLFIRABRAX with prophylactic pegfilgrastim Q14 days. CT scans were obtained Q8 weeks. UGT1A1 *1/*1, *1/*28, and *28/*28 patients (pts) received initial IRI doses of 180, 135, and 90mg/m2, respectively. 5-FU 2400mg/m2 over 46 hours (no bolus), leucovorin 400mg/m2, and NP 125mg/m2 were given IV Q14 days. DLT during cycle 1 was defined as Grade (Gr) 3/4 febrile neutropenia (FN), Gr 4 neutropenia ≥ 5 days, Gr 3/4 non-hematologic toxicity despite medical management, or treatment delay > 14 days due to toxicity. Doses were tolerable if DLT rate during cycle 1 was ≤ 35%. Enrollment of 17 pts per genotype would allow for an α level of 0.05 with 80% power under a sequential toxicity monitoring procedure, with 6 or fewer DLTs being tolerable. Results: 39 pts are evaluable for toxicity: 23 pancreatic cancer (PC), 6 gastroesophageal cancer (GE), 9 biliary tract cancer (BTC), 1 neuroendocrine. DLTs were observed in 4/20 (20%) *1/*1 pts, 1/15 (7%) *1/*28 pts, and 0/4 *28/*28 pts. DLTs were Gr 3 diarrhea (2 pts), Gr 3 nausea (2), and Gr 3 FN (1). ORR is 6/29 (21%), with responses in PC (3/17 evaluable pts, 18%) and GE (3/5 pts, 60%), but no responses in BTC (0/7 pts). Conclusions: FOLFIRABRAX with genotype-guided dosing of IRI is tolerable in pts with advanced GI cancers and UGT1A1*1*1 or UGT1A1*1*28 genotypes. There is activity in PC and GE but not in BTC. Accrual is ongoing to the 3 genotype cohorts to a goal of 51 pts. Study conducted by the University of Chicago Personalized Cancer Care Consortium Clinical trial information: NCT02333188.

Association of RAS mutations with race in metastatic colorectal cancer: CALGB/SWOG 80405 (ALLIANCE)

638

Background: Colorectal cancer (CRC) is a heterogeneous disease with distinct molecular subtypes in part based on RAS mutational status. It is plausible that RAS mutations are differentially distributed between CC and AA and may contribute to poor outcomes in AAs with CRC. Methods: We did a retrospective analysis of CALGB/SWOG 80405 trial patients. We divided the entire cohort into 2 groups: a) Common RAS: mutation in KRAS exon 2, codon 12 or 13; b) Extended RAS: any NRAS mutations or mutation in KRAS except those listed above. We then analyzed these two subgroups for association between RAS mutations and race (3 categories: Caucasian, AA, Others) using chi-square test for univariate analyses and logistic regression for multivariate analysis. We also analyzed the effect of extended RAS testing on prognosis of metastatic CRC by estimating the overall survival (OS) using Kaplan-Meier method and 95% confidence interval (CI). Cox proportional-hazard model was used for multivariate analyses. Results: There were 1729 CRC patients in common RAS group of which 357 (20.6%) had mutations present. Extended RAS group had 621 patients of which 95 (15.5%) had mutations present. There was no significant difference in the rate of common RAS mutations between CC and AA (20.5% vs. 24%, p=0.22). However, extended RAS mutations were significantly more in AA as compared to CC (25% vs. 14%, p=0.02). Multivariate analysis adjusted for age, gender, prior adjuvant chemotherapy and pelvic radiation confirmed higher odds of extended RAS mutation in AA compared to CC (adjusted OR 1.12; 95% CI 1.01-1.23; p=0.02). The median OS in patients with an extended RAS mutation was shorter as compared to those without extended RAS mutation (25.3 vs. 31.9 months; HR 1.26; 95% CI 0.99-1.62; p=0.05). Multivariate analyses adjusted for age, gender, race, prior adjuvant chemotherapy and pelvic radiation showed a trend towards longer OS in patients without extended RAS mutation as compared those with extended RAS mutation (adjusted HR= 1.24, 95% CI, 0.97-0.1.58, p=0.08). Conclusions: Extended RAS mutations are significantly more common in AA as compared to CC. Additionally, presence of extended RAS mutation may confer a poor prognosis in CRC patients.

Impact of Nab-Paclitaxel-based Second-line Chemotherapy in Metastatic Pancreatic Cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with median survival of 20% at 1 year. We conducted a retrospective study to assess the efficacy and tolerability of nab-paclitaxel (NP)-based second-line chemotherapy in metastatic PDAC.

PATIENTS AND METHODS

The Indiana University Simon Cancer Center pancreatic cancer program was used to identify patients with metastatic PDAC who received any second-line chemotherapy. Demographic, clinical and outcomes data were collected by manual chart abstraction. Patients were divided into two groups: a NP-based treatment group and a non- NP-based treatment group. Overall (OS) and progression-free (PFS) survival were estimated using Kaplan-Meier method. Cox proportional hazards regression was used for multivariate analyses.

RESULTS

A total of 120 patients received second-line chemotherapy. There were 47 (39%) patients in the NP group and 73 (61%) in the non-NP group. As compared to the non-NP group, the NP group showed improved median PFS [2.8 vs. 2.1 months; hazard ratio (HR)=0.62, 95% confidence interval (CI)=0.38-1.02; p=0.06] and median OS (7.5 vs. 4.7 months; HR=0.67, 95% CI=0.45-1.00; p=0.05). Multivariate analyses adjusted for age showed a significantly improved PFS (adjusted HR=0.60, 95% CI=0.36-0.98; p=0.04) and a suggestion of improved OS (adjusted HR=0.67, 95% CI=0.44-1.01, p=0.05) in the NP group as compared to non-NP group. Serious adverse events were seen in 13.3% of patients in the non-NP group and 17.1% patients in the NP group.

CONCLUSION

In a single-institution retrospective cohort study, we report a significant improvement in the PFS and suggestion of improvement in the OS with NP-based second-line chemotherapy with an acceptable toxicity rate.

