Pitot, Henry C.

Abstract Purpose: The categorical definition of response assessed via the Response Evaluation Criteria in Solid Tumors has documented limitations. We sought to identify alternative metrics for tumor response that improve prediction of overall survival. Experimental Design: Individual patient data from three North Central Cancer Treatment Group trials (N0026, n = 117; N9741, n = 1,109; and N9841, n = 332) were used. Continuous metrics of tumor size based on longitudinal tumor measurements were considered in addition to a trichotomized response [TriTR: response (complete or partial) vs. stable disease vs. progression). Cox proportional hazards models, adjusted for treatment arm and baseline tumor burden, were used to assess the impact of the metrics on subsequent overall survival, using a landmark analysis approach at 12, 16, and 24 weeks postbaseline. Model discrimination was evaluated by the concordance (c) index. Results: The overall best response rates for the three trials were 26%, 45%, and 25%, respectively. Although nearly all metrics were statistically significantly associated with overall survival at the different landmark time points, the concordance indices (c-index) for the traditional response metrics ranged from 0.59 to 0.65; for the continuous metrics from 0.60 to 0.66; and for the TriTR metrics from 0.64 to 0.69. The c-indices for TriTR at 12 weeks were comparable with those at 16 and 24 weeks. Conclusions: Continuous tumor measurement–based metrics provided no predictive improvement over traditional response–based metrics or TriTR; TriTR had better predictive ability than best TriTR or confirmed response. If confirmed, TriTR represents a promising endpoint for future phase II trials. Clin Cancer Res; 17(20); 6592–9. ©2011 AACR.

Purpose Previous studies have suggested that higher plasma 25-hydroxyvitamin D3 [25(OH)D] levels are associated with decreased colorectal cancer risk and improved survival, but the prevalence of vitamin D deficiency in advanced colorectal cancer and its influence on outcomes are unknown. Patients and Methods We prospectively measured plasma 25(OH)D levels in 515 patients with stage IV colorectal cancer participating in a randomized trial of chemotherapy. Vitamin D deficiency was defined as 25(OH)D lower than 20 ng/mL, insufficiency as 20 to 29 ng/mL, and sufficiency as ≥ 30 ng/mL. We examined the association between baseline 25(OH)D level and selected patient characteristics. Cox proportional hazards models were used to calculate hazard ratios (HR) for death, disease progression, and tumor response, adjusted for prognostic factors. Results Among 515 eligible patients, 50% of the study population was vitamin D deficient, and 82% were vitamin D insufficient. Plasma 25(OH)D levels were lower in black patients compared to white patients and patients of other race (median, 10.7 v 21.1 v 19.3 ng/mL, respectively; P < .001), and females compared to males (median, 18.3 v 21.7 ng/mL, respectively; P = .0005). Baseline plasma 25(OH)D levels were not associated with patient outcome, although given the distribution of plasma levels in this cohort, statistical power for survival analyses were limited. Conclusion Vitamin D deficiency is highly prevalent among patients with stage IV colorectal cancer receiving first-line chemotherapy, particularly in black and female patients.

