J. Pai

Phase 2 multi‐institutional trial evaluating gemcitabine and stereotactic body radiotherapy for patients with locally advanced unresectable pancreatic adenocarcinoma

This phase 2 multi‐institutional study was designed to determine whether gemcitabine (GEM) with fractionated stereotactic body radiotherapy (SBRT) results in acceptable late grade 2 to 4 gastrointestinal toxicity when compared with a prior trial of GEM with single‐fraction SBRT in patients with locally advanced pancreatic cancer (LAPC).

Baseline Metabolic Tumor Volume and Total Lesion Glycolysis Are Associated With Survival Outcomes in Patients With Locally Advanced Pancreatic Cancer Receiving Stereotactic Body Radiation Therapy

PURPOSE Although previous studies have demonstrated the prognostic value of positron emission tomography (PET) parameters in other malignancies, the role of PET in pancreatic cancer has yet to be well established. We analyzed the prognostic utility of PET for patients with locally advanced pancreatic cancer (LAPC) undergoing fractionated stereotactic body radiation therapy (SBRT). MATERIALS AND METHODS Thirty-two patients with LAPC in a prospective clinical trial received up to 3 doses of gemcitabine, followed by 33 Gy in 5 fractions of 6.6 Gy, using SBRT. All patients received a baseline PET scan prior to SBRT (pre-SBRT PET). Metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum and peak standardized uptake values (SUVmax and SUVpeak) on pre-SBRT PET scans were calculated using custom-designed software. Disease was measured at a threshold based on the liver SUV, using the equation Livermean + [2 × Liversd]. Median values of PET parameters were used as cutoffs when assessing their prognostic potential through Cox regression analyses. RESULTS Of the 32 patients, the majority were male (n=19, 59%), 65 years or older (n=21, 66%), and had tumors located in the pancreatic head (n=27, 84%). Twenty-seven patients (84%) received induction gemcitabine prior to SBRT. Median overall survival for the entire cohort was 18.8 months (95% confidence interval [CI], 15.7-22.0). An MTV of 26.8 cm(3) or greater (hazard ratio [HR] 4.46, 95% CI 1.64-5.88, P<.003) and TLG of 70.9 or greater (HR 3.08, 95% CI 1.18-8.02, P<.021) on pre-SBRT PET scan were associated with inferior overall survival on univariate analysis. Both pre-SBRT MTV (HR 5.13, 95% CI 1.19-22.21, P=.029) and TLG (HR 3.34, 95% CI 1.07-10.48, P=.038) remained independently associated with overall survival in separate multivariate analyses. CONCLUSIONS Pre-SBRT MTV and TLG are potential predictive factors for overall survival in patients with LAPC and may assist in tailoring therapy.

Re-irradiation with stereotactic body radiation therapy as a novel treatment option for isolated local recurrence of pancreatic cancer after multimodality therapy: experience from two institutions

Limited treatment options exist for isolated local recurrence of pancreatic ductal adenocarcinoma (PDA) following surgical resection accompanied by neoadjuvant or adjuvant chemoradiation therapy (CRT). While select patients are eligible for re-resection, recurrent lesions are often unresectable. Stereotactic body radiation therapy (SBRT) represents a possible minimally invasive treatment option for these patients, although published data in this setting are currently lacking. This study examines the safety, efficacy, and palliative capacity of re-irradiation with SBRT for isolated local PDA recurrence. All patients undergoing SBRT at two academic centers from 2008-2012 were retrospectively reviewed to identify those who received re-irradiation with SBRT for isolated local recurrence or progression of PDA after previous conventionally fractionated CRT. Information regarding demographics, clinicopathologic characteristics, therapies received, survival, symptom palliation, and toxicity was obtained from patient charts. Kaplan-Meier statistics were used to analyze survival and the log-rank test was used to compare survival among patient subgroups. Eighteen patients were identified. Fifteen had previously undergone resection with neoadjuvant or adjuvant CRT, while 3 received definitive CRT for locally advanced disease. Median CRT dose was 50.4 Gy [interquartile range (IQR), 45.0-50.4 Gy] in 28 fractions. All patients subsequently received gemcitabine-based maintenance chemotherapy, but developed isolated local disease recurrence or progression without evidence of distant metastasis. Locally recurrent or progressive disease was treated with SBRT to a median dose of 25.0 Gy (range, 20.0-27.0 Gy) in 5 fractions. Median survival from SBRT was 8.8 months (95% CI, 1.2-16.4 months). Despite having similar clinicopathologic disease characteristics, patients who experienced local progression greater than vs. less than 9 months after surgery/definitive CRT demonstrated superior median survival (11.3 vs. 3.4 months; P=0.019) and progression-free survival (10.6 vs. 3.2 months; P=0.030) after SBRT. Rates of freedom from local progression at 6 and 12 months after SBRT were 78% (14 of 18 patients) and 62% (5 of 8 patients), respectively. Effective symptom palliation was achieved in 4 of 7 patients (57%) who reported symptoms of abdominal or back pain prior to SBRT. Five patients (28%) experienced grade 2 acute toxicity; none experienced grade ≥3 acute toxicity. One patient (6%) experienced grade 3 late toxicity in the form of small bowel obstruction. In conclusion, re-irradiation with hypofractionated SBRT in this salvage scenario appears to be a safe and reasonable option for palliation of isolated local PDA recurrence or progression following previous conventional CRT. Patients with a progression-free interval of greater than 9 months prior to isolated local recurrence or progression may be most suitable for re-irradiation with SBRT, as they appear to have a better prognosis with survival that is long enough for local control to be of potential benefit.