A phase Ib/II study of cancer stemness inhibitor napabucasin (BBI-608) in combination with gemcitabine (gem) and nab-paclitaxel (nabPTX) in metastatic pancreatic adenocarcinoma (mPDAC) patients (pts)

4106

Background: Cancer stem cells are fundamentally important for resistance to therapy, recurrence and metastasis. Napabucasin is a first-in-class cancer stemness inhibitor in development identified by its ability to inhibit STAT3-driven gene transcription and spherogenesis of cancer stem cells (Li et al, PNAS 112(6):1839, 2015). Preclinical studies suggest that napabucasin sensitizes heterogeneous cancer cells to chemotherapy and targeted agents. Methods: A phase Ib/II multi-center study in mPDAC pts was performed to confirm the RP2D, PK profile and evidence of anticancer activity of napabucasin in combination with nabPTX and Gem. Pts received napabucasin 240 mg BID with weekly nabPTX 125 mg/m2 and gem 1000 mg/m2for 3 out of every 4 weeks until disease progression (PD) or other discontinuation criterion. Results: Of 71 intent to treat (ITT) pts enrolled, 49 (69%) were treatment-naïve and 22 (31%) received neoadjuvant treatment. There were no significant PK interactions, dose-limiting or unexpected toxicities. Most common adverse events (AEs) included grade 1 diarrhea/cramping, nausea and fatigue with grade 3 AEs noted in 12 pts: fatigue (8), electrolyte imbalance (2), diarrhea (1), dehydration (1), nausea (1) and weight loss (1). Among pts who received RECIST evaluation (60), disease control (DCR; CR+PR+SD) was observed in 55 (92%), with 1 CR (2%) and 26 PR (43%) (31 - 78% regression). Of 11 pts with non-evaluable disease, treatment stopped due to compliance (4), consent withdrawal (3), clinical PD (1), toxicity (1), insurance (1) and death (1). Among 71 ITT pts, DCR was observed in 55 (77%), with 1 CR (1.4%) and 26 PR (37%). Maturing median progression free survival and overall survival (OS) in ITT pts is >7.1 and >10.4 m, respectively. Conclusions: This study showed that napabucasin can be combined with nabPTX and gem, with encouraging signs of efficacy in mPDAC now being confirmed in a phase 3 study. Clinical trial information: NCT02231723. [Table: see text]

A phase II study of pembrolizumab in combination with mFOLFOX6 for patients with advanced colorectal cancer

3541

Background: Pembrolizumab (PEM) has activity in patients with deficient mismatch repair (dMMR) colorectal cancer (CRC). Oxaliplatin (OX) and 5FU lead to immunogenic cell death and increased antigen presentation. We hypothesized that combining mFOLFOX6 and PEM may enhance immunogenic cell death and improve outcome in patients with CRC irrespective of MMR status. Methods: Subjects ≥18 years old with untreated, unresectable CRC were assigned to a single arm study. The study had a safety run in cohort of six patients (OX 85 mg/m2, leucovorin 400 mg/m2, 5FU 400 mg/m2, 5FU infusion 2400 mg/m2over 46 hours) and PEM 200 mg Q 3 weeks, followed by a phase II cohort. The primary objective was median progression free survival (mPFS), with secondary objectives: safety and toxicity per CTCAE V4.03, median overall survival, response rate, immune related response, disease control rate, and molecular correlates. Results: Between 4/2015 and 9/2016, 30 subjects were enrolled with following characteristics: 11 female, 26 Caucasian, median age: 45 years (25-75), 3 with dMMR, 22 MMR-proficient, and 5 with no available data. During the safety run in, 2 patients had G3 febrile neutropenia (FN) and 1 G4 neutropenia. The data safety monitoring committee recommended dose reduction of mFOLFOX6 to OX 68 mg/m2, leucovorin 400 mg/m2, 5FU of 320 mg/m2, 5FU infusion of 1920 mg/m2over 46 hours and PEM 200 mg Q 3 weeks. At the data cut off (12/29/16), median follow up was 24 weeks (10-66) and 27 patients remained on study. Rate of G3/4 toxicity associated with FOLFOX/PEM and PEM alone was 36.7% and 13.2%, respectively. No further FN was observed. No grade 5 toxicity was seen on study. Best response was recorded as: 1 complete response, 15 partial response (CR +PR = 53%), and 14 stable disease, with 100% DCR at 8 weeks. One patient with dMMR had resection after 2 months of therapy with complete pathologic response. MPFS has not been reached (95% CI: 5.5 months, NR). Conclusions: Based on these preliminary results, PEM/mFOLFOX6 has acceptable toxicity though demonstrated a suggestion of increased neutropenia in the initial cohort. Clinical activity was seen in patients with untreated advanced CRC including those with proficient MMR. Clinical trial information: NCT02375672.

Survival after recurrence following curative intent resection of pancreatic adenocarcinoma

e15760

Background: Limited data exist on outcomes after recurrence after curative intent resection for pancreatic adenocarcinoma (PC). We analyzed the prognostic significance of time to recurrence and associated factors in patients with post-pancreatectomy recurrence. Methods: Patients with a documented recurrence were identified from a prospectively maintained database of all patients undergoing pancreatectomy for PC between 2009-2015 at Indiana University Simon Cancer Center. Patients were divided into early (≤12 mos after surgery) and late recurrence ( > 12 mos after surgery) groups. Demographic (age, race, sex) and clinical (CA19-9, bilirubin, tumor location, diabetes at presentation, ECOG performance status, margin status, adjuvant radiation, and adjuvant and metastatic chemotherapy) data were obtained by manual chart abstraction and the IUSCC cancer registry. The primary outcome was survival after recurrence (SAR- time from recurrence to death). Chi-square was used for univariate analysis (except t-test for age). SAR was estimated with the Kaplan-Meier method and 95% CI. Cox proportional-hazard model was used for multivariate analysis (MVA). Results: Of 437 patients undergoing surgical resection for PC, 235 had documented recurrence. More patients had an early recurrence (ER) as compared to late recurrence (LR; 58.3% vs 41.7%). Median SAR was significantly shorter in ER vs LR patients (6.2 vs 8.6 months; HR, 0.71; 95% CI, 0.53-0.95; P = 0.02). Median age was higher in ER vs LR groups (64.7 and 64.2 years, P = 0.002). Diabetes at presentation was more common in ER vs LR group (42.3% vs 30.6%, P = 0.09). ER patients were significantly less likely to have received adjuvant chemotherapy (70.7% vs 84.7%, P = 0.02) or adjuvant radiation (17.8% vs 40%, P < .001). MVA showed a trend towards longer SAR in LR vs ER group (adjusted HR = 0.75, 95% CI, 0.55-0.1.03, p = 0.08) however age, adjuvant chemotherapy, adjuvant radiation and diabetes at presentation were not significant predictors of SAR. Conclusions: Early recurrence after resection of PC is associated with poor SAR. Patients with early recurrence tend to be older, diabetic at presentation and were less likely to have received adjuvant chemotherapy or adjuvant radiation.