Abstract We have demonstrated that crosstalk between the Hedgehog-GLI-GLI and EGFR signaling pathway exists and contribute to pancreatic tumorigenesis. This interaction can be abrogated by targeting both pathways simultaneously and results in a synergistic antitumor effect in vitro and in vivo in pancreatic tumor models. Based on these results we have undertaken a phase I trial of GDC-0449 (an orally administered Hedgehog pathway inhibitor) and erlotinib (EGFR tyrosine kinase inhibitor to: 1) determine the maximally tolerated dose (MTD) of GDC-0449 combined with erlotinib in unresectable solid tumors; 2) describe the adverse events associated with this treatment combination; 3) describe the responses of this treatment combination; and 4) to assess the effect of the erlotinib and GDC-0449 combination on selected biomarkers in circulating tumor cells (CTCs), tumor biopsies, and FDG-PET in a cohort of patients with metastatic pancreatic cancer patients treated at the MTD. During the dose escalation portion of the trial, eligible patients receive GDC-0449 150 mg p.o. daily and erlotinib 50, 75, 100, or 150 mg daily p.o. at dose levels 1, 2, 3, and 4 respectively. Eligibility criteria include: histologic proof of solid tumors that are unresectable, not amenable to any other standard therapies, or patient refused standard therapy,; ANC ≥&gt; 1500/μL; PLT ≥&gt; 100,000/ μL; Total bilirubin ≤&lt; upper limit of normal (ULN); AST ≤&lt; 3 x ULN; Creatinine ≤&lt; 1.5 x ULN; Hemoglobin ≥&gt; 9.0 g/dL; INR within normal limits (Cohort II [MTD Cohort] only); ECOG performance status (PS) 0, 1 or ≤ 2. For the MTD cohort, only patients with metastatic adenocarcinoma of the pancreas without prior systemic therapy for metastatic disease and tumor amenable to biopsies are eligible. Toxicity assessment is performed at each 28-day treatment cycles and response assessment every second treatment 28 day cycle. 12 patients have been entered-pancreas (3), colorectal (3), neuroendocrine (2), scc anus (2), gallbladder (1), thymoma (1). No dose-limiting toxicity (DLT) was reported at dose level 4. At the MTD, up to 20 patients with previously untreated metastatic pancreatic cancer will be entered to assess the biologic effect of GDC-0449+erlotinib. Pre- and post- treatment biopsies of metastases and FDG-PET will be performed. Weekly collection of CTCs will be undertaken and immunofluorescence microscopy of total & phosphoMAPK, EGFR, AKT, PATCHED1, GLI1, BCL-2, and quantitative PCR (Q-PCR) of PATCHED1, GLI1, and its target genes (BCL-2, BFL-1/A1, 4-1BB) will be performed. In addtion, total & phosphoMAPK, EGFR, and AKT, as well as PATCHED1, GLI1, BCL-2 by immunohistochemistry and Q-PCR of PATCHED1, GLI1, BCL-2, BFL-1/A1, 4-1BB will be analyzed in tumor biopsies. Supported by CA69912, CA136526 and CA102701. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1807.

Background —Carcinoid diarrhoea is associated with rapid small bowel and proximal colonic transit. Intravenous administration of a serotonin type 3 receptor (5HT 3 ) antagonist restores postprandial colonic tone towards normal in carcinoid patients. Aims —To evaluate the medium term effects of an oral 5HT 3 antagonist, alosetron, on symptoms, stool fat, and transit in patients with carcinoid diarrhoea. Methods —In 27 patients with carcinoid diarrhoea, symptoms were recorded daily and gastrointestinal transit was measured by scintigraphy in a three dose (0.1, 0.5, 2.0 mg, twice daily), randomised (1:1:1), parallel group, four week study. Placebo was given during the first week. Loperamide (2 mg capsules) was used as rescue medication. Results —There were numerical improvements in median diarrhoea score, stool weight, loperamide use, and overall colonic transit at four hours, but no overall significant drug effect was shown. Alosetron reduced the proximal colon emptying rate (p<0.05 in 20 evaluable comparisons), but did not significantly alter small bowel transit. Conclusions —Alosetron retardation of proximal colonic emptying in patients with carcinoid diarrhoea confirms the potential role of a 5HT 3 mechanism in this disorder. Doses of alosetron higher than 2.0 mg twice daily will be required for symptomatic benefit in carcinoid diarrhoea.

PurposeBiliary cancers overexpress epidermal growth factor receptor (EGFR), and angiogenesis has been correlated with poor outcome. Erlotinib, an EGFR tyrosine kinase inhibitor, and bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor have each been shown to have activity in biliary cancer. The primary objective of this study was to evaluate the response rate by Response Evaluation Criteria in Solid Tumors (RECIST). Secondary end points included overall survival (OS), time to progression (TTP), VEGF levels, and molecular studies of EGFR and k-ras.Patients and MethodsEligible patients had advanced cholangiocarcinoma or gallbladder cancer. Patients were treated with bevacizumab 5 mg/kg intravenously on days 1 and 15 and erlotinib 150 mg by mouth daily on days 1 through 28. Responses were evaluated by RECIST. VEGF levels were collected, and samples were analyzed for EGFR mutation by polymerase chain reaction.ResultsFifty-three eligible patients were enrolled at eight sites. Of 49 evaluable patients, six (12%; 95% CI, 6% to 27%) had a confirmed partial response. Stable disease was documented in another 25 patients (51%). Rash was the most common grade 3 toxicity. Four patients had grade 4 toxicities. Median OS was 9.9 months, and TTP was 4.4 months. Low repeats (< 16) in EGFR intron 1 polymorphism and G>G k-ras Q38 genotype (wild type) were associated with improved outcomes.ConclusionCombination chemotherapy with bevacizumab and erlotinib showed clinical activity with infrequent grade 3 and 4 adverse effects in patients with advanced biliary cancers. On the basis of preliminary molecular analysis, presence of a k-ras mutation may alter erlotinib efficacy. The combination of bevacizumab and erlotinib may be a therapeutic alternative in patients with advanced biliary cancer.