Statin and Metformin Use Prolongs Survival in Patients With Resectable Pancreatic Cancer.

Objectives The aim of this study was to investigate the impact of statin and metformin therapy on disease outcome for patients with pancreatic ductal adenocarcinoma (PDAC). Methods This retrospective study included 171 PDAC patients who underwent surgical resection at the Stanford Cancer Institute between 1998 and 2013. No patients received neoadjuvant therapy. Statin and metformin use was defined as use during initial consult and continuing upon discharge from the hospital after surgery. Dose of each medication was recorded, as was the type of statin taken. Results The median follow-up for all patients was 11.23 months (range, 0.2–105.0 months). Among the 171 patients included in our analysis, 18 patients (10.5%) took metformin and 34 patients (19.9%) took statins. Statin use was associated with better overall survival (OS) in patients with PDAC (P = 0.011). Metformin use was also associated with better OS (P = 0.035). The use of statins remained significant on multivariate analysis for OS (P = 0.014; hazards ratio, 0.33; 95% confidence interval, 0.139–0.799), but metformin use did not (P = 0.33; hazards ratio 0.60, 95% confidence interval, 0.211–1.675). Conclusions Statin and metformin use is associated with improved OS in patients with resectable PDAC. These medications should be further investigated for possible long-term use in the general population.

The Prognostic Significance of Pretreatment Hematologic Parameters in Patients Undergoing Resection for Colorectal Cancer.

Objectives: The prognostic value of several hematologic parameters, including platelet, lymphocyte, and neutrophil counts, has been studied in a variety of solid tumors. In this study, we examined the significance of inflammatory markers and their prognostic implications in patients with colorectal cancer (CRC). Materials and Methods: Patients with stage I-III CRC who underwent surgical resection at the Stanford Cancer Institute between 2005 and 2009 were included. Patients were excluded if they did not have preoperative complete blood counts performed within 1 month of surgical resection, underwent preoperative chemotherapy or radiation, had metastatic disease at diagnosis, or had another previous malignancy. We included 129 eligible patients with available preoperative complete blood counts in the final analysis. Results: A preoperative neutrophil-to-lymphocyte ratio of>3.3 was significantly associated with worse disease-free (DFS) and overall survival (OS) (P=0.009, 0.003), as was a preoperative lymphocyte-to-monocyte ratio of ⩽2.6 (P=0.01, 0.002). Preoperative lymphopenia (P=0.002) was associated with worse OS but not DFS (P=0.09). In addition, preoperative thrombocytosis was associated with worse DFS (P=0.006) and OS (P=0.010). Preoperative leukocytosis was associated with worse OS (P=0.048) but not DFS (P=0.49). Preoperative hemoglobin was neither associated with OS (P=0.24) or DFS (P=0.15). Conclusions: Pretreatment lymphopenia, thrombocytosis, a decreased lymphocyte-to-monocyte ratio, and an elevated neutrophil-to-lymphocyte ratio independently predict for worse OS in patients with CRC.

Smad4 inactivation predicts for worse prognosis and response to fluorouracil-based treatment in colorectal cancer

Aims To determine whether expression of Smad4, a tumour suppressor found to be absent in 10% of colorectal cancer (CRC), is associated with outcomes in patients with CRC. Methods Tumour samples from 241 consecutive patients with CRC who underwent upfront colon resection between 2005 and 2009 were obtained. Triplicate tissue cores from resected primary colon tumours and matched normal controls were used to construct the tissue microarrays (TMAs). We examined the expression of Smad4 using immunohistochemistry. Clinicopathological records were obtained for all patients. TMAs were reviewed by two pathologists and scored as either ‘positive’ or ‘negative’ for nuclear staining. In total, 21 of 241 tumours (8.6%) were Smad4 negative. Results Loss of Smad4 expression correlated with significantly worse overall survival (OS) (p=0.011) and disease-free survival (DFS) (p=0.024). Patients with loss of Smad4 expression had a median OS of 31 months compared with 89 months positive Smad4 expression. Loss of Smad4 remained significant on multivariate analysis for OS (p=0.0097). In patients with node-positive disease, loss of Smad4 predicts for worse DFS (p=0.012). In patients with metastatic and recurrent disease, Smad4 loss predicts for worse OS (p=0.012). Of the patients that received capecitabine over the course of their treatment, those with Smad4 loss (n=13) had significantly worse DFS (p=0.003) and OS (p=0.0007). Conclusions Loss of Smad4 expression is associated with worse DFS and OS in multiple subsets of patients with CRC. Further studies are required to validate our findings and ascertain the role of Smad4 status in the management of this disease.