A pharmacodynamic study of sirolimus and metformin in patients with advanced solid tumors

TPS11628

Background: Sirolimus is an inhibitor of the mammalian target of rapamycin (mTOR). Metformin has shown anti-cancer activity through its cellular (e.g., AMPK activation) and systemic effects (e.g., inhibition of IGF-1). We conducted a pilot study to test the hypothesis that metformin may potentiate mTOR inhibition by sirolimus. Methods: An open-label, randomized study was conducted in which eligible patients with advanced solid tumors were started on sirolimus (3mg daily) alone for the first 7 days. On day 8, patients were randomized to either receive metformin XL (500 mg daily) plus sirolimus (Arm A) or sirolimus alone (Arm B) for until day 21. From day 22 onwards, all patients recieved metformin XL plus sirolimus. The pharmacodynamic (PD) biomarkers were collected at baseline, day 8 and day 22 of cycle 1. The primary endpoint was to compare the change in PD biomarker phospho-p70S6K, using a two-sample t test (log ratio D22/D8 in arm A vs. arm B). The phospho-p70S6K was measured in peripheral blood T cells using Western blot. The secondary endpoints were to assess objective response rate (RECIST 1.1), toxicity (CTCAE V4.0) and changes in the serum levels of PD biomarkers: fasting glucose, triglycerides, insulin, C-peptide, IGF-1, IGF-1R, IGF-BP, leptin and adiponectin using two-sample t tests. Results: 24 patients were enrolled, at which time an interim futility analysis was conducted. 18 patients were evaluable for the primary endpoint (8 in arm A; 10 in arm B). The mean log ratios D22/D8 in phospho-p70S6K in arms A and B were -0.12 (SD = 0.13) and -0.16 (SD = 0.29), respectively (P = 0.64). Of the 17 pts evaluable for response, the best response was stable disease in 9 patients and progressive disease in 8 patients. There were no dose-limiting or unexpected toxicities. Of the 21 patients evaluable for serum PD biomarkers, there were no significant differences between arms A and B in fasting glucose, triglycerides, insulin, C-peptide, IGF-1, IGF-BP1, IGF-BP3, leptin and adiponectin (P > 0.05 for all). Conclusions: The addition of metformin to sirolimus, although well-tolerated, was not associated with significant changes in phospho-p70S6k and other PD biomarkers. Based on the results of the interim analysis, the trial was terminated. Clinical trial information: NCT02145559.

Excellent response to Anti-PD-1 therapy in a patient with hepatocellular carcinoma: case report and review of literature

Hepatocellular carcinoma (HCC) is an aggressive cancer associated with high mortality worldwide. HCC develops in the setting of underlying cirrhosis due to chronic liver disease. Surgery is usually considered the treatment of choice for early disease; however, most patients have locally advanced or metastatic HCC at diagnosis in which case treatments are limited. Immune checkpoint blockade of programmed death receptor-1 (PD-1) pathway offers a potential treatment strategy based on the encouraging results of the phase I/II trial of nivolumab (Checkmate 040 trial). This has led to the off-label use of nivolumab after failure of treatment with sorafenib either due to intolerance or progression of disease. Although rare (<5%), clinical response to anti-PD-1 antibody may be preceded by "pseudoprogression" -- increase in the size and number of tumor lesions before actual tumor shrinkage. We report a case of pseudoprogression followed by an excellent response in an HCC patient treated with nivolumab and review the literature for ongoing trials of immune checkpoint blockade in HCC. The pseudoprogression in our case is supported by increase in both tumor size and alpha-fetoprotein after four treatments with nivolumab; however, regression of tumor size and normalization of alpha-fetoprotein occurred after subsequent treatments. To our knowledge, there are no reports of pseudoprogression in HCC although pseudoprogression has been well described in melanoma.

Patterns of computed tomography surveillance in survivors of colorectal cancer at Veterans Health Administration facilities

BACKGROUND

Annual computed tomography (CT) scans are a component of the current standard of care for the posttreatment surveillance of survivors of colorectal cancer (CRC) after curative-intent resection. The authors conducted a retrospective study with the primary aim of assessing patient, physician, and organizational characteristics associated with the receipt of CT surveillance among veterans.

METHODS

The Department of Veterans Affairs Central Cancer Registry was used to identify patients diagnosed with AJCC collaborative stage I to III CRC between 2001 and 2009. Patient sociodemographic and clinical (ie, CRC stage and comorbidity) characteristics, provider specialty, and organizational characteristics were measured. Hierarchical multivariable logistic regression models were used to assess the association between patient, provider, and organizational characteristics on receipt of 1) consistently guideline-concordant care (at least 1 CT every 12 months for both of the first 2 years of CRC surveillance) versus no CT receipt and 2) potential overuse (>1 CT every 12 months during the first 2 years of CRC surveillance) of CRC surveillance using CT. The authors also analyzed the impact of the 2005 American Society of Clinical Oncology update in CRC surveillance guidelines on care received over time.

RESULTS

For 2263 survivors of stage II/III CRC who were diagnosed after 2005, 19.4% of patients received no surveillance CT, whereas potential overuse occurred in both surveillance years for 14.9% of patients. Guideline-concordant care was associated with younger age, higher stage of disease (stage III vs stage II), and geographic region. In adjusted analyses, younger age and higher stage of disease (stage III vs stage II) were found to be associated with overuse. There was no significant difference in the annual rate of CT scanning noted across time periods (year ≤ 2005 vs year > 2005).