Purpose The primary goal of this multicenter phase III trial was to determine whether overall survival (OS) of fluorouracil (FU) -refractory patients was noninferior when treated with second-line infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX4; arm B) versus irinotecan (arm A). Cross-over to the other treatment on disease progression was mandated. Patients and Methods Patients who experienced treatment failure with one prior FU-based therapy and had not received prior irinotecan or oxaliplatin, either for metastatic disease or within 6 months of adjuvant FU therapy, were randomly assigned to arm A (irinotecan 350 or 300 mg/m2 every 3 weeks) or arm B (FOLFOX4). Results A total of 491 patients were randomly assigned (arm A, n = 245; arm B, n = 246); 288 (59%) had experienced treatment failure with FU for metastatic colorectal cancer. Two hundred twenty-seven patients (46%) received protocol-mandated third-line therapy (arm A, 43%; arm B, 57%). Median survival was 13.8 months (95% CI, 12.2 to 15.0 months) for initial treatment with FOLFOX4 and 14.3 months (95% CI, 12.0 to 15.9 months) for irinotecan (P = .38; hazard ratio = 0.92; 95% CI, 0.8 to 1.1). Response rates (RR; 28% v 15.5%; P = .0009) and time to progression (TTP; 6.2 v 4.4 months; P = .0009) were significantly superior with FOLFOX4. In the nonrandom subset of patients who crossed over, RR and TTP improvements with FOLFOX4 continued into third-line treatment. Irinotecan therapy was associated with more grade 3 nausea, vomiting, diarrhea, and febrile neutropenia; FOLFOX4 was associated with more neutropenia and paresthesias. Conclusion In patients who experienced treatment failure with front-line FU therapy, OS does not significantly differ whether second-line therapy begins with irinotecan or FOLFOX4. FOLFOX4 produces higher RR and longer TTP. Both arms had notable OS in patients who experienced treatment failure with first-line FU therapy.

Abstract Purpose: Insulin-like growth factor (IGF)-I and IGF-II stimulate neoplastic cell growth and inhibit apoptosis, whereas IGF-binding protein-3 (IGFBP-3) inhibits the bioavailability of IGF-I and has independent proapoptotic activity. We examined the influence of baseline plasma levels of IGF-I, IGF-II, IGFBP-3, and C-peptide on outcome among patients receiving first-line chemotherapy for metastatic colorectal cancer. Experimental Design: The plasma levels of IGF-I, IGF-II, IGFBP-3, and C-peptide as well as data on prognostic factors and body size were measured at baseline among 527 patients participating in a randomized trial of first-line chemotherapy for metastatic colorectal cancer. Results: Higher baseline plasma IGFBP-3 levels were associated with a significantly greater chemotherapy response rate (P = 0.03) after adjusting for other prognostic factors, whereas neither IGF-I nor IGF-II levels significantly predicted tumor response. Higher levels of IGF-I, IGF-II, and IGFBP-3 were all univariately associated with improved overall survival (P = 0.0001 for all). In a model that mutually adjusted for IGF-I and IGFBP-3, as well as other prognostic factors, increasing baseline-circulating IGFBP-3 was associated with a significantly longer time to tumor progression (P = 0.03), whereas circulating IGF-I was not associated with disease progression (P = 0.95). Levels of C-peptide were not associated with any measure of patient outcome. Conclusion: Among colorectal cancer patients receiving first-line chemotherapy, increasing levels of IGFBP-3, an endogenous antagonist to IGF-I, are associated with an improved objective treatment response and a prolonged time to cancer progression. The IGF pathway may represent an important target for future treatment strategies.