Patient-reported outcomes of a multicenter phase 2 study investigating gemcitabine and stereotactic body radiation therapy in locally advanced pancreatic cancer

PURPOSE We previously reported clinical outcomes and physician-reported toxicity of gemcitabine and hypofractionated stereotactic body radiation therapy (SBRT) in locally advanced pancreatic cancer (LAPC). Here we prospectively investigate the impact of gemcitabine and SBRT on patient-reported quality of life (QoL). METHODS AND MATERIALS Forty-nine LAPC patients received 33 Gy SBRT (6.6 Gy daily fractions) upfront or after ≤3 doses of gemcitabine (1000 mg/m2) followed by gemcitabine until progression. European Organization for Research and Treatment of Cancer QoL core cancer (QLQ-C30) and pancreatic cancer-specific (European Organization for Research and Treatment of Cancer QLQ-PAN26) questionnaires were administered to patients pre-SBRT and at 4 to 6 weeks (first follow-up [1FUP]) and 4 months (2FUP) post-SBRT. Changes in QoL scores were deemed clinically relevant if median changes were at least 5 points in magnitude. RESULTS Forty-three (88%) patients completed pre-SBRT questionnaires. Of these, 88% and 51% completed questionnaires at 1FUP and 2FUP, respectively. There was no change in global QoL from pre-SBRT to 1FUP (P = .17) or 2FUP (P > .99). Statistical and clinical improvements in pancreatic pain (P = .001) and body image (P = .007) were observed from pre-SBRT to 1FUP. Patients with 1FUP and 2FUP questionnaires reported statistically and clinically improved body image (P = .016) by 4 months. Although pancreatic pain initially demonstrated statistical and clinical improvement (P = .020), scores returned to enrollment levels by 2FUP (P = .486). A statistical and clinical decline in role functioning (P = .002) was observed in patients at 2FUP. CONCLUSIONS Global QoL scores are not reduced with gemcitabine and SBRT. In this exploratory analysis, patients experience clinically relevant short-term improvements in pancreatic cancer-specific symptoms. Previously demonstrated acceptable clinical outcomes combined with these favorable QoL data indicate that SBRT can be easily integrated with other systemic therapies and may be a potential standard of care option in patients with LAPC.

A novel biomarker panel examining response to gemcitabine with or without erlotinib for pancreatic cancer therapy in NCIC Clinical Trials Group PA.3

Purpose NCIC Clinical Trials Group PA.3 was a randomized control trial that demonstrated improved overall survival (OS) in patients receiving erlotinib in addition to gemcitabine for locally advanced or metastatic pancreatic cancer. Prior to therapy, patients had plasma samples drawn for future study. We sought to identify biomarkers within these samples. Experimental Design Using the proximity ligation assay (PLA), a probe panel was built from commercially available antibodies for 35 key proteins selected from a global genetic analysis of pancreatic cancers, and used to quantify protein levels in 20 uL of patient plasma. To determine if any of these proteins levels independently associated with OS, univariate and mulitbaraible Cox models were used. In addition, we examined the associations between biomarker expression and disease stage at diagnosis using Fishers exact test. The correlation between Erlotinib sensitivity and each biomarkers was assessed using a test of interaction between treatment and biomarker. Results and Conclusion Of the 569 eligible patients, 480 had samples available for study. Samples were randomly allocated into training (251) and validation sets (229). Among all patients, elevated levels of interleukin-8 (IL-8), carcinoembryonic antigen (CEA), hypoxia-inducible factor 1-alpha (HIF-1 alpha), and interleukin-6 were independently associated with lower OS, while IL-8, CEA, platelet-derived growth factor receptor alpha and mucin-1 were associated with metastatic disease. Patients with elevated levels of receptor tyrosine-protein kinase erbB-2 (HER2) expression had improved OS when treated with erlotinib compared to placebo. In conclusion, PLA is a powerful tool for identifying biomarkers from archived, small volume serum samples. These data may be useful to stratify patient outcomes regardless of therapeutic intervention. Trial Registration ClinicalTrials.gov NCT00040183