CONCLUSIONS

Among a minority of veteran survivors of CRC, both underuse and potential overuse of CT surveillance were present. Patient factors, but no provider or organizational characteristics, were found to be significantly associated with patterns of care. The 2005 change in American Society of Clinical Oncology guidelines did not appear to have an impact on rates of surveillance CT. Cancer 2017;123:2338-2351. © 2017 American Cancer Society.

Demographic, clinical, and outcomes characteristics associated with screening colonoscopy in colorectal cancer patients

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Background: Screening colonoscopy has well established role in CRC prevention. Factors associated with underutilization of screening colonoscopy, and how underutilization affects the CRC outcomes is unclear. We conducted a retrospective study with an aim to identify demographic, clinical and outcome characteristics associated with screening colonoscopy in patients with CRC. Methods: The Indiana Network for Patient Care (INPC) was used to identify patients diagnosed with CRC between 2001-2015. The INPC is the largest and longest tenured clinical data warehouse of the Indiana Health Information Exchange in the USA. Patient demographic (age, race, gender, median household income, insurance type, geographical location), clinical (BMI, year of diagnosis, stage, tumor location, CEA, surgery, chemotherapy, comorbidity) and outcome characteristics were obtained. Only patients who had colonoscopy prior to diagnosis were included, and divided those who received screening colonoscopy versus diagnostic colonoscopy. Chi-square was used for univariate analysis. Multivariate logistic regression was used to model the association of colonoscopy with overall mortality, and CRC-specific mortality. Results: A total of 1546 patients were identified, of which 361 (23.3%) and 1185 (76.6%) had screening and diagnostic colonoscopy, respectively. On univariate analyses, older age, female gender, Caucasian race, lower BMI and lack of insurance, were significantly associated with screening colonoscopy (P < 0.05). Additionally, patients receiving screening colonoscopy had higher likelihood to undergo surgery and receive chemotherapy (P < 0.05). Multivariate analyses adjusted for age, gender, race, surgery, chemotherapy and insurance status showed that screening colonoscopy (as compared with diagnostic colonoscopy) is associated with a 38% lower odds of overall mortality (adjusted OR = 0.62, 95% CI, 0.46-0.83, p < 0.001), and 68% lower odds of CRC-specific mortality (adjusted OR = 0.32, 95% CI, 0.19-0.51, p < 0.001). Conclusions: Screening colonoscopy is associated with decreased odds of overall and CRC-specific mortality and individuals with older age are more likely to receive it.

Impact of nab-paclitaxel-based second-line chemotherapy on the outcomes of pancreatic cancer

483

Background: Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with no standard second line chemotherapies. We conducted a retrospective study with the primary aim to examine the effect of second line chemotherapy with nab-paclitaxel-based regimen on the overall survival (OS) and progression-free survival (PFS) of locally advanced and metastatic PDAC patients. Methods: Indiana University Simon Cancer Center (IUSCC) Cancer Registry was used to identify patients with locally advanced or metastatic PDAC between 2009 and 2015. Only patients who received second line chemotherapies were included in the study. These patients were divided in to two groups: a) nab-paclitaxel-based treatment and, b) non-nab-paclitaxel-based treatment. Demographic (age, race, gender, year of diagnosis, family history, comorbidity), clinical (histology, CA 19-9, bilirubin, tumor location, performance status, metastatic sites, chemotherapy, surgery or radiation) and outcome (OS, PFS) characteristics were obtained. OS and PFS were estimate by using Kaplan-Meier method and 95% CI. Cox proportional-hazard model was used for multivariate analysis. Results: Forty-seven (39%) and seventy-three (61%) patients received nab-paclitaxel-based and non-nab-paclitaxel-based second line chemotherapy, respectively. In the univariate analyses, nab-paclitaxel-based treatment was only associated with younger age (60.4 vs. 64 years; P = 0.02). The median PFS was 2.8 and 2.1 months (HR 0.62; 95% CI 0.38-1.02; P = 0.06), and the median OS was 7.5 and 4.7 months (HR 0.67; 95% CI 0.45-1.00; P = 0.05) in patients who received nab-paclitaxel based second line treatment versus not, respectively. Multivariate analyses adjusted for age showed a significantly improved PFS (adjusted HR 0.60, 95% CI 0.36-0.98; P = 0.04) and a suggestion of improved OS (adjusted HR 0.67; 95% CI 0.44-1.01, P = 0.05) in the nab-paclitaxel based second line treatment group versus not, respectively. Conclusions: In a single institution retrospective study, we report significant improvement in the PFS and a suggestion of improvement in the OS with nab-paclitaxel based treatment as compared with non-nab-paclitaxel based treatment in the second line setting.

Abstract B89: Neoadjuvant FOLFIRINOX in patients with resectable pancreatic cancer

Background: Only 15-20% of patients with pancreatic cancer are eligible for curative surgery, and despite surgical resection and adjuvant therapy, 5 years survival of this group remains poor at 20%. Neoadjuvant studies combining gemcitabine and radiation demonstrated improved median overall survival in patients who completed therapy and their disease was resected. FOLFIRINOX is superior to gemcitabine in advanced disease (Conroy et al), however, its tolerability and efficacy in early stage disease is unknown.

Patients and Methods: Patients who presented to Indiana University Simon Cancer Center and have resectable pancreatic cancer after evaluation by a pancreatobiliary surgeon were offered to be treated on an IRB approved protocol with 2 months of FOLFIRINOX (oxaliplatin 85 mg/m2, irinotecan 180 mg/m2, leucovorin 400 mg/m2 day 1, 5-FU 400 mg/m2 bolus followed by 2400 mg/m2 x 48 hours, peg-filgrastim 6 mg SQ day 3). Four to six weeks after completing therapy, patients underwent restaging CT scan and surgical consultation to assess for resectability. In case of suspected metastases due to rising CA 19-9 or suspicious lesions, diagnostic laparoscopy was performed first to assess for resectability. After recovery, patients received adjuvant therapy based on the treating physician’s discretion.