Abstract Purpose: 17-Allylamino-17-demethoxygeldanamycin (17-AAG) is a benzoquinone ansamycin antibiotic with antiproliferative activity in several mouse xenograft models, including prostate cancer models. A two-stage phase II study was conducted to assess the activity and toxicity profile of 17-AAG administered to patients with metastatic, hormone-refractory prostate cancer. Experimental Design: Patients with at least one prior systemic therapy and a rising prostate-specific antigen (PSA) were eligible. Patients received 17-AAG at a dose of 300 mg/m2 i.v. weekly for 3 of 4 weeks. The primary objective was to assess the PSA response. Secondary objectives were to determine overall survival, to assess toxicity, and to measure interleukin-6, interleukin-8, and maspin levels and quality of life. Results: Fifteen eligible patients were enrolled. The median age was 68 years and the median PSA was 261 ng/mL. Patients received 17-AAG for a median number of two cycles. Severe adverse events included grade 3 fatigue (four patients), grade 3 lymphopenia (two patients), and grade 3 back pain (two patients). The median PSA progression-free survival was 1.8 months (95% confidence interval, 1.3-3.4 months). The 6-month overall survival was 71% (95% confidence interval, 52-100%). Conclusions: 17-AAG did not show any activity with regard to PSA response. Due to insufficient PSA response, enrollment was stopped at the end of first stage per study design. The most significant severe toxicity was grade 3 fatigue. Further evaluation of 17-AAG at a dose of 300 mg/m2 i.v. weekly as a single agent in patients with metastatic, hormone-refractory prostate cancer who received at least one prior systemic therapy is not warranted.

Purpose In this report, we update survival (OS) and time-to-progression (TTP) data for the Intergroup trial N9741 after a median 5 years of follow-up by using risk-stratified and prognostic factor analyses to determine if treatment outcomes differ in specific patient subgroups. Patients and Methods A total of 1,691 patients were randomly assigned to one of seven fluorouracil-, oxaliplatin-, and irinotecan-containing regimens. OS and TTP were calculated by treatment arm and baseline risk group (on the basis of WBC, performance status, number of sites of disease, and alkaline phosphatase). Multivariate prognostic factor analysis was used to assess clinical factors for their relationships to OS, TTP, response, and toxicity by using Cox and logistic regression models. Results The observed 5-year survival with infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) of 9.8% was better than with irinotecan plus bolus fluorouracil and leucovorin (IFL; 3.7%; P = .04) or with bolus irinotecan/oxaliplatin (IROX; 5.1%; P = .128). OS and TTP were significantly longer for FOLFOX (20.2 months and 8.9 months, respectively) than for IFL (14.6 months and 6.1 months, respectively; P < .001 for both) or for IROX (17.3 months and 6.7 months, respectively; P < .001 for both). OS differed by risk group: 20.7 months for low risk, 17.4 months for intermediate risk, and 9.4 months for high risk (P < .001). FOLFOX treatment was superior in all risk groups and was the most powerful prognostic factor for OS, TTP, response rate, and toxicity. Conclusion The 9.8% 5-year OS in patients with metastatic colorectal cancer who were treated with first-line FOLFOX sets a new benchmark. Neither baseline risk group nor any prognostic factor examined was predictive of treatment-specific outcome. However, treatment efficacy and patient longevity varied as a function of risk group.

Purpose To evaluate clinical characteristics and survival outcomes among patients with locally advanced or metastatic colorectal cancer who achieve a complete response (CR) to systemic treatment either alone or with multimodality approach. Patients and Methods Data were collected retrospectively from CRC patients enrolled onto the phase III trial N9741, a National Cancer Institute–funded and Gastrointestinal Cancer Intergroup–sponsored study coordinated by the North Central Cancer Treatment Group. Patients were randomly assigned to combinations of oxaliplatin, fluorouracil (FU)/leucovorin (LV) and irinotecan. The three treatment arms consist of IFL (irinotecan + FU/LV), FOLFOX4 (oxaliplatin + FU/LV), and IROX (irinotecan + oxaliplatin). Median follow-up was 42.6 months. Results Sixty-two (4%) of 1,508 patients had a CR to chemotherapy alone, and an additional 32 (2%) had a CR after multimodality treatment. Factors associated with achieving CR with systemic chemotherapy alone included FOLFOX4 treatment, patients with assessable disease, or a single site of metastasis. Continuing protocol treatment beyond two cycles after documentation of CR was not associated with improved survival. The rate of curative intent resection was significantly higher for patients treated with oxaliplatin-containing regimens (P = .02). Median survival was similar between patients with CR after chemotherapy alone (44.3 months) or after multimodality approach (47.4 months; P = .81). Conclusion FOLFOX4 was more likely to produce a CR than were IFL or IROX. Oxaliplatin regimens were more likely to result in successful surgical resections. Patients who have CR to systemic chemotherapy alone can achieve impressive survival outcomes similar to those seen among patients who attained a CR status after multimodality treatment.