Results: Between June 2014 and December 2015, 26 patients with ECOG PS 0/1 were consented, of whom 22; (male/female: 14/8), median age was 65 (45-75 years), proceeded with therapy. Radiographic responses per RECIST after two months of therapy for evaluable patients were as follows: 2 with partial response, 13 with stable disease, and 1 with progressive disease. Fifteen completed preoperative therapy, and 13 underwent tumor resection. For the patients whom did not proceed to surgery the reason was (patients’ death: 2, toxicity 2 (shortly after being off study developed metastatic disease), distant metastatic disease on imaging: 1, and occult metastases found at the time of surgery: 2). Grades 3-5 toxicities per CTCAE V4.03 was (G5:2, G4: none, G3: one of each: dehydration, fatigue, neutropenia, and two with diarrhea). For the patients who died on study, one patient had significant cardiac history and had a sudden death, one patient developed treatment related complications. Of patients who had resection, 11 had R0 resection and 2 patients had R1 resection. TNM staging at resection was: Stage IIA (T3N0): 2, and stage IIB (T3N1): 11. Pathologic response using Evans criteria demonstrated minimal response (grade I) in 11 patients and moderate response (Grade IIA) in 2 patients. There was no apparent delayed surgical recovery related to neoadjuvant chemotherapy and patients who recovered, preceded to receive adjuvant therapy. DFS was evaluated for 13 patients who received surgery. The 25th percentile DFS was 52 weeks. Median OS for the entire group and for the group who had successful surgery is 65 weeks and not reached, respectively.

Conclusion: Neoadjuvant FOLFIRINOX is feasible in patients with resectable pancreatic cancer. In our small study, objective and pathologic responses were uncommon; which may be related to a short course of therapy. Our study included a higher percentage of patients with node positive disease, and older patients not included in previous FOLFIRINOX studies (27% age ≥ 70 years). There is a need for a larger study and a longer follow up to detect a signal of efficacy.

Citation Format: Safi Shahda, Michael G. House, C Max Schmidt, Attila Nakeeb, Amikar Sehdev, Jingmei Lin, Harvey M. Cramer, Yan Tong, Janet R. Flynn, Nicholas J. Zyromski, Bert H. O’Neil.{Authors}. Neoadjuvant FOLFIRINOX in patients with resectable pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B89.

The Role of Aspirin, Vitamin D, Exercise, Diet, Statins, and Metformin in the Prevention and Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a worldwide health problem leading to significant morbidity and mortality. Several strategies based on either lifestyle modifications or pharmacological interventions have been developed in an attempt to reduce the risk of CRC. In this review article, we discuss these interventions including aspirin (and other non-steroidal anti-inflammatory drugs), vitamin D, exercise, diet, statins, and metformin. Depending upon the risk of developing CRC, the current evidence supports the beneficial role of aspirin, vitamin D, diet, and exercise especially in high-risk individuals (advanced adenoma or CRC). However, even with these established interventions, there are significant knowledge gaps such as doses of aspirin and 25-hydroxy vitamin D are not well established. Similarly, there is no convincing data from randomized controlled trials that a high fiber diet or a low animal fat diet reduces the risk of CRC. Some potential interventions, such as statins and metformin, do not have convincing data for clinical use even in high-risk individuals. However, these may have emerging roles in the prevention and treatment of CRC. Greater understanding of molecular mechanisms and the application of genomic tools to risk stratify an individual and tailor the interventions based on that individual's risk will help further advance the field. Some of this work is already underway and is a focus of this article.

Pathological complete response with anti-PD-1 therapy in a patient with microsatellite instable high, BRAF mutant metastatic colon cancer: a case report and review of literature

IMPORTANCE

Mismatch repair (MMR) and BRAF mutation status are established independent prognostic factors for colorectal cancer (CRC). MMR deficient tumors are considered to have better prognosis whereas BRAF mutation is associated with poor prognosis. Studies evaluating the combined effect of BRAF and MMR status suggest MSI-high and BRAF mutant patients have a poorer prognosis as compared to MSI-high and BRAF wild type patients. Emerging evidence suggests MMR status predicts the immune response to anti-PD-1 therapy in CRC patients; however little is known about combined MMR and BRAF mutation status in this context. Therefore, it is important to identify whether there is a differential response to anti-PD-1 therapy based on BRAF status in the subset of MSI-high CRC patients.

OBSERVATIONS

We report the first case of MSI-high, BRAF mutant metastatic CRC that had an excellent response (pathologic complete response) to anti-PD-1 therapy. We take this opportunity to review the similar cases in literature and discuss combined MMR and BRAF status as a potential biomarker for anti-PD-1 therapy.

CONCLUSION AND RELEVANCE

The case presented illustrates that anti-PD-1 therapy can be effectively used to treat CRC patients with MSI-high and BRAF mutant status which is usually considered a poor prognostic category as opposed to MSI-high and BRAF wild type tumors. Future studies with anti-PD-1 therapy distinguishing these molecular subgroups will improve our knowledge of whether BRAF status can add to MMR status as a predictive biomarker for anti-PD-1 therapy in patients with metastatic CRC.

The quality of CT surveillance in resected colorectal cancer survivors at Veterans Health Administration facilities

525

Background: Annual CT scan for three years is the current standard for post-treatment surveillance of colorectal cancer (CRC) survivors following curative treatment. We conducted a retrospective study with the primary aim to assess the patient, physician & organizational characteristics associated with quality of CT surveillance at Veterans Administration (VA) facilities. Methods: The Department of Veterans Affairs Central Cancer Registry was used to identify patients with stage I-III CRC between 2001 & 2009. Patient (age, race, marital status, income, priority status, year of diagnosis, stage, comorbidity), provider (primary care, specialist, other) & facility (region & organizational survey) characteristics were measured. In the primary analysis, we analyzed the impact of the 2005 ASCO update in CRC surveillance guidelines. In the secondary analysis, we included only patients diagnosed after 2005 to avoid any bias due to change in guidelines. Overuse (OU) was defined as > 1 CT/12 months, whereas underuse (UU) was defined as < 1 CT/12 months. The Wald test was used for univariate analysis & logistic regression models, for multivariate analysis. Results: The primary analysis demonstrated no change in the receipt of CT scans before & after the 2005 guideline update, as there was an increasing trend favoring more CT scans in general.In the secondary analysis, there were a total of 2,263 patients. Overall, UU (19.44% patients) occurred more often than OU (15% patients). In univariate analyses, age, stage, insurance status, provider type & facility region were significant in both OU & UU analyses (p <.001). Comorbidity was associated with OU only (p =.02). Different organizational characteristics were significant for OU & UU cohorts. Multivariate analyses showed younger age [AOR = 2.17 (1.65 - 2.86)] & higher stage [AOR =.71 (.59 -.85)] were associated with OU at p <.001. Older age [AOR = 1.89 (1.54 - 3.10)], lower stage [AOR =.63 (.49 -.81)] at p <.001 & facility region [AOR = 1.84 (1.01 - 3.35)] at p =.04 were associated with UU. Conclusions: While present, there did not appear to be substantial rates of UU or OU among CRC survivors in the VA. Age & cancer stage were associated with the quality of CT surveillance.

Abstract A54: Possible targets of metformin in colorectal cancer

Background: Growing evidence suggests metformin improves survival in diabetic colorectal cancer (CRC) patients. However, the mechanism of action remains unclear. In order to explore the mechanistic relationship between metformin and colon cancer, we examined the expression levels of several proteins implicated in metformin's action.

Methods: We collected clinical-pathological and outcomes data on all CRC patients treated at the University of Chicago (UC) from 2006-2010. The data was collected through UC cancer registry and chart review. Diabetic CRC patients and matched controls (matched on race and stage) were selected for immunostaining (IHC). Tissues blocks (FFPE) were retrieved and tissue microarray (TMA) were constructed. IHC was performed for pAMPK, pmTOR, p70S6K, 4E-BP1, pAKT, IGF1R, beta-Catenin and Ki-67. Total score was calculated from the intensity and percentage scoring. The results were analyzed in two groups: diabetic CRC patients on metformin (group 1) and diabetic or non-diabetic CRC patients not on metformin (group 2). Chi-square test was done for estimating statistical significance between groups keeping a level of significance at 10% (alpha &lt; 0.10).

Results: The mean age of CRC patients was 62.7 years, 49% were males. Out of a total of 700 patients, 79 (11.21%) were diabetic. Metformin was prescribed to 40.5% of diabetic patients. Only 52 diabetics have FFPE block available so TMA was constructed with 104 patients in total (52 cases and 52 controls). Immunostaining was analyzable for a total of 84 patients. There were 18 and 66 patients in group 1 and 2, respectively. We found a lower expression of Ki-67 in the metformin group (group 1; 39%) as compared to non-metformin group (group 2; 64%) which was statistically significant (p = 0.04). IGF1R and beta-Catenin showed a higher expression in non-metformin group (89% and 95%, respectively) as compared to metformin group (72% and 83%, respectively) which was close to significance (p=0.12 and p=0.13, respectively). There was no significant difference between the expression of pAMPK, pmTOR, p70S6K, 4E-BP1 and pAKT in the two groups.

Conclusions: Metformin appears to improve the survival of CRC patients by decreasing proliferation. The results need to be validated in a larger study.

Citation Format: Amikar Sehdev, Galina Khramtsova, Nora Joseph, Blase P. Polite, Marc B. Bissonnette, Olopade I. Olufunmilayo. Possible targets of metformin in colorectal cancer. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr A54.

Metformin for primary colorectal cancer prevention in patients with diabetes: a case-control study in a US population

BACKGROUND

Emerging evidence from observational studies has suggested that metformin may be beneficial in the primary prevention of colorectal cancer (CRC). However, to the authors' knowledge, none of these studies was conducted in a US population. Because environmental factors such as Western diet and obesity are implicated in the causation of CRC, a large case-control study was performed to assess the effects of metformin on the incidence of CRC in a US population.

METHODS

MarketScan databases were used to identify diabetic patients with CRC. A case was defined as having an incident diagnosis of CRC. Up to 2 controls matched for age, sex, and geographical region were selected for each case. Metformin exposure was assessed by prescription tracking within the 12-month period before the index date. Conditional logistic regression was used to adjust for multiple potential confounders and to calculate adjusted odds ratios (AORs).

RESULTS

The mean age of the study participants was 55 years and 57 years, respectively, in the control and case groups (P = 1.0). Approximately 60% of the study participants were male and 40% were female in each group. In the multivariable model, any metformin use was associated with a 15% reduction in the odds of CRC (AOR, 0.85; 95% confidence interval, 0.76-0.95 [P = .007]). After adjusting for health care use, the beneficial effect of metformin was reduced to 12% (AOR, 0.88; 95% confidence interval, 0.77-1.00 [P = .05]). The dose-response analyses demonstrated no significant association with metformin dose, duration, or total exposure.

CONCLUSIONS

Metformin use appears to be associated with a reduced risk of developing CRC among diabetic patients in the United States.

The role of statins for primary prevention in non-elderly colorectal cancer patients

BACKGROUND

There is conflicting evidence for the role of statins in the primary prevention of colorectal cancer (CRC). We conducted a case control study (N=357,702) in the non-elderly adult US population (age=18-64 years) with the primary objective to examine the association between CRC and statin use.

PATIENTS AND METHODS

MarketScan® databases were used to identify patients with CRC. A case was defined as having an incident diagnosis of CRC. Up to ten individually matched controls (age, sex, region and date of diagnosis) were selected per case. Statin exposure was assessed by prescription tracking in the 12 months prior to the index date. Conditional logistic regression was used to adjust for multiple potential confounders and calculate adjusted odds ratios (AOR).

RESULTS

The mean age of participants was 54 years; 52% males and 48% females. In a multivariable model, any statin use was associated with 26% reduced odds of CRC (AOR, 0.74, 95% confidence interval (CI), 0.72-0.77, p<0.001). Age-stratified analyses showed a stronger effect of statins on CRC in participants aged 55 years or younger (AOR, 0.67, 95% CI, 0.63-0.71, p<0.001) than in participants aged above 55 years (AOR, 0.79, 95% CI, 0.76-0.82, p<0.001); the age-by-statin interaction was statistically significant (p<0.001). The dose-response analyses performed with simvastatin only showed a trend towards significance between the duration of simvastatin exposure and odds of developing CRC (p=0.06).

CONCLUSIONS

Statins appears to reduce the risk of CRC in non-elderly US population. Chemoprevention with statin might be more effective in non-elderly US population.

The role of metformin for primary prevention in non-elderly diabetic colorectal cancer patients

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Background: There is growing evidence for the beneficial effect of metformin in reducing the incidence of colorectal cancer (CRC) in diabetic patients. However, no such studies are done in the US population. We conducted a case control study (N=8,046) in non-elderly diabetic adult US population (age 18-64 years) to investigate the role of metformin for the primary prevention of CRC. Methods: MarketScan claims database was used to identify diabetic patients with CRC using ICD-9 codes. Only incident cases of CRC in diabetic patients were included in the study. Two matched controls (matched for age, sex, and geographical region) were selected per case. The exposure to metformin was assessed from prescriptions in the 12 months prior to the earliest date of CRC diagnosis. The primary objective was to assess the odds of having CRC in metformin users as compared nonusers. Adjusted odds ratios (AOR) were calculated by adjusting for multiple potential confounders using conditional logistic regression. Results: The mean age of CRC patients was 56 years, 60% were males. Metformin was prescribed to 38.13% patients. A total of 37% (995/2,682) patients developed CRC in metformin exposed group compared to 62.9% (1,687/2,682) patients in non-metformin exposed group. In a multivariate model, any metformin use was associated with a statistically significant 12% reduced risk of developing CRC (AOR 0.88, 95% CI, 0.79-0.98, p<0.026). Prescribed NSAIDs were also associated with decreased incidence of CRC (AOR 0.84, 95% CI, 0.73-0.97, p=0.019). Variables associated with increased incidence of CRC in the multivariate model were IBD (AOR 1.94, 95% CI, 1.13-3.33, p<0.015); use of insulin (AOR 1.45, 95% CI, 1.27-1.65, p<0.001); coronary artery disease (AOR 1.66, 95% CI, 1.43-1.93, p<0.001). There was no significant relationship between CRC incidence and obesity (AOR 1.19, 95% CI, 0.93-1.53, p=0.158); polycystic ovary disease (AOR 0.32, 95% CI, 0.03-2.76, p=0.3); sulfonylureas (AOR 1.09, 95% CI, 0.96-1.24, p=0.15); thiazolidinediones (AOR 0.94, 95% CI, 0.82-1.08, p=0.41); statins (AOR 0.914, 95% CI, 0.82-1.01, p=0.108). Conclusions: The use of metformin appears to reduce the incidence of CRC in non-elderly diabetic adult US population.

Perioperative therapy for locally advanced gastroesophageal cancer: current controversies and consensus of care

Gastroesophageal cancer (GEC) remains a challenging problem in oncology. Anatomically, GEC is comprised of distal gastric adenocarcinoma (GC), classically associated with Helicobacter Pylori, while proximal esophagogastric adenocarcinoma (EGJ AC) has increased significantly in incidence over the past years. Despite contrasting etiologies, histologies, and molecular phenotypes of distal and proximal GEC, in many cases perioperative (and metastatic) treatment strategies converge to similar approaches. For patients undergoing curative intent surgery, advances in perioperative chemotherapy and/or chemoradiotherapy, either before and/or after surgery, have demonstrated improved survivals compared to surgery alone. This review focuses on how the 'boundary' of the Z-line and/or the anatomical distinction of 'proximal' (EGJ) vs. 'distal' (GC) cancer has led to diverse inclusion/exclusion criteria for clinical trial enrollment, embodying various combinations of chemotherapy and radiation before and/or after surgery. Supporting evidence of each of these approaches consequently has led to a number of varying practices by geographical region and Institution/Physician, based on differing experience, preference, and clinical circumstance. Adequate direct comparison of these approaches is lacking currently, but data from a number of concerted efforts should be available in the next years to further direct best standards of care. Introduction of biologically targeted agents, namely anti-angiogenics and anti-HER family therapeutics are being evaluated to determine whether further therapeutic gains can be realized over classic cytotoxic chemotherapy alone (with/without radiotherapy). To date, novel molecularly targeted agents have yet to demonstrate benefit in this setting. In the following comprehensive review we will address the intricacies of perioperative treatment of locally advanced GEC, with focus on clinical trials supporting the diverse set of perioperative multidisciplinary approaches.

Gastroesophageal cancer: focus on epidemiology, classification, and staging

Gastroesophageal cancer (GEC), comprising proximal esophagogastric junction (EGJ) and distal gastric cancer (GC), is a significant public health concern. The epidemiology of these tumors has significantly changed over the past several decades especially in developed countries. There is a recognized decrease in incidence and mortality of distal GC and an increase in incidence and mortality of proximal EGJ cancer. The changing epidemiology is thought to be mainly due to changing trends of risk factors such as lower incidence of Helicobacter pylori infection and increasing incidence of obesity and gastroesophageal reflux. Histologically, EGJ cancers are adenocarcinoma (AC), while distal esophagus may be squamous cell carcinoma (SCC) or AC. Distal GC is predominantly AC. Following anatomical and histological distinction, tumors are staged with endoscopic ultrasound (EUS), computerized tomography (CT), and often positron emission tomography (PET) with or without diagnostic laparoscopic and peritoneal washing. Accurate staging of tumors, with emphasis on excluding occult metastasis, is imperative to avoid unnecessary surgical resection. Therefore, it is crucial to understand how these tumors are classified, the associated epidemiology, and the current standards of staging prior to selecting the appropriate course of therapy. In this review we will discuss the epidemiology, classification, and staging of locally advanced GEC.

The role of statins for primary prevention in non-elderly colorectal cancer patients

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Background: There is conflicting evidence for the effect of statins in primary prevention of colorectal cancer (CRC). We conducted a case control study (N=357,702) in non-elderly adult US population (age 18-64 years) to investigate the role of statins in primary prevention of CRC. Methods: We used MarketScan claims database to identify patients with CRC using ICD-9 codes. A case was defined as having an incident diagnosis of CRC. Up to ten controls (matched for age, sex, and geographical region) were selected per case. Statins exposure was assessed from prescriptions in the 12 months prior to the earliest date of CRC diagnosis. The primary objective was to assess the incidence of CRC in statin users and nonusers. Conditional logistic regression was used to adjust for multiple potential confounders and calculate adjusted odds ratios (AOR). Results: The mean age of CRC patients was 54 years, 52% were males.Statins were prescribed to 19.1% (68,461/357,702) patients.A total of 8.3% (5,704/68,461) patients developed CRC in statin exposed group compared to 9.3% (26,912/289,241) patients in non-statin exposed group. In a multivariate model, any statin use was associated with 25% reduced risk of CRC (AOR 0.75, 95% CI, 0.73-0.78, p<0.001). An age-stratified analysis showed more benefit in patients aged 55 years or less than those above age 56 years (AOR 0.68 and AOR 0.79 respectively; p<0.001 for interaction between age group and statin exposure). Variables associated with increased incidence of CRC in the multivariate model were obesity (AOR 1.3, 95% CI, 1.2-1.4, p<0.001); DM (AOR 1.2, 95% CI, 1.1-1.2, p<0.001); IBD (AOR 3.1, 95% CI, 2.8-3.5, p<0.001); use of insulin (AOR 1.2, 95% CI, 1.1-1.3, p<0.001) and sulfonylureas (AOR 1.2, 95% CI, 1.1-1.3, p<0.001). Prescribed NSAIDs showed modest reduction in CRC incidence (AOR 0.94, 95% CI, 0.91-0.97, p=0.002). There was no significant relationship between CRC incidence and other oral hypoglycemic drugs. Conclusions: Statins appears to reduce the incidence of CRC in non-elderly adult US population. A randomized controlled trial is needed to validate this finding.

Statins for the prevention of venous thromboembolism? a narrative review

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a substantial public health problem. The majority of VTE events are associated with transient periods of heightened risk, such as prolonged hospitalization, undergoing major surgery, experiencing trauma or lower extremity immobility, use of oral contraceptives, or having active cancer. Although pharmacologic thromboprophylaxis agents (eg, unfractionated heparin, low-molecular-weight heparins, warfarin, and novel oral anticoagulants) are effective, they remain underused, with concerns about increased bleeding risk often cited as a reason. The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (ie, statins), although used primarily for lipid lowering and arterial thrombosis risk reduction, have pleiotrophic effects that affect coagulation and inflammation, and do not increase bleeding risk. There is emerging evidence to suggest that through these pleiotrophic effects, statins may be effective in reducing the incidence of VTE. This article summarizes the literature with regard to statins' effect on VTE and suggests that additional investigations are needed to assess a potential adjunctive role for primary VTE thromboprophylaxis.

Primary small cell carcinoma of the tonsil: a case report and review of the literature

Small cell cancer (SCC) of the tonsil is a rare and aggressive cancer. There are only 10 cases of tonsillar SCC reported in the English literature. We present a case of tonsillar SCC successfully treated with induction chemotherapy using carboplatin and etoposide followed by concurrent chemoradiation therapy with cisplatin as radiosensitizer. The patient remained free of recurrence after 3 years of follow-up. We also provide a succinct review of all tonsillar SCC cases reported in the English literature and their outcomes.

Trends in hypothesis testing and related variables in nursing research: a retrospective exploratory study

AIM

To compare the inclusion and the influences of selected variables on hypothesis testing during the 1980s and 1990s.

BACKGROUND

In spite of the emphasis on conducting inquiry consistent with the tenets of logical positivism, there have been no studies investigating the frequency and patterns of hypothesis testing in nursing research

DATA SOURCES

The sample was obtained from the journal Nursing Research which was the research journal with the highest circulation during the study period under study. All quantitative studies published during the two decades including briefs and historical studies were included in the analyses

REVIEW METHODS

A retrospective design was used to select the sample. Five years from the 1980s and 1990s each were randomly selected from the journal, Nursing Research. Of the 582 studies, 517 met inclusion criteria.

DISCUSSION

Findings suggest that there has been a decline in the use of hypothesis testing in the last decades of the 20th century. Further research is needed to identify the factors that influence the conduction of research with hypothesis testing.

CONCLUSION

Hypothesis testing in nursing research showed a steady decline from the 1980s to 1990s. Research purposes of explanation, and prediction/ control increased the likelihood of hypothesis testing.

IMPLICATIONS FOR PRACTICE

Hypothesis testing strengthens the quality of the quantitative studies, increases the generality of findings and provides dependable knowledge. This is particularly true for quantitative studies that aim to explore, explain and predict/control phenomena and/or test theories. The findings also have implications for doctoral programmes, research preparation of nurse-investigators, and theory testing.

Epidermal growth factor receptor is required for colonic tumor promotion by dietary fat in the azoxymethane/dextran sulfate sodium model: roles of transforming growth factor-{alpha} and PTGS2

PURPOSE

Colon cancer is a major cause of cancer deaths. Dietary factors contribute substantially to the risk of this malignancy. Western-style diets promote development of azoxymethane-induced colon cancer. Although we showed that epidermal growth factor receptors (EGFR) controlled azoxymethane tumorigenesis in standard fat conditions, the role of EGFR in tumor promotion by high dietary fat has not been examined.

EXPERIMENTAL DESIGN

A/J x C57BL6/J mice with wild-type Egfr (Egfr(wt)) or loss-of-function waved-2 Egfr (Egfr(wa2)) received azoxymethane followed by standard (5% fat) or western-style (20% fat) diet. As F(1) mice were resistant to azoxymethane, we treated mice with azoxymethane followed by one cycle of inflammation-inducing dextran sulfate sodium to induce tumorigenesis. Mice were sacrificed 12 weeks after dextran sulfate sodium. Tumors were graded for histology and assessed for EGFR ligands and proto-oncogenes by immunostaining, Western blotting, and real-time PCR.

RESULTS

Egfr(wt) mice gained significantly more weight and had exaggerated insulin resistance compared with Egfr(wa2) mice on high-fat diet. Dietary fat promoted tumor incidence (71.2% versus 36.7%; P < 0.05) and cancer incidence (43.9% versus 16.7%; P < 0.05) only in Egfr(wt) mice. The lipid-rich diet also significantly increased tumor and cancer multiplicity only in Egfr(wt) mice. In tumors, dietary fat and Egfr(wt) upregulated transforming growth factor-alpha, amphiregulin, CTNNB1, MYC, and CCND1, whereas PTGS2 was only increased in Egfr(wt) mice and further upregulated by dietary fat. Notably, dietary fat increased transforming growth factor-alpha in normal colon.

CONCLUSIONS

EGFR is required for dietary fat-induced weight gain and tumor promotion. EGFR-dependent increases in receptor ligands and PTGS2 likely drive diet-related tumor promotion.